Next-to-Leading Order Cross Sections for Tagged Reactions

TL;DR

The paper develops a generalized next-to-leading order framework by extending the phase space slicing method to handle tagged final-state hadrons via fragmentation (and tagging) functions and to accommodate massive quarks. It introduces tagging functions to couple parton-level NLO calculations with fragmentation, and derives heavy-quark soft and collinear contributions, including massive-splitting functions and scheme-dependent counterterms. The methodology enables fully differential, Monte Carlo-friendly predictions for hadron-tagged reactions and lays the groundwork for a variable flavor number scheme that resums ln(Q/m) terms through fragmentation-function evolution. This work provides a comprehensive formalism for incorporating fragmentation and heavy-quark mass effects into NLO cross sections, with practical implications for precision collider phenomenology.

Abstract

We extend the phase space slicing method of Giele, Glover and Kosower for performing next-to-leading order jet cross section calculations in two important ways: we show how to include fragmentation functions and how to include massive particles. These extensions allow the application of this method to not just jet cross sections but also to cross sections in which a particular final state particle, including a $D$ or $B$-meson, is tagged.