Charged Particle Production in Proton-, Deuteron-, Oxygen- and Sulphur-Nucleus Collisions at 200 GeV per Nucleon

The transverse momentum and rapidity distributions of net protons and negatively charged hadrons have been measured for minimum bias proton-nucleus and deuteron-gold interactions, as well as central oxygen-gold and sulphur-nucleus collisions at 200 GeV per nucleon. The rapidity density of net protons at midrapidity in central nucleus-nucleus collisions increases both with target mass for sulphur projectiles and with the projectile mass for a gold target. The shape of the rapidity distributions of net protons forward of midrapidity for d+Au and central S+Au collisions is similar. The average rapidity loss is larger than 2 units of rapidity for reactions with the gold target. The transverse momentum spectra of net protons for all reactions can be described by a thermal distribution with `temperatures' between 145 +- 11 MeV (p+S interactions) and 244 +- 43 MeV (central S+Au collisions). The multiplicity of negatively charged hadrons increases with the mass of the colliding system. The shape of the transverse momentum spectra of negatively charged hadrons changes from minimum bias p+p and p+S interactions to p+Au and central nucleus-nucleus collisions. The mean transverse momentum is almost constant in the vicinity of midrapidity and shows little variation with the target and projectile masses. The average number of produced negatively charged hadrons per participant baryon increases slightly from p+p, p+A to central S+S,Ag collisions.Comment: 47 pages, submitted to Z. Phys.

Solitary Bone Cyst

A classic solitary bone cyst is discussed. Radiology and histology is reviewed

STUDY OF PARTICLE SPECTRA WITH AN OPTICALLY READOUT RICH DETECTOR IN THE NA35 EXPERIMENT

The first identified particle spectra obtained with a proximity focusing RICH detector using an optical readout in the high particle density environment of heavy ion collisions at ultrarelativistic energies are presented. The rapidity and transverse momentum spectra of identified pions, kaons, and protons measured in the reaction S-Au at 200 GeV/nucleon are shown and compared with the predictions of two event generators (Fritiof and VENUS)

CHARGED-PARTICLE SPECTRA IN CENTRAL S+S COLLISIONS AT 200 GEV/C PER NUCLEON

The transverse momentum and rapidity distributions of negative hadrons and participant protons have been measured for central S-32 + S-32 collisions at p(lab) = 200 GeV/c per nucleon. The proton mean rapidity shift [DELTAy] approximately 1.6 and mean transverse momentum [p(T)] approximately 0.6 GeV/c are much higher than in pp or peripheral AA collisions and indicate an increase in the nuclear stopping power. All p(T) spectra exhibit similar source temperatures. Including previous results for K(S)0, LAMBDA, and LAMBDABAR, we account for all important contributions to particle production

Pion Interferometry in ultrarelativistic nuclear collisions

Pion interferometry is the unique tool to study the space-time evolution of the systems created in the ultrarelativistic nuclear collisions. Five different data sets have been analyzed in terms of cylindrical coordinates, and all yield consistent results. We conclude that the system expands longitudinally, the decoupling proper time is ∼5 fm/c, the duration of particle emission is very short <2 fm/c, and the transverse decoupling size is 1.5 to 2 times larger than the one corresponding to the collision geometry. That gives a causally consistent space-time evolution picture. © 1992

PION INTERFEROMETRY IN ULTRARELATIVISTIC NUCLEAR COLLISIONS

Pion interferometry is the unique tool to study the space-time evolution of the systems created in the ultrarelativistic nuclear collisions. Five different data sets have been analyzed in terms of cylindrical coordinates, and all yield consistent results. We conclude that the system expands longitudinally, the decoupling proper time is approximately 5 fm/c, the duration of particle emission is very short <2 fm/c, and the transverse decoupling size is 1.5 to 2 times larger than the one corresponding to the collision geometry. That gives a causally consistent space-time evolution picture

Antibaryon production in sulphur nucleus collisions at 200 GeV per nucleon

Antiproton production near midrapidity has been studied in central collisions of S-32 With sulphur, silver and gold nuclei at 200 GeV per nucleon. The measured transverse mass distributions can be described by an exponential with inverse slope parameters of about 200 MeV, similar to those obtained from spectra. The rapidity density increases weakly with the target mass, ranging from 0.4 to 0.7. The ratio near midrapidity is approximately 1.4 on average, significantly larger than the corresponding ratio observed in proton-proton and proton-nucleus collisions