Energy dependence of pi, p and pbar transverse momentum spectra for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV
We study the energy dependence of the transverse momentum (pT) spectra for charged pions, protons and anti-protons for Au+Au collisions at sqrt sNN = 62.4 and 200 GeV. Data are presented at mid-rapidity (lbar y rbar< 0.5) for 0.2< pT< 12 GeV/c. In the intermediate pT region (2< pT< 6 GeV/c), the nuclear modification factor is higher at 62.4 GeV than at 200 GeV, while at higher pT (pT> 7 GeV/c) the modification is similar for both energies. The p/pi+ and pbar/pi- ratios for central collisions at sqrt sNN = 62.4 GeV peak at pT _~;; 2 GeV/c. In the pT range where recombination is expected to dominate, the p/pi+ ratios at 62.4 GeV are larger than at 200 GeV, while the pbar/pi- ratios are smaller. For pT> 2 GeV/c, the pbar/pi- ratios at the two beam energies are independent of pT and centrality indicating that the dependence of the pbar/pi- ratio on pT does not change between 62.4 and 200 GeV. These findings challenge various models incorporating jet quenching and/or constituent quark coalescence.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Nuclear Science Division
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 936577
- Report Number(s):
- LBNL-824E; TRN: US0805542
- Journal Information:
- Physical Letters B, Journal Name: Physical Letters B
- Country of Publication:
- United States
- Language:
- English
Similar Records
K*0 production in Cu+Cu and Au+Au collisions at sqrt sNN = 62.4 GeV and 200 GeV
K*{sup 0} production in Cu + Cu and Au + Au collisions at {radical}(s{sub NN})=62.4 GeV and 200 GeV