Rolf Paul Scharenberg

Elliptic flow: Transition from out-of-plane to in-plane emission in Au + Au collisions

We have measured the proton elliptic flow excitation function for the Au + Au system spanning the beam energy range 2 -- 8 AGeV. The excitation function shows a transition from negative to positive elliptic flow at a beam energy,

Radial flow in Au + Au collisions at E = (0.25-1.15)A GeV

E_{tr} \sim

Statistical signatures of critical behavior in small systems

4 AGeV. Detailed comparisons with calculations from a relativistic Boltzmann-equation are presented. The comparisons suggest a softening of the nuclear equation of state (EOS) from a stiff form (K \sim 380 MeV) at low beam energies (E_{Beam} \le 2 AGeV) to a softer form (K \sim 210 MeV) at higher energies (E_{Beam} \ge

The energy dependence of flow in Ni induced collisions from 400A to 1970A MeV

4 AGeV) where the calculated baryon density

Nuclear multifragmentation, percolation and the Fisher Droplet model: common features of reducibility and thermal scaling

\rho \sim 4 \rho_0

Search for charged strange quark matter produced in 11.5A GeV/c Au+Pb collisions

.

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

A systematic study of energy spectra for light particles emitted at midrapidity from Au+Au collisions at {ital E}= (0.25--1.15){ital A} GeV reveals a significant nonthermal component consistent with a collective radial flow. This component is evaluated as a function of bombarding energy and event centrality. Comparisons to quantum molecular dynamics and Boltzmann-Uehling-Uhlenbeck models are made for different equations of state.

Centrality and momentum-selected elliptic flow: Tighter constraints for the nuclear equation of state

The cluster distributions of three different systems are examined to search for signatures of a continuous phase transition. In a system known to possess such a phase transition, both sensitive and insensitive signatures are present; while in systems known not to possess such a phase transition, only insensitive signatures are present. It is shown that nuclear multifragmentation results in cluster distributions belonging to the former category, suggesting that the fragments are the result of a continuous phase transition.

Antideuteron yield at the AGS and coalescence implications

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in (400{endash}1970){ital A} MeV Ni+Au and (1000{endash}1970){ital A} MeV Ni+Cu reactions. The flow increases with energy, appears to reach a maximum, and then to decrease at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is introduced, which demonstrates a more-or-less common scaling behavior among flow values from different systems. {copyright} {ital 1997} {ital The American Physical Society}

Accelerator internal target experiments using a supersonic gas jet

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+/-0.02. The EOS Collaboration Au multifragmentation data yield barriers with a power-law exponent of 0.68+/-0.03. Values of the surface energy coefficient of a low density nuclear system are also extracted.