Article

# A Single explanation for both the baryon and dark matter densities

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## Abstract

It is shown that in a general class of models in which the baryon number of the Universe is created by electroweak anomalies, the energy density in dark matter may be related to the energy density in baryons as {Omega}{sub {ital b}}/{Omega}{sub dm}={ital c} times (proton mass)/(weak scale), where the number {ital c} is order unity and calculable from the anomaly equation. The scenario unambiguously predicts charged and neutral particles with weak-scale masses which carry a new conserved quantum number and can be pair produced via the weak interactions.

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... Yet, current axion models cannot explain why the DM relic density is so close to that of baryonic matter. Though this may be totally coincidental, it nevertheless suggests a link between DM and baryogenesis [8], another prominent cosmological enigma. Actually, it suggests DM is not foreign to baryon B or lepton L number (see Ref. [9] and references therein for a recent analysis), or that DM is somehow related to B being spontaneously broken [10]. ...
... Thus, any ∆L = 2 effect would come indirectly, e.g. as in a 0 →ν R ν L → ν R ν L . The situation in the DFSZ scenario is similar, though the U (1) P Q arises from a specific combination of U (1) φ and U (1) Y , see Eq. (8). This situation also corresponds to that often found in simple GUT models. ...
... The symmetry patterns are more difficult to analyze in the DFSZ case because the PQ and hypercharge symmetries are entangled, see Eq.(8). Thus, further entangling U (1) B and U (1) L with the U (1)s associated to H u and H d rephasing blurs the picture completely. ...
Preprint
In this paper, axion models supplemented by leptoquarks and diquarks are systematically analyzed. Turning on some couplings to and among these latter states permits to unify the PQ symmetry with baryon (B) and lepton (L) numbers, such that the axion becomes associated to the spontaneous breaking of the three $U(1)$ symmetries. All possible four- and six-fermion patterns of B and L violation are discussed, including those inducing proton decay, with $\Delta B = 1$ and $\Delta L = \pm 1, \pm 3$, neutron-antineutron oscillations with $\Delta B = 2$, and Majorana neutrino masses with $\Delta L = 2$. Scenarios in which one or two axion fields necessarily appear in any B and/or L violating operators are also constructed. Nucleon decays would then necessarily involve an axion in the final state, while neutron-antineutron oscillations would only happen in an axionic background. This could have implications for the neutron lifetime puzzle, and more generally, opens the door to new phenomenological and cosmological applications.
... The nature of dark matter is one of the most important open questions in fundamental physics. The asymmetric dark matter paradigm [1][2][3][4][5][6][7][8][9][10][11][12] (for reviews see [13][14][15]) is a particularly attractive solution to the dark matter problem because it explains the abundance of dark matter in the same way that the abundance of baryons in the universe arises, via an asymmetry of (dark) matter over (dark) anti-matter. This paradigm can explain why the abundances of matter and dark matter in the universe only differ by a factor of five. ...
... In Sec. 3, we explore bounds from EDMs, in Sec. 4, we analyze bounds from ∆F = 2 processes, and in Sec. 5 we compute constraints and discovery prospects from ∆F = 1 processes. We compare the ∆F = 2 and ∆F = 1 constraints in Sec. ...
... We can absorb one of the phases by making a phase change to Q, so we are left with two CP violating phases, which we call δ and δ . 5 We will use the following parametrization for λ ...
Preprint
Full-text available
Confining hidden sectors at the GeV scale are well motivated by asymmetric dark matter and naturalness considerations and can also give interesting collider signatures. Here we study such sectors connected to the Standard Model by a TeV scale mediator charged under both QCD and the dark force. Such a mediator admits a Yukawa coupling between quarks and dark quarks which is generically flavour and $CP$ violating. We show that in contrast to expectation, electric dipole moments do not place a strong constraint on this scenario even with $O(1)$ $CP$-violating phases. We also quantitatively explore constraints from $\Delta F=1,2$ processes as a function of the number of dark quark flavours. Finally, we describe the reach of upcoming measurements at Belle-II and KOTO, and we propose new $CP$-odd observables in rare meson decays that may be sensitive to the $CP$-violating nature of the dark sector.
... The asymmetric dark matter (ADM) scenario is an attractive scenario motivated by this coincidence problem [1][2][3][4][5][6][7][8][9][10][11] ( [12][13][14] for reviews). The ADM scenario assumes that the dark sector, which contains the DM, shares matter-antimatter asymmetry with the visible sector, i.e., the Standard Model sector. ...
... where f ′ π denotes the dark pion decay constant, π ′ i (x) (i = 1, 2, 3) are three Nambu-Goldstone (NG) bosons and σ i (i = 1, 2, 3) are the Pauli matrices. 5 Of these three NG bosons, π ′ 3 becomes the longitudinal component of the dark photon, which is evident that U(1) D is 5 We take the normalization of Eqs. (8) and (9) so that the corresponding f π in the QCD is f π ≃ 93 MeV. ...
... where f ′ π denotes the dark pion decay constant, π ′ i (x) (i = 1, 2, 3) are three Nambu-Goldstone (NG) bosons and σ i (i = 1, 2, 3) are the Pauli matrices. 5 Of these three NG bosons, π ′ 3 becomes the longitudinal component of the dark photon, which is evident that U(1) D is 5 We take the normalization of Eqs. (8) and (9) so that the corresponding f π in the QCD is f π ≃ 93 MeV. ...
Preprint
The asymmetric dark matter (ADM) scenario solves the baryon-dark matter coincidence problem when the dark matter (DM) mass is of $\mathcal{O}(1)$GeV. Composite ADM models based on QCD-like strong dynamics are particularly motivated since the strong dynamics naturally provides the DM mass of $\mathcal{O}(1)$GeV and the large annihilation cross-section simultaneously. In those models, the sub-GeV dark photon often plays an essential role in transferring the excessive entropy in the dark sector into the visible sector, i.e., the Standard Model sector. This paper constructs a chiral composite ADM model where the $U(1)_D$ gauge symmetry is embedded into the chiral flavor symmetry. Due to the dynamical breaking of the chiral flavor symmetry, the model naturally provides the masses of the dark photon and the dark pions in the sub-GeV range, both of which play crucial roles for a successful ADM model.
... The amount of the asymmetry as well as the behavior is consistent with the analytic estimation in the previous section. 8 In figure 3, we show the produced baryon asymmetry at the first scatterings by varying E cm with T R = 90 GeV and Λ = 100 TeV. The other parameters are fixed to be the same as the previous figure. ...
... Asymmetric dark matter[7][8][9][10][11], or baryogenesis before the last period of reheating[12] can also explain the baryon asymmetry in this temperature range. ...
Article
Full-text available
A bstract We show a new mechanism for baryogenesis where the reheating temperature can be smaller than the electroweak scale. The baryon number symmetry is violated by a dimension nine operator which conserves a baryon parity. A high energy quark from the decay of a heavy particle, e.g. inflaton, modulus or gravitino, undergoes flavor oscillation, and is thermalized due to the scatterings with the ambient thermal plasma. We point out that the baryon asymmetry of our universe can be generated due to the scatterings via the baryon number violating operator. Our scenario can be tested in neutron-antineutron oscillation experiments as well as other terrestrial experiments.
... It is easy to see that one obtains a quartet of spin-3/2 states, plus a doublet of spin-1/2 states, the latter being the lightest states. 8 In analogy with the proton and the neutron of regular isospin, these two states will be ...
... with Π the 'hyperpion' field Π = Π a T a , and T a = τ a /2 with the Pauli matrices τ a . Further denoting the elements of the global SU(2) F L and SU(2) F R symmetries as L and R, one has 8 Similarly as in Gell-Mann's 'eightfold way', such multiplets are obtained by first taking the fully symmetric irrep under spin × flavor, in our case SU(2 × 2), which yields a 20, and then decomposing the latter into a direct sum of irreps under SU(2) ⊗ SU(2), which yields (2, 2) + (4, 4). ...
Article
Full-text available
A bstract We present a model of composite Dark Matter (DM), in which a new QCD-like confining “hypercolor” sector generates naturally stable hyperbaryons as DM candidates and at the same time provides mass to new weakly coupled gauge bosons H that serve as DM mediators, coupling the hyperbaryons to the Standard Model (SM) fermions. By an appropriate choice of the H gauge symmetry as a horizontal SU(2) h SM flavor symmetry, we show how the H gauge bosons can be identified with the horizontal gauge bosons recently put forward as an explanation for discrepancies in rare B -meson decays. We find that the mass scale of the H gauge bosons suggested by the DM phenomenology intriguingly agrees with the one needed to explain the rare B -decay discrepancies.
