Direct Detection Cross Section Research Articles

Dark sink enhances the direct detection of freeze-in dark matter

We describe a simple dark sector structure which, if present, has implications for the direct detection of dark matter (DM); . A dark sink transports energy density from the DM into light dark-sector states that do not appreciably contribute to the DM density. As an example, we consider a light, neutral fermion ψ which interacts solely with DM χ via the exchange of a heavy scalar Φ. We illustrate the impact of a dark sink by adding one to a DM freeze-in model in which χ couples to a light dark photon γ′ which kinetically mixes with the Standard Model (SM) photon. This freeze-in model (absent the sink) is itself a benchmark for ongoing experiments. In some cases, the literature for this benchmark has contained errors; we correct the predictions and provide them as a public code. We then analyze how the dark sink modifies this benchmark, solving coupled Boltzmann equations for the dark-sector energy density and DM yield. We check the contribution of the dark sink ψ’s to dark radiation; consistency with existing data limits the maximum attainable cross section. For DM with a mass between MeV−O(10 GeV), adding the dark sink can increase predictions for the direct detection cross section all the way up to the current limits. Published by the American Physical Society 2024

NMSSM explanation for excesses in the search for neutralinos and charginos and a 95 GeV Higgs boson

The observed excesses in the search for neutralinos and charginos by ATLAS and CMS can be fitted simultaneously in the minimal supersymmetric standard model (MSSM) assuming a light higgsino mass, of magnitude less than about 250 GeV, and a compressed higgsino dominated neutralino and chargino spectrum, with 5–10% mass splittings. However, light higgsinos as dark matter would have far too large direct detection cross sections. We consider the Next-to-MSSM (NMSSM) with an additional singlino-like lightest supersymmetric particle (LSP) a few GeV below the next-to-lightest supersymmetric particle (NLSP). Sparticles prefer to decay first into the NLSP and remnants from the final decay into the LSP are too soft to contribute to the observed signals. Co-annihilation in the higgsino-sector can generate a relic density in the WMAP/Planck window. The singlino-like LSP has automatically a direct detection cross section below present and future sensitivities: a direct detection signal in the near future would exclude this scenario. The singlet-like Higgs scalar of the NMSSM can have a mass around 95 GeV and signal cross sections in the bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$b\\bar{b}$$\\end{document} channel at LEP and in the γγ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma \\gamma $$\\end{document} channel at the LHC compatible with the respective observations.

Radiative corrections to aid the direct detection of the Higgsino-like neutralino dark matter: Spin-independent interactions

The lightest neutralino (χ˜10) is a good dark matter (DM) candidate in the R-parity conserving minimal supersymmetric Standard Model. In this work, we consider the light Higgsino-like neutralino as the lightest stable particle, thanks to a rather small Higgsino mass parameter μ. We then estimate the prominent radiative corrections to the neutralino-neutralino-Higgs boson vertices. We show that for Higgsino-like χ˜10, these corrections can significantly influence the spin-independent direct detection cross section, even contributing close to 100% in certain regions of the parameter space. These corrections, therefore, play an important role in deducing constraints on the mass of the Higgsino-like lightest neutralino DM, and thus the μ parameter. Published by the American Physical Society 2024

Confronting electroweak MSSM through one-loop renormalized neutralino-Higgs interactions for dark matter direct detection and the muon g−2

We compute the next-to-leading order (NLO) corrections to the vertices where a pair of the lightest neutralino couples to CP-even (light or heavy) Higgs scalars. In particular, the lightest neutralino is assumed to be a dominantly binolike mixed state, composed of bino and Higgsino or bino, wino, and Higgsino. After computing all the three-point functions in the electroweak minimal supersymmetric Standard Model (MSSM), we detail the contributions from the counterterms that arise in renormalizing these vertices in one-loop order. The amendment of the renormalized vertices impacts the spin-independent direct detection cross sections of the scattering of nucleons with dark matter. We perform a comprehensive numerical scan over the parameter space where all the points satisfy the present B-physics constraints and accommodate the muon’s anomalous magnetic moment. Finally, we exemplify a few benchmark points, which indulge the present searches of supersymmetric particles. After including the renormalized one-loop vertices, the spin-independent DM-nucleon cross sections may be enhanced up to 20% compared to its tree-level results. Finally, with the NLO cross section, we use the recent LUX-ZEPLIN (LZ) results on the neutralino-nucleon scattering to display the relative rise in the lowest allowed band of the Higgsino mass parameter in the M1−μ plane of the electroweak MSSM. Published by the American Physical Society 2024

