Genevieve Bélanger

Genevieve Bélanger
French National Centre for Scientific Research | CNRS · LAPTH

PhD

About

265
Publications
100,746
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21,455
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Additional affiliations
September 1994 - present
French National Centre for Scientific Research
Position
  • LAPTH
January 1988 - September 1994
Université de Montréal

Publications

Publications (265)
Article
Full-text available
In a previous publication, we studied the parameter space of the phenomenological minimal Supersymmetric standard model with a light neutralino thermal dark matter ( M χ ˜ 1 0 ≤ M h / 2 ) and observed that the recent results from the dark matter and collider experiments put strong constraints on this scenario. In this work, we present in detail the...
Preprint
We consider a simple extension of the standard model with fermionic dark matter (DM) and a $Z'$ gauge boson acting as a mediator. We also assume a scenario where cosmic reheating occurs at low temperatures due to the decay of a massive inflaton into standard model states. To follow the evolution of the background and the dark sector states, we impl...
Preprint
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We study the connection between collider and dark matter phenomenology in the singlet extension of the Georgi-Machacek model. In this framework, the singlet scalar serves as a suitable thermal dark matter (DM) candidate. Our focus lies on the region $v_{\chi}<1$ GeV, where $v_{\chi}$ is the common vacuum expectation value of the neutral components...
Article
We briefly review scenarios with feebly interacting massive particles (FIMPs) as dark matter candidates. The discussion covers issues with dark matter production in the early universe as well as signatures of FIMPs at the high energy and high intensity frontier as well as in astroparticle and cosmology.
Preprint
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We briefly review scenarios with feebly interacting particles (FIMPs) as dark matter candidates. The discussion covers issues with dark matter production in the early universe as well as signatures of FIMPs at the high energy and high intensity frontier as well as in astroparticle and cosmology.
Article
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We explore the parameter space of the phenomenological minimal supersymmetric standard model with a light neutralino thermal dark matter (mχ˜10≤mh/2) that is consistent with current collider and astrophysical constraints. We consider both positive and negative values of the higgsino mass parameter (μ). Our investigation shows that the recent experi...
Article
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A bstract We investigate, for the first time, a scenario where the dark matter consists of three complex scalar fields that are stabilized by a single Z 7 symmetry. As an extension of the well-known scalar Higgs-portal, this Z 7 model is also subject to important restrictions arising from the relic density constraint and from direct detection exper...
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A bstract The present-day B -anomalies involving b → sμ ⁺ μ − or b → cτ − $$ \overline{\nu} $$ ν ¯ transitions can all be explained with the addition of a vector U 1 leptoquark with a mass of $$ {M}_{U_1} $$ M U 1 ≳ 1 . 8 TeV. In the scalar singlet dark matter model (SSDMM), the DM is a scalar S that couples to the Higgs via λ hS S ² |H| ² . We upd...
Article
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In scenarios with very small dark matter (DM) couplings and small mass splittings between the DM and other dark sector particles, so-called “co-scattering” or “conversion-driven freeze-out” can be the dominant mechanism for DM production. We present the inclusion of this mechanism in micrOMEGAs together with a case study of the phenomenological imp...
Preprint
Full-text available
We investigate, for the first time, a scenario where the dark matter consists of three complex scalar fields that are stabilized by a single $Z_7$ symmetry. As an extension of the well-known scalar Higgs-portal, this $Z_7$ model is also subject to important restrictions arising from the relic density constraint and from direct detection experiments...
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A bstract We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a Z 2 symmetry, thus the model features two possible dark matter candidates. The two remaining Z 2 -even triplet fermi...
Article
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We consider multicomponent dark matter in a model where one dark matter component is feebly interacting (FIMP) while the second is weakly interacting (WIMP). The model contains an inert scalar doublet and a complex scalar singlet and features a discrete Z4 symmetry. Using new features of micromegas that allow us to compute the relic density for mul...
Preprint
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We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a $Z_2$ symmetry, thus the model features two possible dark matter candidates. The two remaining $Z_2$-even triplet fermions can...
Preprint
In scenarios with very small dark matter (DM) couplings and small mass splittings between the DM and other dark sector particles, so-called "co-scattering" or "conversion-driven freeze-out" can be the dominant mechanism for DM production. We present the inclusion of this mechanism in micrOMEGAs together with a case study of the phenomenological imp...