... The coincidence seems to require a conspiracy between a mechanism that determines the DM abundance and baryogenesis since slight baryon asymmetry generated in the early Universe determines the present baryon abundance. The asymmetric dark matter (ADM) scenario is an attractive scenario motivated by this coincidence problem [1][2][3][4][5][6][7][8][9][10][11][12] ( [13][14][15] for reviews). The ADM scenario assumes that the dark sector, which contains the DM, shares matter-antimatter asymmetry with the visible sector, i.e., the Standard Model sector. ...
... On the other hand, U(1) B−L is not broken by the condensations, and hence, U(1) B−L and U(1) 3 are exact (accidental) symmetries up to U(1) D anomaly. 5 Associated with spontaneous breaking of SU(2) L ×SU(2) R into SU(2) V , there are three pseudo Nambu-Goldstone (NG) bosons. The low energy effective theory of the NG bosons is well described by the matrix-valued SU(2) field, ...
Article
Full-text available
A bstract The asymmetric dark matter (ADM) scenario solves the baryon-dark matter coincidence problem when the dark matter (DM) mass is of $$\mathcal{O}(1)$$ O 1 GeV. Composite ADM models based on QCD-like strong dynamics are particularly motivated since the strong dynamics naturally provides the DM mass of $$\mathcal{O}(1)$$ O 1 GeV and the large annihilation cross-section simultaneously. In those models, the sub-GeV dark photon often plays an essential role in transferring the excessive entropy in the dark sector into the visible sector, i.e., the Standard Model sector. This paper constructs a chiral composite ADM model where the U(1) D gauge symmetry is embedded into the chiral flavor symmetry. Due to the dynamical breaking of the chiral flavor symmetry, the model naturally provides the masses of the dark photon and the dark pions in the sub-GeV range, both of which play crucial roles for a successful ADM model.
... This community effort involves studying nuclear recoils at very low energies in the order of 10 eV. These could be produced either by low-mass dark matter (DM) candidates [1][2][3][4] or by coherent elastic neutrino-nucleus scattering (CE NS) [5,6]. A thorough understanding of the detector response at these energy scales is therefore of the utmost importance. ...
... We have demonstrated the unique feature of this calibration method to combine an accuracy on the scale of one percent and a uniform exploration of the bolometer volume with nuclear recoils in the 100 eV range. (1 ). Left: cryodetector spectrum. ...
Article
The development of low-threshold detectors for the study of coherent elastic neutrino-nucleus scattering and for the search for light dark matter necessitates methods of low-energy calibration. We suggest this can be provided by the nuclear recoils resulting from the γ emission following thermal neutron capture. In particular, several MeV-scale single-γ transitions induce well-defined nuclear recoil peaks in the 100 eV range. Using the FIFRELIN code, complete schemes of γ-cascades for various isotopes can be predicted with high accuracy to determine the continuous background of nuclear recoils below the calibration peaks. We present a comprehensive experimental concept for the calibration of CaWO4 and Ge cryogenic detectors at a research reactor. For CaWO4 the simulations show that two nuclear recoil peaks at 112.5 eV and 160.3 eV should be visible above background simply in the spectrum of the cryogenic detector. Then we discuss how the additional tagging for the associated γ increases the sensitivity of the method and extends its application to a wider energy range and to Ge cryogenic detectors.
... Most theories with a DM asymmetry do not purport to explain why the dark sector mass gap is close to that of Standard Model (SM) QCD. The first efforts to relate the DM density to the baryon density mostly relied on physics at the electroweak scale [1][2][3][4][5], with a Boltzmann suppression factor to generate the needed hierarchy of about two orders of magnitude between the electroweak and the QCD scale. Attempts to justify the similar scale for QCD and the dark matter mass have considered a mirror QCD, which is entwined with the SM QCD by an exact [6,7] or spontaneously broken [8][9][10] Z 2 mirror symmetry. ...
... ∆ 0 → 3 JETs + MET at colliders. Squark searches constrain the mass of the stop to mq > 1.3 ...
Preprint
Motivated by the observed ratio of dark matter to baryon mass densities, $\rho_D/\rho_B \simeq 5$, we propose a theory of dark-color unification. In this theory, the dark to visible baryon masses are fixed by the ratio of dark to visible confinement scales, which are determined to be nearby in mass through the unification of the dark and visible gauge theories at a high scale. Together with a mechanism for darko-baryo-genesis, which arises naturally from the grand unification sector, the mass densities of the two sectors must be nearby, explaining the observed mass density of dark matter. We focus on the simplest possible example of such a theory, where Standard Model color $SU(3)_C$ is unified with dark color $SU(2)_D$ into $SU(5)$ at an intermediate scale of around $10^8-10^9$ GeV. The dark baryon consists of two dark quarks in an isotriplet configuration. There are a range of important cosmological, astrophysical and collider signatures to explore, including dark matter self-interactions, early matter domination from the dark hadrons, gravitational wave signatures from the hidden sector phase transition, contributions to flavor observables, as well as Hidden Valley-like signatures at colliders.
... Most theories with a DM asymmetry do not purport to explain why the dark sector mass gap is close to that of Standard Model (SM) QCD. The first efforts to relate the DM density to the baryon density mostly relied on physics at the electroweak scale [1][2][3][4][5], with a Boltzmann suppression factor to generate the needed hierarchy of about two orders of magnitude between the electroweak and the QCD scale. Attempts to justify the similar scale for QCD and the dark matter mass have considered a mirror QCD, which is entwined with the SM QCD by an exact [6,7] or spontaneously broken [8][9][10] Z 2 mirror symmetry. ...
... ∆ 0 → 3 JETs + MET at colliders. Squark searches constrain the mass of the stop to mq > 1.3 ...
Article
Full-text available
Motivated by the observed ratio of dark matter to baryon mass densities, ρ_D/ρ_B ≃ 5, we propose a theory of dark-color unification. In this theory, the dark to visible baryon masses are fixed by the ratio of dark to visible confinement scales, which are determined to be nearby in mass through the unification of the dark and visible gauge theories at a high scale. Together with a mechanism for darko-baryo-genesis, which arises naturally from the grand unification sector, the mass densities of the two sectors must be nearby, explaining the observed mass density of dark matter. We focus on the simplest possible example of such a theory, where Standard Model color SU(3)_C is unified with dark color SU(2)_D into SU(5) at an intermediate scale of around 10⁸−10⁹ GeV. The dark baryon consists of two dark quarks in an isotriplet configuration. There are a range of important cosmological, astrophysical and collider signatures to explore, including dark matter self-interactions, early matter domination from the dark hadrons, gravitational wave signatures from the hidden sector phase transition, contributions to flavor observables, as well as Hidden Valley-like signatures at colliders.
... Asymmetric dark matter (ADM) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] is one of the frameworks where the coincidence between the relic abundances of the DM and baryon is realized. In this framework, an asymmetry of the DM and anti-DM number densities is produced in the early universe. ...
... Therefore the mixing between CPeven neutral components of η and σ is negligible although µ plays an important role in the dark matter production and should not be zero. Additionally, we assume λ 6 , λ 7 1 to avoid constraints from direct detection experiments and thermalization of the DM in the early universe. After the SM Higgs acquires a nonzero VEV, the masses of the charged, CP-even, and CP-odd components of the inert doublet scalar, η = (η + , η 0 ) T with η 0 = (η R +iη I )/ √ 2, split and are given by ...
Preprint
The scotogenic model is the Standard Model (SM) with Z_2 symmetry and the addition of Z_2 odd right-handed Majorana neutrinos and SU(2)_L doublet scalar fields. We have extended the original scotogenic model by an additional Z_2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z_2 odd doublet scalar are simultaneously produced through CP-violating right-handed neutrino decays. While the former is converted into baryon asymmetry through the sphaleron process, the latter is relaid to the DM density through the decay of SU(2)_L doublet scalar that is named "asymmetric mediator". In this way, we provide an extended scotogenic model that predicts the energy densities of baryon and dark matter being in the same order of magnitude, and also explains the low-energy neutrino masses and mixing angles.
