Pion polarizabilities: Theory vs Experiment

TL;DR

This paper compares theoretical predictions of charged pion polarizabilities from chiral perturbation theory with recent experimental results, finding good agreement within uncertainties.

Contribution

It provides a detailed comparison between two-loop chiral perturbation theory calculations and experimental measurements of pion polarizabilities.

Findings

Theoretical value for $( ext{alpha}- ext{beta})_{ ext{pi}^ ext{±}}$ is $(5.7 extpm 1.0) imes 10^{-4} ext{ fm}^3$.

Experimental result for $( ext{alpha}- ext{beta})_{ ext{pi}^ ext{±}}$ is $(4.0 extpm 1.2_{ ext{stat}} extpm 1.4_{ ext{sys}}) imes 10^{-4} ext{ fm}^3$.

The theoretical prediction aligns well with the experimental measurement.

Abstract

The values of charged pion polarizabilities obtained in the framework of chiral perturbation theory at the level of two-loop accuracy are compared with the experimental result recently reported by COMPASS Collaboration. It is found that the calculated value for the dipole polarizabilities $(\alpha-\beta)_{\pi^\pm}= (5.7\pm 1.0)\times 10^{-4}\,{\rm fm}^3$ fits quite well the experimental result $(\alpha-\beta)_{\pi^\pm} = (4.0 \pm 1.2_{\rm stat} \pm 1.4_{\rm syst}) \times 10^{-4}\,{\rm fm}^3$.