scholarly journals Long-lived dark Higgs and inelastic dark matter at Belle II

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Michael Duerr ◽  
Torben Ferber ◽  
Camilo Garcia-Cely ◽  
Christopher Hearty ◽  
Kai Schmidt-Hoberg
Keyword(s):  
Dark Matter ◽  
Higgs Field ◽  
Mass Splitting ◽  
Dark Sector ◽  
Missing Momentum ◽  
Belle Ii ◽  
Displaced Vertex ◽  
Inelastic Dark Matter ◽  
Near Future ◽  
Matter Detection

Abstract Inelastic dark matter is an interesting scenario for light thermal dark matter which is fully consistent with all cosmological probes as well as direct and indirect dark matter detection. The required mass splitting between dark matter χ1 and its heavier twin χ2 is naturally induced by a dark Higgs field which also provides a simple mechanism to give mass to the dark photon A′ present in the setup. The corresponding dark Higgs boson h′ is naturally the lightest dark sector state and therefore decays into Standard Model particles via Higgs mixing. In this work we study signatures with displaced vertices and missing momentum at Belle II, arising from dark Higgs particles produced in association with dark matter. We find that Belle II can be very sensitive to this scenario, in particular if a displaced vertex trigger is available in the near future.

scholarly journals Exploring properties of long-lived particles in inelastic dark matter models at Belle II

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Dong Woo Kang ◽  
P. Ko ◽  
Chih-Ting Lu
Keyword(s):  
Dark Matter ◽  
Excited State ◽  
Early Stage ◽  
Ground States ◽  
Mass Splitting ◽  
Matter Model ◽  
Belle Ii ◽  
Displaced Vertex ◽  
Inelastic Dark Matter ◽  
Dark Matter Model

Abstract The inelastic dark matter model is one kind of popular models for the light dark matter (DM) below O(1) GeV. If the mass splitting between DM excited and ground states is small enough, the co-annihilation becomes the dominant channel for thermal relic density and the DM excited state can be long-lived at the collider scale. We study scalar and fermion inelastic dark matter models for $$ \mathcal{O} $$ O (1) GeV DM at Belle II with U(1)D dark gauge symmetry broken into its Z2 subgroup. We focus on dilepton displaced vertex signatures from decays of the DM excited state. With the help of precise displaced vertex detection ability at Belle II, we can explore the DM spin, mass and mass splitting between DM excited and ground states. Especially, we show scalar and fermion DM candidates can be discriminated and the mass and mass splitting of DM sector can be determined within the percentage of deviation for some benchmark points. Furthermore, the allowed parameter space to explain the excess of muon (g− 2)μ is also studied and it can be covered in our displaced vertex analysis during the early stage of Belle II experiment.

scholarly journals Higgs portal to dark matter and $$B\rightarrow K^{(*)}$$ decays

2020 ◽  
Vol 80 (7) ◽  
Author(s):  
Aliaksei Kachanovich ◽  
Ulrich Nierste ◽  
Ivan Nišandžić
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Decay Rates ◽  
Dark Sector ◽  
Mixing Angle ◽  
Decay Modes ◽  
Simultaneous Study ◽  
Belle Ii ◽  
Displaced Vertex ◽  
Higgs Portal

Abstract We consider a Higgs portal model in which the 125-GeV Higgs boson mixes with a light singlet mediator $$h_2$$h2 coupling to particles of a Dark Sector and study potential $$b\rightarrow s h_2$$b→sh2 decays in the Belle II experiment. Multiplying the gauge-dependent off-shell Standard-Model b-s-Higgs vertex with the sine of the Higgs mixing angle does not give the correct b-s-$$h_2$$h2 vertex. We clarify this issue by calculating the b-s-$$h_2$$h2 vertex in an arbitrary $$R_\xi $$Rξ gauge and demonstrate how the $$\xi $$ξ dependence cancels from physical decay rates involving an on-shell or off-shell $$h_2$$h2. Then we revisit the $$b\rightarrow s h_2$$b→sh2 phenomenology and point out that a simultaneous study of $$B\rightarrow K^* h_2$$B→K∗h2 and $$B\rightarrow K h_2$$B→Kh2 helps to discriminate between the Higgs portal and alternative models of the Dark Sector. We further advocate for the use of the $$h_2$$h2 lifetime information contained in displaced-vertex data with $$h_2$$h2 decaying back to Standard-Model particles to better constrain the $$h_2$$h2 mass or to reveal additional $$h_2$$h2 decay modes into long-lived particles.