... Recently, there has been a growing number of studies on the DM generated in association with a first-order cosmic phase transition (FOPT). During an FOPT, the discontinuity of the scalar vacuum expectation value (VEV) could be crucial in DM physics, by altering the decay of DM [7][8][9], by generating asymmetric DM [10][11][12][13][14][15][16][17][18], by producing DM nonthermally [19], by filtering DM to the true vacuum [20][21][22], by condensing particles into the false vacuum to form (scalar) Q-ball DMs [23,24] or quark (or quark-like fermion) nuggets [25][26][27][28][29][30][31][32], and by producing the primordial black holes [33,34]. 1 In this paper, we propose a new mechanism in which during an FOPT dark fermions are trapped inside the false vacuum to subsequently form compact macroscopic DM candidates, which we call "Fermi-balls." This scenario requires the following three conditions to be satisfied: ...
... For example, it can be generated nonperturbatively by the Uð1Þ Q -breaking sphaleron process during the FOPT. After the phase transition, the sphaleron is frozen, thus Uð1Þ Q is conserved again but net Q-charge has been accumulated in the Universe [10][11][12][13][14][15][16][17][18]. This scenario is analogous to electroweak baryogenesis. ...
Article
Full-text available
We propose a novel dark matter (DM) scenario based on a first-order phase transition in the early Universe. If dark fermions acquire a huge mass gap between true and false vacua, they can barely penetrate into the new phase. Instead, they get trapped in the old phase and accumulate to form macroscopic objects, dubbed Fermi-balls. We show that Fermi-balls can explain the DM abundance in a wide range of models and parameter space, depending most crucially on the dark-fermion asymmetry and the phase transition energy scale (possible up to the Planck scale). They are stable by the balance between fermion’s quantum pressure against free energy release, hence turn out to be macroscopic in mass and size. However, this scenario generally produces no detectable signals (which may explain the null results of DM searches), except for detectable gravitational waves for electroweak scale phase transitions; although the detection of such stochastic gravitational waves does not necessarily imply a Fermi-ball DM scenario.
... (32) as the U L,R and D L,R matrices are scanned over with the constraint U † L D L = V CKM (and no other constraint, in particular from flavor observables). 8 We remark that, even for V N + 3g 2 A A N as large as it gets, σ N remains safely below (a naive high-mass extrapolation of) the Xenon1T bound [53], keeping in mind that for v HC ≥ 10 TeV, one has M χ ≥ 100 TeV. ...
... Several models with a composite DM made stable by a similar symmetry mechanism have been proposed. Those we are aware of include[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. For a review, see[24]. ...
Preprint
We present a model of composite Dark Matter (DM), in which a new QCD-like confining "hypercolor" sector generates naturally stable hyperbaryons as DM candidates and at the same time provides mass to new weakly coupled gauge bosons $H$ that serve as DM mediators, coupling the hyperbaryons to the Standard Model (SM) fermions. By an appropriate choice of the $H$ gauge symmetry as a horizontal $SU(2)_h$ SM flavor symmetry, we show how the $H$ gauge bosons can be identified with the horizontal gauge bosons recently put forward as an explanation for discrepancies in rare $B$-meson decays. We find that the mass scale of the $H$ gauge bosons suggested by the DM phenomenology intriguingly agrees with the one needed to explain the rare $B$-decay discrepancies.
... Such a connection is hinted by the fact that the abundances of dark matter and ordinary matter are roughly of the same order. This observation lies at the heart of theories of asymmetric dark matter [25][26][27][28][29][30], in which the asymmetries in the dark and visible sectors are generated simultaneously, and the natural mass scale for the dark matter particle is on the order of the proton mass. Apart from the GeV-scale dark matter candidate itself, models of asymmetric dark matter contain new heavy particles, which determine the properties of the out-of-equilibrium dynamics. ...
... The remaining requirements, i.e., violation of baryon number, charge, and the charge-parity symmetry, are also present in the model. As shown in [86], this leads to a successful mechanism for baryogenesis, which combines the features of asymmetric dark matter [25][26][27][28][29][30], Dirac leptogenesis [92,93], and baryon asymmetry generation from an earlier phase transition [94] (see also [95]). In this section, we summarize the most important aspects of this proposal. ...
Preprint
Full-text available
We investigate the prospects for probing asymmetric dark matter models through their gravitational wave signatures. We concentrate on a theory extending the Standard Model gauge symmetry by a non-Abelian group, under which leptons form doublets with new fermionic partners, one of them being a dark matter candidate. The breaking of this new symmetry occurs at a high scale, and results in a strong first order phase transition in the early Universe and production of domain walls. The model accommodates baryogenesis in an asymmetric dark matter setting and predicts a gravitational wave signal within the reach of near-future experiments.
... Major advances in low-threshold detector technology have opened up new avenues for low-mass Dark Matter (DM) searches [1][2][3][4] and coherent elastic neutrinonucleus scattering (CEvNS) [5,6]. Steeply rising signal rates towards low energies, as expected for light-mass DM or CEvNS at nuclear reactors, entail a high discovery potential for new physics with miniaturized detectors. ...
Preprint
The development of low-threshold detectors for neutrinos and dark matter necessitates low-energy calibration. We suggest this can be provided by the nuclear recoils resulting from the $\gamma$ emission following neutron capture. There is often a well defined MeV-scale $\gamma$ associated to a nuclear recoil in the 100 eV range. Using the FIFRELIN code, $\gamma$-cascades of various isotopes can be predicted with high accuracy. We present a comprehensive experimental concept for the calibration of CaWO$_4$ and Ge cryogenic detectors and show the potential of additional $\gamma$-tagging to extend the reach of the method.
... In the Majorana case, there is no vector interaction, i.e., the coupling A µ χ † σ µ χ takes the form of an axial vector interaction when packaged into a 4-component field. If dark matter carries an approximately conserved charge, we should consider a Dirac fermion, and the dark matter abundance may be primarily of one charge (asymmetric dark matter [39][40][41]) or it may contain particles of both charges (symmetric dark matter). Scattering in the asymmetric case, χχ → χχ, receives contributions from only t-and u-channel diagrams. ...
Article
Full-text available
A bstract If dark matter has strong self-interactions, future astrophysical and cosmological observations, together with a clearer understanding of baryonic feedback effects, might be used to extract the velocity dependence of the dark matter scattering rate. To interpret such data, we should understand what predictions for this quantity are made by various models of the underlying particle nature of dark matter. In this paper, we systematically compute this function for fermionic dark matter with light bosonic mediators of vector, scalar, axial vector, and pseudoscalar type. We do this by matching to the nonrelativistic effective theory of self-interacting dark matter and then computing the spin-averaged viscosity cross section nonperturbatively by solving the Schrödinger equation, thus accounting for any possible Sommerfeld enhancement of the low-velocity cross section. In the pseudoscalar case, this requires a coupled-channel analysis of different angular momentum modes. We find, contrary to some earlier analyses, that nonrelativistic effects only provide a significant enhancement for the cases of light scalar and vector mediators. Scattering from light pseudoscalar and axial vector mediators is well described by tree-level quantum field theory.
... It is observationally known that the baryon and the dark mater (DM) abundances in the Universe are close to each other: ρ DM /ρ B 5. This fact tempts us to pursue the possibility that these abundances have a common origin. Among various DM models, asymmetric DM (ADM) scenario [1][2][3][4][5][6][7][8][9][10][11][12] (see Refs. [13][14][15] for reviews) is one of those that have a potential ability to address the similarity of DM and baryon asymmetries. In the ADM scenario, the current DM abundance is described as DM particle-antiparticle asymmetry, which has a common origin with the baryon asymmetry. ...
Preprint
We propose a scenario that the Electroweak-Skyrmion, a solitonic object made of the Higgs field and the electroweak gauge fields, is identified as an asymmetric dark matter. In this scenario, the relic abundance of the dark matter is related to the baryon asymmetry of the Universe through a sphaleron-like process. We show that the observed ratio of dark matter abundance to the baryon asymmetry can be explained by this scenario with an appropriate choice of model parameters that is allowed by currently available experimental constraints.
... This work will study a possible connection between asymmetry generation and dark matter production. This interplay has already been explored in the literature: the initial ideas were discussed in the 90s [1][2][3] and many more were published during a resurgence of this topic about a decade or two later, amongst those were [4][5][6][7][8]. Of particular interest to us are models in which a condensate triggers baryogenesis [9,10] while being itself the dark matter [11]. ...
