Multiple Parton Interactions in Z+jets production at the LHC. A comparison of factorized and non--factorized double parton distribution functions

TL;DR

This paper investigates the impact of Multiple Parton Interactions on Z+jets production at the LHC, comparing correlated and factorized double parton distribution functions to assess measurement feasibility and dominant event characteristics.

Contribution

It provides a comparative analysis of correlated versus factorized double parton distribution functions in modeling MPI effects in Z+jets production at the LHC.

Findings

MPI contribution measurable with 1 fb^{-1} at 7 TeV

Z+2 jets production potentially easier to observe than gamma+3 jets

MPI cross section dominated by soft events with balanced jets

Abstract

We examine the contribution of Multiple Parton Interactions to Z+n-jets production at the LHC, n=2,3,4, where the Z boson is assumed to decay leptonically. We compare the results obtained with the correlated GS09 double parton distribution function with those obtained with two instances of fully factorized single parton distribution functions: MSTW2008LO and CTEQ6LO. It appears quite feasible to measure the MPI contribution to Z+2/3/4 jets already in the first phase of the LHC with a total luminosity of one inverse femtobarn at 7 TeV. If as expected the trigger threshold for single photons is around 80 GeV, Z+2-jets production may well turn out to be more easily observable than the gamma+3-jets channel. The MPI cross section is dominated by relatively soft events with two jets balancing in transverse momentum.