Dark Matter Candidate Research Articles

SEARCH FOR DARK MATTER CANDIDATE PRODUCED IN ASSOCIATION WITH A HIGGS BOSON AND TAU LEPTONS AT √s=14 TeV

A search for dark matter produced in association with a Higgs boson in final states with two 𝜏-leptons and missing transverse momentum, pp→A→ahτ+τ- is presented. The corresponding experimental analysis between 2015–2018 years used 139 fb−1 of proton–proton collision data at √s = 13 TeV collected by the ATLAS experiment at the LHC. The results are interpreted in terms of a 2HDM+a model with physics beyond the Standard Model featuring two scalar Higgs doublets and a pseudoscalar singlet field. Two sets of parameters, derived from experimental exclusion limits, for calculating the axions and bosons production cross sections were selected using the MADGRAPH5@NLO computer program. The obtained information, together with kinematic constraints on the transverse momentum and angular distribution of axions and bosons, allows us to conclude about the existence of CP-odd Higgs bosons with a mass in the region of 400 GeV and a dark matter candidate, the axion, with a mass of up to 200 GeV.

Astrophysical constraints on decaying dark gravitons

In the dark dimension scenario, which predicts an extra dimension of micron scale, dark gravitons (KK modes) are a natural dark matter candidate. In this paper, we study observable features of this model. In particular, their decay to standard matter fields can distort the CMB and impact other astrophysical signals. Using this we place bounds on the parameters of this model. In particular we find that the natural range of parameters in this scenario is consistent with these constraints and leads to the prediction that the mean mass of the dark matter today is close to a few hundred keV and the effective size of the extra dimension is around 1–30 μm.

Right-handed neutrino as a common progenitor of baryon number asymmetry and dark matter

Cosmological and astrophysical observations suggest that both energy densities of baryon and dark matter take the same order values in the present Universe. We propose a scenario to give an answer for this problem in a scotogenic model and its extension. The model naturally provides dark matter candidates as its crucial ingredients to explain the small neutrino mass. If a neutral component of an inert doublet scalar plays a role of dark matter and leptogenesis occurs at TeV scales, both dark matter abundance and baryon number asymmetry could be explained with a same mother particle. Coincidence between the order of their energy densities might be understood through such a background. Published by the American Physical Society 2024

A realistic theory of E6 unification through novel intermediate symmetries

We propose a non-supersymmetric E6 GUT with the scalar sector consisting of 650 ⨁ 351′ ⨁ 27. Making use of the first representation for the initial symmetry breaking to an intermediate stage, and the latter two representations for second-stage breaking to the Standard Model and a realistic Yukawa sector, this theory represents the minimal E6 GUT that proceeds through one of the intermediate stages that are novel compared to SU(5) or SO(10) GUT: trinification SU(3)C × SU(3)L × SU(3)R, SU(6) × SU(2) and flipped SO(10) × U(1). We analyze these possibilities under the choice of vacuum that preserves a ℤ2 “spinorial parity”, which disentangles the chiral and vector-like fermions of E6 and provides a dark matter candidate in the form of a (scalar) inert doublet. Three cases are shown to consistently unify under the extended survival hypothesis (with minimal fine-tuning): trinification symmetry SU(3)C × SU(3)L × SU(3)R with either LR or CR parity, and SU(6)CR × SU(2)L. Although the successful cases give a large range for proton lifetime estimates, all of them include regions consistent with current experimental bounds and within reach of forthcoming experiments. The scenario investigated in this paper essentially represents the unique (potentially) viable choice in the class of E6 GUTs proceeding through a novel-symmetry intermediate stage, since non-minimal alternatives seem to be intrinsically non-perturbative.

Troubles mounting for multipolar dark matter

In this paper, we revisit the experimental constraints on the multipolar dark matter that has derivative coupling to the visible sector mediated by the Standard Model photon. The momentum dependent interaction enables them to be captured efficiently within massive celestial bodies boosted by their steep gravitational potential. This phenomena makes compact celestial bodies as an efficient target to probe such type of dark matter candidates. We demonstrate that a synergy of the updated direct detection results from DarkSide-50 and LUX-ZEPLIN together with IceCube bounds on high energy solar neutrinos from dark matter capture disfavour the viable parameter space of the dipolar dark matter scenario. Whereas, for the anapole dark matter scenario, a narrow window survives that lies within the reach of prospective heating signals due to the capture of dark matter at cold neutron stars.

