Near-threshold production of the multistrange Xi- hyperon.

The yield for the multistrange Xi(-) hyperon has been measured in 6A GeV Au+Au collisions via reconstruction of its decay products pi(-) and Lambda, the latter also being reconstructed from its daughter tracks of pi(-) and p. The measurement is rather close to the threshold for Xi(-) production and therefore provides an important test of model predictions. The measured yield for Xi(-) and Lambda are compared for several centralities.

Comparison of source images for protons, pi-'s, and lambda's in 6A GeV Au+Au collisions.

Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs p Lambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p.

Longitudinal flow of protons from (2-8)A GeV central Au+Au collisions.

Rapidity distributions of protons from central 197Au+197Au collisions measured by the E895 Collaboration in the energy range from (2-8)A GeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, (L), as a function of the logarithm of beam energy.

Directed flow of lambda hyperons in (2-6 )A GeV Au+Au collisions.

Directed flow measurements for Lambda hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2A, 4A, and 6A GeV; b<5-6 fm). The measurements indicate that Lambda hyperons flow consistently in the same direction but with smaller magnitudes. A strong positive flow [for Lambdas] has been predicted in calculations which include the influence of the Lambda-nucleon potential.

Bombarding energy dependence of pi(-) interferometry at the brookhaven AGS.

We present the first excitation function of pi(-) intensity interferometry at Alternating Gradient Synchrotron (AGS) energies (2-8 A GeV). The sensitivity of the multidimensional correlation functions to the geometry and dynamics of the pion-emitting system provides a stringent test of transport models of heavy ion collisions. Detailed comparisons with a realistic transport model, both with and without an explicit nuclear mean field, suggest that the beam energy evolution in the reaction dynamics is different in the model than in the data.

Nuclear multifragmentation, percolation, and the fisher droplet model: common features of reducibility and thermal scaling.

It is shown that the Fisher droplet model, percolation, and nuclear multifragmentation share the common features of reducibility (stochasticity in multiplicity distributions) and thermal scaling (one-fragment production probabilities are Boltzmann factors). Barriers obtained, for cluster production on percolation lattices, from the Boltzmann factors show a power-law dependence on cluster size with an exponent of 0.42+/-0.

Antiflow of K(0)(s) mesons in 6A GeV Au + Au collisions.

We have measured the sideward flow of neutral strange ( K(0)(s)) mesons in 6A GeV Au+Au collisions. A prominent antiflow signal is observed for an impact parameter range ( b less, similar7 fm) which spans central and midcentral events. Since the K(0)(s) scattering cross section is relatively small in nuclear matter, this observation suggests that the in-medium kaon vector potential plays an important role in high density nuclear matter.