Publications (124)337.63 Total impact
 [Show abstract] [Hide abstract]
ABSTRACT: 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 Run1 on the Higgs couplings, sparticles searches and flavour observables, we define the parameter space of the model which is compatible with both collider and dark matter (DM) properties. Among the regions compatible with these constraints, implemented through NMSSMTools, SModelS and MadAnalysis5, only one with a singlino lightest supersymmetric particle (LSP) with a mass around 5 GeV can explain all the DM abundance of the universe, while heavier mixed singlinos can only form one of the DM components. Typical collider signatures for each region of the parameter space are investigated. In particular, the decay of the 125 GeV Higgs into light scalars and/or pseudoscalars and the decay of the heavy Higgs into charginos and neutralinos, provide distinctive signatures of the model. Moreover, the sfermion decays usually proceed through heavier neutralinos rather than directly into the LSP, as the couplings to the singlino are suppressed. We also show that direct detection searches are complementary to collider ones, and that a future tonscale detector could completely probe the region of parameter space with a LSP mass around 65 GeV.  [Show abstract] [Hide abstract]
ABSTRACT: 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 quarks, the limits on the spin dependent cross section are more stringent than those obtained in direct detection experiments. The new functions that allow to derive those limits are described.  [Show abstract] [Hide abstract]
ABSTRACT: 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 Bphysics and on new particle searches as well as dark matter constraints, we show that this model offers two viable dark matter candidates, the righthanded (RH) sneutrino or the neutralino. Limits on supersymmetric partners from LHC simplified model searches are imposed using SModelS and allow for light squarks and gluinos. Moreover the upper limit on the relic abundance often favours scenarios with longlived particles. Searches for a Z' at the LHC remain the most unambiguous probes of this model. Interestingly, the Dterm contributions to the sfermion masses allow to explain the anomalous magnetic moment of the muon in specific corners of the parameter space with light smuons or lefthanded (LH) sneutrinos. We finally emphasize the interplay between direct searches for dark matter and LHC simplified model searches.  [Show abstract] [Hide abstract]
ABSTRACT: 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 as well as semiannihilation is presented. Both DM signals in direct and indirect detection are computed as well. An extension of the standard model with two scalar doublets and a singlet is used as an example.  [Show abstract] [Hide abstract]
ABSTRACT: We study the dark matter from an inert doublet and a complex scalar singlet stabilized by N symmetries. This field content is the minimal one that allows dimensionless semiannihilation couplings for N > 2. We consider explicitly the 3 and 4 cases and take into account constraints from perturbativity, unitarity, vacuum stability, necessity for the electroweak N preserving vacuum to be the global minimum, electroweak precision tests, upper limits from direct detection and properties of the Higgs boson. Coannihilation and semiannihilation of dark sector particles as well as dark matter conversion significantly modify the cosmic abundance and direct detection phenomenology.  [Show abstract] [Hide abstract]
ABSTRACT: We present the activities of the "New Physics" working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 321 June, 2013). Our report includes new computational tool developments, studies of the implications of the Higgs boson discovery on new physics, important signatures for searches for natural new physics at the LHC, new studies of flavour aspects of new physics, and assessments of the interplay between direct dark matter searches and the LHC.  [Show abstract] [Hide abstract]
ABSTRACT: We study the dark matter from an inert doublet and a complex scalar singlet stabilized by $\mathbb{Z}_N$ symmetries. This field content is the minimal one that allows dimensionless semiannihilation couplings for $N > 2$. We consider explicitly the $\mathbb{Z}_3$ and $\mathbb{Z}_4$ cases and take into account constraints from perturbativity, unitarity, vacuum stability, necessity for the electroweak $\mathbb{Z}_N$ preserving vacuum to be the global minimum, electroweak precision tests, upper limits from direct detection and properties of the Higgs boson. Coannihilation and semiannihilation of dark sector particles as well as dark matter conversion significantly modify the cosmic abundance and direct detection phenomenology.  [Show abstract] [Hide abstract]
ABSTRACT: These lecture notes describe the micrOMEGAs code for the calculation of Dark Matter observables in extensions of the standard model.  [Show abstract] [Hide abstract]
ABSTRACT: These lecture notes describe the micrOMEGAs package for the calculation of Dark Matter observables in extensions of the standard model.  [Show abstract] [Hide abstract]
ABSTRACT: We study a simple model that can give rise to isospinviolating interactions of Dirac fermion asymmetric dark matter to protons and neutrons through the interference of a scalar and U(1)$'$ gauge boson contribution. The model can yield a large suppression of the elastic scattering cross section off Xenon relative to Silicon thus reconciling CDMSSi and LUX results while being compatible with LHC findings on the 126 GeV Higgs, electroweak precision tests and flavour constraints.  [Show abstract] [Hide abstract]
