A
bstract
The recent confirmation by the Fermilab-based Muon g-2 experiment of the (
g −
2)
μ
anomaly has important implications for allowed particle spectra in softly broken supersymmetry (SUSY) ...models with neutralino dark matter (DM). Generally, the DM has to be quite light, with the mass up to a few hundred GeV, and bino-dominated if it is to provide most of DM in the Universe. Otherwise, a higgsino or wino dominated DM is also allowed but only as a strongly subdominant component of at most a few percent of the total density. These general patterns can easily be found in the phenomenological models of SUSY but in GUT-constrained scenarios this proves much more challenging. In this paper we revisit the issue in the framework of some unified SUSY models with different GUT boundary conditions on the soft masses. We study the so-called non-universal gaugino model (NUGM) in which the mass of the gluino is disunified from those of the bino and the wino and an SO(10) and an SU(5) GUT-inspired models as examples. We find that in these unified frameworks the above two general patterns of DM can also be found, and thus the muon anomaly can also be accommodated, unlike in the simplest frameworks of the CMSSM or the NUHM. We show the resulting values of direct detection cross-section for points that do and do not satisfy the muon anomaly. On the other hand, it will be challenging to access those solutions at the LHC because the resulting spectra are generally very compressed.
Increasingly stringent limits from LHC searches for new physics, coupled with lack of convincing signals of weakly interacting massive particle (WIMP) in dark matter searches, have tightly ...constrained many realizations of the standard paradigm of thermally produced WIMPs as cold dark matter. In this article, we review more generally both thermally and non-thermally produced dark matter (DM). One may classify DM models into two broad categories: one involving bosonic coherent motion (BCM) and the other involving WIMPs. BCM and WIMP candidates need, respectively, some approximate global symmetries and almost exact discrete symmetries. Supersymmetric axion models are highly motivated since they emerge from compelling and elegant solutions to the two fine-tuning problems of the Standard Model: the strong CP problem and the gauge hierarchy problem. We review here non-thermal relics in a general setup, but we also pay particular attention to the rich cosmological properties of various aspects of mixed SUSY/axion dark matter candidates which can involve both WIMPs and BCM in an interwoven manner. We also review briefly a panoply of alternative thermal and non-thermal DM candidates.
A
bstract
Minimal scenarios with light (sub-GeV) dark matter whose relic density is obtained from thermal freeze-out must include new light mediators. In particular, a very well-motivated case is ...that of a new “dark” massive vector gauge boson mediator. The mass term for such mediator is most naturally obtained by a “dark Higgs mechanism” which leads to the presence of an often long-lived dark Higgs boson whose mass scale is the same as that of the mediator. We study the phenomenology and experimental constraints on two minimal, self-consistent dark sectors that include such a light dark Higgs boson. In one the dark matter is a pseudo-Dirac fermion, in the other a complex scalar. We find that the constraints from BBN and CMB are considerably relaxed in the framework of such minimal dark sectors. We present detection prospects for the dark Higgs boson in existing and projected proton beam-dump experiments. We show that future searches at experiments like Xenon1T or LDMX can probe all the relevant parameter space, complementing the various upcoming indirect constraints from astrophysical observations.
Many existing or proposed intensity-frontier search experiments look for decay signatures of light longlived particles (LLPs), highly displaced from the interaction point, in a distant detector that ...is well-shielded from the StandardModel background. This approach is, however, limited to new particles with decay lengths similar to or larger than the baseline of those experiments. In this study, we discuss how this basic constraint can be overcome in non-minimal beyond standard model scenarios. If more than one light new particle is present in the model, an additional secondary production of LLPs may take place right in front of the detector, opening this way a new lifetime regime to be probed.We illustrate the prospects of such searches in the future experiments FASER, MATHUSLA, and SHiP, for representative models, emphasizing possible connections to dark matter or an anomalous magnetic moment of muon. We also analyze additional advantages from employing dedicated neutrino detectors placed in front of the main decay volume.
