CAREER: Search for CP-Violating Hadronic Physics Beyond the Standard Model with Polyatomic Molecules

California Institute Of Technology, Pasadena CA

Investigators

Abstract

The origin of matter in the universe is a mystery. According to all known physical laws, there should be equal amounts of matter and anti-matter in existence. However, scientists have not found any large clumps of anti-matter such as anti-stars or anti-planets. One way to explain this asymmetry may involve new particles and forces that are not described by the Standard Model of particle physics. The hypothesized forces could violate some fundamental symmetries such as Charge conjugation (C), Parity (P), or Time reversal (T) symmetry in order to explain the matter to anti-matter asymmetry in the universe. But these same forces would cause other "forbidden" interactions between electrons, nucleons and electromagnetic fields, which may be detected by sensitive laboratory experiments. These effects are significantly amplified in polar molecules due to their very large internal electromagnetic fields. Searching for these effects with modern, quantum techniques enables "tabletop" searches for evidence of new particles and forces. This can promote the progress of science by opening up new, unexplored areas of fundamental physics. This project will search for a nuclear magnetic quadrupole moment (MQM) in polyatomic 173YbOH molecules. The MQM is a CP-violating electromagnetic moment that can exist in nuclei with spin I>1/2, and is enhanced in quadrupole deformed nuclei such as 173Yb. The MQM would arise from sources such as CP-violating nuclear forces, quark EDMs, and more, making it a sensitive probe for many hadronic sources beyond the Standard Model. Polyatomic molecules are a powerful platform for precision measurement since they generically enable full polarization and internal co-magnetometer states without interfering with laser cooling. This is a combination of features not available in other systems. This team will perform a molecular beam spin precession measurement to search for a nuclear MQM while simultaneously developing this new platform for precision measurements, which will be useful in the many systems that benefit from quantum control in molecules. 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.