Inclusive ${b+Z}$, ${Z\rightarrow \mu^+\mu^-, e^+e^-}$ production at CMS

Abstract

The production of Z bosons in association with at least one b-jet and Z decaying into muons or electrons is studied. This analysis is done by using proton–proton collisions delivered by the Large Hadron Collider (LHC) at a centre of mass energy of 7 TeV and with data recorded by the CMS detector in 2010, representing an integrated luminosity of 36 pb^− 1. A final state of two well-identified muons or electrons and at least one b-tagged jet are required in order to perform this study. The event yields and shapes of kinematic variables are compared with Monte Carlo predictions from MADGRAPH. The ratio σ(Z + b) /σ(Z + j) is found to be 0.054±0.016 (0.046 ±0.014) in the data for the Z→ee (Z→μμ) selection, compared to 0.043±0.005 (0.047±0.005) estimated from NLO theory predictions.