scholarly journals Probing the explanation of the muon (g-2) anomaly and thermal light dark matter with the semi-visible dark photon channel

2021 ◽  
Vol 81 (10) ◽  
Author(s):  
C. Cazzaniga ◽  
P. Odagiu ◽  
E. Depero ◽  
L. Molina Bueno ◽  
Yu. M. Andreev ◽  
...  
Keyword(s):  
Dark Matter ◽  
Detection Efficiency ◽  
Vector Boson ◽  
Large Mass ◽  
New Physics ◽  
Mass Splitting ◽  
Dark Photon ◽  
Dark Matter Relic Density ◽  
Relic Abundance ◽  
Pseudo Scalar

AbstractWe report the results of a search for a new vector boson ($$ A'$$ A ′ ) decaying into two dark matter particles $$\chi _1 \chi _2$$ χ 1 χ 2 of different mass. The heavier $$\chi _2$$ χ 2 particle subsequently decays to $$\chi _1$$ χ 1 and an off-shell Dark Photon $$ A'^* \rightarrow e^+e^-$$ A ′ ∗ → e + e - . For a sufficiently large mass splitting, this model can explain in terms of new physics the recently confirmed discrepancy observed in the muon anomalous magnetic moment at Fermilab. Remarkably, it also predicts the observed yield of thermal dark matter relic abundance. A detailed Monte-Carlo simulation was used to determine the signal yield and detection efficiency for this channel in the NA64 setup. The results were obtained re-analyzing the previous NA64 searches for an invisible decay $$A'\rightarrow \chi \overline{\chi }$$ A ′ → χ χ ¯ and axion-like or pseudo-scalar particles $$a \rightarrow \gamma \gamma $$ a → γ γ . With this method, we exclude a significant portion of the parameter space justifying the muon g-2 anomaly and being compatible with the observed dark matter relic density for $$A'$$ A ′ masses from 2$$m_e$$ m e up to 390 MeV and mixing parameter $$\varepsilon $$ ε between $$3\times 10^{-5}$$ 3 × 10 - 5 and $$2\times 10^{-2}$$ 2 × 10 - 2 .

scholarly journals Dark matter bound state formation in fermionic Z2 DM model with light dark photon and dark Higgs boson

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Pyungwon Ko ◽  
Toshinori Matsui ◽  
Yi-Lei Tang
Keyword(s):  
Dark Matter ◽  
Higgs Boson ◽  
Gauge Symmetry ◽  
State Formation ◽  
Vector Boson ◽  
Goldstone Boson ◽  
Bound State ◽  
Dark Photon ◽  
Potential Matrix ◽  
Relic Abundance

Abstract If fermionic dark matter (DM) is stabilized by dark U(1) gauge symmetry that is spontaneously broken into its subgroup Z2, the particle contents of the model becomes very rich: DM and excited DM, both of them are Majorana fermions, as well as two dark force mediators, dark photon and dark Higgs boson are naturally present due to the underlying dark gauge symmetry. In this paper, we study the DM bound state formation processes within this scenario, assuming both dark photon and dark Higgs are light mediators and including the effects of excited DM. The Goldstone boson contributions to the potential matrix in the Schrödinger equations are found to be important. The emissions of a longitudinal vector boson (or somehow equivalently a Goldstone boson) during the DM bound state formations are crucial to induce a significant reannihilation process, reducing the dark matter relic abundance. Most of the stringent constraints for this kind of dark matter considered in the literature are simply evaded.

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 Kinetic mixing, dark photons and extra dimensions. Part III. Brane localized dark matter

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Thomas G. Rizzo ◽  
George N. Wojcik
Keyword(s):  
Dark Matter ◽  
Extra Dimensions ◽  
Model Building ◽  
New Physics ◽  
Model Complexity ◽  
Complex Scalar ◽  
Dark Photon ◽  
Complex Models ◽  
The Cost ◽  
D Model

Abstract Extra dimensions have proven to be a very useful tool in constructing new physics models. In earlier work, we began investigating toy models for the 5-D analog of the kinetic mixing/vector portal scenario where the interactions of dark matter, taken to be, e.g., a complex scalar, with the brane-localized fields of the Standard Model (SM) are mediated by a massive U(1)D dark photon living in the bulk. These models were shown to have many novel features differentiating them from their 4-D analogs and which, in several cases, avoided some well-known 4-D model building constraints. However, these gains were obtained at the cost of the introduction of a fair amount of model complexity, e.g., dark matter Kaluza-Klein excitations. In the present paper, we consider an alternative setup wherein the dark matter and the dark Higgs, responsible for U(1)D breaking, are both localized to the ‘dark’ brane at the opposite end of the 5-D interval from where the SM fields are located with only the dark photon now being a 5-D field. The phenomenology of such a setup is explored for both flat and warped extra dimensions and compared to the previous more complex models.

