Phenomenology of GeV-scale scalar portal

Self Cite

Traditional direct searches for dark matter, looking for nuclear recoils in deep underground detectors, are challenged by an almost complete loss of sensitivity for light dark matter particles. Consequently, there is a significant effort in the community to devise new methods and experiments to overcome these difficulties, constantly pushing the limits of the lowest dark matter mass that can be probed this way. From a model-building perspective, the scattering of sub-GeV dark matter on nucleons essentially must proceed via new light mediator particles, given that collider searches place extremely stringent bounds on contact-type interactions. Here we present an updated compilation of relevant limits for the case of a scalar mediator, including a new estimate of the near-future sensitivity of the NA62 experiment as well as a detailed evaluation of limits from Big Bang nucleosynthesis. We also derive updated and more general limits on DM particles upscattered by cosmic rays, applicable to arbitrary energy-and momentum dependences of the scattering cross section. Finally we stress that dark matter self-interactions place stringent limits independently of the dark matter production mechanism. These are, for the relevant parameter space, generically comparable to those that apply in the commonly studied freeze-out case. We conclude that the combination of existing (or expected) constraints from accelerators and astrophysics, combined with cosmological requirements, puts robust limits on the maximally possible nuclear scattering rate. In most regions of parameter space these are at least competitive with the best projected limits from currently planned direct detection experiments.arXiv:1909.08632v2 [hep-ph]

Section: Constraints From Particle Physics Experimentsmentioning

confidence: 99%

Direct detection and complementary constraints for sub-GeV dark matter

Bondarenko

Boyarsky

Bringmann

et al. 2020

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“…[23][24][25][26][27][28] as well as the discussion in Section 7). In particular, -Different groups use different prescription for scalar production [1,19,[27][28][29] -the decay width and hadronic branching fractions for scalars with masses from ∼ 0.5 GeV to few GeV are subject to large uncertainties, see [25,26]; -multi-hadronic HNL decays are not accounted for by any of the existing simulation tools. Yet they account for the largest part of the HNLs with masses around few GeV [24,30].…”

Section: Contentsmentioning

confidence: 99%

“…For the scalars the production from D mesons is negligible as compared to the B +/0 mesons decays even for masses m K M S m D . The B c mesons are not relevant for their production (see, e.g., [23,28]). The branching ratios of the production of the HNLs and the scalars used for our estimations are given in Appendix B.1.…”

Section: B and D Mesonsmentioning

confidence: 99%

“…Therefore, we will use different prescriptions for production and/or decay in different sections below, in order to facilitate the comparison of our approach with the Monte Carlo results of other groups. Our current view of the HNL phenomenology is summarized in [24] and for scalar in [28]. Our method of obtaining the sensitivity curves is summarized in Appendix F.…”

Section: Comparison With Simulationsmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity of the intensity frontier experiments for neutrino and scalar portals: analytic estimates

Bondarenko

Boyarsky

Ovchynnikov

et al. 2019

Self Cite

In recent years, a number of intensity frontier experiments have been proposed to search for feebly interacting particles with masses in the GeV range. We discuss how the characteristic shape of the experimental sensitivity regions -upper and lower boundaries of the probed region, the maximal mass reach -depends on the parameters of the experiments. We use the SHiP and the MATHUSLA experiments as examples. We find a good agreement of our estimates with the results of the Monte Carlo simulations. This simple approach allows to cross-check and debug Monte Carlo results, to scan quickly over the parameter space of feebly interacting particle models, and to explore how sensitivity depends on the geometry of experiments.

“…that allows S to decay both into hadrons and leptons. The phenomenology of this model for a GeV scale S has been extensively studied in the literature, see e.g., [34,[47][48][49][50][51][52] and references therein. We use the branching ratio and lifetime of S derived in [34] to set our bounds.…”

Section: The Hadrophilic Higgs Portalmentioning

confidence: 99%

Exclusive displaced hadronic signatures in the LHC forward region

Vidal

Tsai

Zurita

2020

The LHCb detector provides accurate vertex reconstruction and hadronic particle identification, which make the experiment an ideal place to look for light long-lived particles (LLP) decaying into Standard Model (SM) hadrons. In contrast with the typical search strategy relying on energetic jets and a high multiplicity of tracks from the LLP decay, LHCb can identify LLPs in exclusive, specific hadronic final states. To illustrate the idea, we study the sensitivity of LHCb to an exotic Higgs decay h → SS, followed by the displaced decay of GeV-scale scalars into charged kaons S → K + K − . We show that the reconstruction of kaon vertices in narrow invariant mass windows can efficiently eliminate the combinatorial backgrounds from B-meson decays. While the same signal is extremely difficult to probe in the existing displaced jet searches at ATLAS/CMS, the LHCb search we propose can probe the branching ratio BR(h → SS) down to 0.1% (0.02%) level with 15 (300) fb −1 of data. We also apply this projected bound to two scenarios with Higgs portal couplings, where the scalar mediator S either couples to a) the SM quarks only, or b) to both quarks and leptons in the minimal flavor violation paradigm. In both scenarios we compare the reach of our proposed search with the expected constraints from ATLAS and CMS on the invisible Higgs width and with the constraints from rare B-decays studies at LHCb. We find that for 1 GeV < m S < 2 GeV and 0.5 mm cτ 10 mm our proposed search will be competitive with the ATLAS and CMS projections, while at the same time providing crucial information of the hadronic interactions of S, which can not be obtained from the indirect measurement of the Higgs invisible width.