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arXiv 2209.07546hep-phastro-ph.CO
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再加热期间的WIMP

WIMPs during Reheating

Nicolás Bernal, Yong Xu

摘要:

弱相互作用大质量粒子(WIMP)是最有动机的暗物质候选者之一。在标准的情景中,冻结发生在暴胀再加热结束之后很久,他们与严格的实验约束相矛盾。在这里,我们调查的热冻结出的WIMP发生{ \it期间}再加热,而暴胀$ϕ$相干振荡在一个通用的潜力$\propto ϕ^n$。根据$n$的值和暴胀子衰变产物的自旋,辐射和暴胀子能量密度的演化可以表现出不同的特征,因此对WIMP的冻结行为有相当大的影响。由于再加热过程中熵的注入,扩大了与观测到的DM遗迹丰度相适应的参数空间。特别是,WIMP的热平均湮灭截面可以是几个幅度低于在标准情况下。最后,我们讨论了目前的暗物质间接探测实验的界限,并探讨了未来的挑战和机遇。

英文摘要:

Weakly Interacting Massive Particles (WIMPs) are among the best-motivated dark matter candidates. In the standard scenario where the freeze-out occurs well after the end of inflationary reheating, they are in tension with the severe experimental constraints. Here, we investigate the thermal freeze-out of WIMPs occurring {\it during} reheating, while the inflaton $ϕ$ coherently oscillates in a generic potential $\propto ϕ^n$. Depending on the value of $n$ and the spin of the inflaton decaying products, the evolution of the radiation and inflaton energy densities can show distinct features, therefore, having a considerable impact on the freeze-out behavior of WIMPs. As a result of the injection of entropy during reheating, the parameter space compatible with the observed DM relic abundance is enlarged. In particular, the WIMP thermally averaged annihilation cross-section can be several magnitudes lower than that in the standard case. Finally, we discuss the current bounds from dark matter indirect detection experiments, and explore future challenges and opportunities.

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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