scholarly journals Gravitational waves from an axion-dark photon system: A lattice study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wolfram Ratzinger ◽  
Pedro Schwaller ◽  
Benjamin Stefanek
Keyword(s):  
Numerical Simulation ◽  
Dark Matter ◽  
Early Universe ◽  
Degree Of Polarization ◽  
Dark Photon ◽  
System A ◽  
Precise Prediction ◽  
Relic Abundance ◽  
Vast Range ◽  
Photon Coupling

In this work, we present a lattice study of an axion - dark photon system in the early Universe and show that the stochastic gravitational wave (GW) background produced by this system may be probed by future GW experiments across a vast range of frequencies. The numerical simulation on the lattice allows us to take into account non-linear backreaction effects and enables us to accurately predict the final relic abundance of the axion or axion-like particle (ALP) as well as its inhomogeneities, and gives a more precise prediction of the GW spectrum. Importantly, we find that the GW spectrum has more power at high momenta due to 2\rightarrow12→1 processes. Furthermore, we find the degree of polarization of the peak of the GW spectrum depends on the ALP-dark photon coupling and that the polarization can be washed out or even flipped for large values thereof. In line with recent results in the literature, we find the ALP relic abundance may be suppressed by two orders of magnitude and discuss possible extensions of the model that expand the viable parameter space. Finally, we discuss the possibility to probe ultralight ALP dark matter via spectral distortions of the CMB.

scholarly journals Relic abundance of dark photon dark matter

2020 ◽  
Vol 801 ◽  
pp. 135136 ◽  
Author(s):  
Prateek Agrawal ◽  
Naoya Kitajima ◽  
Matthew Reece ◽  
Toyokazu Sekiguchi ◽  
Fuminobu Takahashi
Keyword(s):  
Dark Matter ◽  
Dark Photon ◽  
Relic Abundance

scholarly journals NEW LIMITS ON TOP SQUARK NLSP FROM ATLAS 4.7 fb-1 DATA

2012 ◽  
Vol 27 (32) ◽  
pp. 1250188 ◽  
Author(s):  
ARGHYA CHOUDHURY ◽  
AMITAVA DATTA
Keyword(s):  
Dark Matter ◽  
Lower Limit ◽  
New Physics ◽  
Supersymmetric Particle ◽  
Top Squark ◽  
Decay Modes ◽  
Dark Matter Relic Density ◽  
Relic Density ◽  
200 Gev ◽  
New Physics Search

Using the ATLAS 4.7 fb-1 data on new physics search in the jets + [Formula: see text] channel, we obtain new limits on the lighter top squark [Formula: see text] considering all its decay modes assuming that it is the next to lightest supersymmetric particle (NLSP). If the decay [Formula: see text] dominates and the production of dark matter relic density is due to NLSP–lightest supersymmetric particle (LSP) co-annihilation then the lower limit on [Formula: see text] is 240 GeV. The limit changes to 200 GeV if the decay [Formula: see text] dominates. Combining these results it follows that [Formula: see text] NLSP induced baryogenesis is now constrained more tightly.

scholarly journals Primordial black holes and the origin of the matter–antimatter asymmetry

2019 ◽  
Vol 377 (2161) ◽  
pp. 20190091 ◽  
Author(s):  
Juan García-Bellido
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Cold Dark Matter ◽  
Hot Spot ◽  
Large Mass ◽  
New Physics ◽  
Primordial Black Holes ◽  
Far From Equilibrium ◽  
The Universe

We review here a new scenario of hot spot electroweak baryogenesis where the local energy released in the gravitational collapse to form primordial black holes (PBHs) at the quark-hadron (QCD) epoch drives over-the-barrier sphaleron transitions in a far from equilibrium environment with just the standard model CP violation. Baryons are efficiently produced in relativistic collisions around the black holes and soon redistribute to the rest of the universe, generating the observed matter–antimatter asymmetry well before primordial nucleosynthesis. Therefore, in this scenario there is a common origin of both the dark matter to baryon ratio and the photon to baryon ratio. Moreover, the sudden drop in radiation pressure of relativistic matter at H 0 / W ± / Z 0 decoupling, the QCD transition and e + e − annihilation enhances the probability of PBH formation, inducing a multi-modal broad mass distribution with characteristic peaks at 10 −6 , 1, 30 and 10 6   M ⊙ , rapidly falling at smaller and larger masses, which may explain the LIGO–Virgo black hole mergers as well as the OGLE-GAIA microlensing events, while constituting all of the cold dark matter today. We predict the future detection of binary black hole (BBH) mergers in LIGO with masses between 1 and 5  M ⊙ , as well as above 80  M ⊙ , with very large mass ratios. Next generation gravitational wave and microlensing experiments will be able to test this scenario thoroughly. This article is part of a discussion meeting issue ‘Topological avatars of new physics’.