Preprint
Full-text available
We explore the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with a light neutralino thermal dark matter ($m_{\tilde{\chi}_1^0} \leq m_h/2$) for both positive and negative values of the higgsino mass parameter ($\mu$) that is consistent with current collider and astrophysical constraints. Our investigation sh...
Article
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A bstract Non-minimal simplified extensions of the Standard Model have gained considerable currency in the context of dark matter searches at the LHC, since they predict enhanced mono-Higgs and mono- W/Z signatures over large parts of the parameter space. However, these non-minimal models obviously lack the simplicity and directness of the original...
Preprint
Full-text available
The present-day $B$-anomalies involving $b \to s \mu^+ \mu^-$ or $b \to c \tau^- {\bar\nu}$ transitions can all be explained with the addition of a vector $U_1$ leptoquark with a mass of $M_{U_1} \ge 1.8$ TeV. In the scalar singlet dark matter model (SSDMM), the DM is a scalar $S$ that couples to the Higgs via $\lambda_{hS} \, S^2|H|^2$. We update...
Preprint
We consider multi-component dark matter in a model where one dark matter component is feebly interacting (FIMP) while the second is weakly interacting (WIMP). The model contains an inert scalar doublet and a complex scalar singlet and features a discrete $Z_4$ symmetry. We determine the parameter space that satisfies theoretical constraints, collid...
Article
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We consider a multicomponent dark matter model where the dark sector contains a scalar doublet and a complex scalar singlet. We impose a discrete Z4 symmetry to ensure such that the lightest component of the doublet, A, and the singlet, S, are both stable. Interactions between the dark sectors impact significantly dark matter observables, and they...
Article
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A bstract The measured branching fractions of B -mesons into leptonic final states derived by the LHCb, Belle and BaBar collaborations hint towards the breakdown of lepton flavour universality. In this work we take at face value the so-called $$ {R}_{D^{\left(\ast \right)}} $$ R D ∗ observables that are defined as the ratios of neutral B -meson cha...
Preprint
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The measured branching fractions of $B$-mesons into leptonic final states derived by the LHCb collaboration hint towards the breakdown of lepton flavour universality. In this work we take at face value the so-called $R_{D^{(*)}}$ observables that are defined as the ratios of neutral $B$-meson charged-current decays into a charged $D$-meson, a charg...
Preprint
Full-text available
Non-minimal simplified extensions of the Standard Model have gained considerable currency in the context of dark matter searches at the LHC, since they predict enhanced mono-Higgs and mono-$W/Z$ signatures over large parts of the parameter space. However, these non-minimal models obviously lack the simplicity and directness of the original simplifi...
Preprint
Full-text available
We consider a multi-component dark matter model where the dark sector contains a scalar doublet and a complex scalar singlet. We impose a discrete $Z_4$ symmetry to ensure such that the lightest component of the doublet, $\tilde{A}$, and the singlet, $\tilde{S}$, are both stable. Interactions between the dark sectors impact significantly dark matte...
Article
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Direct detection experiments obtain 90% upper limits on the elastic scattering cross sections of dark matter with nucleons assuming point-like interactions and standard astrophysical and cosmological parameters. In this paper we provide a recasting of the limits from XENON1T, PICO-60, CRESST-III and DarkSide-50 and include them in micrOMEGAs. The c...
Article
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Unlike its minimal counterpart, the next to minimal supersymmetric Standard Model (NMSSM) allows the possibility that the lightest neutralino could have a mass as small as ∼1 GeV while still providing a significant component of relic dark matter (DM). Such a neutralino can provide an invisible decay mode to the Higgs as well. Further, the observed...
Article
In this article we review the case for a light (<mh125∕2) neutralino and sneutrino being a viable Dark Matter (DM) candidate in Supersymmetry (SUSY). To that end we recapitulate, very briefly, three issues related to the DM which impact the discussions: calculation of DM relic density, detection of the DM in Direct and Indirect experiments and crea...
Preprint
In this article we review the case for a light ($< m_{h_{125}}/2$) neutralino and sneutrino being a viable Dark Matter (DM) candidate in Supersymmetry(SUSY). To that end we recapitulate, very briefly, three issues related to the DM which impact the discussions : calculation of DM relic density, detection of the DM in Direct and Indirect experiments...