ABSTRACT: This discovery of the Higgs boson last year has created new possibilities for testing candidate theories for explaining physics beyond the Standard Model. Here we explain the ways in which new physics can leave its marks in the experimental Higgs data, and how we can use the data to constrain and compare different models. In this proceedings paper we use two models, Minimal Universal Extra Dimensions and the 4D Composite Higgs model, as examples to demonstrate the technique.  [Show abstract] [Hide abstract]
ABSTRACT: micrOMEGAs is a code to compute dark matter observables in generic extensions of the standard model. This new version of micrOMEGAs is a major update which includes a generalization of the Boltzmann equations to accommodate models with asymmetric dark matter or with semiannihilation and a first approach to a generalization of the thermodynamics of the Universe in the relic density computation. Furthermore a switch to include virtual vector bosons in the final states in the annihilation cross sections or relic density computations is added. Effective operators to describe loopinduced couplings of Higgses to twophotons or twogluons are introduced and reduced couplings of the Higgs are provided allowing for a direct comparison with recent LHC results. A module that computes the signature of DM captured in celestial bodies in neutrino telescopes is also provided. Moreover the direct detection module has been improved as concerns the implementation of the strange "content" of the nucleon. New extensions of the standard model are included in the distribution.  [Show abstract] [Hide abstract]
ABSTRACT: micrOMEGAs calculates the properties of cold dark matter in a generic model of particle physics. First developed to compute the relic density of dark matter, the code also computes the rates for dark matter direct and indirect detection. The code provides the mass spectrum, crosssections, relic density and exotic fluxes of gamma rays, positrons and antiprotons. The propagation of charged particles in the Galactic halo is handled with a module that allows to easily modify the propagation parameters. The crosssections for both spin dependent and spin independent interactions of WIMPS on protons are computed automatically as well as the rates for WIMP scattering on nuclei in a large detector. Annihilation crosssections of the dark matter candidate at zero velocity, relevant for indirect detection of dark matter, are computed automatically, and the propagation of charged particles in the Galactic halo is also handled.  [Show abstract] [Hide abstract]
ABSTRACT: We study the production and decay of charged scalars, η ±, in the context of a CPViolating InertDoublet Model. The model is an extended version of the Inert Doublet Model with an extra Higgs doublet and provides new sources of CP violation and a dark matter candidate. As compared with the 2HDM, the particle spectrum contains two additional neutral scalars and a charged pair. These particles are subject to a Z 2 symmetry, but can be pairproduced in hadronic collisions. If a charged scalar is included in the pair, it decays to the stable darkmatter candidate (i.e., the lightest neutral inert scalar) plus Standard Model matter that consists of either two jets or a single lepton (from a virtual or real W or Z) plus missing transverse energy. Since the single production channel is available only at hadronic colliders, we consider the Large Hadron Collider environment, hence we discuss experimental perspectives and possible hallmarks of the model, such as events with a displaced vertex. 
Article: $Z_3$ Scalar Singlet Dark Matter
[Show abstract] [Hide abstract]
ABSTRACT: We consider the minimal scalar singlet dark matter stabilised by a $Z_3$ symmetry. Due to the cubic term in the scalar potential, semiannihilations, besides annihilations, contribute to the dark matter relic density. Unlike in the $Z_2$ case, the dark matter spin independent direct detection cross section is no more linked to the annihilation cross section. We study the extrema of the potential and show that a too large cubic term would break the $Z_3$ symmetry spontaneously, implying a lower bound on the direct detection cross section, and allowing the whole parameter space to be tested by XENON1T. In a small region of the parameter space the model can avoid the instability of the standard model vacuum up to the unification scale. If the semiannihilations are large, however, new physics will be needed at TeV scale because the model becomes nonperturbative. The singlet dark matter mass cannot be lower than 53.8 GeV due to the constraint from Higgs boson decay into dark matter.  [Show abstract] [Hide abstract]
ABSTRACT: Searches for Dark Matter (DM) particles with indirect detection techniques have reached important milestones with the precise measurements of the antiproton () and gammaray spectra, notably by the PAMELA and FERMILAT experiments. While the γray results have been used to test the thermal Dark Matter hypothesis and constrain the Dark Matter annihilation cross section into Standard Model (SM) particles, the antiproton flux measured by the PAMELA experiment remains relatively unexploited. Here we show that the latter can be used to set a constraint on the neutralinochargino mass difference. To illustrate our point we use a Supersymmetric model in which the gauginos are light, the sfermions are heavy and the Lightest Supersymmetric Particle (LSP) is the neutralino. In this framework the W+W− production is expected to be significant, thus leading to large and γray fluxes. After determining a generic limit on the Dark Matter pair annihilation cross section into W+W− from the data only, we show that one can constrain scenarios in which the neutralinochargino mass difference is as large as 20 GeV for a mixed neutralino (and intermediate choices of the propagation scheme). This result is consistent with the limit obtained by using the FERMILAT data. As a result, we can safely rule out the pure wino neutralino hypothesis if it is lighter than 450 GeV and constitutes all the Dark Matter.  [Show abstract] [Hide abstract]
