Sea contributions to the electric polarizability of the hadrons

TL;DR

This paper presents a lattice QCD calculation of the electric polarizability of the neutron and other neutral hadrons, explicitly including sea quark effects through a perturbative reweighting method, achieving the most precise result to date.

Contribution

It introduces a novel perturbative reweighting technique to incorporate sea quark effects in lattice QCD calculations of hadron polarizability.

Findings

Neutron polarizability measured as 2.70(55) x 10^{-4} fm^3

First lattice QCD result including sea effects with high precision

Uses aggressive dilution scheme to reduce stochastic noise

Abstract

We present a lattice QCD calculation of the polarizability of the neutron and other neutral hadrons that includes the effects of the background field on the sea quarks. This is done by perturbatively reweighting the charges of the sea quarks to couple them to the background field. The main challenge in such a calculation is stochastic estimation of the weight factors, and we discuss the difficulties in this estimation. Here we use an extremely aggressive dilution scheme to reduce the stochastic noise to a manageable level. The pion mass in our calculation is 306 MeV and the lattice size is 3 fm. For neutron, we find that $\alpha_E = 2.70(55) * 10^{-4}fm^3$, which is the most precise lattice QCD determination of the polarizability to date that includes sea effects.