Search for K+ decays to a muon and invisible particles
Search for K+ decays to a muon and invisible particles
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寻找 K 衰变为 μ 子和不可见粒子
DOI：
10.1016/j.physletb.2021.136259
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发表时间：
2021
影响因子：
4.4
通讯作者：
Velghe, B.
中科院分区：
文献类型：
--
作者：
Cortina Gil, E.;Kleimenova, A.;Minucci, E.;Padolski, S.;Petrov, P.;Shaikhiev, A.;Volpe, R.;Numao, T.;Petrov, Y.;Velghe, B.
CERN的NA 62实验报告了使用2016-2018数据集搜索K+→ μ+ N和K+→ μ+ ν X衰变，其中N和X是大质量不可见粒子。假设N粒子是重中性轻子，结果表示为中微子混合参数的上限O（10− 8| U μ 4| 2的N质量在200-384 MeV/c2和寿命超过50纳秒。X粒子被认为是一个标量或矢量的隐扇形介质，衰变到一个不可见的终态，X质量在10-370 MeV/c 2范围内的衰变分支分数的上限首次被报道，范围从O（10− 5）到O（10− 7）。在K+→ μ+ ν $>分支分数的90% CL下，建立了一个改进的上限1.0× 10− 6。
The NA62 experiment at CERN reports searches for K+→ μ+ N and K+→ μ+ ν X decays, where N and X are massive invisible particles, using the 2016–2018 data set. The N particle is assumed to be a heavy neutral lepton, and the results are expressed as upper limits of O (10− 8) of the neutrino mixing parameter| U μ 4| 2 for N masses in the range 200–384 MeV/c 2 and lifetime exceeding 50 ns. The X particle is considered a scalar or vector hidden sector mediator decaying to an invisible final state, and upper limits of the decay branching fraction for X masses in the range 10–370 MeV/c 2 are reported for the first time, ranging from O (10− 5) to O (10− 7). An improved upper limit of 1.0× 10− 6 is established at 90% CL on the K+→ μ+ ν ν ν¯ branching fraction.