Preprint
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We investigate the possibility that the dark matter abundance is sourced by the baryon/lepton asymmetry of the early Universe. It turns out that a Goldstone field of a local classically preserved symmetry in the Standard Model experiences a kick during a period of baryon/lepton number generation. This mechanism can be regarded as dynamical generation of initial conditions for misalignment yet the prediction for relic abundance presents an inverse dependence on the coupling in parallel with freeze-in vs freeze-out. We explore two realizations of this mechanism and show that in conjunction with leptogenesis, it is possible to identify a viable promising region of parameter space for dark matter production with mass 10 MeV - 1 GeV and decay constant f in the range of $10^{10} - 10^{12}$ GeV.
... refs. [133][134][135][136][137]). ...
Article
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A bstract An axion-like particle (ALP) with mass m ϕ ∼ 10 − 15 eV oscillates with frequency ∼1 Hz. This mass scale lies in an open window of astrophysical constraints, and appears naturally as a consequence of grand unification (GUT) in string/M-theory. However, with a GUT-scale decay constant such an ALP overcloses the Universe, and cannot solve the strong CP problem. In this paper, we present a two axion model in which the 1 Hz ALP constitutes the entirety of the dark matter (DM) while the QCD axion solves the strong CP problem but contributes negligibly to the DM relic density. The mechanism to achieve the correct relic densities relies on low-scale inflation ( m ϕ ≲ H inf ≲ 1 MeV), and we present explicit realisations of such a model. The scale in the axion potential leading to the 1 Hz axion generates a value for the strong CP phase which oscillates around $${\overline{\theta}}_{\mathrm{QCD}}\sim {10}^{-12}$$ θ ¯ QCD ∼ 10 − 12 , within reach of the proton storage ring electric dipole moment experiment. The 1 Hz axion is also in reach of near future laboratory and astrophysical searches.
... The DM particles are non-self annihilating [89,90,91,92,93], and self-interacting fermions [94]. Similarly to [70,84], the DM particles have masses: 1, 5, 10, 50, 100, 200, or 500 GeV. ...
Preprint
In this paper, we studied the hyperon puzzle", a problem that nevertheless the large number of studies is still an open problem. The solution of this issue requires one or more mechanisms that could eventually provide the additional repulsion needed to make the EoS stiffer and, therefore, the value of $M_{\rm{max}, T}$ compatible with the current observational limits. In this paper we proposed that including dark matter (DM) admixed with ordinary matter in neutron stars (NSs), change the hydrostatic equilibrium and may explain the observed discrepancies, regardless to hyperon multi-body interactions, which seem to be unavoidable. We have studied how non-self-annihilating\Movv{, and self-interacting, } DM admixed with ordinary matter in NSs changes their inner structure, and discussed the mass-radius relations of such NSs. We considered DM particle masses of 1, 10 and 100 GeV, while taking into account a rich list of the DM interacting strengths, $y$. By analyzing the multidimensional parameter space, including several quantities like: a. the DM interacting strength, b. the DM particle mass as well as the quantity of DM in its interior, and c. the DM fraction, ${\rm f}_{DM}$, we put constraints in the parameter space ${\rm f}_{DM} - p^{\prime}_{\rm DM}/p^{\prime}_{\rm OM}$. Our bounds are sensitive to the recently observed NSs total masses.
... This relation may hint the dark and visible matter have a common asymmetric origin [14]. ...
Preprint
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We propose a low scale leptogenesis scenario in the framework of composite Higgs models supplemented with singlet heavy neutrinos. One of the neutrinos can also be considered as a dark matter candidate whose stability is guaranteed by a discrete $\mathbb{Z}_2$ symmetry of the model. In the spectrum of the strongly coupled system, bound states heavier than the pseudo Nambu-Goldstone Higgs boson can exist. Due to the decay of these states to heavy right-handed neutrinos, an asymmetry in the visible and dark sector is simultaneously generated. The resulting asymmetry is transferred to the standard model leptons which interact with visible right-handed neutrinos. We show that the sphaleron-induced baryon asymmetry can be provided at the TeV scale for resonant bound states. Furthermore, depending on the coupling strength of dark neutrino interaction, a viable range of the dark matter mass is allowed in the model.
... This relation may hint the dark and visible matter have a common asymmetric origin [14]. ...
Article
Full-text available
We propose a low scale leptogenesis scenario in the framework of composite Higgs models supplemented with singlet heavy neutrinos. One of the neutrinos can also be considered as a dark matter candidate whose stability is guaranteed by a discrete Z2 symmetry of the model. In the spectrum of the strongly coupled system, bound states heavier than the pseudo Nambu–Goldstone Higgs boson can exist. Due to the decay of these states to heavy right-handed neutrinos, an asymmetry in the visible and dark sector is simultaneously generated. The resulting asymmetry is transferred to the standard model leptons which interact with visible right-handed neutrinos. We show that the sphaleron-induced baryon asymmetry can be provided at the TeV scale for resonant bound states. Depending on the coupling strength of dark neutrino interaction, a viable range of the dark matter mass is allowed in the model. Furthermore, taking into account the effective interactions of dark matter, we discuss low-energy processes and experiments.
... If the baryon and dark matter asymmetries are related, then such models have the appealing property that they explain the fact that the contemporary dark matter and baryon abundances are of the same order of magnitude, which is otherwise surprising because these relic abundances are determined by unrelated physics in the WIMP scenario. Indeed, this was one of the early motivations for ADM-like models (e.g., Nussinov 1985; Barr et al. 1990;Chivukula & Walker 1990;Kaplan 1992). The variety of specific incarnations of ADM is broad, but ADM models often predict particle masses smaller than the classic WIMP (mDM ∼ 1 − 10 GeV) and little or no contemporary dark matter annihilation for lack of relic dark matter anti-particles. ...
Preprint
Most of the dark matter (DM) search over the last few decades has focused on WIMPs, but the viable parameter space is quickly shrinking. Asymmetric Dark Matter (ADM) is a WIMP-like DM candidate with slightly smaller masses and no present day annihilation, meaning that stars can capture and build up large quantities. The captured ADM can transport energy through a significant volume of the star. We investigate the effects of spin-dependent ADM energy transport on stellar structure and evolution in stars with $0.9 \leq M_{\star}/\mathrm{M}_{\odot} \leq 5.0$ in varying DM environments. We wrote a MESA module that calculates the capture of DM and the subsequent energy transport within the star. We fix the DM mass to 5 GeV and the cross section to $10^{-37}$ cm${^2}$, and study varying environments by scaling the DM capture rate. For stars with radiative cores ($M_{\star} \lesssim 1.3\ \mathrm{M}_{\odot}$), the presence of ADM flattens the temperature and burning profiles in the core and increases MS lifetimes ($X_c > 10^{-3}$) by up to $\sim 20\%$. We find that strict requirements on energy conservation are crucial to the simulation of ADM's effects on these stars. In higher-mass stars, ADM energy transport shuts off core convection, limiting available fuel and shortening MS lifetimes by up to $\sim 40\%$. This may translate to changes in the luminosity and effective temperature of the MS turnoff in population isochrones. The tip of the red giant branch may occur at lower luminosities. The effects are largest in DM environments with high densities and/or low velocity dispersions, making dwarf and early forming galaxies most likely to display the effects.
... In general, the asymmetries in the dark sector and visible sector may or may not be related, and in the latter case the asymmetry generation in the dark sector can be independently studied. A large number of mechanisms have been proposed for generating asymmetric DM, many of which connecting the asymmetries in the visible and dark sectors [10,[13][14][15][16][17][18][19][20][21]. 1 Among the DM number changing topologies, the simplest topologies with two DM, or two anti-DM, or one DM and one anti-DM particles in the initial state can involve either zero or one (anti-)DM particle in the final state, if there is a conserved stabilizing symmetry. The former final state corresponds to the standard pair-annihilation employed in the JHEP08(2020)149 Figure 1. ...
Article
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A bstract We show that a general semi-annihilation scenario, in which a pair of dark matter (DM) particles annihilate to an anti-DM, and an unstable state that can mix with or decay to standard model states, can lead to particle anti-particle asymmetry in the DM sector. The present DM abundance, including the CP-violation in the DM sector and the resulting present asymmetry are determined entirely by a single semi-annihilation process at next-to-leading order. For large CP-violation in this process, we find that a nearly complete asymmetry can be obtained in the DM sector, with the observed DM density being dominated by the (anti-)DM particle. The presence of additional pair-annihilation processes can modify the ratio of DM and anti-DM number densities further, if the pair-annihilation is active subsequent to the decoupling of the semi-annihilation. For such a scenario, the required CP-violation for generating the same present asymmetry is generically much smaller, as compared to the scenario with only semi-annihilation present. We show that a minimal model with a complex scalar DM with cubic self-interactions can give rise to both semi- and pair-annihilations, with the required CP-violation generated at one-loop level. We also find that the upper bound on the DM mass from S-matrix unitarity in the purely asymmetric semi-annihilation scenario, with maximal CP-violation, is around 15 GeV, which is much stronger than in the WIMP and previously considered asymmetric DM cases, due to the required large non-zero chemical potential for such asymmetric DM.
