A
bstract
We examine the Inert Doublet Model in light of the discovery of a Higgs-like boson with a mass of roughly 126 GeV at the LHC. We evaluate one-loop corrections to the scalar masses and ...perform a numerical solution of the one-loop renormalization group equations. Demanding vacuum stability, perturbativity, and
S
-matrix unitarity, we compute the scale up to which the model can be extrapolated. From this we derive constraints on the model parameters in the presence of a 126 GeV Higgs boson. We perform an improved calculation of the dark matter relic density with the Higgs mass fixed to the measured value, taking into account the effects of three- and four-body final states resulting from off-shell production of gauge bosons in dark matter annihilation. Issues related to direct detection of dark matter are discussed, in particular the role of hadronic uncertainties. The predictions for the interesting decay mode
h
0
→
γγ
are presented for scenarios which fulfill all model constraints, and we discuss how a potential enhancement of this rate from the charged inert scalar is related to the properties of dark matter in this model. We also apply LHC limits on Higgs boson decays to invisible final states, which provide additional constraints on the mass of the dark matter candidate. Finally, we propose three benchmark points that capture different aspects of the relevant phenomenology.
LHC-friendly minimal freeze-in models Bélanger, G.; Desai, N.; Goudelis, A. ...
The journal of high energy physics,
02/2019, Letnik:
2019, Številka:
2
Journal Article
Recenzirano
Odprti dostop
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 assess the current constraints and future high luminosity reach of these scenarios at the LHC from searches for heavy stable charged particles, disappearing tracks, displaced vertices and displaced leptons. We show that the LHC constitutes a powerful probe of freeze-in dark matter and can further provide interesting insights on the validity of vanilla baryogenesis and leptogenesis scenarios.
micrOMEGAs is a numerical code to compute dark matter (DM) observables in generic extensions of the Standard Model (SM) of particle physics. We present a new version of micrOMEGAs that includes a ...generalization of the Boltzmann equations governing the DM cosmic abundance evolution which can be solved to compute the relic density of N-component DM. The direct and indirect detection rates in such scenarios take into account the relative contribution of each component such that constraints on the combined signal of all DM components can be imposed. The co-scattering mechanism for DM production is also included, whereas the routines used to compute the relic density of feebly interacting particles have been improved in order to take into account the effect of thermal masses of t-channel particles. Finally, the tables for the DM self-annihilation - induced photon spectra have been extended down to DM masses of 110 MeV, and they now include annihilation channels into light mesons.
Program title: micrOMEGAs6.0
CPC Library link to program files:https://doi.org/10.17632/4ck6jf5vxf.3
Licensing provisions: GNU General Public License 3
Programming language: C and Fortran
Journal reference of previous version: Comput. Phys. Comm. 231 (2018) 173.
Does the new version supersede the previous version?: Yes
Reasons for the new version: Previous versions of micrOMEGAs worked within the assumption that DM is composed of one or two components. The new version allows for more components which can be either weekly or feebly interacting. The possibility of co-scattering is also implemented.
Summary of revisions: This version includes new routines to compute the abundance of multi-component DM that contains either weakly or feebly interacting dark matter particles in generic extensions of the SM of particle physics. The co-scattering mechanism for DM production is also included. The routines to compute the relic density of feebly interacting particles through the freeze-in mechanism have been improved in order to take into account the effect of thermal masses of t-channel particles. The tables for the photon spectra resulting from pair annihilation have been extended down to dark matter masses of 110 MeV and they now include annihilation channels into light mesons.
Nature of problem: DM candidates that satisfy cosmological constraints cover a wide range of masses and interaction strengths. Moreover, the dark sector could contain several stable neutral particles that can all contribute to DM. We provide the first public code to perform a precise computation of the relic density for generic extensions of the SM with more than two component dark matter.
Solution method: We solve N Boltzmann equations treating both the cases where the DM components are in thermal equilibrium with the thermal bath in the early Universe, as well as the case where the DM is too feebly interacting to reach equilibrium. We also include decay terms in the Boltzmann equations. All the signals for DM direct and indirect detection take into account the contribution of each component to the total relic density.
We consider the singlet scalar model of dark matter and study the expected antiproton and positron signals from dark matter annihilations. The regions of the viable parameter space of the model that ...are excluded by present data are determined, as well as those regions that will be probed by the forthcoming experiment AMS-02. In all cases, different propagation models are investigated, and the possible enhancement due to dark matter substructures is analyzed. We find that the antiproton signal is more easily detectable than the positron one over the whole parameter space. For a typical propagation model and without any boost factor, AMS-02 will be able to probe --via antiprotons-- the singlet model of dark matter up to masses of 600 GeV. Antiprotons constitute, therefore, a promising signal to constraint or detect the singlet scalar model. Keywords->
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 assumptions as possible concerning the phase-space distributions of the particles involved in the dark matter production process. We further show that this formalism allows us to treat different freeze-in scenarios and discuss the way it is implemented in the code. We find that, depending on the New Physics scenario under consideration, the effect of a proper treatment of statistics on the predicted dark matter abundance can range from a few percent up to a factor of two, or more. We moreover illustrate the underlying physics, as well as the various novel functionalities of micrOMEGAs, by presenting several example results obtained for different dark matter models.
Program title: micrOMEGAs5.
