Title: Opening up New Parameter Space for Sterile Neutrino Dark Matter Show Chinese title

Title: 为惰性中微子暗物质开启新的参数空间

Abstract: Sterile neutrinos are compelling dark matter (DM) candidates, yet the minimal production mechanism solely based on active ($\nu_a$)-sterile ($\nu_s$) oscillations is excluded by astrophysical observations. Non-standard self-interactions in either active ($\nu_a-\nu_a$) or sterile ($\nu_s-\nu_s$) sector are known to alter the sterile neutrino DM production in the early Universe, which could alleviate the tension with astrophysical constraints to some extent. Here we propose a novel solution where scalar-mediated non-standard interactions between active and sterile neutrinos ($\nu_a-\nu_s$) generate new production channels for $\nu_s$, independent of the active-sterile mixing and without the need for any fine-tuned resonance or primordial lepton asymmetry. This framework enables efficient sterile neutrino DM production even at vanishingly small mixing angles and opens up new viable regions of parameter space that can be tested with future $X$-ray and gamma-ray observations. Show Chinese abstract

Abstract: 无菌中微子是引人注目的暗物质（DM）候选者，然而仅基于活性（$\nu_a$）-无菌（$\nu_s$）振荡的最小产生机制已被天体物理观测排除。 在活性（$\nu_a-\nu_a$）或无菌（$\nu_s-\nu_s$）领域中的非标准自相互作用已知会改变早期宇宙中无菌中微子DM的产生，这在一定程度上可以缓解与天体物理约束之间的矛盾。 在这里我们提出一种新解决方案，即活性和无菌中微子（$\nu_a-\nu_s$）之间的标量媒介非标准相互作用为$\nu_s$生成了新的产生通道，这与活性-无菌混合无关，且不需要任何精细调节的共振或原初轻子不对称性。 该框架即使在混合角极小的情况下也能有效产生无菌中微子DM，并开辟了新的可行参数空间，这些空间可以通过未来的$X$-射线和伽马射线观测进行检验。