On the role of heavy flavor parton distributions at high energy colliders

TL;DR

This paper compares fixed and variable flavor number schemes for parton distributions at high energy colliders, showing their predictions are compatible within 10-20% when the invariant mass exceeds heavy quark masses.

Contribution

It introduces radiatively generated VFNS parton distributions based on recent LO and NLO FFNS distributions, analyzing their impact on heavy particle production at colliders.

Findings

VFNS and FFNS predictions agree within 10-20% at LHC energies.

Heavy quark flavors can be treated as massless partons at high invariant masses.

The study supports the use of VFNS for high-energy collider predictions.

Abstract

We compare `fixed flavor number scheme' (FFNS) and `variable flavor number scheme' (VFNS) parton model predictions at high energy colliders. Based on our recent LO- and NLO-FFNS dynamical parton distributions, we generate radiatively two sets of VFNS parton distributions where also the heavy quark flavors h=c,b,t are considered as massless partons within the nucleon. By studying the role of these distributions in the production of heavy particles (h\bar{h}, t\bar{b}, hW^{+-}, Higgs--bosons, etc.) at high energy ep, p\bar{p} and pp colliders, we show that the VFNS predictions are compatible with the FFNS ones (to within about 10-20% at LHC, depending on the process) when the invariant mass of the produced system far exceeds the mass of the participating heavy quark flavor.