Colored-hadron distribution in hadron scattering in SU(2) lattice QCD

TL;DR

This study investigates colored-diquark distributions in SU(2) lattice QCD hadron scattering, revealing short-range enhancements due to one-gluon exchange processes and distinguishing genuine color exchange effects from trivial components.

Contribution

It provides the first lattice QCD analysis of colored-diquark distributions in hadron scattering, highlighting the role of one-gluon exchange in short-range color excitations.

Findings

Colored-diquark components are enhanced at short distances (≤0.2 fm).

Tails of distributions exhibit single-exponential damping.

Short-range enhancement is confirmed as genuine OGE-origin color excitation.

Abstract

In color SU(2) lattice QCD, we investigate colored-diquark distributions in two-hadron scatterings by means of Bethe-Salpeter amplitudes on the lattice. With colored-diquark operators in the Coulomb gauge, we measure components of two colored diquarks realized as intermediate states via one gluon exchange (OGE) processes in hadron scattering. From the colored-diquark distributions, we estimate the dominant range of gluon (color) exchanges between closely located two hadrons. We find that the colored-diquark components are enhanced at the short range ($\leq$0.2 fm) and their tails show the single-exponential damping. In order to distinguish the genuine colored-diquark components originating in the color exchange processes from trivial colored two-quark components contained in two color-singlet hadrons as a result of simple transformation of hadronic basis, we repeat the analyses on the artificially constructed gauge fields, where low- and high-momentum gluon components are decoupled and only restricted pair of quarks can share and exchange low-momentum gluons. We observe qualitatively the same behaviors and confirm that the short-range enhancement of the colored-diquark distributions is the genuine OGE-origin color excitation in hadron scattering.