Article
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A bstract Scenarios for multi-component scalar dark matter based on a single Z N ( N ≥ 4) symmetry are simple and well-motivated. In this paper we investigate, for the first time, the phenomenology of the Z 5 model for two-component dark matter. This model, which can be seen as an extension of the well-known singlet scalar model, features two compl...
Article
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We present a thorough analysis of the sequential freeze-in mechanism for dark matter production in the early Universe. In this mechanism the dark matter relic density results from pair annihilation of mediator particles which are themselves produced by thermal collisions of standard model particles. Below some critical value of the mediator couplin...
Preprint
Scenarios for multi-component scalar dark matter based on a single $Z_N$ ($N\geq 4$) symmetry are simple and well-motivated. In this paper we investigate, for the first time, the phenomenology of the $Z_5$ model for two-component dark matter. This model, which can be seen as an extension of the well-known singlet scalar model, features two complex...
Preprint
Unlike its minimal counterpart, the Next to Minimal supersymmetric Standard Model (NMSSM) allows the possibility that the lightest neutralino could have a mass as small as $\sim 1~{\rm GeV}$ while still providing a significant component of relic dark matter (DM). Such a neutralino can provide an invisible decay mode to the Higgs as well. Further, t...
Preprint
We present a thorough analysis of the sequential freeze-in mechanism for dark matter production in the early universe. In this mechanism the dark matter relic density results from pair annihilation of mediator particles which are themselves produced by thermal collisions of standard model particles. Below some critical value of the mediator couplin...
Preprint
This report presents the activities of the `New Physics' working group for the `Physics at TeV Colliders' workshop (Les Houches, France, 10--28 June, 2019). These activities include studies of direct searches for new physics, approaches to exploit published data to constrain new physics, as well as the development of tools to further facilitate the...
Preprint
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We present a class of dark matter models, in which the dark matter particle is a feebly interacting massive particle (FIMP) produced via the decay of an electrically charged and/or colored parent particle. Given the feeble interaction, dark matter is produced via the freeze-in mechanism and the parent particle is long-lived. The latter leads to int...
Article
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A bstract We propose simple freeze-in models where the observed dark matter abundance is explained via the decay of an electrically charged and/or coloured parent particle into Feebly Interacting Massive Particles (FIMP). The parent particle is long-lived and yields a wide variety of LHC signatures depending on its lifetime and quantum numbers. We...
Article
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A bstract The minimal supersymmetric (SUSY) standard model (MSSM) augmented by right chiral sneutrinos may lead to one such sneutrino serving as the lightest supersymmetric particle and a non-thermal dark matter candidate, especially if neutrinos have Dirac masses only. In such cases, if the lightest MSSM particle is a stau, the signal of SUSY at t...
Preprint
The minimal supersymmetric (SUSY) standard model (MSSM) augmented by right chiral sneutrinos may lead to one such sneutrino serving as the lightest supersymmetric particle and a non-thermal dark matter candidate, especially if neutrinos have Dirac masses only. In such cases, if the lightest MSSM particle is a stau, the signal of SUSY at the LHC con...
Article
We present a major upgrade of the micrOMEGAs dark matter code to compute the abundance of feebly interacting dark matter candidates through the freeze-in mechanism in generic extensions of the Standard Model of particle physics. We develop the necessary formalism in order to solve the freeze-in Boltzmann equations while making as few simplifying as...
Preprint
We present a major upgrade of the micrOMEGAs dark matter code to compute the abundance of feebly interacting dark matter candidates through the freeze-in mechanism in generic extensions of the Standard Model of particle physics. We develop the necessary formalism in order to solve the freeze-in Boltzmann equations while making as few simplifying as...
Article
Full-text available
In the context of searches for long-lived particles (LLP), we have shown, using several benchmarks, that objects which emerge from a secondary vertex due to the decay of an LLP at the TeV scale, are often at large angular separations with respect to the direction of the parent LLP and a fraction of the decay products can even go in the backward dir...
Preprint
In contrast to the decay products ensuing from a fast moving particle which are collimated along the original direction of the parent, those from a slow moving particle are distributed over a wide region. In the context of searches for heavy long-lived particles (LLP) at the Large Hadron Collider (LHC), we quantitatively demonstrate, using a few be...
Article
We study the decay of 125 GeV Higgs boson to a pair of lightest neutralinos in the phenomenological minimal supersymmetric standard model in the context of collider searches and astrophysical experiments. We consider the parameter space for light neutralinos that can be probed via the invisible Higgs decays and Higgsino searches at the ILC. We cons...
