Search for lepton flavour violation at LHCb

详细信息    查看全文

• 作者：Vicente Rives Molina ; on behalf of the LHCb collaboration
• 关键词：lepton flavour violation ; lepton number violation ; Majorana neutrinos ; Rare Decays ; LHCb
• 刊名：Nuclear and Particle Physics Proceedings
• 出版年：2016
• 出版时间：April-June 2016
• 年：2016
• 卷：273-275
• 期：Complete
• 页码：2388-2390
• 全文大小：237 K

文摘

We report the first searches for lepton flavour violating τ   decays at a hadron collider. In particular, a search for the decay τ→μμμ$\tau \to \mu \mu \mu$ is presented, using data corresponding to an integrated luminosity of 1.0 fb^-1 collected at 7 TeV by LHCb in 2011. The upper limit on the branching ratio could be set, B(τ⁻→μ⁺μ⁻μ⁻)<8.0×10⁻⁸$B({\tau }^{-}\to {\mu }^{+}{\mu }^{-}{\mu }^{-})<8.0\times {10}^{-8}$ at 90 % confidence level (the inclusion of the charge conjugate process is included).

In addition, we report on the search for heavy Majorana neutrinos in lepton number violating B⁻→π⁺μ⁻μ⁻$B^{-}\to {\pi }^{+}{\mu }^{-}{\mu }^{-}$ decay (as well as in its charge conjugate). In this case, the whole LHCb dataset is used (1.0 fb^-1 at $\sqrt{s}=7\text{TeV}$ and 2 fb^-1 at $\sqrt{s}=8\text{TeV}$). No signal is found, and a limit on the branching ratio is set, B(B⁻→π⁺μ⁻μ⁻)<4×10⁻⁹$\text{B}(B^{-}\to {\pi }^{+}{\mu }^{-}{\mu }^{-})<4\times {10}^{-9}$ at 95 % confidence level. This limit is then used to set limits on the coupling between the hypothetical Majorana neutrino and muons.