scholarly journals Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Amin Aboubrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Small Mass ◽  
Big Bang ◽  
Mass Splitting ◽  
Recoil Energy ◽  
Dirac Fermions ◽  
Dark Sector ◽  
Dark Photon ◽  
Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

scholarly journals Model-independent identification of inelastic WIMPs from direct Dark Matter detection experiments

2014 ◽  
Vol 29 (05) ◽  
pp. 1450014 ◽  
Author(s):  
Sen Miao ◽  
Chung-Lin Shan ◽  
Yu-Feng Zhou
Keyword(s):  
Dark Matter ◽  
Data Analysis ◽  
Mass Splitting ◽  
Data Sets ◽  
Independent Data ◽  
Nucleus Scattering ◽  
Model Independent ◽  
Dark Matter Detection ◽  
Matter Detection ◽  
Direct Dark Matter

In this paper, we introduce model-independent data analysis procedures for identifying inelastic WIMP-nucleus scattering as well as for reconstructing the mass and the mass splitting of inelastic WIMPs simultaneously and separately. Our simulations show that, with 𝒪(50) observed WIMP signals from one experiment, one could already distinguish the inelastic WIMP scattering scenarios from the elastic one. By combining two or more data sets with positive signals, the WIMP mass and the mass splitting could even be reconstructed with statistical uncertainties of less than a factor of two.

scholarly journals Exposing dark sector with future Z-factories

2019 ◽  
Vol 34 (13n14) ◽  
pp. 1940010 ◽  
Author(s):  
Jia Liu ◽  
Lian-Tao Wang ◽  
Xiao-Ping Wang ◽  
Wei Xue
Keyword(s):  
Dark Matter ◽  
Independent Study ◽  
Dark Sector ◽  
Dark Matter Search ◽  
Hidden Sector ◽  
Leading Role ◽  
Model Independent ◽  
Higgs Portal ◽  
Inelastic Dark Matter ◽  
The Universe

We investigate the prospects of searching dark sector models via exotic [Formula: see text]-boson decay at future [Formula: see text] colliders with Giga [Formula: see text] and Tera [Formula: see text] options. Four general categories of dark sector models: Higgs portal dark matter, vector portal dark matter, inelastic dark matter and axion-like particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model independent study of the sensitivities of [Formula: see text]-factories in probing exotic decays. The limits on branching ratios of the exotic [Formula: see text] decay are typically [Formula: see text] for the Giga [Formula: see text] and [Formula: see text] for the Tera [Formula: see text], and they are compared with the projection for the high luminosity LHC. We demonstrate that future [Formula: see text]-factories can provide its unique and leading sensitivity, and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits, and the existing collider limits. Future [Formula: see text] factories will play a leading role to uncover the hidden sector of the universe in the future.

scholarly journals Searches for Dark Photons at Accelerators

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Matt Graham ◽  
Christopher Hearty ◽  
Mike Williams
Keyword(s):  
Dark Matter ◽  
Online Publication ◽  
Science Volume ◽  
Annual Review ◽  
Electromagnetic Current ◽  
Publication Date ◽  
Dark Sector ◽  
Ordinary Matter ◽  
Dark Photon ◽  
Near Future

Dark matter particles may interact with other dark matter particles via a new force mediated by a dark photon, A′, which would be the dark-sector analog to the ordinary photon of electromagnetism. The dark photon can obtain a highly suppressed mixing-induced coupling to the electromagnetic current, providing a portal through which dark photons can interact with ordinary matter. This review focuses on A′ scenarios that are potentially accessible to accelerator-based experiments. We summarize the existing constraints placed by such experiments on dark photons, highlight what could be observed in the near future, and discuss the major experimental challenges that must be overcome to improve sensitivities. Expected final online publication date for the Annual Review of Nuclear and Particle Science, Volume 71 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Inelastic dark matter, small scale problems, and the XENON1T excess

