eta 介子衰变为轻子 - 反轻子对的测量
高能物理 - 实验
2013-05-29 v3
摘要
利用 CELSIUS 上的 WASA 探测器对 eta 介子的稀有轻子衰变进行了搜寻。报道了两个双 Dalitz 衰变 eta->e+e-e+e- 事例候选者，背景为 1.3+/-0.2 个事例。据此设定分支比的上限为 9.7E-5 (90% CL)。确定衰变 eta->e+e-gamma 的分支比为 (7.8+/-0.5 stat+/-0.8 syst)E-3。eta->e+e- 衰变分支比的上限 (90% CL) 为 2.7E-5，eta->mu+mu-mu+mu- 和 eta->pi+pi-mu+mu- 衰变之和的限值为 3.6E-4。
引用
@article{arxiv.0711.3531,
title = {Measurement of eta meson decays into lepton-antilepton pairs},
author = {WASA Collaboration and M. Berłowski and Chr. Bargholtz and M. Bashkanov and D. Bogoslawsky and A. Bondar and H. Calén and F. Cappellaro and H. Clement and L. Demirörs and C. Ekström and K. Fransson and L. Gerén and L. Gustafsson and B. Höistad and G. Ivanov and M. Jacewicz and E. Jiganov and T. Johansson and S. Keleta and I. Koch and S. Kullander and A. Kupść and A. Kuzmin and A. Kuznetsov and I. V. Laukhin and K. Lindberg and P. Marciniewski and R. Meier and B. Morosov and W. Oelert and C. Pauly and H. Pettersson and Y. Petukhov and A. Povtorejko and R. J. M. Y. Ruber and K. Schönning and W. Scobel and R. Shafigullin and B. Shwartz and T. Skorodko and V. Sopov and J. Stepaniak and P. -E. Tegnér and P. Thörngren Engblom and V. Tikhomirov and A. Turowiecki and G. J. Wagner and M. Wolke and A. Yamamoto and J. Zabierowski and I. Zartova and J. Złomańczuk},
journal= {arXiv preprint arXiv:0711.3531},
year = {2013}
}
备注
9 pages, 10 Postscript figures, uses revtex4.sty, revised version after referee comments; conclusions unchanged