Partonic transverse momenta in soft collisions

TL;DR

This paper models the energy-dependent growth of partonic transverse momenta in high-energy collisions using BFKL diffusion, and proposes experimental methods to measure the transverse momentum distribution via heavy meson spectra.

Contribution

It introduces a BFKL-based model incorporating low k_t absorption to estimate transverse momentum growth and suggests experimental approaches using heavy meson spectra.

Findings

Growth of <k_t> with energy demonstrated in the model

Model predicts measurable effects in collider secondary particle distributions

Proposed experimental method to evaluate parton transverse momentum distribution

Abstract

The partonic transverse momentum, k_t distribution plays a crucial role in driving high-energy hadron interactions. If k_t is limited we have old fashioned Regge Theory. If k_t increases with energy the interaction may be described by perturbative QCD. We use BFKL diffusion in ln k_t, supplemented by a stronger absorption of low k_t partons, to estimate the growth of the mean transverse momenta <k_t> with energy. This growth reveals itself in the distribution of secondaries produced at the collider energies. We present a simple, BFKL-based, model to demonstrate the possible size of the effect. Moreover, we propose a way to evaluate experimentally the shape of the parton transverse momenta distribution by studying the spectra of the (D or B) mesons which contain one heavy quark.