Nmssm with correct relic density and an additional 95 GeV Higgs boson

We investigate whether it is possible within the NMSSM to describe simultaneously a correct dark matter relic density complying with the latest null results from the LZ experiment, an extra Higgs boson with a mass of ∼95\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 95$$\\end{document} GeV visible in the bb channel at LEP and the diphoton channel at the LHC, and the deviation of the anomalous magnetic moment of the muon from its value within the Standard Model. We find that this is still possible for a variety of dark matter annihilation mechanisms, for singlino-like but also bino-like lightest supersymmetric particles. We show the signal rates of the extra Higgs boson and the dark matter detection rates as function of the dark matter mass and annihilation mechanism. The dark matter direct detection cross section may well fall below the neutrino floor. The masses of the lightest electroweakly interacting supersymmetric particles are typically not far above 100 GeV, but not excluded due to unconventional decays.

Bigravity portal dark matter

We consider a model where the interaction between dark matter and the Standard Model particles is mediated by a ghost-free bigravity portal. The bigravity model invokes a massive spin-2 particle coupled to the usual massless graviton as well as generic bimetric matter couplings. The cross sections for dark matter direct detection are computed and confronted with the experimental bounds. The presence of the massive spin-2 mediator resolves the core-cusp problem, which in turn significantly constrains the dark matter coupling in such a bigravity theory. Yet, there remains a window of the parameter space where the model can be tested in the upcoming direct detection experiments such as XENONnT and PandaX-30T. The model also predicts a reheating temperature on the order of 106 GeV. Published by the American Physical Society 2024

Observable ΔNeff\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ extrm{N}}_{\ extrm{eff}}$$\\end{document} in Dirac scotogenic model

We study the possibility of probing the radiative Dirac seesaw model with dark sector particles going inside the loop, popularly referred to as the Dirac scotogenic model via measurements of effective relativistic degrees of freedom ΔNeff\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ extrm{N}}_{\ extrm{eff}}$$\\end{document} at cosmic microwave background (CMB) experiments. The loop suppression and additional free parameters involved in neutrino mass generation allow large (∼O(1))\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(\\sim {\\mathcal {O}}(1))$$\\end{document} coupling of light Dirac neutrinos with the dark sector particles. Such large Yukawa coupling not only dictates the relic abundance of heavy fermion singlet dark matter but also can lead to the thermalisation of the right chiral part of Dirac neutrinos, generating additional relativistic degrees of freedom ΔNeff.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ extrm{N}}_{\ extrm{eff}}.$$\\end{document} We find that the parameter space consistent with dark matter phenomenology and neutrino mass bounds can also be probed at future cosmic microwave background experiments like CMB-S4 via precision measurements of ΔNeff.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta {\ extrm{N}}_{\ extrm{eff}}.$$\\end{document} The same parameter space, while leading to loop-suppressed direct detection cross-section of dark matter outside future sensitivities, can also have other interesting and complementary observational prospects via charged lepton flavour violation and collider signatures.

Dark Matter Direct Detection in 𝗍-channel mediator models

We perform a comprehensive study of the Direct Detection phenomenology of singlet Dark Matter t-channel portal models. For that purpose, we present a complete one-loop matching onto a Heavy Dark-Matter Effective Field Theory, leading to a complete computation of the loop induced Direct Detection cross-section for both scalar and fermionic Dark Matter candidates. The results are compared with current and future bounds from Direct Detection experiments, as well as with the requirement of the correct Dark Matter relic density.

