# Hard Probes 2012

27 May 2012 to 1 June 2012
Cagliari - Italy
Europe/Rome timezone

## Dijet transverse momentum imbalance, fragmentation functions and jet-track correlations in PbPb collisions at sqrt(s)=2.76TeV with CMS

31 May 2012, 14:00
20m
Plenary room T1 A+B (Cagliari - Italy)

### Plenary room T1 A+B

#### Cagliari - Italy

T-Hotel Conference Centre
Oral presentation

### Speaker

Yetkin Yilmaz (MIT)

### Description

Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by an excess of low transverse momentum particles over a large range in the hemisphere of the second most energetic, away-side jet. Jet fragmentation functions measured in PbPb collisions will also be presented, constructed with charged particle tracks with transverse momenta pT > 4 GeV/c in a sample of dijet events. Both the leading and subleading jets show a fragmentation pattern similar to that of a jet in vacuum, as seen by comparisons to pp data at 2.76 TeV.

 Slides