Flow and HBT measurements in the E895 experiment

There has been considerable interest in the energy dependence of sideward flow in non-central heavy ion collisions in the transition region between Bevalac/SIS (similar to1 AGeV) and top AGS (similar to 10 AGeV) energies, as a suggested "dip" in flow may signal the onset of Quark Gluon Plasma formation at these energies. The E895 Collaboration has measured the excitation function of sideward flow. While the data are smooth as a function of energy, displaying no dramatic dips, transport models are severely challenged as they try to reproduce the details of the flow. At the same time, E895 has mapped out the azimuthal dependence of two-pion correlations, and observes a new effect that provides unprecedented information on the spatial orientation of the hot matter created in these collisions. This new information should provide further insight into the nature of directed flow at these energies.