Additional Higgs Bosons near 95 and 650 GeV in the NMSSM

Hints for an additional Higgs boson with a mass of about 95 GeV originate from LEP and searches in the diphoton channel by CMS and ATLAS. A search for resonant production of SM plus BSM Higgs bosons in the diphoton plus bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$b\\bar{b}$$\\end{document} channel by CMS showed some excess for a 650 GeV resonance decaying into the SM Higgs plus a 95 GeV Higgs boson. We investigate whether these phenomena can be interpreted simultaneously within the NMSSM subject to the latest constraints on couplings of the SM Higgs boson, on extra Higgs bosons from the LHC, and on dark matter direct detection cross sections. We find that the hints for a 95 GeV Higgs boson in the diphoton channel by CMS and ATLAS and in the diphoton plus bb¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$b\\bar{b}$$\\end{document} channel by CMS can be fitted simultaneously within the 2σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$2\\,\\sigma $$\\end{document} level.

A solar investigation of multicomponent dark matter

If multiple thermal weakly interacting massive particle (WIMP) dark matter candidates exist, then their capture and annihilation dynamics inside a massive star such as Sun could change from conventional method of study. With a simple correction to time evolution of dark matter (DM) number abundance inside the Sun for multiple dark matter candidates, significant changes in DM annihilation flux depending on annihilation, direct detection cross-section, internal conversion and their contribution to relic abundance are reported in present work.

Loop enhancement of direct detection cross section in a fermionic dark matter model

We investigate the effect of one loop quantum corrections on the elastic scattering of dark matter off the nucleon in a fermionic dark matter model. The model introduces two new singlet fermions and a singlet scalar. The fermions communicate with the SM particles through a Higgs portal. It is found that some viable regions in the parameter space respecting the bounds from the observed relic density, the Higgs invisible decay width, and direct detection experiment, will be shrunk significantly when one loop effects are taken into account. The regions already resided below the neutrino floor, partly may come into regions which are testable by the current or future direct detection experiments. In addition, some regions being viable at tree level, may be excluded when quantum corrections are included.

Conformal B−L and pseudo-Goldstone dark matter

We show that a conformal extension of the standard model with local B-L symmetry and two complex scalars breaking B-L can provide a unified description of neutrino mass, origin of matter and dark matter. There are two hierarchical B-L breaking vacuum expectation value (VEV) scales in the model, the higher denoted by $v_B$ and the lower by $v_A$. The higher breaking scale is dynamically implemented via the Coleman-Weinberg mechanism and plays a key role in the model since it induces electroweak symmetry breaking as well as the lower B-L breaking scale. It is also responsible for neutrino masses via the seesaw mechanism and origin of matter. The imaginary part of the complex scalar with lower B-L breaking VEV plays the role of a pseudo-Goldstone dark matter (DM). The DM particle is unstable with its lifetime naturally longer than $10^{28}$ seconds. We show that its relic density arises from the freeze-in mechanism for a wide parameter domain. Due to the pseudo-Goldstone boson nature of the DM particle, the direct detection cross section is highly suppressed. The model also predicts the dark matter to be heavier than 100 TeV and it decays to two high energy neutrinos which can be observable at the IceCube, providing a test of this model.

