Gravitational form factors and transverse spin sum rule in a light front quark-diquark model in AdS/QCD

TL;DR

This paper calculates gravitational form factors and explores the transverse spin sum rule in a light front quark-diquark model based on AdS/QCD, providing insights into nucleon structure and spin dynamics.

Contribution

It introduces a novel calculation of flavor-dependent gravitational form factors using a light front wave function from the soft-wall AdS/QCD model, linking form factors to the transverse spin sum rule.

Findings

Calculated flavor-dependent form factors $A(Q^2)$, $B(Q^2)$, and $ar{C}(Q^2)$.

Demonstrated the role of $ar{C}$ in the intrinsic spin sum rule.

Analyzed longitudinal momentum densities in impact parameter space.

Abstract

The gravitational form factors are related to the matrix elements of the energy-momentum tensor $T^{\mu\nu}$. Using the light front wave functions of the scalar quark-diquark model for nucleon predicted by the soft-wall AdS/QCD, we calculate the flavor dependent $A(Q^2)$, $B(Q^2)$ and $\bar{C}(Q^2)$ form factors. We also present all the matrix element of the energy-momentum tensor in a transversely polarized state. Further, we evaluate the matrix element of Pauli-Lubanski operator in this model and show that the intrinsic spin sum rule involves the form factor $\bar{C}$. The longitudinal momentum densities in the transverse impact parameter space are also discussed for both unpolarized and transversely polarized nucleons.