Article
We present a full one-loop renormalisation of the Higgs sector of the Next-to-Minimal- Supersymmetric-Standard-Model (NMSSM) and its implementation within SloopS, a code for the automated computations of one-loop processes in theories beyond the Stan- dard Model. The present work is the sequel to the study we performed on the renor- malisation of t...
Article
Models in which dark matter particles communicate with the visible sector through a pseudoscalar mediator are well-motivated both from a theoretical and from a phenomenological standpoint. With direct detection bounds being typically subleading in such scenarios, the main constraints stem either from collider searches for dark matter, or from indir...
Preprint
We present a full one-loop renormalisation of the Higgs sector of the Next-to-Minimal- Supersymmetric-Standard-Model (NMSSM) and its implementation within SloopS, a code for the automated computations of one-loop processes in theories beyond the Stan- dard Model. The present work is the sequel to the study we performed on the renor- malisation of t...
Preprint
Models in which dark matter particles communicate with the visible sector through a pseudoscalar mediator are well-motivated both from a theoretical and from a phenomenological standpoint. With direct detection bounds being typically subleading in such scenarios, the main constraints stem either from collider searches for dark matter, or from indir...
Preprint
We study the decay of 125 GeV Higgs boson to light LSP neutralino in the phenomenological minimal supersymmetric standard model in the context of collider searches and astrophysical experiments. We consider the parameter space for light neutralinos that can be probed via the invisible Higgs decays and higgsino searches at the ILC. We consider the c...
Article
We revisit a set of dark sector models, motivated by anomalies observed in B decays and the muon anomalous magnetic moment, in the light of a recently reported diphoton excess around 750 GeV. Interpreting the excess as a scalar resonance associated with the symmetry breaking sector of a dark gauge group, we show that a diphoton cross section of O(f...
Article
Full-text available
This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. The main goal of the working group was to present the state-of-the-art of Higgs physics at the LHC, integrating all new results that have appeared in the last few years. The first part compiles the most up-to-date predictions o...
Article
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Heavy vector-like quarks coupled to a scalar $S$ will induce a coupling of this scalar to photons and/or gluons. The decay of the heavy quark into $Sq$, with $q$ being a SM quark, could provide a new search channel for heavy quarks. For illustration, we consider the case of a singlet vector-like partner of the top quark and show that it can be sear...
Preprint
Heavy vector-like quarks coupled to a scalar $S$ will induce a coupling of this scalar to gluons and possibly (if electrically charged) photons. The decay of the heavy quark into $Sq$, with $q$ being a Standard Model quark, provides, if kinematically allowed, new channels for heavy quark searches. Inspired by naturalness considerations, we consider...
Article
Results from the LHC put severe constraints on models of new physics. This includes constraints on the Higgs sector from the precise measurement of the mass and couplings of the 125 GeV Higgs boson, as well as limits from searches for other new particles. We present the procedure to use these constraints in micrOMEGAs by interfacing it to the exter...
Preprint
Results from the LHC put severe constraints on models of new physics. This includes constraints on the Higgs sector from the precise measurement of the mass and couplings of the 125GeV Higgs boson, as well as limits from searches for other new particles. We present the procedure to use these constraints in micrOMEGAs by interfacing it to the extern...
Article
Full-text available
Current data (LHC direct searches, Higgs mass, dark matter-related bounds) severely affect the constrained minimal SUSY standard model (CMSSM) with neutralinos as dark matter candidates. But the evidence for neutrino masses coming from oscillations requires extending the SM with at least right-handed neutrinos with a Dirac mass term. In turn, this...
Preprint
Current data (LHC direct searches, Higgs mass, dark matter-related bounds) severely affect the constrained minimal SUSY standard model (CMSSM) with neutralinos as dark matter candidates. But the evidence for neutrino masses coming from oscillations requires extending the SM with at least right-handed neutrinos with a Dirac mass term. In turn, this...
Article
We revisit a set of dark sector models, motivated by anomalies observed in $B$ decays and the muon anomalous magnetic moment, in the light of a recently reported diphoton excess around 750$\,$GeV. Interpreting the excess as a scalar resonance associated with the symmetry breaking sector of a dark gauge group, we show that a diphoton cross section o...