ABSTRACT: We present version 3.4 of the CalcHEP software package which is designed for effective evaluation and simulation of high energy physics collider processes at parton level. The main features of CalcHEP are the computation of Feynman diagrams, integration over multiparticle phase space and event simulation at parton level. The principle attractive keypoints along these lines are that it has: a) an easy startup even for those who are not familiar with CalcHEP; b) a friendly and convenient graphical user interface; c) the option for a user to easily modify a model or introduce a new model by either using the graphical interface or by using an external package with the possibility of cross checking the results in different gauges; d) a batch interface which allows to perform very complicated and tedious calculations connecting production and decay modes for processes with many particles in the final state. With this features set, CalcHEP can efficiently perform calculations with a high level of automation from a theory in the form of a Lagrangian down to phenomenology in the form of cross sections, parton level event simulation and various kinematical distributions. In this paper we report on the new features of CalcHEP 3.4 which improves the power of our package to be an effective tool for the study of modern collider phenomenology.  [Show abstract] [Hide abstract]
ABSTRACT: Large Hadron Collider (LHC) searches for the SM Higgs boson provide a powerful limit on models involving Universal Extra Dimensions (UED) where the Higgs production is enhanced. We have evaluated all oneloop diagrams for Higgs production from gluon fusion and decay to two photons within "minimal" UED (mUED), independently confirming previous results, and we have evaluated enhancement factors for Higgs boson production and decay over the mUED parameter space. Using these we have derived limits on the parameter space, combining data from both ATLAS and CMS collaborations for the most recent 7 TeV and 8 TeV LHC data. We have performed a rigorous statistical combination of several Higgs boson search channels which is important because mUED signatures from the Higgs boson are not universally enhanced. We have found that 1/R < 500 GeV is excluded at 95% CL, while for larger 1/R only a very narrow (\pm14 GeV) mass window around m_h = 125 GeV and another window (up to 2 GeV wide for 1/R > 1000 GeV) around m_h = 118 GeV are left. The latter is likely to be excluded as more data becomes available whereas the region around 125 GeV is where the recently discovered Higgslike particle was observed and therefore where the exclusion limit is weaker. It is worth stressing that mUED predicts an enhancement for all channels for Higgs production by gluon fusion and decay while the vector boson fusion process WW/ZZ > h > AA is generically suppressed and WW/ZZ > h > WW*/ZZ* is standard. Therefore, as more 8 TeV LHC data becomes available, the information on individual Higgs boson production and decay processes provided by the CMS and ATLAS experiments can be effectively used to favour mUED or exclude it further.  [Show abstract] [Hide abstract]
ABSTRACT: We study the impact of semiannihilations x_i x_j <> x_k X, where x_i is any dark matter and X is any standard model particle, on dark matter phenomenology. We formulate minimal scalar dark matter models with an extra doublet and a complex singlet that predict nontrivial dark matter phenomenology with semiannihilation processes for different discrete Abelian symmetries Z_N, N>2. We implement two such example models with Z_3 and Z_4 symmetry in micrOMEGAs and work out their phenomenology. We show that both semiannihilations and annihilations involving only particles from two different dark matter sectors significantly modify the dark matter relic abundance in this type of models. We also study the possibility of dark matter direct detection in XENON100 in those models.  [Show abstract] [Hide abstract]
ABSTRACT: We present the activities of the "New Physics" working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 30 May17 June, 2011). Our report includes new agreements on formats for interfaces between computational tools, new tool developments, important signatures for searches at the LHC, recommendations for presentation of LHC search results, as well as additional phenomenological studies.
Publication Stats
6k  Citations  
337.63  Total Impact Points  
Top Journals
Institutions

20032015

Lomonosov Moscow State University
 Skobeltsyn Institute of Nuclear Physics
Moskva, Moscow, Russia


19912015

Moscow State Forest University
Mytishi, MO, Russia


2010

University of Bonn
 Physics Institute
Bonn, North RhineWestphalia, Germany 
Universität Hamburg
 I. Institut für Theoretische Physik
Hamburg, Hamburg, Germany


2007

Tsinghua University
 Center for High Energy Physics
Beijing, Beijing Shi, China


19992006

Budker Institute of Nuclear Physics
NovoNikolaevsk, Novosibirsk, Russia
