论文标题
用MEV提高暗物质的Xenon1t过量的解释
Interpretation of XENON1T excess with MeV boosted dark matter
论文作者
论文摘要
Xenon1t过量的keV电子后坐力事件可能是由电子和具有MEV质量和高速的长寿命颗粒的散射引起的。我们考虑了一个有形的模型，该模型由两个标量MEV暗物质（DM）粒子$ s_a $和$ s_b $组成，以通过Boosted $ S_B $来解释Xenon1t kev多余。 A small mass splitting $m_{S_A}-m_{S_B}>0$ is introduced and the boosted $S_B$ can be produced by the dark annihilation process of $S_A S_A^\dagger \to ϕ\to S_B S_B^\dagger$ via a resonant scalar $ϕ$. $ s_b- $电子散射由矢量玻色子$ x $中介。 Although the constraints from BBN, CMB and low-energy experiments set the $X-$mediated $S_B-$electron scattering cross section to be $\lesssim 10^{-35} \mathrm{cm}^2$, the MeV scale DM with a resonance enhanced dark annihilation today can still provide enough boosted $S_B$ and induce the XENON1T keV excess. $ s $ s $ s $ wave的过程$ s_b s_b^\ dagger \ x x $大大降低了$ s_b $的遗物密度大大降低，这是由CMB和21 cm吸收的约束所允许的。 $ s_b $的很小的遗物分数与DM直接检测中的未增强$ S_B $ -ELECTRON散射的严格边界兼容，并且还允许$ S_A $ -ELECTRON散射。
The XENON1T excess of keV electron recoil events may be induced by the scattering of electrons and long-lived particles with MeV mass and high-speed. We consider a tangible model composed of two scalar MeV dark matter (DM) particles $S_A$ and $S_B$ to interpret the XENON1T keV excess via boosted $S_B$. A small mass splitting $m_{S_A}-m_{S_B}>0$ is introduced and the boosted $S_B$ can be produced by the dark annihilation process of $S_A S_A^\dagger \to ϕ\to S_B S_B^\dagger$ via a resonant scalar $ϕ$. The $S_B-$electron scattering is intermediated by a vector boson $X$. Although the constraints from BBN, CMB and low-energy experiments set the $X-$mediated $S_B-$electron scattering cross section to be $\lesssim 10^{-35} \mathrm{cm}^2$, the MeV scale DM with a resonance enhanced dark annihilation today can still provide enough boosted $S_B$ and induce the XENON1T keV excess. The relic density of $S_B$ is significantly reduced by the $s$-wave process of $S_B S_B^\dagger \to X X$ which is allowed by the constraints from CMB and 21-cm absorption. A very small relic fraction of $S_B$ is compatible with the stringent bounds on un-boosted $S_B$-electron scattering in DM direct detection and the $S_A$-electron scattering is also allowed.
