DPF 2011

Azimuthal decorrelations and multiple parton interactions in Undefined control sequence \boldsymbol and Undefined control sequence \boldsymbol events in Undefined control sequence \boldsymbol collisions at Undefined control sequence \boldsymbol~TeV

12 Aug 2011, 08:00

20m

551 A (Rhode Island Convention Center)

Parallel contribution Perturbative and non-Perturbative QCD Perturbative and non-Perturbative QCD

Speaker

Dmitry Bandurin (Kansas State University)

Description

Samples of inclusive $\gamma +2\mathrm{j}\mathrm{e}\mathrm{t}$ and $\gamma +3\mathrm{j}\mathrm{e}\mathrm{t}$ events collected by the D0 experiment with an integrated luminosity of about 1~fb${}^{-1}$ in $p\overline{p}$ collisions at $\sqrt{s}=1.96$ TeV are used to measure cross sections as a function of the angle in the plane transverse to the beam direction between the transverse momentum ($p_T$) of the $\gamma +$leading jet system (jets are ordered in $p_T$) and $p_T$ of the other jet for $\gamma +2\mathrm{j}\mathrm{e}\mathrm{t}$, or $p_T$ sum of the two other jets for $\gamma +3\mathrm{j}\mathrm{e}\mathrm{t}$ events. The results are compared to different models of multiple parton interactions (MPI) in the {\sc pythia} and {\sc sherpa} Monte Carlo (MC) generators. The data indicate a contribution from events with double parton (DP) interactions and are well described by predictions provided by the {\sc pythia} MPI models with $p_T$-ordered showers and by {\sc sherpa} with the default MPI model. The $\gamma +2\mathrm{j}\mathrm{e}\mathrm{t}$ data are also used to determine the fraction of events with DP interactions as a function of the azimuthal angle and as a function of the second jet $p_T$.

Presentation materials

Slides

bandurin_DPF_DP.pdf