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，以建造被称为Centrex的新实验--冷分子核时间反转实验--所需的设备和部件。Centrex是一项合作努力，通过精确测量嵌入到极性分子Tl氟化物中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实验的目标是探测原子核形状的特殊变形，即所谓的原子核希夫矩。这将推动科学的进步，因为只有在存在在时间方向颠倒下不对称的基本相互作用时，才会出现沿着原子核自旋轴的希夫矩。这种类型的相互作用可以通过新的、尚未被检测到的粒子来调节，这些粒子被预测将在一些理论模型中出现，这些理论模型扩展了当前的粒子物理标准模型。如果希夫矩的大小足以被投影灵敏度Centrex探测到，则可能表明存在质量远高于已知最重粒子的新粒子，甚至超出了大型强子对撞机(LHC)的探测范围。因此，Centrex将提供为数不多的已知方法之一，来搜索与大型强子对撞机上无法产生的太大粒子相关的标准模型以外的物理。一项具有Centrex基本发现潜力的实验也可以吸引普通公众的兴趣，并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几名年轻的仪器开发科学家提供机会。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，并提供异常广泛的实验物理培训，有利于国家科学工作者的发展。沿粒子角动量轴存在不对称电荷分布，如电偶极矩(EDM)或希夫矩(SM)，需要违反时间反转(T)对称性，这相当于更广泛讨论的CP破坏现象。在电流极限的几个数量级内观察到EDM或SM将是粒子物理理论标准模型之外的现象的证据。此外，粒子理论和宇宙学有强烈的动机，希望在这个实验可达的范围内出现EDM或SM。EDM或SM的发现可以解释所观察到的宇宙物质-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(大型强子对撞机没有探索的能量范围)下的新物理，携带着新的CP破坏相，自然会在当前的实验极限附近产生EDM和SM。因此，在对短信息的敏感性方面的任何进展都将以一种补充大型强子对撞机当前努力的方式推动粒子物理学的前沿。Centrex设备将通过集成一系列广泛的子系统来开发-许多是定制设计和建造的-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的概念设计建立在最新进展的基础上，利用双原子分子的特性来放大由于新的基本力而产生的信号，并精确地检测和操纵分子。这一新颖的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相对于当前技术状态的30倍的灵敏度，对于某些类型的违反时间逆转对称性的相互作用，这些相互作用可能导致宇宙中的宇宙物质-反物质不对称。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.