Sensitivity Studies of Color Re-connection in Top Underlying Event Measurements

Abstract

Sensitivities studies of color re-connection (CR) effects in tt underlying events were performed for the fully leptonic and fully hadronic final states (FLFS and FHFS respectively) events. Effects of CR parameters were studied. Differences between predictions with and without CR were observed of ~ 8-15% for the investigated observables, charged particle multiplicity, charged particle average transverse momentum and transverse momentum sum. For different color re-connection models, effects around 5% were observed. No differences for predictions with and without CR between FLFS and FHFS were found for all the observables. This study shows the sensitivity of the UE observables to CR effects and may help to decrease the uncertainties due to the UE simulation in top mass measurements.