Non-perturbative flavor asymmetry in the nucleon and deuteron: The light-front Hamiltonian effective field theory approach

TL;DR

This paper develops a Light-Front Hamiltonian Effective Field Theory approach to study non-perturbative multi-pion contributions to nucleon flavor asymmetry, revealing significant deviations from perturbative predictions and enabling analysis of nuclear effects.

Contribution

It introduces a systematic Fock sector expansion within LFHEFT to incorporate pionic degrees of freedom for non-perturbative flavor asymmetry analysis.

Findings

Non-perturbative distributions differ significantly from perturbative predictions.

Higher-order Fock components are crucial for accurate nucleon structure.

Framework can be extended to study nuclear effects in light nuclei.

Abstract

We investigate non-perturbative multi-pion contributions to nucleon flavor asymmetry within the framework of Light-Front Hamiltonian Effective Field Theory (LFHEFT). Utilizing a Fock sector expansion, we systematically incorporate pionic degrees of freedom, with the nucleon-pion interactions governed by a scalar variant of chiral effective field theory. Our results demonstrate that the non-perturbatively calculated longitudinal momentum distributions exhibit significant deviations from leading-order perturbative predictions, emphasizing the importance of higher-order Fock components in describing the proton's sea quark structure. Furthermore, we demonstrate the feasibility of extending this framework to investigate nuclear effects in light nuclei, such as the deuteron. This unified approach provides a consistent basis for analyzing the interplay between intrinsic nucleon structure and nuclear modifications, potentially offering new insights into the flavor asymmetry observed in fixed-target and collider experiments.