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arXiv 2301.02835hep-ph
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通过轻费米子媒介体的暗物质冻结:禁戒衰变与散射

Dark matter freeze-in via a light fermion mediator: forbidden decay and scattering

Shao-Ping Li

AI总结:

本文研究通过轻费米子媒介体的冻结暗物质产生,发现禁戒衰变与散射共享耦合阶数,且其贡献在热耦合0.1-1时可达4%-45%。

摘要:

隐藏的非热扇区与热等离子体之间的联系可以通过一个轻的热费米子媒介体来建立。当费米子媒介体远轻于隐藏物种时,媒介体的运动学禁戒衰变可以在有限温度下被打开,从而产生隐藏物种。与具有四次耦合的玻色子不同,可重整化的禁戒费米子衰变通常与散射共享相同阶数的耦合。我们对通过热费米子媒介体的冻结暗物质产生进行了专门研究。我们证明了等离子体诱导的衰变率与通过树级振幅计算的衰变率不同,但前者可以通过常数重标度从后者获得。此外,我们发现禁戒衰变和散射对暗物质遗迹密度的相对影响可以通过等离子体与媒介体之间的热耦合来简单估计。应用于不同的热相互作用,我们表明对于0.1-1的热耦合,禁戒衰变贡献可以达到4%-45%的水平。

英文摘要:

The connection between a hidden nonthermal sector and a thermal plasma can be established by a light thermal fermion mediator. When the fermion mediator is much lighter than the hidden species, kinematically forbidden decay of the mediator can be opened at finite temperatures to produce the hidden species. Unlike bosons having quartic couplings, renormalizable forbidden fermion decay generically shares the same order of couplings with the scattering. We present a dedicated investigation into the freeze-in dark matter production via a thermal fermion mediator. We demonstrate that the plasma-induced decay rate differs from that calculated via the tree-level amplitude, but the former can be obtained from the latter via constant rescaling. Furthermore, we find that the relative effect of the forbidden decay and the scattering on the dark matter relic density can be simply estimated via the thermal coupling between the plasma and the mediator. Applying to different thermal interactions, we show that the forbidden decay contribution can reach the level of $4\%-45\%$ for a thermal coupling at $0.1-1$.

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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