Author: Blevis IraPublisher:
ISBN:
Category :
Languages : en
Pages : 89
Book Description
Spectra of Pions and Protons in Nuclear Collisions at 200 GeV-nucleon
Author: Blevis IraNeutral Pion Production in Nucleus-nucleus Collisions at 158 and 200 GeV/nucleon
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
Two years ago, at the 12th Winter Workshop on Nuclear Dynamics held here in Snowbird, the authors presented WA80 limits on direct photon production in 200-GeV 32S + Au collisions. It was found that the results were consistent (within 1[sigma]) with the absence of an excess of photons over those that can be accounted for by the two-photon decay branches of [pi]° and [eta] mesons and by the small photon contributions from other radiative decays. They are in the process of finalizing the direct-photon production results from collisions of lead nuclei at 158 GeV/nucleon. The author briefly discusses the status of the analysis and gives some preliminary results at the end of this talk. However, most of this presentation is concerned with a very different aspect of the photon measurements: distributions of neutral pions. In contrast to direct photons which probe initial collision conditions, hadrons, such as neutral pions, interact strongly and decouple late in the reaction evolution and, thus, provide information concerning the system at freeze out. Transverse momentum spectra at low and intermediate p{sub T} relate to thermodynamic and hydrodynamic descriptions of the hot, dense systems. In addition, the high-p{sub T} region reflects the hard-scattering regime and may help one understand initial-state particle production by forming a bridge to proton-proton and proton-nucleus results. It follows that it is essential that the [pi]° measurements cover a large p{sub T} range.
Parameterizations of Pion Energy Spectrum in Nucleon-Nucleon Collisions
Author: Francis A. CucinottaPublisher:
ISBN:
Category : Extraterrestrial radiation
Languages : en
Pages : 30
Book Description
Transverse Momentum Distributions of Neutral Pions from Sup 16 O + Au Collisions at 200 GeV/nucleon
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
One means of studying the properties of the compressed and highly excited reaction zone is the investigation of {sub pT} spectra of produced pions and their dependence on the centrality of the reaction. To distinguish different contributing processes and to provide a reliable basis for comparisons with p + p scattering, a large {sub pT} coverage is required. In particular, data at high {sub pT} values, where hard processes become important and may be calculated by perturbative QCD are of interest. The present study of [pi]° spectra concentrates on measurements of {sub pT} spectra up to 2.8 GeV/c and on selections of the data according to the centrality of the reaction. 8 refs., 4 figs.
Cross-Section Parameterizations for Pion and Nucleon Production From Negative Pion-Proton Collisions
Author: John W. NorburyPublisher:
ISBN:
Category : Extraterrestrial radiation
Languages : en
Pages : 50
Book Description
Phi Meson Production in P+p Collisions at 200 GeV Measured by the PHENIX Experiment at the Relativistic Heavy Ion Collider
Author: Dmitri Vladimirovitch KotchetkovPublisher:
ISBN:
Category : Collisions (Nuclear physics)
Languages : en
Pages : 522
Book Description
Transverse Mass and Rapidity Spectra of Pions and Protons from AuAu Collisions at the Alternating Gradient Synchrotron
Author: Jennifer Lynn KlayNuclear Science Abstracts
Author: Pi. ° Spectra and Correlations from 16O + Au Collisions at 200 A GeV.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
The production of neutral pions by the interaction of 200 A GeV proton and 16O projectiles with an Au target has been studied for 1.5 d"[eta] d"2.1. Transverse momentum spectra have been measured between 0.4 GeV/c and 2.8 GeV/c and their dependence on the centrality of the reaction has been investigated. The peripheral spectrum shows a marked change of slope with a hard component starting at about 1.8 GeV/c in close similarity to p + p data. Preliminary analyses of photon data yield an excess over known photon sources for central data which is absent for peripheral reactions. Correlations of 4 photons representing neutral pions have been studied in ultrarelativistic heavy ion collisions. Data were taken in the WA80 experiment at the CERN-SPS with a 200 A GeV oxygen beam. The .pi.° are detected via their decay photons with a high-granularity lead glass array. Special features of interferometry using neutral pions will be discussed. The extracted preliminary parameters for high p/sub T/ pions emitted near midrapidity in O + Au collisions lead to rather small effective source sizes. 23 refs., 8 figs.
Pion Production at 180? in Nucleus-nucleus Collisions
Author: Stephen Alan ChessinPublisher:
ISBN:
Category :
Languages : en
Pages : 354
Book Description