在LSND探测器中寻找π⁰→μ子中微子μ子中微子衰变。

Search for pi(0)-->nu(mu)nu(mu) decays in the LSND detector.

作者信息

Auerbach L B, Burman R L, Caldwell D O, Church E D, Cochran A K, Donahue J B, Fazely A R, Garvey G T, Gunasingha R M, Imlay R L, Kahrimanis G, Louis W C, Majkic R, Malik A, McIlhany K L, Metcalf W J, Mills G B, Rupnik D, Sandberg V D, Smith D, Somodi R F, Stancu I, Strossman W D, Sung M, Tayloe R, VanDalen G J, Vernon W, Wadia N, White D H, Yellin S, Yi H

机构信息

Temple University, Philadelphia, Pennsylvania 19122, USA.

出版信息

Phys Rev Lett. 2004 Mar 5;92(9):091801. doi: 10.1103/PhysRevLett.92.091801. Epub 2004 Mar 4.

DOI:10.1103/PhysRevLett.92.091801

PMID:15089459

Abstract

We observe a net beam excess of 8.7+/-6.3(stat)+/-2.4(syst) events, above 160 MeV, resulting from the charged-current reaction of nu(micro) and/or nu;(mu) on C and H in the LSND detector. No beam-related muon background is expected in this energy regime. Within an analysis framework of pi(0)-->nu(mu)nu;(mu), we set a direct upper limit for this branching ratio of Gamma(pi(0)-->nu(mu)nu;(mu))/Gamma(pi(0)-->all)<1.6 x 10(-6) at 90% confidence level.

摘要

我们观察到，在LSND探测器中，μ子中微子和/或反μ子中微子与碳和氢发生带电流反应，在能量高于160 MeV时，净束流事例数超出8.7±6.3（统计）±2.4（系统）。在这个能量区域，预计不存在与束流相关的μ子本底。在π0→μ子中微子反μ子中微子的分析框架内，我们在90%置信水平下，为该分支比Γ（π0→μ子中微子反μ子中微子）/Γ（π0→所有衰变）设定了一个直接上限，即小于1.6×10−6 。