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Seungwon Baek
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Gauge Coupling ◽  
Photoelectric Effect ◽  
Elastic Cross Section ◽  
Small Scale ◽  
Generic Model ◽  
Dark Sector ◽  
Relic Abundance ◽  
Inelastic Dark Matter

Abstract We study a generic model in which the dark sector is composed of a Majorana dark matter χ1, its excited state χ2, both at the electroweak scale, and a light dark photon Z′ with mz′ ∼ 10−4 eV. The light Z′ enhances the self-scattering elastic cross section χ1χ1 → χ1χ1 enough to solve the small scale problems in the N-body simulations with the cold dark matter. The dark matter communicates with the SM via kinetic mixing parameterized by ϵ. The inelastic scattering process χ1χ1 → χ2χ2 followed by the prompt decay χ2 → χ1Z′ generates energetic Z′. By setting δ ≡ mχ2− mχ1 ≃ 2.8 keV and ϵ ∼ 10−10 the excess in the electron-recoil data at the XENON1T experiment can be explained by the dark-photoelectric effect. The relic abundance of the dark matter can also be accommodated by the thermal freeze-out mechanism via the annihilation χ1χ1(χ2χ2) → Z′Z′ with the dark gauge coupling constant αX ∼ 10−3.

scholarly journals The Echo Method for Axion Dark Matter Detection

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2150
Author(s):  
Ariel Arza ◽  
Elisa Todarello
Keyword(s):  
Dark Matter ◽  
Angular Frequency ◽  
Spontaneous Breaking ◽  
Dark Matter Candidate ◽  
Echo Signal ◽  
Axion Mass ◽  
Analytical Formulas ◽  
Near Future ◽  
Axion Decay ◽  
Matter Detection

The axion is a dark matter candidate arising from the spontaneous breaking of the Peccei–Quinn symmetry, introduced to solve the strong CP problem. It has been shown that radio/microwave radiation sent out to space is backscattered in the presence of axion dark matter due to stimulated axion decay. This backscattering is a feeble and narrow echo signal centered at an angular frequency very close to one-half of the axion mass. In this article, we summarize all the relevant results found so far, including analytical formulas for the echo signal, as well as sensitivity prospects for possible near-future experiments.

scholarly journals The local dark sector

2021 ◽  
Author(s):  
Joel Bergé ◽  
Laura Baudis ◽  
Philippe Brax ◽  
Sheng-Wey Chiow ◽  
Bruno Christophe ◽  
...  
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Dark Energy ◽  
Solar System ◽  
Gravitational Potential ◽  
Atomic Clock ◽  
Dark Sector ◽  
New Knowledge ◽  
Near Future

AbstractWe speculate on the development and availability of new innovative propulsion techniques in the 2040s, that will allow us to fly a spacecraft outside the Solar System (at 150 AU and more) in a reasonable amount of time, in order to directly probe our (gravitational) Solar System neighborhood and answer pressing questions regarding the dark sector (dark energy and dark matter). We identify two closely related main science goals, as well as secondary objectives that could be fulfilled by a mission dedicated to probing the local dark sector: (i) begin the exploration of gravitation’s low-acceleration regime with a spacecraft and (ii) improve our knowledge of the local dark matter and baryon densities. Those questions can be answered by directly measuring the gravitational potential with an atomic clock on-board a spacecraft on an outbound Solar System orbit, and by comparing the spacecraft’s trajectory with that predicted by General Relativity through the combination of ranging data and the in-situ measurement (and correction) of non-gravitational accelerations with an on-board accelerometer. Despite a wealth of new experiments getting online in the near future, that will bring new knowledge about the dark sector, it is very unlikely that those science questions will be closed in the next two decades. More importantly, it is likely that it will be even more urgent than currently to answer them. Tracking a spacecraft carrying a clock and an accelerometer as it leaves the Solar System may well be the easiest and fastest way to directly probe our dark environment.

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