Constituent quark and diquark properties from small angle proton-proton elastic scattering at high energies

TL;DR

This paper models high-energy elastic proton-proton scattering assuming a quark-diquark structure of the nucleon, successfully fitting data and revealing size differences between constituents.

Contribution

It introduces a quark-diquark model for proton structure that explains elastic scattering data at high energies, providing insights into constituent sizes.

Findings

Quark is relatively small in size.

Diquark is comparable in size to the proton.

Model fits data well up to -t = 2 GeV^2/c.

Abstract

Small momentum transfer elastic proton-proton cross-section at high energies is calculated assuming the nucleon composed of two constituents - a quark and a diquark. A comparison to data (described very well up to -t = 2 GeV^2/c) allows to determine some properties of the constituents. While quark turns out fairly small, the diquark appears to be rather large, comparable to the size of the proton.