Evidences for two scales in hadrons

TL;DR

The paper proposes that hadrons contain two distinct scales, with gluons confined to small regions, explaining various high-energy collision phenomena such as suppressed diffractive radiation and slow cross-section growth.

Contribution

It introduces the concept of two scales within hadrons, providing a unified explanation for multiple experimental observations in high-energy hadronic collisions.

Findings

Gluons are confined within small spots occupying about 10% of hadron area.

The two-scale model explains slow energy dependence of total cross sections.

It accounts for the suppression of diffractive gluon radiation and weak shadowing effects.

Abstract

Some unusual features observed in hadronic collisions at high energies can be understood assuming that gluons in hadrons are located within small spots occupying only about 10% of the hadron's area. Such a conjecture about the presence of two scales in hadrons helps to explain: why diffractive gluon radiation so much suppressed; why the triple-Pomeron coupling shows no t-dependence; why total hadronic cross sections rise with energy so slowly; why diffraction cone shrinks so slowly, and why $\alpha^\prime_P\ll\alpha^\prime_R$; why the transition from hard to soft regimes in the structure functions occurs at rather large $Q^2$; why the observed Cronin effect at collider energies is so weak; why hard reactions sensitive to primordial parton motion (direct photon, Drell-Yan dileptons, heavy flavors, back-to-back di-hadrons, seagull effect, etc.) demand such a large transverse momenta of the projectile partons, which is not explained by NLO calculations; why the onset of nuclear shadowing for gluons is so much delayed compared to quarks, and why shadowing is so weak.