scholarly journals Collider probes of real triplet scalar dark matter

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Cheng-Wei Chiang ◽  
Giovanna Cottin ◽  
Yong Du ◽  
Kaori Fuyuto ◽  
Michael J. Ramsey-Musolf
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Hadron Collider ◽  
Mass Splitting ◽  
Dark Matter Candidate ◽  
Soft Pion ◽  
Dark Matter Relic Density ◽  
Pile Up ◽  
Higgs Portal ◽  
Scalar Sector

Abstract We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV pp collider. We focus on the scenario in which the neutral triplet scalar is stable and contributes to the dark matter relic density. When produced in pp collisions, the charged triplet scalar decays to the neutral component plus a soft pion or soft lepton pair, yielding a disappearing charged track in the detector. We recast current 13 TeV LHC searches for disappearing tracks, and find that the LHC presently excludes a real triplet scalar lighter than 248 (275) GeV, for a mass splitting of 172 (160) MeV with ℒ = 36 fb−1. The reach can extend to 497 (520) GeV with the collection of 3000 fb−1. We extrapolate the 13 TeV analysis to a prospective 100 TeV pp collider, and find that a ∼ 3 TeV triplet scalar could be discoverable with ℒ = 30 ab−1, depending on the degree to which pile up effects are under control. We also investigate the dark matter candidate in our model and corresponding present and prospective constraints from dark matter direct detection. We find that currently XENON1T can exclude a real triplet dark matter lighter than ∼ 3 TeV for a Higgs portal coupling of order one or larger, and the future XENON20T will cover almost the entire dark matter viable parameter space except for vanishingly small portal coupling.

scholarly journals Light dark photon dark matter from inflation

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Yuichiro Nakai ◽  
Ryo Namba ◽  
Ziwei Wang
Keyword(s):  
Dark Matter ◽  
Photon Mass ◽  
Dark Photon ◽  
Photon Field ◽  
Relic Abundance ◽  
Large Wavelength

Abstract We discuss the possibility of producing a light dark photon dark matter through a coupling between the dark photon field and the inflaton. The dark photon with a large wavelength is efficiently produced due to the inflaton motion during inflation and becomes non-relativistic before the time of matter-radiation equality. We compute the amount of production analytically. The correct relic abundance is realized with a dark photon mass extending down to 10−21 eV.

scholarly journals Thermal relic of self-interacting dark matter with retarded decay of mediator

2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Bin Zhu ◽  
Murat Abdughani
Keyword(s):  
Dark Matter ◽  
Direct Detection ◽  
Large Mass ◽  
Bound State ◽  
Blind Spot ◽  
Mass Splitting ◽  
Temperature Evolution ◽  
S Wave ◽  
Sommerfeld Enhancement ◽  
Freeze Out

Abstract The existence of a light mediator is beneficial to some phenomena in astroparticle physics, such as the core-cusp problem and diversity problem. It can decouple from Standard Model to avoid direct detection constraints, generally realized by retard decay of the mediator. Their out-of-equilibrium decay process changes the dark matter (DM) freeze-out via temperature discrepancy. This type of hidden sector (HS) typically requires a precision calculation of the freeze-out process considering HS temperature evolution and the thermal average of the cross-section. If the mediator is light sufficiently, we can not ignore the s-wave radiative bound state formation process from the perspective of CMB ionization and Sommerfeld enhancement. We put large mass splitting between DM and mediator, different temperature evolution on the same theoretical footing, discussing the implication for DM relic density in this HS. We study this model and illustrate its property by considering the general Higgs-portal dark matter scenario, which includes all the relevant constraints and signals. It shows that the combination of BBN and CMB constraint favors the not-too-hot HS, rinf< 102, for the positive cubic interaction of mediator scenario. On the other hand, the negative cubic interaction is ruled out except for our proposed blind spot scenario.

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