The role of vectors in reheating

We explore various aspects concerning the role of vector bosons during the reheating process. Generally, reheating occurs during the period of oscillations of the inflaton condensate and the evolution of the radiation bath depends on the inflaton equation of state. For oscillations about a quadratic minimum, the equation of state parameter, w = p/ρ = 0, and the evolution of the temperature, T(a) with respect to the scale factor is independent of the spin of the inflaton decay products. However, for cases when w > 0, there is a dependence on the spin, and here we consider the evolution when the inflaton decays or scatters to vector bosons. We also investigate the gravitational production of vector bosons as potential dark matter candidates. Gravitational production predominantly occurs through the longitudinal mode. We compare these results to the gravitational production of scalars.

Vector wave dark matter and terrestrial quantum sensors

(Ultra)light spin-1 particles — dark photons — can constitute all of dark matter (DM) and have beyond Standard Model couplings. This can lead to a coherent, oscillatory signature in terrestrial detectors that depends on the coupling strength. We provide a signal analysis and statistical framework for inferring the properties of such DM by taking into account (i) the stochastic and (ii) the vector nature of the underlying field, along with (iii) the effects due to the Earth's rotation. Owing to equipartition, on time scales shorter than the coherence time the DM field vector typically traces out a fixed ellipse. Taking this ellipse and the rotation of the Earth into account, we highlight a distinctive three-peak signal in Fourier space that can be used to constrain DM coupling strengths. Accounting for all three peaks, we derive latitude-independent constraints on such DM couplings, unlike those stemming from single-peak studies. We apply our framework to the search for ultralight B - L DM using optomechanical sensors, demonstrating the ability to delve into previously unprobed regions of this DM candidate's parameter space.

Search for Nearly Mass-Degenerate Higgsinos Using Low-Momentum Mildly Displaced Tracks in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

Higgsinos with masses near the electroweak scale can solve the hierarchy problem and provide a dark matter candidate, while detecting them at the LHC remains challenging if their mass splitting is O(1 GeV). This Letter presents a novel search for nearly mass-degenerate Higgsinos in events with an energetic jet, missing transverse momentum, and a low-momentum track with a significant transverse impact parameter using 140 fb^{-1} of proton-proton collision data at sqrt[s]=13 TeV collected by the ATLAS experiment. For the first time since LEP, a range of mass splittings between the lightest charged and neutral Higgsinos from 0.3 to 0.9GeV is excluded at 95% confidence level, with a maximum reach of approximately 170GeV in the Higgsino mass.

Improved constraints for axion-like particles from 3-photon events at e+e-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$e^+e^-$$\\end{document} colliders

Axions and axion-like particles (ALPs) are one of the most widely discussed extensions of the Standard Model when it comes to the strong CP problem and dark matter candidates. Current experiments are focused on the indirect searches of invisible pseudoscalars in a wide parameter range. In this paper we investigate limits on ALP mass, and its couplings to photons and leptons from 3-photon annihilation at e+e-\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$e^+e^-$$\\end{document} colliders. We provide detailed calculations and apply them to the particular kinematics of the Belle II experiment, covering the ALP mass range from few hundred MeV to around 10 GeV. Our results, which improve upon previous analyses by also including the ALP coupling to electrons, show that such future analyses will allow to significantly extend the ALP search range and impose much more stringent restrictions on their couplings.

Collective excitations of self-gravitating bose-einstein condensates: Breathing mode and appearance of anisotropy under self-gravity

Abstract We investigate the collective mode of a self-gravitating Bose-Einstein condensate (BEC) described by the Gross-Pitaevskii-Poisson (GPP) equations. The self-gravitating BEC has garnered considerable attention in cosmology and astrophysics, being proposed as a plausible candidate for dark matter. Our inquiry delves into the breathing and anisotropic collective modes by numerically solving the GPP equations and using the variational method. The breathing mode demonstrates a reduction in period with increasing total mass due to the density dependence of the self-gravitating BEC, attributed to the density-dependent nature of self-gravitating BECs, aligning quantitatively with our analytical findings. Additionally, we investigate an anisotropic collective mode in which the quadrupole mode intertwines with the breathing mode. The period of the quadrupole mode exhibits similar total mass dependence to that of the breathing mode. The characteristics of these periods differ from those of a conventional BEC confined by an external potential. Despite the differences in density dependence, the ratio of their periods equals that of the BEC confined by an isotropic harmonic potential. Furthermore, an extension of the variational method to a spheroidal configuration enables the isolation of solely the quadrupole mode from the anisotropic collective mode.

