Sea Contributions to Hadron Electric Polarizabilities through Reweighting

TL;DR

This paper investigates the impact of sea quarks on hadron electric polarizabilities using reweighting techniques in lattice QCD, introducing a new estimator optimized for small field perturbations.

Contribution

It presents a novel reweighting estimator for sea quark effects in electric polarizability calculations, leveraging a hopping parameter expansion for variance reduction.

Findings

Successful implementation of a variance-reduced estimator for small field reweighting

Demonstration of sea quark contributions to hadron electric polarizabilities

Enhanced accuracy in lattice QCD polarizability measurements

Abstract

As part of our ongoing lattice study of the electric polarizabilities of hadrons using the background field approach, we use reweighting to examine the effect of the field on the sea quarks. As with other reweighting studies, the chief difficulty lies in the construction of a stochastic estimate of the ratio of the fermion determinants. In contrast to the case of reweighting in the quark mass, these estimators converge extremely slowly, and are resistant to common variance-reduction techniques such as low-mode subtraction. However, it is possible to construct an alternate estimator, taking advantage of the fact that we are interested in only perturbatively small fields; this estimator is susceptible to a variance-reduction technique based on a hopping parameter expansion.