... The MWT model contains a wealth of particles beyond the SM, including dark matter candidate particles called Technicolor Interacting Massive Particles (TIMPs) [27][28][29][30][31][32][33][34][35][36][37][38][39]. The simplest of these is the lightest technibaryon with a conservation technibaryon number. ...
Article
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We investigate the strongly coupled minimal walking technicolor model (MWT) in the framework of a bottom-up holographic model, where the global SU(4) symmetry breaks into subgroups. In the holographic model, we found that 125 GeV composite Higgs particles and small Peskin–Takeuchi S parameter can be achieved simultaneously. In addition, the model predicts a large number of particles at the TeV scale, including dark matter candidates Technicolor Interacting Massive Particles (TIMPs). If we consider the dark matter nuclear spin-independent cross-section in the range of , which can be detected by future experiments, the mass range of TIMPs predicted by the holographic technicolor model is TeV.
... This work will study a possible connection between asymmetry generation and dark matter production. This interplay has already been explored in the literature: the initial ideas were discussed in the 90s [1][2][3] and many more were published during a resurgence of this topic about a decade or two later, amongst those were [4][5][6][7][8][9]. Of particular interest to us are models in which a condensate triggers baryogenesis [10,11] while being itself the dark matter [12]. ...
Article
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We investigate the possibility that the dark matter abundance is sourced by the baryon/lepton asymmetry of the early Universe. It turns out that a Goldstone field of a global classically preserved symmetry in the Standard Model experiences a kick during a period of baryon/lepton number generation. This mechanism can be regarded as dynamical generation of initial conditions for misalignment yet the prediction for relic abundance presents an inverse dependence on the coupling in parallel with freeze-in vs freeze-out. We explore two realizations of this mechanism and show that in conjunction with leptogenesis, it is possible to identify a viable promising region of parameter space for dark matter production with mass 10 MeV–1 GeV and decay constant f in the range of 1010–1012 GeV.
... This has led to the proliferation of exploring alternative DM candidates beyond of the WIMP paradigm. Asymmetric dark matter (ADM) [5][6][7][8][9][10] is one alternative to WIMP DM, inspired by the DM-baryon "coincidence". In this framework, the DM particle is distinct from its antiparticle, and an asymmetry in the particle-antiparticle number densities is generated in the early universe. ...
Article
Full-text available
A bstract We propose a new mechanism where asymmetric dark matter (ADM) and the baryon asymmetry are both generated in the same decay chain of a metastable weakly interacting massive particle (WIMP) after its thermal freezeout. Dark matter and baryons are connected by a generalized baryon number that is conserved, while the DM asymmetry and baryon asymmetry compensate each other. This unified framework addresses the DM-baryon coincidence while inheriting the merit of the conventional WIMP miracle in predicting relic abundances of matter. Examples of renormalizable models realizing this scenario are presented. These models generically predict ADM with sub-GeV to GeV-scale mass that interacts with Standard Model quarks or leptons, thus rendering potential signatures at direct detection experiments sensitive to low mass DM. Other interesting phenomenological predictions are also discussed, including: LHC signatures of new intermediate particles with color or electroweak charge and DM induced nucleon decay; the long-lived WIMP may be within reach of future high energy collider experiments.
... Yet, current axion models cannot explain why the DM relic density is so close to that of baryonic matter. Though this may be totally coincidental, it nevertheless suggests a link between DM and baryogenesis [8], another prominent cosmological enigma. Actually, it suggests DM is not foreign to baryon B or lepton L number (see Ref. [9] and references therein for a recent analysis), or that DM is somehow related to B being spontaneously broken [10]. ...
Article
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In this paper, axion models supplemented by leptoquarks and diquarks are systematically analyzed. Turning on some couplings to and among these latter states permits us to unify the Peccei-Quinn symmetry with baryon (B) and lepton (L) numbers, such that the axion becomes associated to the spontaneous breaking of the three U(1) symmetries. All possible four- and six-fermion patterns of B and L violation are discussed, including those inducing proton decay, with ΔB=1 and ΔL=±1,±3, neutron-antineutron oscillations with ΔB=2, and Majorana neutrino masses with ΔL=2. Scenarios in which one or two axion fields necessarily appear in any B and/or L violating operators are also constructed. Nucleon decays would then necessarily involve an axion in the final state, while neutron-antineutron oscillations would only happen in an axionic background. This could have implications for the neutron lifetime puzzle, and more generally, opens the door to new phenomenological and cosmological applications.
... We know that the existence of dark matter in the Universe is a striking evidence that physics goes beyond the Standard Model, although its nature remains a mystery. At the same time, the closeness of the energy densities of DM and baryons Ω DM ≈ 5.3Ω baryon [64,65] motivates the idea of asymmetric dark matter (ADM) [66][67][68][69][70][71][72][73][74], based on the assumption that the current DM density is determined by the η DM asymmetry in the DM sector, similar to the baryon asymmetry η baryon . Then ...
Preprint
We develop the general laws of the theory of the almost empty anchored magnetic flux tubes (MFT) with B~10^7G, starting from tachocline to the surface of the Sun. The main result of this theory is the formation of the solar axions and the magnetic O-loop inside the MFT near the tachocline. In this magnetic O-loop (based on the Kolmogorov turbulent cascade) the axions are converted to photons, producing the axion origin photons near the tachocline. On the other hand, high-energy photons from the radiation zone through the axion-photon oscillations in the O-loop produce the axions of photon origin under the sunspot. This means that at such strong magnetic fields the Parker-Biermann cooling effect of MFT develops due to the "disappearance" of the Parker's convective heat transport, and consequently, the temperature in the lower part of the magnetic tube with the help of the axions of photonic origin near the tachocline. As a result, a free path for photons of axion origin opens from the tachocline to the photosphere! We show that the high-energy photons passing from the radiation zone turn into axions, which almost completely eliminates the radiation heating of the almost empty MFT. A certain flux of photons coming from the radiation zone through the tachocline, passes through the "ring" of a strong magnetic tube by virtue of convective heating. It allows to determine the velocity and the lifetime of the MFT before the reconnection, from tachocline to the surface of the Sun, as well as the rate of the MFT reconnection near the tachocline. Finally, we show that the formation of sunspot cycles is is the manifestation of dark matter -- solar axions in the core of the Sun, whose modulations are controlled by the 11-year modulation of asymmetric dark matter density in the solar interior.
... Furthermore, whether this model can accommodate the observed baryon asymmetry in the Universe remains to be seen. The feature that new sources of CPV are associated with interactions of the messenger scalar with the dark matter and the Higgs boson may indicate a connection between the proximity between the observed baryon relic abundance and the dark matter relic abundance [55][56][57]. ...
Preprint
We propose a simple model of dark matter and CP violation and consider the associated triple and quadruple productions of 125 GeV Higgs bosons at the Large Hadron Collider (LHC). In the model, the dark matter is a vector-like dark fermion $(\bar{\chi}, \chi)$ interacting with the Standard Model only through a complex messenger scalar $S$ which is an electroweak singlet. New sources of CP violation reside in the most general scalar potential involving the doublet $H$ and the singlet $S$, as well as in the dark Yukawa coupling between $S$ and $(\bar{\chi}, \chi)$. We study current experimental constraints from Higgs measurements, searches for new scalars at the LHC, precision electroweak measurements, EDM measurements, dark matter relic density, as well as direct and indirect detections of dark matter. A smoking-gun signature of CP violation could come from the Higgs-to-Higgs decays, $h_3\to h_2h_1$, where $h_3/h_2/h_1$ are the heaviest scalar, second heaviest scalar and the SM-like 125-GeV Higgs, respectively. Taking into account other Higgs-to-Higgs decays, such as $h_3\to 2h_2$ and $h_3/h_2\to 2h_1$, then gives rise to novel $3h_1$ and $4h_1$ final states, which have yet to be searched for experimentally. We present four benchmarks and show the event rates for $3h_1$ and $4h_1$ final states could be as large as ${\cal O}(10)\ {\rm fb}$ and ${\cal O}(1)\ {\rm fb}$, respectively, at the 14-TeV LHC. This work opens up a new frontier of searching for triple and quadruple Higgs bosons at a high energy collider.
