The Electric Dipole Moment and Parity Violating Spin Rotations of the Neutron

9321608黑克尔的资金用于两个独立的实验。第一个是使用储存在瓶子中的超冷中子测量中子电偶极矩(EDM)的实验。非零中子电火花加工将是时间反转(T)和宇称(P)对称性破坏的证据。对于确定T对称性破坏的理论解释是正确的，对中子电火花加工的限制是至关重要的。第二个实验的目标是测量破坏中子和氦原子核之间弱相互作用的P。这一信息是对其他测量的补充，并将有助于完全参数化低能核子-核子弱相互作用，以提供对标准电子弱理论的测试。我们计划测量一束横向极化的冷中子束在50厘米厚的液氦中传输时，弱相互作用引起的极化矢量的旋转。这一效应预计约为10-7弧度，代表着前所未有的实验灵敏度。

9321608 Heckel Funding is for two separate experiments. The first is an experiment to measure the electric dipole moment (EDM) of the neutron using ultracold neutrons stored in a bottle. A non-zero neutron EDM would be evidence for a breakdown of both Time Reversal (T) and Parity (P) symmetries. Limits on the neutron EDM are crucial for determining which theoretical explanations for T symmetry violation are correct. The goal of the second experiment is to measure the P violating weak interaction between neutrons and helium nuclei. This information complements other measurements and will help fully parameterized the low energy nucleon-nucleon weak interaction to provide a test of a standard eletroweak theory. We plan to measure the weak-interaction induced rotation of the polarization vector of a transversely polarized cold neutron beam on propagation through 50 cm of liquid helium. The effect, expected to be of order 10-7 radians, represents an unprecedented experimental sensitivity.