[en] The STAR level-3 trigger is a MYRINET interconnected ALPHA processor farm, performing online tracking of N_track≥8000 particles (N_point≤45 per track) with a design input rate of R=100 Hz. A large-scale prototype system was tested in 12/99 with laser and cosmic particle events

[en] Net proton and negative hadron spectra for central Pb+Pb collisions at 158GeV per nucleon at the CERN Super Proton Synchrotron were measured and compared to spectra from lighter systems. Net baryon distributions were derived from those of net protons. Stopping (rapidity shift with respect to the beam) and mean transverse momentum left-angle p_T right-angle of net baryons increase with system size. The rapidity density of negative hadrons scales with the number of participant nucleons for nuclear collisions, whereas their left-angle p_T right-angle is independent of system size. The left-angle p_T right-angle dependence upon particle mass and system size is consistent with larger transverse flow velocity at midrapidity for Pb+Pb compared to S+S central collisions. copyright 1999 The American Physical Society

[en] The directed and elliptic flow of protons and charged pions has been observed from the semicentral collisions of a 158GeV/nucleon Pb beam with a Pb target. The rapidity and transverse momentum dependence of the flow has been measured. The directed flow of the pions is opposite to that of the protons but both exhibit negative flow at low p_t . The elliptic flow of both is fairly independent of rapidity but rises with p_t . copyright 1998 The American Physical Society

[en] The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large-volume TPCs for tracking and particle identification via dE/dx. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions