Nearly Degenerate Majorana Dark Matter and Its Self-Interactions in a Gauged $U(1)_{L_μ- L_τ}$ Model
Fuente:
arXiv
Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866918491619065856 |
|---|---|
| author | Yang, Kwei-Chou |
| author_facet | Yang, Kwei-Chou |
| contents | We propose a model of nearly degenerate Majorana dark matter (DM) in a gauged $U(1)_{L_μ- L_τ}$ extension of the Standard Model. Spontaneous symmetry breaking generates a dominant Majorana mass via a strong Yukawa coupling, splitting the dark fermion into two nearly degenerate states. The lighter state ($χ_-$) is the DM candidate, with an allowed mass of $\sim 10$ GeV to several hundred GeV. Crucially, within the $10 \sim 75$ GeV mass range and a scalar mediator at the tens of MeV scale, this strong coupling dictates the thermal relic abundance and induces significant elastic self-interactions. These self-interactions naturally resolve small-scale structure anomalies, such as the core-cusp problem, while satisfying massive cluster constraints. Furthermore, we place stringent joint constraints on the scalar mass and the Higgs mixing angle $α$ using the latest LZ 2025 direct detection data. The model's gauge boson $Z^\prime$ maintains early-Universe thermal equilibrium and accommodates the muon anomalous magnetic moment $(g-2)_μ$, remaining consistent with updated cosmological and experimental bounds. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_05694 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Nearly Degenerate Majorana Dark Matter and Its Self-Interactions in a Gauged $U(1)_{L_μ- L_τ}$ Model Yang, Kwei-Chou High Energy Physics - Phenomenology Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies High Energy Astrophysical Phenomena High Energy Physics - Experiment We propose a model of nearly degenerate Majorana dark matter (DM) in a gauged $U(1)_{L_μ- L_τ}$ extension of the Standard Model. Spontaneous symmetry breaking generates a dominant Majorana mass via a strong Yukawa coupling, splitting the dark fermion into two nearly degenerate states. The lighter state ($χ_-$) is the DM candidate, with an allowed mass of $\sim 10$ GeV to several hundred GeV. Crucially, within the $10 \sim 75$ GeV mass range and a scalar mediator at the tens of MeV scale, this strong coupling dictates the thermal relic abundance and induces significant elastic self-interactions. These self-interactions naturally resolve small-scale structure anomalies, such as the core-cusp problem, while satisfying massive cluster constraints. Furthermore, we place stringent joint constraints on the scalar mass and the Higgs mixing angle $α$ using the latest LZ 2025 direct detection data. The model's gauge boson $Z^\prime$ maintains early-Universe thermal equilibrium and accommodates the muon anomalous magnetic moment $(g-2)_μ$, remaining consistent with updated cosmological and experimental bounds. |
| title | Nearly Degenerate Majorana Dark Matter and Its Self-Interactions in a Gauged $U(1)_{L_μ- L_τ}$ Model |
| topic | High Energy Physics - Phenomenology Cosmology and Nongalactic Astrophysics Astrophysics of Galaxies High Energy Astrophysical Phenomena High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2512.05694 |