# QM 2011 - XXII International Conference on Ultrarelativistic Nucleus-Nucleus Collisions

May 22 – 28, 2011
Centre Bonlieu
Europe/Zurich timezone

## Event-by-event mean $p_{T}$ fluctuations in pp and PbPb collisions measured by the ALICE experiment at the LHC

May 24, 2011, 4:20 PM
20m
Rotonde de l'Europe (Imperial Palace)

### Rotonde de l'Europe

#### Imperial Palace

Allée Impérial 74000 Annecy, France Tél. : +33 4 50 09 30 00
Parallel Correlations and fluctuations

### Speaker

Stefan Heckel (Johann-Wolfgang-Goethe Univ.)

### Description

Non-statistical event-by-event fluctuations of the mean transverse momentum of charged particles in pp and Pb--Pb collisions are studied using the ALICE experiment at the LHC. The analysis is performed at $|\eta| < 0.8$ and $0.15 < p_{T} < 2$~GeV/c. Multiplicity dependent results are obtained for pp collisions at $\sqrt{s}$~=~0.9, 2.76 and 7~TeV. Pb--Pb collisions at $\sqrt{s_{NN}}$~=~2.76~TeV are analysed in intervals of multiplicity and centrality, the latter in bins of 5\%. Little collision energy dependence is observed in pp collisions. The data indicate a common scaling behaviour with event multiplicity from pp to semi-central Pb--Pb collisions. In central Pb--Pb collisions, the results deviate from this trend, exhibiting a significant reduction of the fluctuation strength. The results are compared to measurements in Au--Au collisions at lower collision energies and to Monte Carlo simulations with PYTHIA and HIJING.

### Primary author

Stefan Heckel (Johann-Wolfgang-Goethe Univ.)

 Slides