John William Harris

THE SEARCH FOR THE QUARK-GLUON PLASMA

▪ Abstract We provide an overview of the present understanding of the transition from hadrons to a quark-gluon plasma, its signatures, and the experimental results so far. We discuss results of numerical simulations of the lattice gauge theory and critically evaluate the various observables that have been proposed as signatures of the QCD phase transition. We place the existing data from relativistic heavy-ion experiments at the Brookhaven Alternating Gradient Synchrotron (AGS) and CERN Super Proton Synchrotron (SPS) into perspective and provide an overview of the techniques and strategies that will be employed in the search for the quark-gluon plasma at heavy-ion colliders, such as the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC).

Multiplicity and transverse energy flux in 16O+Pb at 200 GeV per nucleon

Abstract First results from ultrarelativistic 16 O+Pb collisions at 200 GeV/nucleon are presented. The transverse energy E T in average central collisions is ≈ 75 GeV for the interval 2.2⩽ y ⩽3.8. A 16-fold convolution of the inelastic p+Au transverse energy spectrum, also measured at 200 GeV, reproduces the mean E T of 16 O+Pb. The amount of nuclear stopping power appears to be high.

PION PRODUCTION AS A PROBE OF THE NUCLEAR MATTER EQUATION OF STATE

Abstract It is shown that thermal and chemical equilibrium are approached during the high density stage in central nucleus-nucleus collisions and that the yield of produced pions is determined at that time. A chemical model with Rankine-Hugoniot compression is used to extract a nuclear matter equation of state from the observed pion yield assuming a partition of the internal energy per nucleon into thermal and compressional energy fractions, with only the former part contributing to particle production.

Neutral strange particle production in sulphur-sulphur and proton-sulphur collisions at 200 GeV/nucleon

AbstractThe production of Λ,

Molecular resonances in /sup 12/C + /sup 12/C inelastic scattering

\bar \Lambda

Negative particle production in nuclear collisions at 60 and 200 GeV/nucleon

andKs0 has been studied in 200 GeV/nucleonp+S and S+S collisions in the streamer chamber of the NA35 experiment at the CERN SPS. Significant enhancement of the multiplicities of all observed strange particles relative to negative hadrons was observed in central S+S collisions, as compared top+p andp+S collisions. The latter collisions show no overall (relative) strangeness enhancement overp+p, but the rapidity distributions and hadron multiplicities indicate some secondary cascading production of Λ particles in thep+S andp+Au collisions. The Λ polarization in central S+S collisions was found to be compatible with zero up topT=2 GeV/c.

The Karari Industry: Early Pleistocene archaeological evidence from the terrain east of Lake Turkana, Kenya

Abstract We report results from a pion interferometry analysis of 200 GeV/nucleon 16 O+Au collisions. Both a gaussian source model and a model based on the inside-outside cascade are used to fit the experimental correlation function, giving transverse and longitudinal shape parameters, a freeze-out time parameter, and a chaoticity parameter for the pion emitting source. We find a transverse source size consistent with the projectile radius except at the CM rapidity, where significantly larger transverse and longitudinal sizes and a longer freeze-out time are measured suggesting a thermalized source. Calculation of correlation lengths, and comparisons with a simple freeze-out model and other pion interferometry experiments are presented.

Charged particle multiplicities and inelastic cross sections in high energy nuclear collisions

The energy dependence of the total cross section for the mutual inelastic scattering reaction /sup 12/C + /sup 12/C ..-->.. /sup 12/C(2/sub 1//sup +/) + /sup 12/C(2/sub 1//sup +/) has been measured from E/sub c. m./(/sup 12/C) = 15 to 45 MeV. A rotationlike sequence of resonances is observed with strengths up to 17% of the unitarity limit and widths approaching the /sup 12/C + /sup 12/C single-particle width.