Dark matter perspective of left-right symmetric gauge model

We consider an incarnation of left-right symmetric model with a local gauge symmetry of SU(3)C⊗SU(2)L⊗U(1)L⊗SU(2)R⊗U(1)R. Heavy scalars and fermions present in the 27 of E6 are included in the matter sector along with the Standard Model (SM) fermions. Two such colour singlet fermions, N and LS, transforming as bi-doublet and singlet under SU(2) s respectively, can be potential candidates for Dark Matter (DM). Assignment of U(1) charges for the matter fields restricts some of the exotic fermions to interact with the SM fermions. We study in some details the prospect of such fermionic dark matters by calculating relic densities and direct detection cross-sections by treating both these particles as relics. In such a two component Dark Matter scenario, LS having smaller interaction with the SM, will dominantly contribute to relic density. However, it cannot be detected at earth bound experiments with their present sensitivity. On the contrary, N having higher rate of interaction with the SM particle has too large annihilation cross-section thus contributes very little to relic density. In fact, its interaction with the SM is too high such that N-nucleon cross-section for a wide range of N mass is higher than the experimental limits from XENON, LUX or PICO. However, such a high N-nucleon cross-section can be tamed by assuming additional dimension-6 operators involving N and SM quarks. We derive limits on the strengths of such interactions from experimental data.

Freezing-in hadrophilic dark matter at low reheating temperatures

If the reheating temperature at the end of inflation is low, of order 10 MeV, then dark matter produced through ultraviolet freeze-in has a large direct detection cross section. We study such a scenario in which dark matter is hadrophilic. This leads to dark matter-nucleon scattering cross sections of interest for near-future experiments for dark matter masses in the range of 100 keV–100 MeV. We explore how these predictions vary if reheating is non-instantaneous.

Maximizing Direct Detection with Highly Interactive Particle Relic Dark Matter

We estimate the maximum direct detection cross section for sub-GeV dark matter (DM) scattering off nucleons. For DM masses in the range 10keV-100MeV, cross sections greater than 10^{-36}-10^{-30} cm^{2} seem implausible. We present a DM candidate which realizes this maximum cross section: highly interactive particle relics (HYPERs). After HYPERs freeze-in, a dark sector phase transition decreases the mediator's mass. This increases the HYPER's direct detection cross section without impacting its abundance or measurements of big bang nucleosynthesis and the cosmic microwave background.

The last complex WIMPs standing

We continue the study of weakly interacting massive particles (WIMP) started in Bottaro et al. (Eur Phys J C 82:31, 2022), focusing on a single complex electroweak n-plet with non-zero hypercharge added to the Standard Model. The minimal splitting between the Dark Matter and its electroweak neutral partner required to circumvent direct detection constraints allows only multiplets with hypercharge smaller or equal to 1. We compute for the first time all the calculable WIMP masses up to the largest multiplet allowed by perturbative unitarity. For the minimal allowed splitting, most of these multiplets can be fully probed at future large-exposure direct detection experiments, with the notable exception of the doublet with hypercharge 1/2. We show how a future muon collider can fully explore the parameter space of the complex doublet combining missing mass, displaced track and long-lived track searches. In the same spirit, we study how a future muon collider can probe the parameter space of complex WIMPs in regions where the direct detection cross section drops below the neutrino floor. Finally, we comment on how precision observables can provide additional constraints on complex WIMPs.

Magnetic moments of leptons, charged lepton flavor violations and dark matter phenomenology of a minimal radiative Dirac neutrino mass model

In a simple extension of the standard model (SM), a pair of vector like lepton doublets (L1 and L2) and a SU(2)L scalar doublet (η) have been introduced to help in accommodating the discrepancy in determination of the anomalous magnetic moments of the light leptons, namely, e and μ. Moreover, to make our scenario friendly to a Dirac like neutrino and also for a consistent dark matter phenomenology, we specifically add a singlet scalar (S) and a singlet fermion (ψ) in the set-up. However, the singlet states also induce a meaningful contribution in other charged lepton processes. A discrete symmetry {mathcal{Z}}_2times {mathcal{Z}}_2^{prime } has been imposed under which all the SM particles are even while the new particles may be assumed to have odd charges. In a bottom-up approach, with a minimal particle content, we systematically explore the available parameter space in terms of couplings and masses of the new particles. Here a number of observables associated with the SM leptons have been considered, e.g., masses and mixings of neutrinos, (g − 2) anomalies of e, μ, charged lepton flavor violating (cLFV) observables and the dark matter (DM) phenomenology of a singlet-doublet dark matter. Neutrinos, promoted as the Dirac type states, acquire mass at one loop level after the discrete {mathcal{Z}}_2^{prime } symmetry gets softly broken, while the unbroken {mathcal{Z}}_2 keeps the dark matter stable. The mixing between the singlet ψ and the doublet vector lepton can be constrained to satisfy the electroweak precision observables and the spin independent (SI) direct detection (DD) cross section of the dark matter. In this analysis, potentially important LHC bounds have also been discussed.