Assisted baryon number violation in 4k+2 dimensions

Proton decay in six-dimensions orbifolded on square T2/Z2 is highly suppressed at tree level. This is because baryon number violating (BNV) operators containing only the zero mode of bulk fermions must satisfy the selection rule 32ΔB±12ΔL=0 mod 4. In this article, we show that the above relation does not prohibit mass dimension-six BNV operators containing Kaluza-Klein partners of the bulk fermions. Together with a “spinless” adjoint scalar partner of hypercharge gauge boson (the dark matter candidate), these novel operators generate dark matter assisted proton decay at mass dimension eight. Here, with explicit examples of scalar and vector baryon number violating interactions, we discuss the importance of such ΔB=1=ΔL and ΔB=2=ΔL operators and derive the limit on new physics. Published by the American Physical Society 2024

Near-quantum-limited haloscope search for dark-photon dark matter enhanced by a high- Q superconducting cavity

We report new experimental results on the search for dark photons based on a near-quantum-limited haloscope equipped with a superconducting cavity. The loaded quality factor of the superconducting cavity is 6×105, so that the expected signal from dark-photon dark matter can be enhanced by more than one order compared to a copper cavity. A Josephson parametric amplifier with a near-quantum-limited noise temperature has been utilized to minimize the noise during the search. Furthermore, a digital acquisition card based on field programmable gate arrays has been utilized to maximize data collection efficiency with a duty cycle being 100%. This work has established the most stringent constraints on dark photons at around 26.965 μeV. In the future, our apparatus can be extended to search for other dark matter candidates, such as axions and axionlike particles, and scrutinize new physics beyond the Standard Model. Published by the American Physical Society 2024

Effects of electroweak symmetry breaking on axionlike particles as dark matter

Axionlike particles (ALPs), the pseudo Nambu-Goldstone bosons associated to the spontaneous breaking of global symmetry, have emerged as promising dark matter candidates. Conventionally, in the context of misalignment mechanism, the nonthermally produced ALPs happen to stay frozen due to Hubble friction initially, and at a later stage, they begin to oscillate (before matter-radiation equality) at characteristic frequencies defined by their masses and behaving like cold dark matter. In this work, we study the influence of electroweak symmetry breaking (EWSB), through a higher order Higgs portal interaction, on the evolution of ALPs. Such an interaction is found to contribute partially to the ALP’s mass during EWSB, thereby modifying oscillation frequencies during EWSB as well as impacting upon the existing correlation between the scale of symmetry breaking and their masses. The novelty of the work lies in broadening the relic satisfied parameter space so as to probe it in near future via a wide range of experiments. Published by the American Physical Society 2024

A comparative lattice analysis of SU(2) dark glueballs* *Supported in part by the Natural Science Foundation of China (12125503, 12335003), and the Natural Science Foundation of Shandong Province, China (ZR2022ZD26)

We study the mass and scattering cross section of glueballs as dark matter candidates using lattice simulations. We employ both naive and improved gauge actions in dimensions with several β values, and we adopt both the traditional Monte Carlo method and flow-based model based on machine learning techniques to generate lattice configurations. The mass of a dark scalar glueball with and the Nambu-Bethe-Salpeter wave function are calculated. Using a coupling constant of as an illustration, we compare the dark glueball mass calculated from the configurations generated from the two methods. While consistent results can be achieved, the two methods demonstrate distinct advantages. Using the Runge-Kutta method, we extract the glueball interaction potential and two-body scattering cross section. From the observational constraints, we obtain the lower bound of the mass of scalar glueballs as candidates of dark matter.

Interplay between Higgs inflation and dark matter models with dark U(1) gauge symmetry

We investigate dark matter phenomenology and Higgs inflation in a dark U(1)D-extended model. The model features two dark matter candidates, a dark fermion and a dark vector boson. When the fermion dark matter ψ is heavier than the vector dark matter WD, there is an ample parameter space where ψ is dominant over WD. The model can then easily evade the stringent bounds from direct detection experiments, since ψ has no direct coupling to the Standard Model particles. Furthermore, the model can accommodate inflation in three different ways, one along the Standard Model Higgs direction, one along the dark Higgs direction, and one along the combination of the two. Considering the running of the parameters and various observational constraints, we perform a detailed numerical analysis and identify allowed parameter spaces that explain both dark matter and Higgs inflation in a unified manner. We discuss in detail how the imposition of Higgs inflation severely constrains the dark matter parameter space. The existence of the dark Higgs field is found to play a crucial role both in dark matter phenomenology and in generalised Higgs inflation.