... [10][11][12][13][14]. Especially, when comes to leptogenesis, the right-handed neutrinos may not only couple to the Standard Model (SM) but also a hidden sector where the dark matter resides, and a lepton asymmetry as well as dark matter production can be both generated by the out-of-equilibrium decay of the right-handed neutrinos [15,16]. However, such scenarios often indicate asymmetric dark matter (ADM) [17][18][19][20], where relic dark matter is not determined by the annihilation cross section but asymmetry between particle-antiparticle number densities of dark matter. ...
Preprint
Full-text available
We consider the interplay between dark matter and leptogenesis in a common framework, where three right-handed neutrinos, one fermionic dark matter and two singlet scalars are introduced into the Standard Model. The mixing of the two singlet scalars not only determine the dark matter relic density but also connect right-handed neutrino with dark matter. We consider that the baryon asymmetry is generated via the resonant leptogenesis and the right-handed neutrino masses are at TeV level. We present a viable parameter space satisfying relic density constraint, and the parameter space is more flexible in the case of a larger mixing angle. We found that the existence of dark matter in the model can not only dilute the baryon asymmetry but can also generate a larger baryon asymmetry due to the process of dark matter annihilation into a pair of right-handed neutrinos even though dark matter mass is lighter than right-handed neutrino mass. The enhanced effect depends on the dark matter mass $m_{\chi}$ as well as right-handed neutrino mass $m_N$, and one still can find a baryon asymmetry enhanced in the case of $m_N=800$ GeV.
... In the most attractive scenarios where the Standard Model is linked to the dark sector by connector interactions with non-trivial Standard Model global quantum numbers, this dark asymmetry may be thought of as dark "baryon" or "lepton" number, though more complicated cases involving, e.g. flavor are also possible [581][582][583][584][585][586][587][588][589][590][591][592]. Then, similarly to protons and baryon number, the lightest symmetry-carrying state in the dark sector is cosmologically stable. ...
Preprint
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The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector.
... The baryon matter density and the dark matter density are similar, ρ DM ≈ 5.4 ρ baryon , which may hint at a common origin of these two unsolved questions. In the asymmetric dark matter scenario [2][3][4][5][6][7], the dark matter and baryon asymmetry puzzles may be related and the dark matter mass could be in the order of GeV. Simultaneous generation of the necessary baryon asymmetry and dark matter density is possible [8][9][10]. ...
Preprint
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A search for invisible decays of the $\Lambda$ baryon is carried out in the process $J/\psi\to\Lambda\bar{\Lambda}$ based on $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events collected with the BESIII detector located at the BEPCII storage ring. No signals are found for the invisible decays of $\Lambda$ baryon, and the upper limit of the branching fraction is determined to be $7.4 \times 10^{-5}$ at the 90% confidence level. This is the first search for invisible decays of baryons; such searches will play an important role in constraining dark sector models related to the baryon asymmetry.
... For Monte Carlo simulation, we use FeynRules [83] to write Lagrangian (20) into an UFO model file [84]. Parton level events are generated by MadGraph5 [85], then showered and hadronized by PYTHIA8 [86]. ...
Article
Full-text available
We propose a model which explains the baryon asymmetry of the universe and dark matter relic density at the same time. In this model, dark matter candidate is the dark baryon composed by dark quarks. A scalar mediator, which couples to the standard model leptons and dark quarks, is introduced to generate the asymmetry of baryon and dark baryon simultaneously. Direct detection and collider detection of this model are studied. We find that current underground direct detection experiments and LHC can hardly detect this model. But future lepton colliders, such as CEPC, have great potential to detect a large portion of the model parameter space, via novel signal “displaced lepton jet”.
... The technibaryon bound states carrying an accidental technibaryon number led to the suggestion of the lightest of these states as a DM candidate. Moreover, it turned out that the relic abundance of this type of DM could be obtained through an asymmetry intertwined with the generation of the ordinary matter-antimatter asymmetry [173,174]. ...
Article
Full-text available
Possible dark matter candidates in particle physics span a mass range extending over fifty orders of magnitude. In this review, we consider the range of masses from a few keV to a few hundred TeV, which is relevant for cold particle dark matter. We will consider models where dark matter arises as weakly coupled elementary fields and models where dark matter is a composite state bound by a new strong interaction. Different production mechanisms for dark matter in these models will be described. The landscape of direct and indirect searches for dark matter and some of the resulting constraints on models will be briefly discussed.
... This has led to the exploration of alternative DM candidates beyond the WIMP paradigm. For example, asymmetric dark matter (ADM) [8][9][10][11][12][13][14] is an alternative inspired by the DM-baryon coincidence. In this framework, the DM particle is distinct from its antiparticle, and an asymmetry in their respective population densities is generated in the early universe. ...
Preprint
Full-text available
We propose a new mechanism where a multi-component dark sector generates the observed dark matter abundance and baryon asymmetry and thus addresses the coincidence between the two. The thermal freeze-out of dark matter annihilating into meta-stable dark partners sets the dark matter relic abundance while providing the out-of-equilibrium condition for baryogenesis. The meta-stable state triggers baryon asymmetry production by its decay well after the freeze-out and potentially induces a period of early matter domination before its decay. The dark matter and baryon abundances are related through number conservation within the dark sector (cogenesis). The "coincidence" is a natural outcome with GeV- to TeV-scale symmetric dark matter and the dark sector's interactions with the Standard Model quarks. We present a UV-complete model and explore its phenomenological predictions, including dark matter direct detection signals, LHC signatures of new massive particles with color charges and long-lived particles with displaced vertices, dark matter-induced nucleon conversions, (exotic) dark matter indirect detection signals, and effects on the cosmological matter power spectrum. As a side result, we provide a novel analytical treatment for dark sector freeze-out, which may prove useful in the study of related scenarios.
Preprint
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We propose a model which explains the baryon asymmetry of the universe and dark matter relic density at the same time. In this model, dark matter candidate is the dark baryon composed by dark quarks. A scalar mediator, which couples to the standard model leptons and dark quarks, is introduced to generate the asymmetry of baryon and dark baryon simultaneously. Direct detection and collider detection of this model are studied. We find that current underground direct detection experiments and LHC can hardly detect this model. But future lepton colliders, such as CEPC, have great potential to detect a large portion of the model parameter space by "displaced lepton jet" signal.
Article
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We calculate the scattering cross section between two 0++ glueballs in SU(2) Yang-Mills theory on a lattice at β=2.1, 2.2, 2.3, 2.4, and 2.5 using the indirect (HAL QCD) method. We employ the cluster-decomposition error reduction technique and use all space-time symmetries to improve the signal. In the use of the HAL QCD method, the centrifugal force was subtracted to remove the systematic effect due to the nonzero angular momenta of lattice discretization. From the extracted interglueball potential, we determine the low energy glueball effective theory by matching with the one-glueball exchange process. We then calculate the scattering phase shift and derive the relation between the interglueball cross section and the scale parameter Λ as σϕϕ=(2–51)Λ−2 (stat+sys). From the observational constraints of galactic collisions, we obtain the lower bound of the scale parameter as Λ>60 MeV. We also discuss the naturalness of the Yang-Mills theory as the theory explaining dark matter.
Article
Superconducting detectors have become an important tool in experimental astroparticle physics, which seeks to provide a fundamental understanding of the Universe. In particular, such detectors have demonstrated excellent potential in two challenging research areas involving rare event search experiments, namely, the direct detection of dark matter and the search for neutrinoless double beta decay. Here, we review the superconducting detectors that have been and are planned to be used in these two categories of experiments. We first provide brief histories of the two research areas and outline their significance and challenges in astroparticle physics. Then, we present an extensive overview of various types of superconducting detectors with a focus on sensor technologies and detector physics, which are based on calorimetric measurements and heat flow in the detector components. Finally, we introduce leading experiments and discuss their future prospects for the detection of dark matter and the search for neutrinoless double beta decay employing superconducting detectors.
Article
A search for invisible decays of the Λ baryon is carried out in the process J/ψ→ΛΛ¯ based on (1.0087±0.0044)×1010 J/ψ events collected with the BESIII detector located at the BEPCII storage ring. No signals are found for the invisible decays of Λ baryon, and the upper limit of the branching fraction is determined to be 7.4×10-5 at the 90% confidence level. This is the first search for invisible decays of baryons; such searches will play an important role in constraining dark sector models related to the baryon asymmetry.
