# DPF 2011

8-13 August 2011
Rhode Island Convention Center
US/Eastern timezone

## Untriggered di-hadron correlations in Pb-Pb collisions at $\sqrt{s_{NN}} =$ 2.76 TeV

10 Aug 2011, 14:50
25m
552 B (Rhode Island Convention Center)

### 552 B

#### Rhode Island Convention Center

Parallel contribution Heavy Ion Physics/Hot and Dense QCD

### Speaker

Dr Anthony Robert Timmins (University of Houston)

### Description

We present measurements of untriggered di-hadron correlations as a function of centrality in Pb-Pb \sNN collisions, for charged hadrons with $p_{T} > 0.15$ GeV$/c$. These measurements provide a map of the bulk correlation structures in heavy-ion collisions. Contributions to these structures may come from jets, initial density fluctuations, elliptic flow, resonances, and/or momentum conservation. We decompose the measured correlation functions via a multi-parameter fit in order to extract the nearside Gaussian, the longer range $\Delta \eta$ correlation often referred to as the soft ridge. The effect of including higher harmonics ($v_{3}$ and $v_{4}$) in this procedure will be discussed. We investigate how the nearside Gaussian scales with the number of binary collisions. Finally, we show the charge dependence of the nearside Gaussian.

### Primary author

Dr Anthony Robert Timmins (University of Houston)

### Presentation Materials

 DPFTimminsv2.pdf DPFTimminsv2.ppt