论文标题
搜索中子以使用中子电偶极矩测量镜像中子振荡
A search for neutron to mirror neutron oscillation using neutron electric dipole moment measurements
论文作者
论文摘要
巴里昂违规是男性生成的关键要素。已经假设，标准模型粒子的奇偶校偶联副本，称为镜子颗粒。这种镜像的存在的存在具有特定的可测试含义，尤其是在中性粒子振荡的领域，即。巴里昂违反了中子的镜像中子（$ n-n'$）振荡。因此，有许多实验搜索了$ n-n'$振荡，并对描述它的参数施加了约束。以前的所有努力都通过比较在两种情况下的一种或两种储存期间存活的超低中子的相对数量来搜索$ n-n'$振荡：（i）将零施加的磁场与非零施加的磁场进行比较，以及（ii）比较施加磁场的方向。但是，$ n-n'$振荡也会导致在翻转施加磁场方向时极化中子的进动频率的变化。我们第一次使用了最新搜索中子电动偶极矩的数据[Phys。莱特牧师。 124，081803（2020）]来限制$ n-n'$振荡。在弥补了影响超低中子和同居$^{199} $ hg原子的进动频率之比的系统效应之后，其中主要是由于它们在不均匀的磁场中的运动所致，我们限制了由于$ N-N'$振荡而引起的任何进一步的扰动。因此，我们提供了$ n-n'$振荡时间常数为$τ_{nn'}/\ sqrt {| \ cos（β）|}> 5.7〜 $ s，$ 0.36〜μ $ t'$ <b'<b'<b'<1.01〜μ $ t'（95 \％c.l.），$ 0.36〜 $ t'（95 \％c.l.此约束是$ 0.36〜μ $ t'U $ <b'<0.40〜μ $ t'的最佳可用范围。
Baryon number violation is a key ingredient of baryogenesis. It has been hypothesized that there could also be a parity-conjugated copy of the standard model particles, called mirror particles. The existence of such a mirror universe has specific testable implications, especially in the domain of neutral particle oscillation, viz. the baryon number violating neutron to mirror-neutron ($n-n'$) oscillation. Consequently, there were many experiments that have searched for $n-n'$ oscillation, and imposed constraints upon the parameters that describe it. All the previous efforts searched for $n-n'$ oscillation by comparing the relative number of ultracold neutrons that survive after a period of storage for one or both of the two cases: (i) comparison of zero applied magnetic field to a non-zero applied magnetic field, and (ii) comparison where the orientation of the applied magnetic field was reversed. However, $n-n'$ oscillations also lead to variations in the precession frequency of polarized neutrons upon flipping the direction of the applied magnetic field. For the first time, we used the data from the latest search for the neutron electric dipole moment [Phys. Rev. Lett. 124, 081803 (2020)] to constrain $n-n'$ oscillation. After compensating for the systematic effects that affect the ratio of precession frequencies of ultracold neutrons and cohabiting $^{199}$Hg-atoms, chief among which was due to their motion in non-uniform magnetic field, we constrained any further perturbations due to $n-n'$ oscillation. We thereby provide a lower limit on the $n-n'$ oscillation time constant of $τ_{nn'}/\sqrt{|\cos(β)|} > 5.7~$s, $0.36~μ$T'$<B'<1.01~μ$T' (95\% C.L.), where $β$ is the angle between the applied magnetic field and the ambient mirror magnetic field. This constraint is the best available in the range of $0.36~μ$T'$<B'<0.40~μ$T'.
