Gluon Gravitational Form Factors at Large Momentum Transfer

TL;DR

This paper uses perturbative QCD to analyze the gluonic gravitational form factors of protons and pions at high momentum transfer, deriving explicit formulas and revealing their asymptotic behaviors.

Contribution

It provides the first explicit factorization formulas for gluonic GFFs at large momentum transfer and details their power-law behaviors, enhancing understanding of hadron internal structure.

Findings

GFFs for pion scale as 1/(-t) at large t

Proton GFFs scale as 1/(-t)^2 and 1/(-t)^3 with logarithmic corrections

Results offer insights into hadron pressure distributions

Abstract

We perform a perturbative QCD analysis of the gluonic gravitational form factors (GFFs) of the proton and pion at large momentum transfer. We derive the explicit factorization formula of the GFFs in terms of the distribution amplitudes of hadrons. At the leading power, we find that $A_g^\pi(t)=C_g^\pi(t)\sim 1/(-t)$ for pion, $A_g^p(t)\sim 1/(-t)^2$ and $C_g^p(t)\sim \ln^2(-t/\Lambda^2)/(-t)^3$ for proton, respectively, where $t$ is the momentum transfer and $\Lambda$ a non-perturbative scale to regulate the endpoint singularity in $C_g^p$ calculation. Our results provide a unique perspective of the momentum dependence of the GFFs and will help to improve our understanding of the internal pressure distributions of hadrons.