寻找轻子味破坏衰变 B^{+}→K^{+}μ^{±}e^{∓}。

Search for Lepton-Flavor Violating Decays B^{+}→K^{+}μ^{±}e^{∓}.

机构信息

Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.

Physik-Institut, Universität Zürich, Zürich, Switzerland.

出版信息

Phys Rev Lett. 2019 Dec 13;123(24):241802. doi: 10.1103/PhysRevLett.123.241802.

DOI:10.1103/PhysRevLett.123.241802

PMID:31922836

Abstract

A search for the lepton-flavor violating decays B^{+}→K^{+}μ^{±}e^{∓} is performed using a sample of proton-proton collision data, collected with the LHCb experiment at center-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of 3 fb^{-1}. No significant signal is observed, and upper limits on the branching fractions are set as B(B^{+}→K^{+}μ^{-}e^{+})<7.0(9.5)×10^{-9} and B(B^{+}→K^{+}μ^{+}e^{-})<6.4(8.8)×10^{-9} at 90% (95)% confidence level. The results improve the current best limits on these decays by more than one order of magnitude.

摘要

使用 LHCb 实验在质心能量为 7 和 8 TeV 以及对应的 3 fb^{-1}积分亮度下收集的质子-质子碰撞数据，对轻子味道破坏衰变 B^{+}→K^{+}μ^{±}e^{∓}进行了搜索。未观察到显著信号，并对分支比设定了上限，B(B^{+}→K^{+}μ^{-}e^{+})<7.0(9.5)×10^{-9}和 B(B^{+}→K^{+}μ^{+}e^{-})<6.4(8.8)×10^{-9}，置信水平分别为 90%（95%）。这些结果将这些衰变的当前最佳限制提高了一个数量级以上。