The emission pattern of charged pions has been measured in Au+Au collisions at 1 GeV/nucleon incident energy. In peripheral collisions and at target rapidities, high-energy pions are emitted ...preferentially towards the target spectator matter. In contrast, low-energy pions are emitted predominantly in the opposite direction. The corresponding azimuthal anisotropy is explained by the interaction of pions with projectile and target spectator matter. This interaction with the spectator matter causes an effective shadowing which varies with time during the reaction. Our observations show that high-energy pions stem from the early stage of the collision whereas low-energy pions freeze out later.
The NA49 large acceptance hadron detector Afanasiev, S.; Alber, T.; Appelshäuser, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/1999, Volume:
430, Issue:
2
Journal Article
Peer reviewed
Open access
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 d
E/d
x. 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.
We present and discuss recent experimental activities of the HADES collaboration on open and hidden strangeness production close or below the elementary NN threshold. Special emphasis is put on the ...feed-down from φ mesons to antikaons, the presence of the Ξ- excess in cold nuclear matter and the comparison of statistical model rates to elementary p+p data. The implications for the interpretation of heavy-ion data are discussed as well.
The RHIC zero-degree calorimeters Adler, C.; Denisov, A.; Garcia, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2003, Volume:
499, Issue:
2
Journal Article
Peer reviewed
The RHIC zero-degree calorimeters provide common event characterization in the four heavy ion experiments which recently completed their first data taking run. Here, we describe simulations which ...lead to the design of these devices, teastbeam performance and initial experience at RHIC.
The RHIC zero-degree calorimeters Adler, C.; Denisov, A.; Garcia, E. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2001, Volume:
461, Issue:
1
Journal Article
Peer reviewed
The RHIC zero-degree calorimeters provide common event characterization in the four heavy ion experiments which recently completed their first data taking run. Here, we describe simulations which ...lead to the design of these devices, teastbeam performance and initial experience at RHIC.
We present first data on event-by-event fluctuations in the average transverse momentum of charged particles produced in Pb+Pb collisions at the CERN SPS. This measurement provides previously ...unavailable information allowing sensitive tests of microscopic and thermodynamic collision models and to search for fluctuations expected to occur in the vicinity of the predicted QCD phase transition. We find that the observed variance of the event-by-event average transverse momentum is consistent with independent particle production modified by the known two-particle correlations due to quantum statistics and final state interactions and folded with the resolution of the NA49 apparatus. For two specific models of non-statistical fluctuations in transverse momentum limits are derived in terms of fluctuation amplitude. We show that a significant part of the parameter space for a model of isospin fluctuations predicted as a consequence of chiral symmetry restoration in a non-equilibrium scenario is excluded by our measurement.
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