Preprint
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We discuss the possibility of light scalar dark matter in a $L_{\mu}-L_{\tau}$ model, in which the dark matter $\phi_{dm}$ carries $U(1)_{L_{\mu}-L_{\tau}}$ charge but it is a singlet in the Standard Model. We consider the case that the right-handed neutrinos not only generate baryon asymmetry but also are related with dark matter production. We assume that dark matter production mainly comes from scattering associated with a pair of right-handed neutrinos while other related processes are highly suppressed due to the tiny $U(1)_{L_{\mu}-L_{\tau}}$ charge of dark matter, and the dark matter relic density are generated via freeze-in mechanism. A feasible parameter space is considered and we found the correct dark matter relic density can be obtained without influencing the result of leptogenesis, and the allowed dark matter mass region is $[\rm 10^{-5}\ GeV,0.1\ GeV]$.
Article
A bstract We propose a new mechanism where a multi-component dark sector generates the observed dark matter abundance and baryon asymmetry and thus addresses the coincidence between the two. The thermal freeze-out of dark matter annihilating into meta-stable dark partners sets the dark matter relic abundance while providing the out-of-equilibrium condition for baryogenesis. The meta-stable state triggers baryon asymmetry production by its decay well after the freeze-out and potentially induces a period of early matter domination before its decay. The dark matter and baryon abundances are related through number conservation within the dark sector (cogenesis). The “coincidence” is a natural outcome with GeV- to TeV-scale symmetric dark matter and the dark sector’s interactions with the Standard Model quarks. We present a UV-complete model and explore its phenomenological predictions, including dark matter direct detection signals, LHC signatures of new massive particles with color charges and long-lived particles with displaced vertices, dark matter-induced nucleon conversions, (exotic) dark matter indirect detection signals, and effects on the cosmological matter power spectrum. As a side result, we provide a novel analytical treatment for dark sector freeze-out, which may prove useful in the study of related scenarios.
Preprint
The search for particle-like dark matter with meV-to-GeV masses has developed rapidly in the past few years. We summarize the science case for these searches, the recent progress, and the exciting upcoming opportunities. Funding for Research and Development and a portfolio of small dark matter projects will allow the community to capitalize on the substantial recent advances in theory and experiment and probe vast regions of unexplored dark-matter parameter space in the coming decade.
Article
Most of the dark matter (DM) search over the last few decades has focused on WIMPs, but the viable parameter space is quickly shrinking. Asymmetric Dark Matter (ADM) is a WIMP-like DM candidate with slightly smaller masses and no present day annihilation, meaning that stars can capture and build up large quantities. The captured ADM can transport energy through a significant volume of the star. We investigate the effects of spin-dependent ADM energy transport on stellar structure and evolution in stars with 0.9 ≤ M⋆/M⊙ ≤ 5.0 in varying DM environments. We wrote a MESA module* that calculates the capture of DM and the subsequent energy transport within the star. We fix the DM mass to 5 GeV and the cross-section to 10−37 cm2, and study varying environments by scaling the DM capture rate. For stars with radiative cores (0.9 ≤ M⋆/M⊙ ≲ 1.3 ), the presence of ADM flattens the temperature and burning profiles in the core and increases MS (Xc > 10−3) lifetimes by up to $\sim 20{{\ \rm per\ cent}}$. We find that strict requirements on energy conservation are crucial to the simulation of ADM’s effects on these stars. In higher-mass stars, ADM energy transport shuts off core convection, limiting available fuel and shortening MS lifetimes by up to $\sim 40{{\ \rm per\ cent}}$. This may translate to changes in the luminosity and effective temperature of the MS turnoff in population isochrones. The tip of the red giant branch may occur at lower luminosities. The effects are largest in DM environments with high densities and/or low velocity dispersions, making dwarf and early forming galaxies most likely to display the effects.
Thesis
The problem of the missing mass of the Universe is one of the most puzzling conundrums of modern physics. Assuming that it stems from the existence of yet unknown dark matter (DM) particles, one can probe the cosmos in the hope of detecting unambiguous signatures thereof. The properties of cold DM (CDM) particle candidates lead to the prediction that gravitational structures form on scales much smaller than typical galaxies, below the resolution scope of current cosmological simulations. This clustering translates into a large population of subhalos in galaxies, hence in the Milky Way. Only analytical models can encompass and describe their full distribution. My work is centred upon building a theoretically consistent and dynamically constrained subhalo population model. This relies mostly on three ingredients: the minimal subhalo mass, the cosmological mass function, and dynamical effects. I start from a simplified model of thermally produced dark matter (with scalar, pseudo-scalar, vector and axial-vector interactions with standard model particles). I classify models in terms of small-scale cut-off on the matter power spectrum, which is directly related to the minimal halo mass, making explicit the role of velocity dependence in the interaction processes. Secondly, I improve on the determination of the cosmological subhalo mass function by deriving it from the excursion set theory and a merger tree, while it was previously calibrated on simulations. Thirdly, I incorporate new dynamical effects by analytically studying the impact of stellar encounters susceptible of occurring in galactic discs. Besides, I illustrate an application of this model for indirect detection experiments looking for traces of DM annihilation in the Milky Way. In light of the 1525 unassociated point sources discovered by the Fermi-LAT collaboration, I give prospects for the detection of point-like subhalos as gamma-ray sources with Fermi-LAT-like and CTA-like instruments. I also shortly discuss the impact of additional effects, like the Sommerfeld effect.
Article
A bstract We propose a scenario that the Electroweak-Skyrmion, a solitonic object made of the Higgs field and the electroweak gauge fields, is identified as an asymmetric dark matter. In this scenario, the relic abundance of the dark matter is related to the baryon asymmetry of the Universe through a sphaleron-like process. We show that the observed ratio of dark matter abundance to the baryon asymmetry can be explained by this scenario with an appropriate choice of model parameters that is allowed by currently available experimental constraints.
Article
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We propose a minimal model for the cosmic coincidence problem $$\Omega _\mathrm{DM}/\Omega _B \sim 5$$ Ω DM / Ω B ∼ 5 and neutrino mass in a type-II seesaw scenario. We extend the standard model of particle physics with a $$\mathrm SU(2)$$ S U ( 2 ) singlet leptonic Dirac fermion $$\chi$$ χ , which represents the candidate of dark matter (DM), and two triplet scalars $$\Delta _{1,2}$$ Δ 1 , 2 with hierarchical masses. In the early Universe, the CP violating out-of-equilibrium decay of lightest $$\Delta$$ Δ generates a net $$B-L$$ B - L asymmetry in the visible sector (comprising of SM fields), where B and L represents the total baryon and lepton number respectively. A part of this asymmetry gets transferred to the dark sector (comprising of DM $$\chi$$ χ ) through a dimension eight operator which conserves $$B-L$$ B - L . Above the electroweak phase transition, the $$B-L$$ B - L asymmetry of the visible sector gets converted to a net B -asymmetry by the $$B+L$$ B + L violating sphalerons, while the $$B-L$$ B - L asymmetry of the dark sector remains untouched which we see today as relics of DM. We show that the observed DM abundance can be explained for a DM mass about 8 GeV. We then introduce an additional singlet scalar field $$\phi$$ ϕ which mixes with the SM-Higgs to annihilate the symmetric component of the DM resonantly which requires the singlet scalar mass to be twice the DM mass, i.e. around 16 GeV, which can be searched at collider experiments. In our model, the active neutrinos also get small masses by the induced vacuum expectation value (vev) of the triplet scalars $$\Delta _{1,2}$$ Δ 1 , 2 . In the later part of the paper we discuss all the constraints on model parameters coming from invisible Higgs decay, Higgs signal strength, DM direct detection and relic density of DM.
