共查询到20条相似文献,搜索用时 15 毫秒
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J. Hüfner 《Physics Reports》1985,125(4):129-185
Mesons, nucleons and light and heavy nuclei are observed as a result of a proton-nucleus or a nucleus-nucleus collision at relativistic energies (Ep≥0.5 GeV/u). This review concentrates on the properties of the heavy fragment nuclei (A ≥10. The experimental results for the distributions in mass, charge, angle and kinetic energy are presented. The data are discussed in the framework of models for spallation, fission and multifragmentation. 相似文献
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M. I. Gorenstein 《Physics of Particles and Nuclei》2008,39(7):1102-1109
We discuss the event-by-event multiplicity fluctuations in relativistic nucleus-nucleus collisions. Recent results of the
transport and statistical approaches are presented and compared with existing data.
The text was submitted by the author in English. 相似文献
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M. Mohsin Khan N. Ahmad A. Kamal A. A. Masoodi M. Irfan 《Indian Journal of Physics》2011,85(1):189-193
Correlation and fluctuations are now well accepted analysis techniques in heavy-ion collisions at relativistic energies. At
the current stage of RHIC exploration, matter in bulk and many of the physics questions about the final stage of collisions
are addressed with the help of correlation techniques. In the present work after a general introduction to the underlying
formalism to the exotic phenomena of correlation and fluctuations, discussion on various parameters disentangling dynamical
fluctuations is presented. Analysis to investigate dynamical fluctuations and correlation is carried out in terms of F
q
- and G
q
-moments. A study of various other parameters involving multiplicity and pseudorapidity of relativistic charged particles
produced in high energy nuclear interactions reveals the presence of correlation and fluctuations in particle production in
these collisions. The experimental data on 14.5A GeV/c 28Si-nucleus interactions has been analyzed. A parallel analysis of correlation free data generated using MC-RAND Monte Carlo
code, UrQMD data and for the HIJING generated events has also been carried out. 相似文献
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B. Friman W. Nörenberg V.D. Toneev 《The European Physical Journal A - Hadrons and Nuclei》1998,3(2):165-170
We compute the modification of the quark condensate <ˉq q> in relativistic nucleus-nucleus collisions and estimate the 4-volume,
where the quark condensate is small (<ˉqq>/<ˉqq>0≤ 0.1–0.3) using hadron phase-space distributions obtained with the quark-gluon string model. As a function of the beam energy
the 4-volume rises sharply at a beam energy Elab/A ≃ (2–5) GeV, remains roughly constant up to beam energies ≃ 20 GeV and rises at higher energies. At low energies the reduction
of the condensate is mainly due to baryons, while at higher energies the rise of the 4-volume is due to the abundant mesons
produced. Based on our results we expect that moderate beam energies on the order of 10 GeV per nucleon are favourable for
studying the restoration of chiral symmetry in a baryon-rich environment in nucleus-nucleus collisions.