Freeze-in production of sterile neutrino dark matter in a gauged U(1)′ model with inverse seesaw

We consider a general, anomaly free U(1)′ extension of the Standard Model (SM) where the neutrino mass is generated at the tree level via the inverse seesaw mechanism. The model contains three right handed neutrinos, three additional singlet fermions, one extra complex scalar and a neutral gauge boson (Z′). Instead of resorting to a specific U(1) extension, we consider a class of models by taking the U(1)′ charges of the scalars to be free parameters. Here, we assign one pair of the pseudo-Dirac degenerate sterile neutrinos as Dark Matter (DM) candidates which are produced by the freeze-in mechanism. Considering different mass regimes of the DM, Z′ and reheating temperature, we obtain constraints on the U(1)′ charges giving the correct relic abundance. We have also obtained constraints on Z′ mass and coupling from consideration of relic density as well as high energy collider experiments like ATLAS in case of heavy Z′ or in intensity and lifetime frontier experiments like DUNE, FASERs, and ILC beam dump which are looking for light Z′. Additionally, in this model, the decay of pseudo-Dirac DM into active neutrinos can explain the 511 keV line observed by the INTEGRAL satellite.

Detection possibility of a pseudo-FIMP in the presence of a thermal WIMP

A dark matter (DM) having feeble interaction with the visible sector can thermalize via substantial interaction with a weakly interacting massive particle (WIMP). Such DM candidates can be categorized as pseudofeebly interacting massive particles (pFIMPs). pFIMPs have both direct and indirect search prospects via a WIMP loop. This work focuses on such possibilities. We provide all such one loop graphs stemming from pFIMP-WIMP interactions involving scalar, fermion, and vector boson particles, assuming both of them are stabilized via Z2⊗Z2′ symmetries. We elaborate upon a model where a fermionic WIMP has a significant Yukawa interaction with a scalar pFIMP with negligible Higgs portal coupling. We study, in detail, the loop induced direct and indirect search prospects of the pFIMP in the relic density allowed region of the model along with collider expectations at the LHC. Published by the American Physical Society 2024

Testing axionic dark matter during gravitational reheating

Assuming axions are potential dark matter (DM) candidate that make up all of the DM abundance, we discuss production of axions via (i) standard misalignment mechanism during the period of reheating and (ii) graviton-mediated 2-to-2 scattering of the inflaton and bath particles, where the inflaton ϕ oscillates in a monomial potential V(ϕ)∝ϕk with a general equation of state. Considering reheating takes place purely gravitationally, mediated by massless gravitons, we explore the viable region of the parameter space that agrees with the observed DM relic abundance, satisfying bounds from big bang nucleosynthesis and cosmic microwave background radiation. We also discuss complementarity between dedicated axion search experiments and futuristic gravitational wave search facilities in probing the viable parameter space, thanks to the presence of detectable primordial gravitational waves with an inflationary origin. Published by the American Physical Society 2024

Gravitational waves from a scotogenic two-loop neutrino mass model

We propose a framework to account for neutrino masses at the two-loop level. This mechanism introduces new scalars and Majorana fermions to the Standard Model. It assumes the existence of a global U(1)×Z2 symmetry which after partial breaking provides the stability of the dark matter candidates of the theory. The rich structure of the potential allows for the possibility of first-order phase transitions (FOPTs) in the early Universe which can lead to the generation of primordial gravitational waves. Taking into account relevant constraints from lepton flavor violation, neutrino physics, as well as the trilinear Higgs couplings at next-to-leading order accuracy, we have found a wide range of possible FOPTs which are strong enough to be probed at the proposed gravitational-wave interferometer experiments such as LISA. Published by the American Physical Society 2024

Féeton (B-L gauge boson) dark matter for the 511-keV gamma-ray excess and the prediction of low-energy neutrino flux* *Supported by the Talent Scientific Start-Up Project of China, the Natural Science Foundation of China (12175134, 12375101, 12090060, 12090064, 12247141), the SJTU Double First Class start-up fund(WF220442604), and the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan

The féeton is the gauge boson of the gauge theory. If the gauge coupling constant is extremely small, the féeton becomes a candidate for dark matter. We show that its decay to a pair of an electron and a positron explains the observed Galactic 511-keV gamma-ray excess in a consistent manner. This féeton dark matter decays mainly into pairs neutrino and anti-neutrino. Future low-energy experiments with improved directional capability will enable capturing these neutrino signals. The seesaw-motivated parameter space predicts a relatively short féeton lifetime that is comparable to the current cosmological constraint.