印度理工学院孟买校区S. Uma Sankar团队研究了跷跷板模型中违反介子的带电勒普顿味衰变。2025年3月25日，《高能物理杂志》发表了这一成果。

中微子振荡的发生要求带电轻子区存在味破坏。不同带电轻子味破坏（CLFV）衰变模式的分支比之间的关系取决于中微子质量模型的细节。研究组考虑了中微子质量的三种简单跷跷板机制，并研究了辐射CLFV衰变与介子CLFV衰变之间的相关性。

结果发现，在II型跷板机制中，介子CLFV衰变分支比小得可以忽略不计，而在I型（III型）跷板机制的情况下，它们被限制为至少比辐射CLFV衰变分枝比小三（两）个数量级。因此，这两种CLFV衰变模式之间的关系有助于区分不同类型的跷跷板机制。如果介子CLFV衰变的分支比大于辐射CLFV衰变，则强烈暗示中微子质量产生机制比简单的跷跷板更复杂。

附：英文原文

Title: Charged Lepton Flavour Violating meson decays in seesaw models

Author: Awasthi, Pravesh Chndra, More, Jai, Pradhan, Akhila Kumar, Rao, Kumar, Sahu, Purushottam, Sankar, S. Uma

Issue&Volume: 2025-03-25

Abstract: The occurrence of neutrino oscillations demands the existence of flavour violation in charged lepton sector. The relation between the branching ratios of different charged lepton flavour violating (CLFV) decay modes depends on the details of the neutrino mass model. In this work, we consider the three types of simple seesaw mechanisms of neutrino masses and study the correlation between the radiative CLFV decays and the meson CLFV decays. We find that the meson CLFV decay branching ratios are negligibly small in type-II seesaw mechanism whereas they are constrained to be at least three (two) orders of magnitude smaller than the radiative CLFV decay branching ratios in the case of type-I (type-III) seesaw mechanism. Thus the relationship between these two modes of CLFV decays helps in distinguishing between different types of seesaw mechanism. If, the branching ratios of CLFV decays of mesons are larger than those of radiative CLFV decays, it provides a strong hint that the neutrino mass generating mechanism is more complicated than simple seesaw.

DOI: 10.1007/JHEP03(2025)183

Source: https://link.springer.com/article/10.1007/JHEP03(2025)183