In a quest to find exotic interactions beyond the Standard Model, researchers from the University of Science and Technology (USTC) in Hefei, China, and UC Berkeley have developed a novel experimental setup named SAPPHIRE which stand for – “Spin Amplifier for Particle PHysIcs REsearch”. This setup searches for a hypothetical Z’ boson-mediated interaction between the spins of electrons and neutrons that breaks the mirror-symmetric of the interaction and thus, violates parity.
The SAPPHIRE setup consists of two chambers filled with the vapor of two elements: rubidium and xenon. The polarized electron spins of rubidium-87 atoms act as a spin source, and the polarized neutron spins of xenon-129, as a spin sensor. The xenon atoms amplify the field generated in the rubidium source, making the effect of a potential exotic field 200 times larger. The nuclear magnetic resonance principle then comes into play, and the rubidium-87 atoms, acting as a magnetometer, determine the strength of the resonance signal.
The detection of such an exotic field in the desired frequency range would indicate the presence of a new interaction. The scientists have already completed a proof-of-principle and started the first series of measurements to search for the exotic interaction. Although they have not yet found a corresponding signal after 24 hours of measurements, the five orders of magnitude increase in sensitivity have allowed them to set constraints on the strength of the new exchange particle’s interaction. Further optimization could even improve the sensitivity to the special exotic interaction by another eight orders of magnitude.
In conclusion, the SAPPHIRE setup is a highly rewarding and challenging experiment that could lead to the discovery of a new physics with potential Z’ bosons. With its intricate design, calibration, and optimization, this novel setup is set to become a new tool in the search for exotic interactions beyond the Standard Model.