Measurement of Dijet Azimuthal Decorrelations at Central Rapidities in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{TeV}$

Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in $p\overline{p}$ collisions at a center-of-mass energy $\sqrt{s}=1.96\mathrm{TeV}$. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of $150{\mathrm{pb}}^{-1}$. Azimuthal correlations are stronger at larger transverse momenta. These are well described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where contributions with low transverse momentum are significant.

Figure 1

The $\Delta {\varphi }_{\mathrm{dijet}}$ distributions in four regions of $p_T^{\max }$. Data and predictions with $p_T^{\max }>100\mathrm{GeV}$ are scaled by successive factors of 20 for purposes of presentation. The solid (dashed) lines show the NLO (LO) PQCD predictions.

Figure 2

Ratios of data to the NLO PQCD calculation for different regions of $p_T^{\max }$. Theoretical uncertainties due to variation of ${\mu }_r$ and ${\mu }_f$ are shown as the shaded regions; the uncertainty due to the PDFs is indicated by the solid lines. The points at large $\Delta {\varphi }_{\mathrm{dijet}}$ are excluded because the calculation is not stable near the divergence at $\pi$.

Figure 3

The $\Delta {\varphi }_{\mathrm{dijet}}$ distributions in different $p_T^{\max }$ ranges. Results from herwig and pythia are overlaid on the data. Data and predictions with $p_T^{\max }>100\mathrm{GeV}$ are scaled by successive factors of 20 for purposes of presentation.