Final state interactions in single- and multi-particle inclusive cross sections for hadronic collisions

TL;DR

This paper investigates how low momentum transfer interactions affect inclusive cross sections in hadronic collisions, revealing their suppression in single-particle cases but significance in multi-particle scenarios, with implications for nonperturbative corrections.

Contribution

It provides a detailed analysis of the role of soft final-state interactions in both single- and multi-particle inclusive cross sections, highlighting their power suppression or significance.

Findings

Soft interactions are power suppressed in single-particle inclusive cross sections.

In multi-particle cases, soft interactions produce leading power corrections.

Nonperturbative corrections are suppressed by powers of b3/4p'_T.

Abstract

We study the role of low momentum transfer (soft) interactions between high-transverse momentum heavy particles and beam remnants (spectators) in hadronic collisions. Such final-state interactions are power suppressed for single-particle inclusive cross sections whenever that particle is accompanied by a recoiling high-p_T partner whose momentum is not fixed. An example is the single-top inclusive cross section in top pair production. Final-state soft interactions in multi-particle inclusive cross sections, including transverse momentum distributions, however, produce leading power corrections in the absence of hard recoiling radiation. Nonperturbative corrections due to scattering from spectators are generically suppressed by powers of \Lambda/p'_T, where \Lambda is a hadronic scale, and p'_T is the largest transverse momentum of radiation recoiling against the particles whose momenta are observed.