Two-particle correlations have been measured for identified $\pi^-$ from central 158 A GeV Pb+Pb collisions and fitted radii of about 7 fm in all dimensions have been obtained. A multi-dimensional ...study of the radii as a function of kT is presented, including a full correction for the resolution effects of the apparatus. The cross term R2out-long of the standard fit in the Longitudinally CoMoving System (LCMS) and the vL parameter of the generalised Yano-Koonin fit are compatible with o, suggesting that the source undergoes a boost invariant expansion. The shapes of the correlation functions in Qinv and Qspace = √Q$2\atop{x}$ + Q$2\atop{y}$ + Q$2\atop{z}$ have been analyzed in detail. They are not Gaussian but better represented by exponentials. As a consequence fitting Gaussians to these correlation functions may produce different radii depending on the acceptance of the experimental setup used for the measurement.
From an exposure of the Fermilab 15-foot bubble chamber to the Tevatron quadrupole triplet neutrino beam, we have determined the ratio of neutral-current (NC) to charged-current (CC) interactions to ...be 0.288{plus minus}0.032 for events with visible hadron momentum above 10 GeV/{ital c}. The mean {nu}({bar {nu}}) event energy is 150 (110) GeV, which is higher than that for any previous beam. This result agrees with those from previous experiments at lower energies. The NC/CC ratio is derived for a combined sample of {nu} and {bar {nu}} events. A value of 0.274{plus minus}0.038 is obtained for the dominant {nu} component assuming {bar {nu}} NC/CC=0.39{plus minus}0.08. For events with visible hadron momentum above 25 GeV/{ital c}, where the neutral hadron contamination remaining in the NC sample is assumed to be negligible, the combined NC/CC is 0.323{plus minus}0.025 and the {ital K}{sup 0} production rates are 0.375{plus minus}0.064 per CC and 0.322{plus minus}0.073 per NC event. The corresponding {Lambda} rates are 0.161{plus minus}0.030 per CC and 0.113{plus minus}0.030 per NC event. The {ital K}{sup 0} and {Lambda} distributions of the fractional hadron energy variable {ital z} in NC events are consistent with those in CC events.
In this letter the distribution of slow target associated particles emitted in Au + Emulsion interactions at 11.6 A GeV/
c is studied. The three models RQMD, FRITIOF and VENUS are used for ...comparisons and especially their treatment of rescattering is investigated.
The production of neutral pions in 158AGeV Pb+Pb collisions has been studied in the WA98 experiment at the CERN SPS. Transverse momentum spectra are studied for the range 0.3 GeV/c mT-m0 4.0 GeV/c. ...The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An invariance of the spectral shape and a simple scaling of the yield with the number of participating nucleons is observed for centralities with greater than about 30 participating nucleons which is most naturally explained by assuming an equilibrated system.
The mean transverse momentum of photons has been determined on an event by event basis in S + Au collisions at 200 A·GeV from the ratio of the measured electromagnetic transverse energy (
E
T
em) to ...the photon multiplicity (
N
γ
). The average value obtained is similar to that determined for the same system using spectroscopic techniques. The centrality dependence of the measured values are in agreement with the predictions of the VENUS event generator.
4
Now at: SUBATECH, Ecole des Mines, Nantes, France.
Pseudorapidity density and multiplicity distributions of charged particles produced in heavy-ion collisions at the BNL AGS have been studied. The multiplicity distributions and pseudorapidity ...distributions of shower particles in Au-induced interactions are presented and compared with model predictions from RQMD, FRITIOF and VENUS. It is shown that the widths of the pseudorapidity distributions of produced particles in central collisions are independent of the interacting system. The results from EMU01 have been compared, and found to agree, with the results from two other heavy-ion experiments, E802 and E814.
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