Quantum Zeno effect and the impact of flavour in leptogenesis
Quantum Zeno effect and the impact of flavour in leptogenesis
复制标题
DOI：
10.1088/1475-7516/2007/03/012
复制
发表时间：
2006-11
影响因子：
6.4
通讯作者：
Steve Blanchet;P. Bari;G. Raffelt
中科院分区：
文献类型：
--
作者：
Steve Blanchet;P. Bari;G. Raffelt
在热轻子生成中，重右手Majorana中微子N衰变为普通轻子和Higgs粒子Φ时的CP破坏产生了宇宙物质-反物质不对称性。如果一些带电轻子汤川耦合在leptogenesis时期处于平衡状态，与背景介质的相互作用是味道敏感的，并且由定义的味道内容的一致性被破坏，修改逆衰变的效率。我们指出，然而，这是不够的，味道敏感的过程是快速的宇宙膨胀的时间尺度，他们必须是快速相对于反应，以免味道振幅保持冻结的重复“测量”。我们更严格的要求是显着的最有趣的“强洗出的情况下”，其中是快速相对于宇宙膨胀率。我们推导出的条件无味的治疗是足够的，风味效果是最大的。在这种“完全调味的状态”下，中微子质量束缚得以存在。为了确定在中间情况下是否可以绕过这个界限，需要进行完全的量子动力学处理。
In thermal leptogenesis, the cosmic matter–antimatter asymmetry is produced by CP violation in the decays of heavy right-handed Majorana neutrinos N into ordinary leptons and Higgs particles Φ. If some charged-lepton Yukawa couplings are in equilibrium during the leptogenesis epoch, the interactions with the background medium are flavour-sensitive and the coherence of their flavour content defined by is destroyed, modifying the efficiency of the inverse decays. We point out, however, that it is not enough that the flavour-sensitive processes are fast on the cosmic expansion timescale, they must be fast relative to the reactions lest the flavour amplitudes of remain frozen by the repeated ‘measurements’. Our more restrictive requirement is significant in the most interesting ‘strong wash-out case’ where is fast relative to the cosmic expansion rate. We derive conditions for the unflavoured treatment to be adequate and for flavour effects to be maximal. In this ‘fully flavoured regime’ a neutrino mass bound survives. To decide if this bound can be circumvented in the intermediate case, a full quantum kinetic treatment is required.