Transition magnetic-dipole dark matter and the LZ230616 high-recoil candidate
Abstract
A transition magnetic dipole connects an endothermic nuclear recoil to a delayed photon. We study this interpretation of LZ230616, the 248-keV candidate in LZ's extended-energy search. Imposing the thermal abundance in a point hypercharge theory fixes a moment near 2.4 × 10−4 TeV−1 at the preferred masses, leaving a mass--splitting fit. The excited state travels about 0.6 m, making its decay relevant to the isolated-recoil selection. A position-dependent TPC-exit response gives conditional maxima at (1.07 TeV ,346 keV ) without the high-energy sideband and (0.44 TeV ,321 keV) with its zero-count proxy. Their line rates exceed the H.E.S.S. Einasto bound by factors of about 11 and 5.5. We examine halo dependence, other direct and indirect probes, and charged-messenger matching. Allowing a smaller moment and additional annihilation preserves the low-mass maxima while admitting heavier fits over 0.1--100 TeV. Delayed recoil--photon data can measure the splitting and moment, testing both the detector response and the assumed connection to thermal annihilation.
Related
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BibTeX
@misc{he2026transition,
title = {{Transition magnetic-dipole dark matter and the LZ230616 high-recoil candidate}},
author = {Yuxuan He},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.10453},
eprint = {2609.10453},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.10453},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Transition magnetic-dipole dark matter and the LZ230616 high-recoil candidate
AU - Yuxuan He
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.10453
UR - https://arxiv.org/abs/2609.10453
AB - A transition magnetic dipole connects an endothermic nuclear recoil to a delayed photon. We study this interpretation of LZ230616, the 248-keV candidate in LZ's extended-energy search. Imposing the thermal abundance in a point hypercharge theory fixes a moment near 2.4 × 10^−4 TeV^−1 at the preferred masses, leaving a mass--splitting fit. The excited state travels about 0.6 m, making its decay relevant to the isolated-recoil selection. A position-dependent TPC-exit response gives conditional maxima at (1.07 TeV ,346 keV ) without the high-energy sideband and (0.44 TeV ,321 keV) with its zero-count proxy. Their line rates exceed the H.E.S.S. Einasto bound by factors of about 11 and 5.5. We examine halo dependence, other direct and indirect probes, and charged-messenger matching. Allowing a smaller moment and additional annihilation preserves the low-mass maxima while admitting heavier fits over 0.1--100 TeV. Delayed recoil--photon data can measure the splitting and moment, testing both the detector response and the assumed connection to thermal annihilation.
SN - 2331-8422
ER -