Precise simulation of the initial-state QCD activity associated with $Z$-boson production in hadron collisions

Abstract

The ${\varphi }_{\eta }^{\ast }$ distribution of the $Z/{\gamma }^{\ast }\to {\ell }^{+}{\ell }^{-}$ production in hadron collisions is simulated using a leading-order event generator, GR@PPA. The initial-state parton shower, which simulates the multiple QCD-radiation effects in the initial state, plays the dominant role in this simulation. The simulation in the default setting agrees with the high-statistics measurement by ATLAS at LHC with the precision at the level of 5%. The observed systematic deviation, which can be attributed to the effects of ignored higher-order contributions, can be reduced by adjusting the arbitrary energy scales in the simulation. The agreement at the level of 1% can be achieved over a very wide range without introducing any modification in the implemented naive leading-logarithmic parton shower.

9 pages, 4 figures

References in corpus (6)

• Parton Distributions for LO Generators
• Production of Drell--Yan lepton pairs in hadron collisions: transverse-momentum resummation at next-to-next-to-leading logarithmic accuracy
• Optimisation of variables for studying dilepton transverse momentum distributions at hadron colliders
• Measurement of angular correlations in Drell-Yan lepton pairs to probe Z/gamma* boson transverse momentum at sqrt(s)=7 TeV with the ATLAS detector
• GR@PPA 2.7 event generator for $pp$/$p\bar{p}$ collisions
• Initial-state parton shower kinematics for NLO event generators

Cited by in corpus (2)

• Consistent simulation of direct-photon production in hadron collisions including associated two-jet production
• Consistent simulation of non-resonant diphoton production in hadron collisions including associated jet production up to two jets