Limiting heavy-quark and gluonphilic real dark matter

We investigate the phenomenological viability of real spin half, zero, and one dark matter candidates, which interact predominantly with third-generation heavy quarks and gluons via the 28 gauge invariant higher-dimensional effective operators. The corresponding Wilson coefficients are constrained one at a time from the relic density ${\mathrm{\ensuremath{\Omega}}}^{\mathrm{DM}}{h}^{2}\ensuremath{\approx}0.1198$. Their contributions to the thermally-averaged annihilation cross sections are shown to be consistent with the FermiLAT and H.E.S.S. experiments' projected upper bound on the annihilation cross section in the $b\overline{b}$ mode. The tree-level gluonphilic and one-loop induced heavy-quarkphilic dark matter (DM) nucleon direct detection cross sections are analyzed. The nonobservation of any excess over expected background in the case of recoiled Xe nucleus events for spin-independent DM-nucleus scattering in XENON-1T sets the upper limits on the 18 Wilson coefficients. Our analysis validates the real DM candidates for the large range of accessible mass spectrum below 2 TeV for all but one interaction induced by the said operators.

Dark matter-induced multi-phase dynamical symmetry breaking

We consider the classically scale invariant Higgs-dilaton model of dynamical symmetry breaking extended with an extra scalar field that plays the role of dark matter. The Higgs boson is light near a critical boundary between different symmetry breaking phases, where quantum corrections beyond the usual Gildener-Weinberg approximation become relevant. This implies a tighter connection between dark matter and Higgs phenomenology. The model has only three free parameters, yet it allows for the observed relic abundance of dark matter while respecting all constraints. The direct detection cross section mediated by the Higgs boson is determined by the dark matter mass alone and is testable at future experiments.

(g-2)_mu and SUSY dark matter: direct detection and collider search complementarity

The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for a variety of experimental data. The EW particles with masses of a few hundred GeV evade the LHC searches owing to their small production cross sections. Such a light EW sector can in particular explain the reinforced 4.2,sigma discrepancy between the experimental result for the anomalous magnetic moment of the muon, (g-2)_mu , and its Standard Model (SM) prediction. The lightest supersymmetric particle (LSP), assumed to be the lightest neutralino, {tilde{chi }_{1}}^0, as a Dark Matter (DM) candidate is furthermore in agreement with the observed limits on the DM content of the universe. Here the Next-to LSP (NLSP) serves as a coannihilation partner and is naturally close in mass to the LSP. Such scenarios are also to a large extent in agreement with negative results from Direct Detection (DD) experiments. The DM relic density can fully be explained by a nearly pure bino or a mixed bino/wino LSP. Relatively light wino and higgsino DM, on the other hand, remains easily below the DM relic density upper bound. Using the improved limits on (g-2)_mu , we explore the mass ranges of the LSP and the NLSP in their correlation with the DM relic density for bino, bino/wino, wino and higgsino DM. In particular, we analyze the sensitivity of future DM DD experiments to these DM scenarios. We find that higgsino, wino and one type of bino scenario can be covered by future DD experiments. Mixed bino/wino and another type of bino DM can reach DD cross sections below the neutrino floor. In these cases we analyze the complementarity with the (HL-)LHC and future e^+e^- linear colliders. We find that while the prospects for the HL-LHC are interesting, but not conclusive, an e^+e^- collider with sqrt{s} lesssim 1 ,, mathrm {TeV} can cover effectively all points of the MSSM that may be missed by DD experiments.