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The nature of neutrinos, whether Dirac or Majorana, is hitherto not known. Assuming that the neutrinos are Dirac, which needs $B-L$ to be an exact symmetry, we make an attempt to explain the observed proportionality between the relic densities of dark matter (DM) and baryonic matter in the present Universe ${\it i.e.,}\,\, \Omega_{\rm DM} \approx 5\, \Omega_{\rm B}$. Assuming the existence of heavy $SU(2)_L$ scalar doublet $(X= (X^0, X^-)^T)$ in the early Universe, an equal and opposite $B-L$ asymmetry can be generated in left and right-handed sectors by the CP-violating out-of-equilibrium decay $X^0 \to \nu_L \nu_R$ since $B-L$ is an exact symmetry. We ensure that $\nu_L-\nu_R$ equilibration does not occur until below the electroweak (EW) phase transition during which a part of the lepton asymmetry gets converted to dark matter asymmetry through a dimension eight operator, which conserves $B-L$ symmetry and is in thermal equilibrium. The remaining $B-L$ asymmetry then gets converted to a net B-asymmetry through EW-sphalerons which are active at a temperature above 100 GeV. To alleviate the small-scale anomalies of $\Lambda$CDM, we assume the DM to be self-interacting via a light mediator, which not only depletes the symmetric component of the DM, but also paves a way to detect the DM at terrestrial laboratories through scalar portal mixing.
Article
A bstract Confining hidden sectors at the GeV scale are well motivated by asymmetric dark matter and naturalness considerations and can also give interesting collider signatures. Here we study such sectors connected to the Standard Model by a TeV scale mediator charged under both QCD and the dark force. Such a mediator admits a Yukawa coupling between quarks and dark quarks which is generically flavour and CP violating. We show that in contrast to expectation, electric dipole moments do not place a strong constraint on this scenario even with O (1) CP -violating phases. We also quantitatively explore constraints from ∆ F = 1 , 2 processes as a function of the number of dark quark flavours. Finally, we describe the reach of upcoming measurements at Belle-II and KOTO, and we propose new CP -odd observables in rare meson decays that may be sensitive to the CP -violating nature of the dark sector.
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The nature of neutrinos, whether Dirac or Majorana, is hitherto not known. Assuming that the neutrinos are Dirac, which needs B − L to be an exact symmetry, we make an attempt to explain the observed proportionality between the relic densities of dark matter (DM) and baryonic matter in the present Universe i.e., ΩDM ≈ 5 ΩB. Assuming the existence of heavy SU (2)L scalar doublet (X = (X 0 , X −) T) in the early Universe, an equal and opposite B − L asymmetry can be generated in left and right-handed sectors by the CP-violating out-of-equilibrium decay X 0 → νLνR since B − L is an exact symmetry. We ensure that νL − νR equilibration does not occur until below the electroweak (EW) phase transition during which a part of the lepton asymmetry gets converted to dark matter asymmetry through a dimension eight operator, which conserves B −L symmetry and is in thermal equilibrium. The remaining B − L asymmetry then gets converted to a net B-asymmetry through EW-sphalerons which are active at a temperature above 100 GeV. To alleviate the small-scale anomalies of ΛCDM, we assume the DM to be self-interacting via a light mediator, which not only depletes the symmetric component of the DM, but also paves a way to detect the DM at terrestrial laboratories through scalar portal mixing.
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We present a new technique for the determination of the integral surface mass density of the galactic disc at the solar galactocentric distance. The requisite observational data are an observed distribution function of velocities and distances for a sample of tracer stars extending ≳ 1 kpc from the galactic plane, and the spatial density distribution corresponding to that tracer population. The analysis involves comparison of the observed distribution function with a variety of model distribution functions, calculated for a wide range of assumed galactic potentials and corresponding force laws Kz(z), to determine the best description of the data. The model distributions are calculated in a sufficiently general way that one can include the quite large effects due to the likely change in the orientation of the stellar velocity ellipsoid as one moves further from the galactic plane. The derived best fit Kz-force law is constrained to be consistent dynamically, in that the local mass density of the extended dark halo generating a large part of the radial acceleration in the Galaxy is also determined, in such a way as to ensure consistency with the observed rotation curve. An important feature of the analysis technique is that it utilizes the full observed distribution function, and so avoids the need for binning data and the use of a few velocity moments to represent a large number of observations.
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Limits on the masses and number of neutral weakly interacting particles are derived using cosmological arguments. No such particles with a mass between 120 eV and 3 GeV can exist within the usual big band model. Similar, but much more severe, restrictions follow for particles that interact only gravitationally. This seems of importance with respect to supersymmetric theories.
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We estimate the rate of the anomalous electroweak baryon-number non-conserving processes in the cosmic plasma and find that it exceeds the expansion rate of the universe at T > (afew) × 102 GeV. We study whether these processes wash out the baryon asymmetry of the universe (BAU) generated at some earlier state (say, at GUT temperatures). We also discuss the possibility of BAU generation by the electroweak processes themselves and find that this does not take place if the electroweak phase transition is of second order. No definite conclusion is made for the strongly first-order phase transition. We point out that the BAU might be attributed to the anomalous decays of heavy () fermions if these decays are unsuppressed.
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We discuss a simple model for baryogenesis during the weak phase transition, which uses the anomalous baryon violation in the weak interactions. A departure from thermal equilibrium is provided if the transition is first order, and CP violation occurs in the neutrino couplings. Generating a sufficiently large baryon number requires that the τ neutrino is heavier than an MeV, or there must be a fourth family with all members heavier than 45 GeV.
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The effect of electroweak fermion number violation in the early universe is to distribute a fermion number excess over all the electroweak doublets. If baryogenesis is due to physics above the weak scale, this can result in the production of heavy stable particles in numbers comparable to the number of baryons. In particular, there may be enough stable technibaryons present today to account for the missing mass of the universe.
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It has recently been suggested that galactic dark matter halos could be made of very heavy charged particles (20–1000 TeV). We show that present observations and experimental limits are hardly compatible with such a scenario. The best chance, if any, would be in the upper mass range near or above 1000 TeV which can be unambiguously explored by specific experiments that we discuss.
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It is shown that the existence of neutral interstellar clouds constrains the interaction of any particulate dark-matter candidate with atomic hydrogen to be quite small. Even for a halo particle of mass 1 PeV (10 to the 6 GeV), it is shown that the cross section with hydrogen must be smaller than the typical atomic cross section that is expected for a positively charged particle bound to an electron. The argument presented is that if the clouds are in equilibrium, then the rate at which energy is deposited by collisions with dark-matter particles must be smaller than the rate at which the cloud can cool. This argument is used to constrain the interaction cross section of dark matter with hydrogen. Remarks are made on the general viability of charged dark matter. Comments are also made on a bound which derives from the dynamical stability of the halo.
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We study the formalism of the sphaleron approximation to baryon-number violation in the standard model at temperatures near 1 TeV. We investigate small fluctuations of the sphaleron, the competition of large-scale sphalerons with thermal fluctuations, and the damping of the transition rate in the plasma. We find a suppression of the rate due to Landau damping and due to factors arising from zero modes. Our approximations are valid in the regime 2MW(T)T2MW(T)/ ±W for models where g2. We find that the rate of baryon-number violation is still significantly larger than the expansion rate of the Universe.
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We consider the possibility that dark matter is in the form of charged massive particles. Several constraints are discussed: (a) the absence of heavy-hydrogen-like atoms in water; (b) the agreement between the observed cosmic abundance of the elements and standard big-bang nucleosynthesis predictions; (c) the observed properties of galaxies, stars, and planets; (d) their nonobservation in -ray and cosmic-ray detectors, and the lack of radiation damage to space-borne electronic components. We find that integer-charged particles less massive than 103 TeV are probably ruled out as dark matter; but note briefly that there is a slim chance they could be blown out of the halo by supernovae. Above this mass the freeze-out abundance of these particles would overclose the Universe; thus their discovery would be evidence for inflation (or other late-time entropy dumping) below mch. We indicate where one should consider looking for charged massive dark matter.
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Processes involving the electroweak anomaly can erase completely a primordial baryon and lepton asymmetry if B-L=0. This has led to the search for plausible mechanisms for weak-scale baryogenesis, or for the generation of a primordial B-L asymmetry. Here it is emphasized that if another quantum number conserved up to anomalies is present electroweak anomaly processes would not necessarily erase a primordial baryon asymmetry even if B-L=0. Moreover, an asymmetry in the new quantum number that is comparable to the baryon asymmetry is generated concomitantly due to the electroweak anomaly. This asymmetry could be the origin of dark matter.
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Interesting limits are set on candidates for cold-dark-matter particles in the halo of our Galaxy from their interaction with a very-low-background Ge detector used to search for double ..beta.. decay. Dirac neutrinos constituting all of dark matter are excluded for masses between 12 GeV/c/sup 2/ and 1.4 TeV/c/sup 2/. There are slightly better limits on magninos and cosmions, proposed massive particles which also explain the solar-neutrino problem but which interact more strongly with Ge. In addition, millicharged shadow matter is ruled out as the main form of dark matter.