We present a measurement of the shape of the $Z/{\ensuremath{\gamma}}^{*}$ boson transverse momentum (${q}_{T}$) distribution in $p\overline{p}\ensuremath{\rightarrow}Z/{\ensuremath{\gamma}}^{*}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}+X$ events at a center-of-mass energy of 1.96 TeV using $0.98\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ 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 ${q}_{T}$, but above the perturbative QCD calculation in the region of ${q}_{T}>30\text{ }\text{ }\mathrm{GeV}/c$. Using events with ${q}_{T}<30\text{ }\text{ }\mathrm{GeV}/c$, we extract the value of ${g}_{2}$, one of the nonperturbative 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.
Tópico:
Particle physics theoretical and experimental studies