| The collision of high energy heavy ions is the most promising laboratory for the study of nuclear matter at high energy density and for creation of the Quark-Gluon Plasma. A new era in this field began with the operation and first collisions of Au nuclei in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory during 2000. This work concentrates on measurement of global hadronic observables in Au + Au interactions at a centre-of-mass energy of = 130 GeV, which mainly address conditions in the final state of the collision. The minimum bias multiplicity distribution, the transverse momentum (p⊥), and pseudorapidity (η) distributions for charged hadrons (h−, h+) are presented. Results on identified π− transverse mass ( m⊥) and rapidity (y) distributions are also discussed. The data were taken with the STAR detector with emphasis on particles near mid-rapidity.; We find that the multiplicity density at mid-rapidity for the 5% most central interactions is = 280 ± 1stat ± 20syst, an increase per participant of 38% relative to pp¯ collisions at similar energy. The mean transverse momentum is 0.508 ± 0.012 GeV/c and is larger than in Pb + Pb collisions at lower energies. The scaling of the h− yield per participant nucleon pair, obtained via a ratio of Au + Au to pp¯ p ⊥ distributions, is a strong function of p ⊥. The pseudorapidity distribution is almost constant within |η| < 1. The π− rapidity distribution is also flat around mid-rapidity in the region |y| < 0.8, with a yield of pions for central collisions of = 287 ± 1stat ± 21syst. However, the slope of the m⊥ distributions is not the same for different rapidity bins, suggesting that boost-invariance is not fully achieved in the collisions. |
