Correlations Between Jets And Charged Particles In Pbpb And Pp Collisions At Sqrts Mathrmnn

Correlations Between Jets and Charged Particles in PbPb and Pp Collisions at $ \sqrt{s_{\mathrm{NN}}}

In this study, the quark-gluon plasma is studied via medium-induced changes to correlations between jets and charged particles in PbPb collisions compared to pp reference data. This analysis uses data sets from PbPb and pp collisions with integrated luminosities of 166 inverse microbarns and 5.3 inverse picobarns, respectively, collected at $ \sqrt{s_{\mathrm{NN}}}=2.76 $ TeV. The angular distributions of charged particles are studied as a function of relative pseudorapidity ([Delta][eta]) and relative azimuthal angle ([Delta][Phi]) with respect to reconstructed jet directions. Charged particles are correlated with all jets with transverse momentum (pT) above 120 GeV, and with the leading and subleading jets (the highest and second-highest in pT, respectively) in a selection of back-to-back dijet events. Modifications in PbPb data relative to pp reference data are characterized as a function of PbPb collision centrality and charged particle pT. A centrality-dependent excess of low-pT particles is present for all jets studied, and is most pronounced in the most central events. This excess of low-pT particles follows a Gaussian-like distribution around the jet axis, and extends to large relative angles of [Delta][eta] ≈ 1 and [Delta][Phi] ≈ 1.

Correlations Between Jets and Charged Particles in PbPb and Pp Collisions at √sNN

Decomposing Transverse Momentum Balance Contributions for Quenched Jets in PbPb Collisions at $ \sqrt{s_{\mathrm{N}\;\mathrm{N}}}

Interactions between jets and the quark-gluon plasma produced in heavy ion collisions are studied via the angular distributions of summed charged-particle transverse momenta (pT) with respect to both the leading and subleading jet axes in high-pt dijet events. The contributions of charged particles in different momentum ranges to the overall event pt balance are decomposed into short-range jet peaks and a long-range azimuthal asymmetry in charged-particle pT. The results for PbPb collisions are compared to those in pp collisions using data collected in 2011 and 2013, at collision energy $ \sqrt{s_{\mathrm{N}\;\mathrm{N}}}=2.76 $ TeV with integrated luminosities of 166 [mu]b-1 and 5.3 pb-1, respectively, by the CMS experiment at the LHC. Furthermore, measurements are presented as functions of PbPb collision centrality, charged-particle pt, relative azimuth, and radial distance from the jet axis for balanced and unbalanced dijets.