Beauty production using D* + mu and mu+ mu- correlations at ZEUS

Abstract

Events with observed D* and/or muons in the final state were used to indicate the presence of beauty quark production and to study the correlations between the particles coming from the same or different B-hadrons. The Next-to-Leading Order (NLO) theoretical predictions for such processes were often available only at parton level. A method to calculate visible level cross sections at NLO, based on an interface of the FMNR program to PYTHIA 6.2, is applied. It uses the NLO description at b-quark level provided by FMNR applying a statistical reduction procedure (REDSTAT) that allows the link to PYTHIA, from where the description of the B-hadron decay chain is obtained. Comparisons of the data and NLO cross sections at visible and b-quark level were found to be consistent and equivalent.