Program Files doi:http://dx.doi.org/10.17632/4ck6jf5vxf.2
Licensing provisions: GNU General Public License 3 (GPL)
Programming language: C and Fortran
Journal reference of previous version: Comput. Phys. Commun. 222 (2018) 327.
Does the new version supersede the previous version?: Yes
Reasons for the new version: Previous versions of micrOMEGAs worked within the assumption that dark matter is in thermal equilibrium with the standard model particles in the early Universe. For several classes of dark matter models this condition is not fulfilled. This new version allows to treat such cases, in particular the one where dark matter is composed of feebly interacting massive particles (FIMPs) that obtain their relic density via the freeze-in mechanism.
Summary of revisions: This version includes new routines 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. A proper treatment of the phase-space distribution functions for bosons and fermions is included. The user must specify which particles are to be considered as FIMPs as well as the reheating temperature, that is the temperature at which dark matter formation starts. The relic density of the (next-to) lightest dark sector particle can also be computed via the freeze-out mechanism. This version includes three new sample models in which dark matter production proceeds through freeze-in.
Nature of problem: Dark matter candidates that satisfy cosmological constraints cover a wide range of masses and interaction strength. One reason for dark matter particles to have escaped all direct, indirect and collider searches so far could be that they are feebly interacting. We provide the first public code to perform a precise computation of the relic density of FIMPs in generic extensions of the standard model in order to check agreement with the value of the relic density extracted from cosmological observations.
Solution method: We solve the freeze-in Boltzmann equations while making as few simplifying assumptions as possible concerning the phase-space distribution of the particles involved in the dark matter production process. We include the case where dark matter is produced through the two-body decay of a particle whether or not it is in thermal equilibrium with the thermal bath as well as the one where dark matter is produced through 2→2 annihilations of a pair of bath particles. Two numerical methods are provided — one where the collision term in the Boltzmann equation is integrated directly and a more efficient one where some of the integrals are performed analytically.
We study the possibility of identifying dark matter properties from XENON-like 100 kg experiments and the GLAST satellite mission. We show that whereas direct detection experiments will probe ...efficiently light WIMPs, given a positive detection (at the 10% level for m{sub {chi}} {approx}< 50 GeV), GLAST will be able to confirm and even increase the precision in the case of a NFW profile, for a WIMP-nucleon cross-section {sigma}{sub {chi}-p} {approx}< 10{sup -8} pb. We also predict the production rate of a WIMP in the next generation of colliders (ILC), and compare their sensitivity to the WIMP mass with the XENON and GLAST projects.
A
bstract
The ATLAS and CMS collaborations recently reported a mild excess in the diphoton final state pointing to a resonance with a mass of around 750 GeV and a potentially large width. We consider ...the possibility of a scalar resonance being produced via gluon fusion and decaying to electroweak gauge bosons, jets and pairs of invisible particles, stable at collider scales. We compute limits from monojet searches on such a resonance and test their compatibility with the requirement for a large width. We also study whether the stable particle can be a a dark matter candidate and investigate the corresponding relic density constraints along with the collider limits. We show that monojet searches rule out a large part of the available parameter space and point out scenarios where a broad diphoton resonance can be reconciled with monojet constraints.
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 scalars that significantly extend previous limits from LEP. Moreover, these LHC constraints allow us to test the IDM in the limit of very small Higgs-inert scalar coupling, where the constraints from direct detection of dark matter and the invisible Higgs width vanish.
A
bstract
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 indirect detection experiments. However, LHC searches for the mediator particles themselves can not only compete with — or even supersede — the reach of direct collider dark matter probes, but they can also test scenarios in which traditional monojet searches become irrelevant, especially when the mediator cannot decay on-shell into dark matter particles or its decay is suppressed. In this work we perform a detailed analysis of a pseudoscalar-mediated dark matter simplified model, taking into account a large set of collider constraints and concentrating on the parameter space regions favoured by cos-mological and astrophysical data. We find that mediator masses above 100-200 GeV are essentially excluded by LHC searches in the case of large couplings to the top quark, while forthcoming collider and astrophysical measurements will further constrain the available parameter space.
Abstract Extensions of the Standard Model featuring light vector bosons have been explored with the goal of resolving certain tensions between theory and experiment, among them the discrepancy in the ...anomalous magnetic moment of the muon, $$\Delta a_{\mu }$$ Δ a μ . In particular, this is the case of a minimal construction including a leptophilic, strictly flavour violating, vector boson $$Z^\prime $$ Z ′ . These new vector bosons are also well-motivated dark matter portals, with non-trivial couplings to stable, weakly interacting states which can account for the correct dark matter density. Here we study the prospects of a Standard Model extension (via a vector boson and a fermionic dark matter candidate) concerning signatures at the LHC, and at future lepton and hadron colliders. We discuss the cross-sections of several processes leading to same- and opposite-sign muon-tau lepton pairs in the final state, as well as final states with missing energy (in the form of neutrinos and/or dark matter). Our findings suggest that a future muon collider offers the best prospects to probe this model (together with searches for dilepton pairs and missing energy signatures at the FCC-ee running at the Z -pole); moreover, the complementarity of the different future high-energy colliders is also paramount to probing distinct $$Z^\prime $$ Z ′ mass regimes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
