PM: Search for New Physics Beyond the Standard Model through Precision Isotope Shift Measurements

低能量下的高精度实验为寻找超越粒子物理标准模型的新物理提供了令人信服的机会。有人建议通过精确测量同位素位移（由于原子核中中子数量的变化而引起的原子发出的光的颜色的微小扰动）来为新的基本力设定改进的边界。通过比较在同一元素发射的不同颜色的光上测量的同位素位移，可以寻找发出新基本力信号的新粒子。拟议的工作将通过培训本科生和研究生，将研究和教育目标结合起来，并努力增加代表性不足群体的参与。为了寻找在100 eV到100 MeV的中间质量范围内与夸克和轻子耦合的新玻色子，建议将镱（Yb）的高精度同位素位移光谱学提高四个数量级（除以光速的平方）。在这种方法中，在所谓的King图中的非线性，它比较了两种不同跃迁的同位素位移，提供了对标准模型之外的物理学的敏感性，以及以前无法达到的核效应。光谱将在激光冷却和捕获Yb+离子的三种不同跃迁上进行，其中精度将从1 kHz到10.1 Hz的电流水平提高四个数量级。这不仅可以观察到以前无法观察到的核效应，而且还可以将新玻色子与标准物质耦合的极限推到以前未经测试的范围内。如果能够获得更多的同位素，那么对新物理学的敏感性将大大提高。因此，将开发一种提取和捕获装置，用于捕获和测量不稳定的166 Yb同位素，并提供在加速器设施中测量其他不稳定同位素的能力。该奖项反映了NSF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。

High-precision experiments at low energies offer compelling opportunities to search for new physics beyond the Standard Model of particle physics. It is proposed to set improved bounds for a new fundamental force by performing precision measurements of isotope shifts (minute perturbations in the colors of light emitted by atoms due to changes in the number of neutrons in the nucleus). By comparing isotope shifts measured on different colors of light emitted by the same element, it is possible to search for new particles that signal a new fundamental force. The proposed work will unite research and educational goals by training undergraduate and graduate students, and strive to increase the participation of underrepresented groups.In particular, it is proposed to improve high-precision isotope shift spectroscopy in Yttervium (Yb) by four orders of magnitude to search for a new boson that couples to quarks and leptons in the intermediate mass range of 100 eV to 100 MeV (divided by the square of the speed of light). In this approach, a nonlinearity in a so-called King plot, which compares isotope shifts for two different transitions, provides sensitivity to physics beyond the Standard Model, as well as to previously inaccessible nuclear effects. Spectroscopy will be performed on three different transitions in laser-cooled and trapped Yb+ ions, where the precision will be improved by four orders of magnitude from the current level of 1 kHz to ∼ 0.1 Hz. This will not only enable the observation of previously inaccessible nuclear effects, but also push the limit for the coupling of the new boson to standard matter into a previously untested range. The sensitivity to new physics can be dramatically improved if additional isotopes can be made available. Therefore, an extraction and trapping apparatus will be developed that will be used to trap and measure the unstable 166Yb isotope, and provide the capability to measure other unstable isotopes at accelerator facilities.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.