CPP/NPP Experiments on Measuring the Polarizabilities of Charged and Neutral Pions

Abstract

Polarizability is a fundamental characteristic of hadronic particles. Measuring the polarizabilities of pions allows for checking the predictions of chiral perturbation theory (ChPT). Currently, an analysis of the CPP and NPP experimental data is being conducted, with the goal of measuring the polarizabilities of pions by determining the Primakoff pair production cross-section. For this purpose, in the summer of 2022, experimental data were collected at the TJNAF accelerator by studying the interactions of a polarized photon beam with energies of 4.5–6.0 GeV with a lead-208 target at the upgraded GlueX setup. Existing experiments on pion polarizability measurements, theoretical predictions of polarizabilities, the design of the CPP/NPP experiments, the expected results from these experiments, and the preliminary analysis of the collected data are discussed.