208 articles – 1940 Notices  [english version]
 HAL : in2p3-00666970, version 1
 Physical Review C 85 (2012) 014903
 System size and energy dependence of near-side di-hadron correlations
 STAR Collaboration(s)
 (2012)
 Two-particle azimuthal ($\Delta\phi$) and pseudorapidity ($\Delta\eta$) correlations using a trigger particle with large transverse momentum ($p_T$) in $d$+Au, Cu+Cu and Au+Au collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV and 200~GeV from the STAR experiment at RHIC are presented. The \ns correlation is separated into a jet-like component, narrow in both $\Delta\phi$ and $\Delta\eta$, and the ridge, narrow in $\Delta\phi$ but broad in $\Delta\eta$. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated $p_T$. The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at $\sqrt{s_{{NN}}}$ = 200 GeV, is also found in Cu+Cu collisions and in collisions at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV, but is found to be substantially smaller at $\sqrt{s_{{NN}}}$ =\xspace 62.4 GeV than at $\sqrt{s_{{NN}}}$ = 200 GeV for the same average number of participants ($\langle N_{\mathrm{part}}\rangle$). Measurements of the ridge are compared to models.
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://inspirehep.net/record/943192
 in2p3-00666970, version 1 http://hal.in2p3.fr/in2p3-00666970 oai:hal.in2p3.fr:in2p3-00666970 Contributeur : Dominique Girod <> Soumis le : Lundi 6 Février 2012, 15:44:54 Dernière modification le : Lundi 6 Février 2012, 15:55:52