arXiv subjects

Wen-Na Yang

Publications and source records attributed to Wen-Na Yang.

7 recordsLinked to original sources

arXiv2026

Inelastic Dark Matter Signature at High Recoil Energy in LUX-ZEPLIN and CRESST

The LUX--ZEPLIN Collaboration recently reported one event at $E_{\mathrm{nr}}=248\pm23~\mathrm{keV}$ with an exposure of $2.84~\mathrm{tonne\cdot yr}$. In this Letter, we interpret this feature using endothermic dark matter (DM). We consider both direct scattering of the surviving ground-state halo component and the contribution of excited states produced by terrestrial upscattering. Our calculations show that explaining the high-energy event requires $m_\chi\gtrsim500~\mathrm{GeV}$ and a mass splitting of $\mathcal{O}(300)~\mathrm{keV}$, for which the production of excited states inside the Earth is kinematically forbidden. For $\bar{\sigma}_n=10^{-37}~\mathrm{cm^2}$, an illustrative two-bin likelihood analysis yields a representative best-fit point at $(m_\chi,\delta)\simeq(1.105~\mathrm{TeV},350~\mathrm{keV})$. The preferred parameter region may be tested by the planned CRESST upgrade.

hep-ph↗

arXiv2026

Dielectric Response for Light Dark Matter Direct Detection Beyond the Longitudinal Approximation

The dielectric formalism for light dark matter--electron scattering in semiconductors has, to date, employed only the longitudinal dielectric function $\epsilon_L$, with the transverse response $\epsilon_T$ universally neglected on qualitative grounds. A complete derivation and quantitative evaluation of $\epsilon_T$ in this context has been lacking. We provide this derivation within the random phase approximation for a homogeneous electron gas. For silicon, we find that the transverse energy loss function is $4--6$ orders of magnitude below the longitudinal one in the bulk plasmon regime, providing the first rigorous justification for the conventional longitudinal approximation. The sizable transverse corrections appear for deposited energies $\omega\lesssim1\,\mathrm{eV}$, which lies below the energy required to reliably produce one electron-hole pair in silicon detectors. Our results provide a quantitative error assessment for existing longitudinal calculations and identify kinematic regimes where transverse corrections ought to be included for relativistic dark-matter interpretations.

hep-ph↗

arXiv2026

Direct Detection of Light Self-Interacting Dark Matter via Electronic Collective Excitations

Models of light dark matter often invoke a light mediator to facilitate interactions with the Standard Model. If sufficiently light, this mediator can induce long-range self-interactions among dark matter particles, offering a compelling resolution to small-scale structure anomalies. However, direct detection of light self-interacting dark matter (SIDM) remains challenging for conventional detectors. In this work, we investigate the sensitivity of searches for light SIDM accelerated by high-energy cosmic rays in silicon detectors. Leveraging the electronic collective excitations, we derive 90\% C.L. exclusion limits using public SENSEI and DAMIC-M ionization data. Our constraints can cover a portion of the light SIDM parameter space favored by galactic small-scale anomalies.

hep-ph↗

arXiv2026

Size Dependence of the Sommerfeld Enhancement for Puffy Dark Matter

We examine the size effects in the Sommerfeld enhancement factor for puffy dark matter annihilation. First, we use the partial-wave method to study the case of puffy dark matter for which only a charge density distribution is given without specifying its internal structure. We find that by using two dimensionless parameters, we can provide a characterization of the resonance structure of the Sommerfeld enhancement. Using this approach, we demonstrate that the finite size of dark matter particle is another fundamental factor, in addition to low velocity, that affects the Sommerfeld enhancement. Then, as an example of puffy dark matter with nontrivial internal structures, we perform the analysis for the nugget-type dark matter, whose Sommerfeld enhancement factor is found to exhibit a resonant behavior similar to that of point-like particles.

hep-ph↗

arXiv2026

Constraints on Axion-Like Particles with the Silicon Detector at a Nuclear Reactor

Axion and axion-like particles (ALPs), predicted in various extensions of the Standard Model, can be abundantly produced in nuclear reactors via the Primakoff process. In this work, we explore the detection of ALPs in silicon detectors through plasmon excitations. Owing to their relativistic nature, reactor-produced ALPs can efficiently excite plasmon resonances, while the accompanying energetic photon typically escapes from the thin detector without depositing an appreciable amount of energy. Utilizing the data from the Connie and Atucha-II experiments, we set the 90\% confidence level upper limits on the ALP-photon coupling $g_{a\gamma\gamma}$ over the axion mass range $0.1-100$ keV. We further show that, for an exposure of 30 kg$\cdot$yr, the projected sensitivity of vIOLETA exceeds the current NEON limit by a factor of three in the same mass range. This improvement would expand the explored region of the QCD axion and ALP parameter space.

hep-ph↗

arXiv2025

Dark Photon Oscillations in Waveguide

Dark photons, which can kinetically mix with ordinary photons, represent the simplest extension to the standard model. Detecting their oscillations with visible photons could provide crucial insights into the nature of dark matter and fundamental interactions beyond the standard model. We propose a novel laboratory-based approach to detect dark photon oscillations using a laser in an Optical Time-domain Relectometry (OTDR) setup. The laser light propagating through the optical fiber undergoes oscillations with the dark photon, leading to measurable changes in the power flow. These oscillations can precisely measured, leveraging its high sensitivity and efficiency in detecting small variations in the optical signal. This approach could provide a new avenue for probing dark photon oscillations in the laboratory and greatly improve the current experimental sensitivity to dark photon in a wide mass range.

hep-ph↗

arXiv2023

The Spin-dependent Scattering of Boosted Dark Matter

Boosted dark matter provides a promising approach to probe the light dark matter, whose computational framework in the spin-independent scattering process is well developed. However, the spin-dependent one lacks a unified treatment. The novelty of this paper is to give the first comprehensive derivation of the cross-section for boosted dark matter in spin-dependent scattering. When the transfer momentum is sufficiently large, there is a sizable enhancement to the proton structure factor from the time component. Besides, we find a residue momentum dependence in the quark-nucleon matching procedure, even without a light mediator. Such behavior can enhance the sensitivity compared with conventional contact interaction. We promote this endeavor by deriving direct limits on sub-GeV spin-dependent boosted dark matter through terrestrial data. The numerical results of the boosted structure factor and the non-relativistic structure factor are given explicitly in the paper and it shows that the excluded region of the boosted structure factor is about six orders larger than the non-relativistic structure factor.

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