摘要
2003到2004年间,CERN的NA48/2实验收集了1.69×107个完全重建的π0-→γe+e事例,动量范围在mee>10 Me V/c2,本底污染可忽略.该样本通过分析衰变链π0→γA',A'→e+e-来寻找暗光子.然而并没有观测到信号,本文给出暗光子质量mA'和混合参数2的排除限.
The NA48 /2 experiment at CERN collected,between 2003 and 2004,1. 69 × 107 fully reconstructed π0→ γe+e-in the kinematic range mee> 10 Me V / c2,with a negligible background contamination. The sample is analysed to search for the presence of dark photons( A') via the decay chain π0→γA',A'→e+e-. No signal has been observed,and the exclusion limits on space of the dark photon mass mA'and the mixing parameter 2are reported.
