Near-side jet peak broadening in Pb–Pb collisions atsNN=2.76 TeV

Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76  TeV.

The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8  GeV/c). A combined fit of the n...

Splitting function in pp and PbPb collisions at 5.02 TeV

A measurement of the splitting function in pp and PbPb collisions at a center of mass energy of 5.02 TeV per nucleon pair is presented. The virtuality evolution of partons traversing the hot QCD medium created in a heavy ion collision is potentially modified due to interactions with the color charges of the medium. This measurement probes this phenomenon by measuring the generalized fragmentati...

Measurement of higher-order harmonic azimuthal anisotropy in PbPb collisions at √ sNN = 2.76 TeV

Measurements are presented by the CMS Collaboration at the Large Hadron Collider (LHC) of the higher-order harmonic coefficients that describe the azimuthal anisotropy of charged particles emitted in √ sNN = 2.76 TeV PbPb collisions. Expressed in terms of the Fourier components of the azimuthal distribution, the n = 3–6 harmonic coefficients are presented for charged particles as a function of ...

Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions atâ‹ısNN=2.76 TeV

The anisotropy of the azimuthal distributions of charged particles produced in √ s NN = 2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, v 2 , defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two-and four-particle cumulants, and Lee-Yang zeros. The aniso...

Measurement of b-jet shapes in inclusive jet production in pp collisions at s=1.96 TeV