HAL : in2p3-00158104, version 1
 arXiv : nucl-ex/0703040
 Physics Letters B 655 (2007) 104-113
 Energy dependence of $\pi^{\pm}$, $p$ and $\bar{p}$ transverse momentum spectra for Au+Au collisions at $\sqrt{s_{NN}}$=62.4 and 200 GeV
 STAR Collaboration(s)
 (2007)
 We study the energy dependence of the transverse momentum $(p_T)$ spectra for charged pions, protons and anti-protons for Au+Au collisions at $\sqrt{S_{NN}$=62.4 and 200 GeV. Data are presented at mid-rapidity (|y|<0.5) for $0.2\le p_T\le12$ GeV/c . In the intermediate $p_T$ region $(0.2\le p_T\le 6 GeV/c$ ), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher $p_T (p_T\ge 7 GeV/c)$ the modification is similar for both energies. The p/$\pi+$ and $\bar{p} \pi^-$ ratios for central collisions at $\sqrt{S_{NN}}$ =62.4 GeV/c peak at $p_t \appeq 2 Gev/c$ . In the $p_T$ range where recombination is expected to dominate, the p/$\pi + ratios at 62.4 GeV are larger than at 200 GeV, while the$\bar{p}$/$\pi _-} ratios are smaller. For $p_T$, the $\bar{p} /\pi_-$ ratios at the two beam energies are independent of $p_T$ and centrality indicating that the dependence of the $\bar{p}:\pi_-$ ratio on $p_T$ does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Mot(s)-clé(s) : Particle production – Recombination – Fragmentation – Jet quenching – Nuclear modification factor – Particle ratios
 Lien vers le texte intégral : http://fr.arXiv.org/abs/nucl-ex/0703040
 in2p3-00158104, version 1 http://hal.in2p3.fr/in2p3-00158104 oai:hal.in2p3.fr:in2p3-00158104 Contributeur : Yvette Heyd <> Soumis le : Jeudi 28 Juin 2007, 10:04:42 Dernière modification le : Mardi 4 Décembre 2007, 09:42:38