Electric Polarizability of Charged Pions from nHYP Four-Point Functions

TL;DR

This paper advances the calculation of charged pion electric polarizability by employing improved lattice QCD techniques, including dynamical nHYP action and smaller pion masses, to enhance accuracy and enable volume extrapolation.

Contribution

It introduces a new approach using dynamical nHYP fermions and smaller pion masses for more precise polarizability calculations.

Findings

Preliminary results show promising agreement with theoretical expectations.

Use of dynamical nHYP action improves calculation accuracy.

Volume extrapolation methods are being developed for better results.

Abstract

Understanding a hadron's electric and magnetic polarizabilities allows one to access internal structural information. Traditionally, the external field two-point function method has been used to calculate polarizabilities. However, recent work has demonstrated the effectiveness of using four-point functions for computing polarizabilities of charged and neutral hadrons. Our previous study on the electric polarizability of the charged pion used a quenched Wilson action on a lattice with pion mass from 1100 MeV to 370 MeV. In this work, we employ a number of improvements, including a dynamical action (nHYP), smaller pion masses (220 MeV and 315 MeV), and a variable lattice size in order to extrapolate to infinite volume. Preliminary results are presented.