Study of production mechanism of universe's baryon number and neutrino masses

自然地解释观测到的小中微子质量的拉锯机制预测了重的马约拉纳中微子。众所周知，重Majorana中微子的衰变产生了轻子不对称，而轻子不对称又转化为重子不对称。因此，可以用Majorana中微子衰变来解释宇宙中重子数的不对称性。在本项目中，我们已经证明了事实确实如此，并且观测到的中微子质量与上述重子发生的机制非常一致。特别是，我们考虑了基于超重力的通货膨胀模型，发现如果上述重力发生，大多数通货膨胀模型会产生太多的引力。我们还发现，超对称破缺的规范和反常调解场景不会受到这个问题的影响。因此，目前基于重Majorana中微子衰变的重子发生方案预测了低能量超粒子的某些光谱，这将在不久的将来的对撞机实验中得到验证，如LHC。

The seesaw mechanism that explains naturally the observed small neutrino masses predicts heavy Majorana neutrinos. It is known that the decay of the heavy Majorana neutrinos produce lepton asymmetry which is converted to the baryon asymmetry. Thus, one may explain the baryon-number asymmetry in the universe by the decay of the Majorana neutrino decay. In the present project we have shown that it is indeed the case and that the observed neutrino masses are very consistent with the mechanism of the above baryogenesis. In particular, we have considered inflation models based on supergravity and found that most of the inflation models produce too much gravitinos if the above baryogenesis takes place. We have also found that gauge and anomaly mediation scenarios for supersymmetry breaking do not suffer from this problem. Therefore the present baryogenesis scenario based on the decay of heavy Majorana neutrinos predicts certain spectra of super-particles at low energies, which will be tested at the near future collider experiments such as LHC.