Measurement of the transverse momentum distribution of Z bosons decaying to dimuons in pp collisions at center-of-mass energy of 8 TeV

Abstract

The measurement of the transverse momentum distribution of the dimuon system, produced in the Drell–Yan process is reported for the Z boson mass range of 60 to 120 GeV/c2 . The results are obtained using a data sample of proton-proton collisions at a center-of-mass energy of 8 TeV, collected by the CMS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 18.4pb-1 . The measured transverse momentum distribution is compared to the most commonly used event generators in the CMS experiment such as Powheg+Pythia, MadGraph. Furthermore, the transverse momentum distribution is compared with several tunes of Pythia for the underlying event in the low transverse momentum regime and the most accurate theoretical calculation at Next-to-Next-to Leading Order (NNLO) from FEWZ package is used in the high transverse momentum regime. It is concluded that Pythia generator with Z2star and Madgraph describe the data well at low qT and high qT regimes, respectively. An overall agreement with the predictions of the standard model is observed.