Measurement of transverse momentum relative to dijet systems in PbPb and pp collisions at $ \sqrt{s_{\mathrm{NN}}}=2.76 $ TeV

An analysis of dijet events in PbPb and pp collisions is performed to explore the properties of energy loss by partons traveling in a quark-gluon plasma. Data are collected at a nucleon-nucleon center-of-mass energy of 2.76 TeV at the LHC. The distribution of transverse momentum (p$_{T}$) surrounding dijet systems is measured by selecting charged particles in different ranges of p$_{T}$ and at different angular cones of pseudorapidity and azimuth. The measurement is performed as a function of centrality of the PbPb collisions, the p$_{T}$ asymmetry of the jets in the dijet pair, and the distance parameter R used in the anti-k$_{T}$ jet clustering algorithm. In events with unbalanced dijets, PbPb collisions show an enhanced multiplicity in the hemisphere of the subleading jet, with the p$_{T}$ imbalance compensated by an excess of low-p$_{T}$ particles at large angles from the jet axes.