A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI
A search for neutron to mirror-neutron oscillations using the nEDM apparatus at PSI
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DOI：
10.1016/j.physletb.2020.135993
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发表时间：
2021-01-10
影响因子：
4.4
通讯作者：
Zsigmond, G.
中科院分区：
文献类型：
--
作者：
Abel, C.;Ayres, N. J.;Zsigmond, G.
有人提出，可能存在标准模型粒子的镜像副本，恢复了全球水平上弱相互作用的宇称对称性。中性标准模型粒子(如中子)和镜像粒子之间的振荡可能会回答当今物理学中的各种长期问题。天体物理研究和由超冷中子存储测量领导的地面实验已经研究了中子到镜像中子的振荡，并对理论参数施加了限制。最近，对这些超冷中子存储实验的进一步分析已经产生了统计上显著的异常信号，这些信号可以被解释为假设镜像磁场为非零的中子到镜像中子的振荡。中子电偶极矩合作小组在保罗·谢勒研究所进行了专门的搜索，没有发现中子到镜像中子振荡的证据。由此得到了振荡时间的新下限：B‘=0(95%C.L.)时的tau(nn’)>；352s，0.4亩T<；B‘<；25.7亩T(95%C.L.)时的tau(nn’)>；25.4µT(95%C.L.)，其中β是施加的磁场和局部镜像磁场之间的固定角度，该局部镜像磁场被假定绑定到地球。到目前为止，这些新的限制条件是在B‘类似于10亩T和B’类似于20亩T的范围内测量得最好的。爱思唯尔出版公司(Elsevier B.V.)
It has been proposed that there could be a mirror copy of the standard model particles, restoring the parity symmetry in the weak interaction on the global level. Oscillations between a neutral standard model particle, such as the neutron, and its mirror counterpart could potentially answer various standing issues in physics today. Astrophysical studies and terrestrial experiments led by ultracold neutron storage measurements have investigated neutron to mirror-neutron oscillations and imposed constraints on the theoretical parameters. Recently, further analysis of these ultracold neutron storage experiments has yielded statistically significant anomalous signals that may be interpreted as neutron to mirror-neutron oscillations, assuming nonzero mirror magnetic fields. The neutron electric dipole moment collaboration performed a dedicated search at the Paul Scherrer Institute and found no evidence of neutron to mirrorneutron oscillations. Thereby, the following new lower limits on the oscillation time were obtained: tau(nn') > 352s at B' = 0(95% C.L.), tau(nn') > 6s for 0.4 mu T < B' < 25.7 mu T(95% C.L.), and tau(nn') /root cos beta > 9s for 5.0 mu T < B' < 25.4 mu T (95% C.L.), where beta is the fixed angle between the applied magnetic field and the local mirror magnetic field, which is assumed to be bound to the Earth. These new constraints are the best measured so far around B' similar to 10 mu T and B' similar to 20 mu T. (C) 2020 The Authors. Published by Elsevier B.V.