Collaborative Research: PM: CeNTREX, A Search for Nuclear Time-Reversal Symmetry Violation with Quantum-State-Controlled TlF Molecules

合作研究：PM：CeNTREX，利用量子态控制的 TlF 分子寻找核时间反转对称性破坏

• 批准号: 2110405
• 负责人: Jonathan Engel
• 金额: $ 21.96万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110405&HistoricalAwards=false
• 关键词: Collaborative; Research; PM; CeNTREX; Search

Fundamental symmetries are at the heart of our understanding of the physical world. In particular, small-scale violations of the time-reversal (T) symmetry are necessary to explain the observed predominance of matter over antimatter, one of the most fundamental problems in modern science. New T-violating physics is likely to be mediated by particles with large masses that exceed the current reach of high-energy accelerators. This experiment will carry out a high-precision search for the nuclear Schiff moment, a charge separation in the thallium (Tl) nucleus, that would signal T-violation. Detecting a Schiff moment with a sensitivity exceeding the best current limit would provide clear evidence for physics beyond the Standard Model, while a null measurement would set a stringent constraint on theories that include sources of T violation, and potentially identify the technical goals for future particle accelerators. Experimental molecular quantum science and theoretical nuclear physics will be combined here in a new collaboration using table-top experiments and state-of-the-art calculations. The Tl Schiff moment will be measured using thallium fluoride (TlF) polar molecules that are aligned with an applied electric field in a long interaction region. The presence of a Schiff moment will be manifested by a precession of the Tl magnetic moment (spin) about the applied field. This project will broadly impact technology and education. Graduate and undergraduate students will be actively involved in research, acquiring hands-on skills that are highly valued in academia, industry, and national labs. The results of this work are expected to have a strong appeal to the media and members of the public, and will be widely disseminated.This project applies the techniques of molecular quantum science to a measurement of time-reversal symmetry (T) violation, as part of the Cold Molecule Nuclear Time Reversal Experiment (CeNTREX). The investigators seek to improve upon previous measurements of T violation in atomic nuclei by nearly two orders of magnitude in terms of sensitivity to fundamental parameters. This level of precision will help address grand challenges such as the observed matter-antimatter asymmetry in the universe. The investigators will use a beam of cold TlF molecules in order to combine the intrinsically high sensitivity of Tl to the T-violating nuclear Schiff moment, the large effective electric field at the Tl nucleus within strongly polarized molecules, and state-of-the-art techniques for controlling individual molecular quantum states including optical cycling for laser cooling and high-fidelity detection. In parallel, they will address the theoretical question of interpreting the measurement by developing modern methods of nuclear physics to accurately calculate the dependence of the Schiff moment on the underlying nucleon-nucleon interactions and to quantify its uncertainty. This measurement will have intellectual synergy with other ongoing T violation searches; complementary experiments can identify the source of an observed symmetry violation via their different sensitivities to fundamental parameters. This project is also complementary to the Large Hadron Collider (LHC) which is poised to detect new high-energy particles and potentially identify the nature of their T-violating interactions. The measurement supported by the current award relies on long-lived coherent superpositions of molecular quantum states, and will make an impact on quantum sensing with molecules via the meticulous quantum state control of TlF, ultrahigh-precision spectroscopy including internal co-magnetometry, and radiation pressure forces applied to novel systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

基本的对称性是我们对物理世界的理解的核心。 特别是，必须进行小规模侵犯时间反转（T）对称性，以解释观察到的物质而不是反物质的占主导地位，而反物质是现代科学中最根本的问题之一。 新的T侵入物理可能是由超过高能量加速器当前覆盖范围的颗粒介导的。 该实验将进行高精度搜索，以搜索核席夫矩，这是thallium（tl）核中的电荷分离，这将表明T侵入性。 检测具有超过最佳当前限制的敏感性的Schiff力矩将为超出标准模型以外的物理学提供明确的证据，而无效测量将对包括违规源的理论设定严格的限制，并有可能确定未来粒子加速器的技术目标。 实验性分子量子科学和理论核物理学将在这里使用桌面实验和最先进的计算进行新的合作。 TL Schiff矩将使用氟化thallium（TLF）极性分子进行测量，这些分子与长相互作用区域中的电场对齐。 Schiff力矩的存在将由TL磁矩（旋转）围绕应用场的进攻表现出来。 该项目将广泛影响技术和教育。 研究生和本科生将积极参与研究，获得学术界，工业和国家实验室高度重视的动手技能。 预计这项工作的结果将对媒体和公众有很大的吸引力，并将被广泛传播。作为冷分子核时间反向实验（Centrex）的一部分，该项目将分子量子科学的技术应用于测量时间反向对称性（T）的测量。 在对基本参数的敏感性方面，研究人员试图改善原子核中T违规的测量值近两个数量级。 这种精确度将有助于应对诸如宇宙中观察到的物质抗对称性等巨大挑战。 研究者将使用一束冷的TLF分子束，以结合TL对T抗核核酸schiff矩的本质上高灵敏度，TL对TL分子内的TL核的大有效电场，以及用于控制单个分子量定状态的最新技术，用于控制光量和高素质的型号。 同时，他们将通过开发现代的核物理学方法来准确计算基础核子核子核子相互作用的依赖性，并通过开发现代的核物理学方法来解释测量值的理论问题。 这种测量将与其他持续的T违反搜索具有智力协同作用；互补实验可以通过对基本参数的不同敏感性来识别观察到的对称违规的根源。 该项目还与大型强子对撞机（LHC）相辅相成，该项目有望检测新的高能量颗粒，并有可能识别其T抗相互作用的性质。 当前奖项支持的测量依赖于分子量子状态的长期相干叠加，并将通过TLF的细致量子态控制对量子感测的影响，超高精确光谱镜检查，包括内部共同测定力，以及通过NOMPATION STERITION应用于NOMPANTIONS。基金会的智力优点和更广泛的影响审查标准。