Spontaneous R-parity breaking, stop LSP decays and the neutrino mass hierarchy
Spontaneous R-parity breaking, stop LSP decays and the neutrino mass hierarchy
复制标题
自发 R 宇称破缺、停止 LSP 衰变和中微子质量等级
DOI：
10.1016/j.physletb.2014.03.052
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
S. Spinner
中科院分区：
文献类型：
--
作者：
Zachary Marshall;B. Ovrut;A. Purves;S. Spinner
具有右手中微子超多重态、B−L对称性和非零中微子期望值的MSSM是自发破坏R宇称的最小理论，与质子稳定性和轻子数破坏的界限一致。这台最小的B−L多重子对撞机可以有一个有色/带电的LSP，其中停止LSP是最容易在大型强子对撞机上观察到的。我们研究了一个Stop LSP到底部夸克和带电轻子的R宇称破坏衰变--这是一般的“混合”Stop的主要模式。通过对参数空间的大范围扫描，数值分析了这些衰落通道的相对分支率。在这个理论中，中微子的真空期望值破坏了R宇称，这一事实将这些分支比直接与中微子的质量等级联系在一起。它展示了在大型强子对撞机上发现底部带电轻子事件如何潜在地确定中微子质量是在正常等级还是在倒置等级中，以及如何确定θ23中微子混合角。最后，这些轻夸克信号的LHC边界被用来设置停止质量的下界。
The MSSM with right-handed neutrino supermultiplets, gauged B− L symmetry and a non-vanishing sneutrino expectation value is the minimal theory that spontaneously breaks R-parity and is consistent with the bounds on proton stability and lepton number violation. This minimal B− L MSSM can have a colored/charged LSP, of which a stop LSP is the most amenable to observation at the LHC. We study the R-parity violating decays of a stop LSP into a bottom quark and charged leptons–the dominant modes for a generic “admixture” stop. A numerical analysis of the relative branching ratios of these decay channels is given using a wide scan over the parameter space. The fact that R-parity is violated in this theory by a vacuum expectation value of a sneutrino links these branching ratios directly to the neutrino mass hierarchy. It is shown how a discovery of bottom-charged lepton events at the LHC can potentially determine whether the neutrino masses are in a normal or inverted hierarchy, as well as determining the θ 23 neutrino mixing angle. Finally, present LHC bounds on these leptoquark signatures are used to put lower bounds on the stop mass.