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

中子的电偶极矩和宇称破坏自旋旋转

• 批准号: 9321608
• 负责人: Blayne Heckel
• 金额: $ 27.68万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-03-15 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9321608&HistoricalAwards=false
• 关键词: Electric; Dipole; Moment; Parity; Violating

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.

9321608 Heckel基金用于两个独立的实验。第一个实验是用储存在瓶子里的超冷中子来测量中子的电偶极矩（EDM）。一个非零中子电火花加工将是时间反转(T)和宇称(P)对称性被破坏的证据。中子电火花加工的限制对于确定T对称违反的理论解释是正确的至关重要。第二个实验的目标是测量中子与氦核之间的弱相互作用。这一信息补充了其他测量结果，并将有助于充分参数化低能核子-核子弱相互作用，从而提供对标准电弱理论的检验。我们计划测量横向极化冷中子束在50厘米液氦中传播时偏振矢量的弱相互作用诱导的旋转。预期的效果是10-7弧度，这代表了前所未有的实验灵敏度。