Light-Front spin-dependent Spectral Function and Nucleon Momentum Distributions for a Three-Body System

TL;DR

This paper develops a Poincare' covariant formalism for spin-dependent spectral functions and momentum distributions in three-fermion systems using light-front dynamics, facilitating advanced nuclear physics calculations.

Contribution

It introduces a novel light-front covariant approach for spectral functions and momentum distributions, applicable to three-fermion systems, based on the Bakamjian-Thomas construction.

Findings

The formalism satisfies normalization and momentum sum rules.

It generalizes to A-nucleon systems.

Applicable to refined nuclear calculations like EMC effect.

Abstract

Poincare' covariant definitions for the spin-dependent spectral function and for the momentum distributions within the light-front Hamiltonian dynamics are proposed for a three-fermion bound system, starting from the light-front wave function of the system. The adopted approach is based on the Bakamjian-Thomas construction of the Poincare' generators, that allows one to easily import the familiar and wide knowledge on the nuclear interaction into a light-front framework. The proposed formalism can find useful applications in refined nuclear calculations, like the ones needed for evaluating the EMC effect or the semi-inclusive deep inelastic cross sections with polarized nuclear targets, since remarkably the light-front unpolarized momentum distribution by definition fulfills both normalization and momentum sum rules. It is also shown a straightforward generalization of the definition of the light-front spectral function to an A-nucleon system.