Collaborative Research: Precision Tests of Physics Beyond the Standard Model with Antihydrogen

作为ALPHA合作项目的一部分，这项研究的目标是寻找氢和反氢（与氢对应的反物质）性质之间的差异。根据我们对物理世界进行数学描述的基本原理，反氢的原子物理性质应该与氢的原子物理性质相同。反氢和氢之间在原子物理学或引力动力学上的任何差异，都将挑战我们周围世界的既定数学描述的基础。这次合作的高精度测量可能会揭示物理学中最重要的问题之一，即重子不对称，即在可观测的宇宙中物质多于反物质。该奖项是在美国国家科学基金会/美国能源部基础等离子科学与工程伙伴关系下获得的，将支持普渡大学和加州大学伯克利分校的一名本科生的合作努力，作为美国能源部在联合项目下获得的奖励的补充。作为ALPHA合作项目的一部分，这项研究的目标是寻找氢和反氢性质之间的差异；这种差异只能由电荷-宇称-时间（CPT）或弱等效原理违反造成。欧洲核子研究中心（CERN）的ALPHA合作项目已经从捕获反氢发展到测量其正电子自旋翻转频率，稍微粗略地测量其引力特性、电荷中性、1S-2S谱和超精细谱。预计在本供资期间，所有这些测量的精度都将大大提高。近期，ALPHA正在建造并预计将安装一种新的垂直实验设备ALPHAg，用于进行上下重力测量。同时，它将继续测量反氢的光学和超精细光谱。在即将到来的两年CERN关闭期间，ALPHA将充分准备ALPHAg，并将建立一个新的原子光谱陷阱ALPHA- iii。在资助的最后两年，计划要求进行高精度测量，利用精细尺度磁强计进行1%水平的重力测量；应用激光和绝热冷却对兰姆位移、反里德伯常数、电荷中性和超精细光谱进行高精度测量。此外，与许多CPT测试不同，ALPHA的测试是独立于模型的，不假设特定的CPT破坏机制。该奖项反映了国家科学基金会的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The goal of this research, part of the ALPHA Collaboration, is to search for differences between the properties of hydrogen and antihydrogen, the antimatter counterpart to hydrogen. According to very general principles that underlie our mathematical description of the physical world, the atomic physics of antihydrogen should be identical to that of hydrogen. Any differences in the atomic physics or gravitational dynamics between antihydrogen and hydrogen would challenge the very basis of established mathematical descriptions of the world around us. The collaboration's high-precision measurements may shed light on one of the most important questions in physics, known as the baryon asymmetry, which is the preponderance of matter over antimatter in the observable universe. This award is made under the NSF/DOE Partnership in Basic Plasma Science and Engineering and will support the collaboration's effort at Purdue University and an undergraduate student at University of California, Berkeley as complementary to a DOE award made under the joint program. The goal of this research, part of the ALPHA Collaboration, is to search for differences between the properties of hydrogen and antihydrogen; such differences could only result from Charge-Parity-Time (CPT) or Weak Equivalence Principle violation. The ALPHA collaboration at CERN has progressed from trapping antihydrogen to measuring its positron spin flip frequency, somewhat crudely its gravitational properties, its charge neutrality, its 1S-2S spectrum, and its hyperfine spectrum. Significant improvement in the precision of all these measurements is expected during the duration of this funding period. In the near term, ALPHA is constructing, and is expected to install, a new vertical experimental apparatus, ALPHAg, to conduct an up/down gravity measurement. In parallel, it will continue measurements on the optical and hyperfine spectra of antihydrogen. During the upcoming two-year CERN shutdown, ALPHA will fully prepare ALPHAg and will build a new atomic spectrum trap, ALPHA-III. During the final two years of funding, plans call for carrying out high-precision measurements utilizing fine scale magnetometry for gravity measurements at the 1% level; and applying laser and adiabatic cooling for high-precision measurements of the Lamb shift, the anti-Rydberg constant, charge neutrality, and the hyperfine spectrum. Moreover, unlike many CPT tests, ALPHA's tests are model-independent and do not presume a particular CPT breaking mechanismThis 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.