Article
The comparison of the results of direct detection of dark matter, obtained with various target nuclei, requires model-dependent, or even arbitrary, assumptions. Indeed, to draw conclusions either the spin-dependent (SD) or the spin-independent (SI) interaction has to be neglected. In the light of the null results from supersymmetry searches at the...
Article
We have completed the one-loop renormalisation of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) allowing for and comparing between different renormalisation schemes. A special attention is paid to on-shell schemes. We study a variety of these schemes based on alternative choices of the physical input parameters. In this paper we present...
Preprint
We have completed the one-loop renormalisation of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) allowing for and comparing between different renormalisation schemes. A special attention is paid to on-shell schemes. We study a variety of these schemes based on alternative choices of the physical input parameters. In this paper we present...
Preprint
The comparison of the results of direct detection of Dark Matter, obtained with various target nuclei, requires model-dependent, or even arbitrary, assumptions. Indeed, to draw conclusions either the spin-dependent (SD) or the spin-independent (SI) interaction has to be neglected. In the light of the null results from supersymmetry searches at the...
Article
Full-text available
Limits on dark matter spin dependent elastic scattering cross section on protons derived from IceCube data are obtained for different dark matter annihilation channels using micrOMEGAs. The uncertainty on the derived limits, estimated by using different neutrino spectra, can reach a factor two. For all dark matter annihilation channels except for q...
Article
If weak scale supersymmetry (SUSY) is to somehow explain the radiative stability of the Higgs boson mass, it is likely that non-minimal variants of SUSY models should be considered. Under the assumption that the dark matter of the universe is comprised of neutralinos, recent limits from direct detection experiments as well as dark matter abundance...
Article
The new minimal supersymmetric standard model (nMSSM), a variant of the general next to minimal supersymmetric standard model (NMSSM) without Z 3 symmetry, features a naturally light singlino with a mass below 75 GeV. In light of the new constraints from LHC Run-1 on the Higgs couplings, sparticles searches and flavour observables, we define the pa...
Article
We show that the recently reported anomalies in $b\to s\mu^+\mu^-$ transitions, as well as the long-standing $g_\mu-2$ discrepancy, can be addressed simultaneously by a new massive abelian gauge boson with loop-induced coupling to muons. Such a scenario typically leads to a stable dark matter candidate with a thermal relic density close to the obse...
Article
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The discovery of a Higgs boson with a mass of 126 GeV at the LHC when combined with the non-observation of new physics both in direct and indirect searches imposes strong constraints on supersymmetric models and in particular on the top squark sector. The experiments for direct detection of dark matter have provided with yet more constraints on the...
Article
The U(1) extended supersymmetric standard model (UMSSM) can accommodate a Higgs boson at 125 GeV without relying on large corrections from the top/stop sector. After imposing LHC results on the Higgs sector, on B-physics and on new particle searches as well as dark matter constraints, we show that this model offers two viable dark matter candidates...
Article
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A comprehensive review of physics at an e+e- Linear Collider in the energy range of sqrt{s}=92 GeV--3 TeV is presented in view of recent and expected LHC results, experiments from low energy as well as astroparticle physics.The report focuses in particular on Higgs boson, Top quark and electroweak precision physics, but also discusses several model...
Article
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Searches in final states with two leptons plus missing transverse energy, targeting supersymmetric particles or invisible decays of the Higgs boson, were performed during Run 1 of the LHC. Recasting the results of these analyses in the context of the Inert Doublet Model (IDM) using MadAnalysis 5, we show that they provide constraints on inert scala...
Article
Weak scale supersymmetry (SUSY) remains a prime explanation for the radiative stability of the Higgs field. A natural account of the Higgs boson mass, however, strongly favors extensions of the Minimal Supersymmetric Standard Model (MSSM). A plausible option is to introduce a new supersymmetric sector coupled to the MSSM Higgs fields, whose associa...
Article
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The positron fraction in cosmic rays was found to be a steadily increasing in function of energy, above $\sim$ 10 GeV. This behaviour is in tension with standard astrophysical mechanisms, in which positrons are secondary particles, produced in the interactions of primary cosmic rays during the propagation in the interstellar medium. The observed an...
Article
micrOMEGAs is a code to compute dark matter observables in generic extensions of the standard model. This version of micrOMEGAs includes a generalization of the Boltzmann equations to take into account the possibility of two dark matter candidates. The modification of the relic density calculation to include interactions between the two DM sectors...
Article
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