Collaborative Research: MRI: Development of Apparatus for the Cold Molecule Nuclear Time-Reversal EXperiment (CeNTREX)

该项目将支持购买设备和部件，用于建造一个名为CeNTREX的新实验，即冷分子核时间反转实验。CeNTREX是一项合作努力，通过精确测量嵌入极性分子氟化铊的原子核的磁共振信号，来探测新型基本力和粒子的证据。CeNTREX实验的目标是检测原子核形状的一种特殊变形，即核希夫矩。这将推动科学的进步，因为沿着原子核自旋轴的希夫矩只能在基本相互作用存在的情况下出现，而这些相互作用在时间方向的反转下是不对称的。这种类型的相互作用可以由新的、尚未检测到的粒子介导，这些粒子在一些理论模型中被预测会出现，这些模型扩展了当前的粒子物理学标准模型。如果希夫矩的大小足够大，可以用预计的灵敏度CeNTREX探测到，这可能表明存在质量远远超过已知最重粒子的新粒子——甚至超出了大型强子对撞机（LHC）的范围。因此，CeNTREX将提供为数不多的已知方法之一，用于寻找与大型强子对撞机无法产生的大质量粒子相关的标准模型之外的物理。一个具有CeNTREX基础发现潜力的实验也可以吸引公众的兴趣，提高对科学的兴奋程度。此外，CeNTREX仪器的设计和建造将为培训仪器开发方面的几位年轻科学家提供机会。这种类型的精密测量科学使学生接触到广泛的智力和技术子领域，并在实验物理方面提供了不同寻常的广泛培训，有利于国家科学劳动力的发展。不对称电荷分布的存在，如沿粒子角动量轴的电偶极矩（EDM）或席夫矩（SM），需要违反时间反转(T)对称性，这相当于更广泛讨论的CP违反现象。在电流限制的几个数量级范围内观察电火花加工或SM将成为粒子物理理论标准模型之外现象的证据。此外，从粒子理论和宇宙学的角度来看，期望在这个实验可及的范围内产生EDM或SM有很强的动机。EDM或SM的发现可以阐明宇宙中物质-反物质不对称的机制，这仍然是宇宙学和粒子物理学的重大挑战之一。此外，在TeV尺度（大型强子对撞机尚未探索的能量范围）上的新物理，携带新的违反cp的相，自然会产生接近当前实验极限的EDM和SM。因此，对SMs的敏感性的任何进步都将推动粒子物理学的前沿，在某种程度上补充了目前在大型强子对撞机上的努力。CeNTREX设备将通过集成一系列广泛的子系统（许多是定制设计和制造的）来开发，包括真空系统、分子束源、激光器、光学控制和检测系统、微波控制和传输系统、精确磁场测量和控制系统以及高压系统。CeNTREX的概念设计基于最近的进展，利用双原子分子的特性来放大由于新的基本力产生的信号，并精确地检测和操纵分子。这种新型仪器将使用双原子分子的低温光束来进行世界上最灵敏的SM测量。使用CeNTREX的第一代测量的详细估计预计将产生30倍的灵敏度提高，相对于目前的技术水平，某些类型的时间反转对称性违反相互作用，可能是宇宙中宇宙物质-反物质不对称的原因。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will support the purchase of equipment and parts needed to construct the apparatus for a new experiment known as CeNTREX, the Cold molecule Nuclear Time-Reversal experiment. CeNTREX is a collaborative effort to detect evidence for new types of fundamental forces and particles, through precise measurements of magnetic resonance signals from nuclei embedded in the polar molecule thallium fluoride. The goal of the CeNTREX experiment is to detect a particular deformation in the shape of an atomic nucleus, known as a nuclear Schiff Moment. This will advance the progress of science because a Schiff Moment along the spin axis of a nucleus can arise only in the presence of fundamental interactions that are not symmetric under reversal of the direction of time. Interactions of this type can be mediated by new, as-yet undetected, particles that are predicted to occur in some theoretical models that extend the current Standard Model of particle physics. A Schiff Moment of size large enough to be detected with the projected sensitivity CeNTREX could indicate the existence of new particles with mass well above that of the heaviest known particles - and even beyond the reach of the Large Hadron Collider (LHC). Hence, CeNTREX will provide one of the few known ways to search for physics beyond the Standard Model associated with particles too massive to be created at the LHC. An experiment with the fundamental discovery potential of CeNTREX can also capture the interest of the general public and raise the level of excitement about science. In addition, design and construction of the CeNTREX apparatus will provide opportunities for training several young scientists in instrumentation development. This type of precision measurement science exposes students to a wide range of intellectual and technical subfields, and provides unusually broad training in experimental physics that benefits development of the scientific workforce of the nation.The existence of an asymmetric charge distribution such as an electric dipole moment (EDM) or a Schiff moment (SM) along a particle's angular momentum axis requires violation of time reversal (T) symmetry, which is equivalent to the more widely-discussed phenomenon of CP violation. Observation of an EDM or SM within a few orders of magnitude of current limits would be evidence for phenomena outside the Standard Model of particle physics theory. Furthermore, there are strong motivations from particle theory and cosmology to expect an EDM or SM in this experimentally-accessible range. Discovery of an EDM or SM could illuminate the mechanism responsible for the observed matter-antimatter asymmetry of the universe, which remains one of the grand challenges of cosmology and particle physics. Moreover, new physics at the TeV scale (the range of energy not being explored at the LHC), carrying new CP-violating phases, naturally give rise to EDM and SM near the current experimental limits. Hence any advance in sensitivity to SMs pushes the frontier of particle physics in a manner complementary to current efforts at the Large Hadron Collider. The CeNTREX apparatus will be developed by integrating a wide array of subsystems - many custom designed and built - including vacuum systems, a molecular beam source, lasers, optical control and detection systems, microwave control and transmission systems, precise magnetic field measurement and control systems, and high voltage systems. The conceptual design of CeNTREX builds from recent advances using the properties of diatomic molecules to amplify signals due to new fundamental forces, and in precisely detecting and manipulating molecules. This novel apparatus will use a cryogenic beam of diatomic molecules to make the world's most sensitive measurement of a SM. Detailed estimates of the first-generation measurement using CeNTREX are projected to yield a 30-fold increase in sensitivity, relative to the current state of the art, to certain types of time-reversal symmetry violating interactions that could be responsible for the cosmological matter-antimatter asymmetry in the Universe.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.