Speaker
Dr
Prabhat Pujahari
(Wayne State University)
Description
Two-particle correlations provide information about particle production mechanisms in heavy-ion collisions. We report on the study of two particle transverse momentum correlations ($\Delta p_{\rm T} \Delta p_{\rm T}$) in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 2.76 TeV and in p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV measured with the ALICE detector at LHC. Unlike the number correlation functions, $\Delta p_{\rm T} \Delta p_{\rm T}$ measures transverse momentum correlations between particle pairs. The $p_{\rm T}$ dependence
of this correlation measure may make it amenable to probe the fluctuations in temperature,
average momentum, flow, hardness of spectrum and hardness of correlations (jet vs non-jets).
Correlation functions for $++$, $+-$, and $--$ charged particle pairs as a function of pair
azimuthal and pseudo-rapidity separation are measured. We study their evolution with collision centrality and particle multiplicity per event. We find that $\Delta p_{\rm T} \Delta p_{\rm T}$ correlation shapes exhibit a strong centrality dependence in Pb-Pb collisions and multiplicity dependence in p-Pb collisions. The correlation function is everywhere positive, indicating that both particles from a pair are more likely to have momentum above or below the average transverse momentum in an event ensemble. We further study the Fourier decomposition of the correlation function dependence on $\Delta \varphi$ as a function of $\Delta \eta$.
Author
Dr
Prabhat Pujahari
(Wayne State University)
