Eur. Phys. J. C (2014) 74: 3199
https://doi.org/10.1140/epjc/s10052-014-3199-2

Regular Article - Theoretical Physics

Partonic transverse momenta in soft collisions

¹ Institute for Particle Physics Phenomenology, University of Durham, Durham, DH1 3LE, UK
² Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina, St. Petersburg, 188300, Russia

^* e-mail: a.d.martin@durham.ac.uk

Received: 2 October 2014
Accepted: 22 November 2014
Published online: 12 December 2014

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 $$\langle k_t\rangle $$ 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.