We propose a novel scenario of generating lepton asymmetry via annihilation and coannihilation of dark sector particles including t-channel processes. In order to realistically implement this idea, we consider the scotogenic model having three right handed neutrinos and a new scalar doublet, all of which are odd under an in-built \(Z_2\) symmetry. The lightest \(Z_2\) odd particle, if electromagnetically neutral, can be a dark matter candidate while annihilation and coannihilation between different \(Z_2\) odd particles into standard model leptons serve as the source of lepton asymmetry. The light neutrino masses arise at one loop level with \(Z_2\) odd fields going inside the loop. We show that experimental data related to light neutrinos, dark matter relic abundance and baryon asymmetry can be simultaneously satisfied in the model for two different cases: one with fermion dark matter and the other with scalar dark matter. In both scenarios, t-channel annihilation as well as coannihilation of \(Z_2\) odd particles play a non-trivial role in producing the non-zero CP asymmetry. Both the scenarios remain allowed from DM direct detection while keeping the scale of leptogenesis as low as TeV or less, lower than the one for vanilla leptogenesis scenario in scotogenic model along with the additional advantage of explaining the baryon-dark matter coincidence to some extent. Due to such low scale, the model is testable through rare decay experiments looking for charged lepton flavour violation.

我们提出了一种通过消灭和共消灭包括t通道过程在内的暗区粒子来产生轻子不对称的新方案。为了现实地实现这个想法，我们考虑具有三个右手中微子和一个新的标量双峰的Scotogenic模型，所有这些在内置\（Z_2 \）对称下都是奇数。最轻的（Z_2 \）奇数粒子（如果具有电磁中性）可能是暗物质的候选者，而不同的\（Z_2 \）奇数粒子之间的ni灭和共an灭则成为轻子不对称的来源。轻中微子质量以\（Z_2 \）出现在一个回路水平奇数场进入循环。我们表明，在两种不同情况下，模型中可以同时满足与轻中微子，暗物质遗迹丰度和重子不对称性有关的实验数据：一种是费米暗物质，另一种是标量暗物质。在这两种情况下，t通道an灭以及\（Z_2 \）的co灭奇数粒子在产生非零CP不对称性中起着重要作用。DM直接检测仍然允许这两种情况，同时使瘦素形成的规模低至TeV或更低，低于在成烟模型中用于香草瘦素形成方案的瘦素，并具有在一定程度上解释重子与暗物质重合的其他优点。由于规模如此之小，该模型可以通过罕见的衰变实验来测试，以寻找违反带电轻子风味的行为。