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arXiv 2603.20145hep-ph
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无味中微子暗物质在最简狄拉克锯齿框架中的研究

Sterile neutrino Dark Matter in the minimal Dirac Seesaw

National Centre for Nuclear Research(国家核研究中心);Universidade de Lisboa(里斯本大学)

J. Adhikary, A. Batra, K. Deka, F. R. Joaquim

AI总结:

本文探讨了在最简I型狄拉克锯齿框架中,通过非热冻结进机制产生轻量无味中微子作为暗物质候选者的可能性,发现额外右旋混合角θ_R可使参数空间中暗物质 relic abundance 与宇宙稳定性相容。

摘要:

我们研究了在最简I型狄拉克锯齿框架中,通过树级产生狄拉克中微子质量的态作为暗物质候选者的无味中微子暗物质。一个$\mathcal{Z}_6$对称性,通过单态标量真空期望值自发破缺为残余$\mathcal{Z}_3$,禁止了Majorana质量算符并确保中微子的狄拉克性。最轻的无味中微子通过冻结进机制非热性地由标准模型粒子和额外标量态衰变产生。我们表明,额外右旋混合角$θ_R$的存在打开了参数空间中的可行区域,使得观测到的暗物质 relic abundance 可以被重现,同时保持宇宙稳定性。这主要源于我们场景中缺乏X射线天体物理约束。我们进一步发现,右旋中微子的冻结进产生对$ΔN_{\rm eff}$的贡献可忽略,与当前宇宙学界限一致。

英文摘要:

We study sterile neutrino dark matter in a minimal Type-I Dirac seesaw framework where the states responsible for generating Dirac neutrino masses at tree level can be viable dark matter candidates. A $\mathcal{Z}_6$ symmetry, spontaneously broken to a residual $\mathcal{Z}_3$ by the vacuum expectation value of a singlet scalar, forbids Majorana mass operators and ensures neutrino Diracness. The lightest sterile neutrino is produced non-thermally via freeze-in from decays of Standard Model particles and an additional scalar state. We show that the presence of an additional right-handed mixing angle, $θ_R$, opens up viable regions of parameter space where the observed dark matter relic abundance can be reproduced while maintaining cosmological stability. This mainly stems from the absence of X-ray astrophysical constraints in our scenario. We further find that the freeze-in production of right-handed neutrinos yields a negligible contribution to $ΔN_{\rm eff}$, consistent with current cosmological bounds.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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