A
bstract
Motivated by the recent anomalies in
b
→
s
transitions that emerged at LHCb, we consider a model with an
L
μ
−
L
τ
gauge symmetry and additional vector-like fermions. We find that by ...introducing supersymmetry the model can be made consistent with the long-standing deviation in the measured value of the anomalous magnetic moment of the muon, (
g
− 2)
μ
, and neutralino dark matter of broad mass ranges and properties. In particular, dark matter candidates include the well-known 1 TeV higgsino, which in the MSSM is typically not compatible with solutions to the (
g
− 2)
μ
puzzle. Moreover, its spin-independent cross section could be at the origin of the recent small excess in XENON-1T data. We apply to the model constraints arising from flavor precision measurements and direct searches at the Large Hadron Collider and show that they do not currently exclude the relevant parameter space regions.
Prospects for dark matter searches in the pMSSM Roszkowski, Leszek; Sessolo, Enrico Maria; Williams, Andrew J.
The journal of high energy physics,
02/2015, Volume:
2015, Issue:
2
Journal Article
Peer reviewed
Open access
A
bstract
We investigate the prospects for detection of neutralino dark matter in the 19-parameter phenomenological MSSM (pMSSM). We explore very wide ranges of the pMSSM parameters but pay ...particular attention to the higgsino-like neutralino at the ∼ 1 TeV scale, which has been shown to be a well motivated solution in many constrained supersymmetric models, as well as to a wino-dominated solution with the mass in the range of 2–3 TeV. After summarising the present bounds on the parameter space from direct and indirect detection experiments, we focus on prospects for detection of the Cherenkov Telescope Array (CTA). To this end, we derive a realistic assessment of the sensitivity of CTA to photon fluxes from dark matter annihilation by means of a binned likelihood analysis for the Einasto and Navarro-Frenk-White halo profiles. We use the most up to date instrument response functions and background simulation model provided by the CTA Collaboration. We find that, with 500 hours of observation, under the Einasto profile CTA is bound to exclude at the 95% C.L. almost all of the ∼ 1 TeV higgsino region of the pMSSM, effectively closing the window for heavy supersymmetric dark matter in many realistic models. CTA will be able to probe the vast majority of cases corresponding to a spin-independent scattering cross section below the reach of 1-tonne underground detector searches for dark matter, in fact even well below the irreducible neutrino background for direct detection. On the other hand, many points lying beyond the sensitivity of CTA will be within the reach of 1-tonne detectors, and some within collider reach. Altogether, CTA will provide a highly sensitive way of searching for dark matter that will be partially overlapping and partially complementary with 1-tonne detector and collider searches, thus being instrumental to effectively explore the nearly full parameter space of the pMSSM.
A
bstract
We present an updated analysis of the CMSSM and the NUHM using the latest experimental data and numerical tools. We map out favored regions of Bayesian posterior probability in light of ...data from the LHC, flavor observables, the relic density and dark matter searches. We present some updated features with respect to our previous analyses: we include the effects of corrections to the light Higgs mass beyond the 2-loop order using FeynHiggs 2.10.0; we include in the likelihood the latest limits from direct searches for squarks and gluinos at ATLAS with ~ 20 fb
−1
; the latest constraints on the spin-independent scattering cross section of the neutralino from LUX are applied taking into account uncertainties in the nuclear form factors. We find that in the CMSSM the posterior distribution now tends to favor smaller values of
M
SUSY
than in the previous analyses. As a consequence, the statistical weight of the A-resonance region increases to about 30% of the total probability, with interesting new prospects for the 14 TeV run at the LHC. The most favored region, on the other hand, still features multi-TeV squarks and gluinos, and ~ 1 TeV higgsino dark matter whose detection prospects by current and one-tonne detectors look very promising. The same region is predominant in the NUHM, although the A-resonance region is also present there as well as a new solution, of neutralino-stau coannihilation through the channel
τ
˜
τ
˜
→
hh
at very large
μ
. We derive the expected sensitivity of the future CTA experiment to ~ 1 TeV higgsino dark matter for both models and show that the prospects for probing both models are realistically good. We comment on the complementarity of this search to planned direct detection one-tonne experiments.
A
bstract
Thermal dark matter scenarios based on light (sub-GeV) fermions typically require the presence of an extra dark sector containing both a massive dark photon along with a dark Higgs boson. ...The latter typically generates both the dark photon mass and an additional mass term for the dark sector fermions. This simple setup has both rich phenomenology and bright detection prospects at high-intensity accelerator experiments. We point out that in addition to the well studied pseudo-Dirac regime, this model can achieve the correct relic density in three different scenarios, and examine in details their properties and experimental prospects. We emphasize in particular the effect of the dark Higgs boson on both detection prospects and cosmological bounds.
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