Paper

{
  "raw_xml": "<entry>\n    <id>http://arxiv.org/abs/2602.19958v1</id>\n    <title>Leptophilic scalar dark matter in U(1)$_{L_μ-L_τ}$: Evading direct detection and prospective neutron star heating</title>\n    <updated>2026-02-23T15:26:25Z</updated>\n    <link href='https://arxiv.org/abs/2602.19958v1' rel='alternate' type='text/html'/>\n    <link href='https://arxiv.org/pdf/2602.19958v1' rel='related' title='pdf' type='application/pdf'/>\n    <summary>Leptophilic dark matter (DM) is a well-motivated thermal WIMP framework that can evade stringent nuclear-recoil searches while remaining testable via DM-induced heating of neutron stars (NS). In this work, we study leptophilic scalar DM in a $\\mathrm{U(1)}_{L_μ-L_τ}$ gauge extension of the Standard Model, which provides a common leptophilic portal for all scenarios considered. To reproduce the observed relic abundance while suppressing direct-detection signals, we investigate three benchmark realizations: (i) a secluded DM scenario in which the relic density is set by annihilation into $\\mathrm{U(1)}_{L_μ-L_τ}$ gauge bosons, and two pseudo-Nambu-Goldstone boson (pNGB) DM models based on (ii) an SO(4) symmetry and (iii) an SO(3) symmetry. In the SO(4) pNGB model, the DM mass arises at tree level from a soft breaking term, while the elastic scattering amplitude is suppressed by a symmetry-protected cancellation. In the SO(3) pNGB model, the DM mass is generated radiatively at one loop via the $\\mathrm{U(1)}_{L_μ-L_τ}$ gauge interaction, and we show that this gauging preserves the same cancellation mechanism, maintaining compatibility with direct-detection null results. We perform a systematic parameter scan imposing relic density, direct- and indirect-detection, and neutrino trident constraints, and identify viable sub-TeV to TeV DM candidates. Assuming maximal capture in NSs, we find that the remaining parameter space can be tested by near-infrared observations of NSs, providing sensitivity complementary to terrestrial searches in regions that are currently weakly constrained.</summary>\n    <category scheme='http://arxiv.org/schemas/atom' term='hep-ph'/>\n    <category scheme='http://arxiv.org/schemas/atom' term='astro-ph.CO'/>\n    <category scheme='http://arxiv.org/schemas/atom' term='astro-ph.HE'/>\n    <published>2026-02-23T15:26:25Z</published>\n    <arxiv:comment>29 pages, 7 figures</arxiv:comment>\n    <arxiv:primary_category term='hep-ph'/>\n    <author>\n      <name>Chengfeng Cai</name>\n    </author>\n    <author>\n      <name>Hong-Hao Zhang</name>\n    </author>\n  </entry>"
}