Measurement of the shape of the boson transverse momentum distribution in ppbar -> Z/gamma* -> ee+X events produced at sqrt{s}=1.96 TeV

TL;DR

This paper measures the transverse momentum distribution of Z/gamma* bosons in proton-antiproton collisions at 1.96 TeV, comparing results with theoretical predictions and extracting non-perturbative parameters.

Contribution

It provides the first detailed measurement of the boson qT distribution at Tevatron energies and tests resummation models against experimental data.

Findings

Data agree with resummation at low qT

Data exceed perturbative QCD at qT>30 GeV/c

Extracted non-perturbative parameter g2

Abstract

We present a measurement of the shape of the Z/gamma* boson transverse momentum (qT) distribution in ppbar -> Z/gamma* -> ee+X events at a center-of-mass energy of 1.96 TeV using 0.98 fb-1 of data collected with the D0 detector at the Fermilab Tevatron collider. The data are found to be consistent with the resummation prediction at low qT, but above the perturbative QCD calculation in the region of qT>30 GeV/c. Using events with qT<30 GeV/c, we extract the value of g2, one of the non-perturbative parameters for the resummation calculation. Data at large boson rapidity y are compared with the prediction of resummation and with alternative models that employ a resummed form factor with modifications in the small Bjorken x region of the proton wave function.