The Second Moment of the Pion Light Cone Wave Function

TL;DR

This paper reports a lattice QCD calculation of the pion's light cone wave function second moment, addressing discrepancies between theory and experiment through symmetry and operator matching techniques.

Contribution

It introduces a method using lattice hypercubic symmetries and 1-loop matching to improve the calculation of the pion's wave function moments.

Findings

Preliminary lattice results for the second moment of the pion wave function.

Reduction of power divergences using hypercubic symmetries.

Implementation of full 1-loop operator matching.

Abstract

We present a preliminary result for second moment of the light cone wave function of the pion. This parameter is the subject of a discrepancy between theoretical predictions (coming from lattice and sum rules) and a recent experimental result (that remarkably agrees with purely perturbative predictions). In this work we exploit lattice hypercubic symmetries to remove power divergences and, moreover, implement a full 1-loop matching for all the contributing operators.