Received: 4 December 1997 / Revised version: 31 July 1998 相似文献
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Elliptic flow measurements at the Brookhaven National Laboratory Relativistic Heavy Ion Collider suggest that quark-gluon fluid flows with very little viscosity compared to weak-coupling expectations, challenging theorists to explain why this fluid is so nearly "perfect." It is therefore vital to find quantitative experimental information on the viscosity of the fluid. We propose that measurements of transverse momentum fluctuations can be used to determine the shear viscosity. We use current data to estimate the viscosity-to-entropy ratio in the range from 0.08 to 0.3 and discuss how future measurements can reduce this uncertainty. 相似文献
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We discuss the short range part of two-particle correlations as it results from the phase space available in cluster decay. In such an approach, certain variables emerge which should be useful to organize the data and extract interesting information. We are in particular concerned with tests of large transverse motion of clusters. 相似文献
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G. T. Jones B. W. Kennedy R. P. Middleton S. W. O'Neale A. M. Cooper A. Grant H. Klein J. Mittendorfer D. R. O. Morrison A. Parker P. Schmid H. Wachsmuth F. Hamisi M. M. Mobayyen O. Villalobos-Baillie M. Aderholz L. Deck N. Schmitz W. Wittek G. Corrigan G. Myatt D. Radojicic M. Retter 《Zeitschrift fur Physik C Particles and Fields》1984,25(2):121-127
Data from a neutrino and antineutrino hydrogen experiment with BEBC are used to investigate transverse properties of the produced charged hadrons. Measurements are presented on average transverse momenta of charged pions as functions of Feynman-x and the hadronic mass, on the transverse momentum flow within an event and on jet-related quantities. The main features of the data are well described by the LUND model. The data favour a version of the model in which soft gluon effects are included and the primordial transverse momentum of the quarks in the proton is small. Effects from 1st order QCD (hard gluon emission) are negligible. 相似文献
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《Physics letters. [Part B]》1988,215(4):617-623
A relativistic quantum kinetic equation is derived corresponding to the non-equilibrium extension of the Dirac-Brueckner approach for nuclear matter. The equation is of the VUU-type with a self-consistent mean field and collision term. 相似文献
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By means of the AKK08 fragmentation function, the net-proton transverse momentum (pT) spectra in A+A collisions are studied with two phenomenological models based on the Color Glass Condensate formalism. After a x2 analysis of the experimental data from BRAHMS, the normalization constant C is extracted at RHIC energies of √SNN =62.4 and 200 GeV, and the theoretical results of the net-proton pT spectra at selected rapidities are also given. It is shown that the theoretical results are in good agreement with the experimental data. Finally, assuming the constant C should have an exponent dependence of √SNN, we also predict the theoretical results of net-proton pT spectra at LHC energies of √SNN = 2.76, 3.94, and 5.52 TeV. 相似文献
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By means of the AKK08 fragmentation function, the net-proton transverse momentum (pT) spectra in A+A collisions are studied with two phenomenological models based on the Color Glass Condensate formalism. After a χ2 analysis of the experimental data from BRAHMS, the normalization constant C is extracted at RHIC energies of √sNN=62.4 and 200 GeV, and the theoretical results of the net-proton pT spectra at selected rapidities are also given. It is shown that the theoretical results are in good agreement with the experimental data. Finally, assuming the constant C should have an exponent dependence of √sNN, we also predict the theoretical results of net-proton pT spectra at LHC energies of √sNN=2.76, 3.94, and 5.52 TeV. 相似文献
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《Physics letters. [Part B]》1986,174(4):458-464
A quantitative test of QCD from high energy photoproduction of large transverse momentum charged hadrons, using incident γ energies between 50 and 150 GeV, is presented. The inclusive hadron P1 and Pt distributions show a clear excess over the VDM contribution. This excess is found to be in good agreement with second-order QCD calculations. This agreement does not depend critically on the choice of the gluon fragmentation function, and is observed over the large kinematical domain covered by this experiment. 相似文献
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T. C. Awes M. A. Bloomer C. Blume D. Bock R. Bock D. Bucher G. Clewing S. Garpman R. Glasow H. Å. Gustafsson H. H. Gutbrod G. Hölker J. Idh P. Jacobs K. H. Kampert B. W. Kolb H. Löhner F. E. Obenshain A. Oskarsson I. Otterlund T. Peitzmann F. Plasil A. M. Poskanzer M. Purschke B. Roters S. Saini R. Santo H. R. Schmidt S. P. Sørensen K. Steffens P. Steinhaeuser E. Stenlund D. Stüken G. R. Young 《Zeitschrift fur Physik C Particles and Fields》1995,69(1):67-76
A detailed analysis of pair correlations of positive pions in the target fragmentation region is presented. Data on nuclear collisions at 200 GeV per nucleon were measured with the Plastic Ball in the WA80 experiment at the CERN SPS. The correlation functions are compared with analytical functions and with simulations incorporating Bose-Einstein symmetrization, final-state interactions and detector resolution. Source radii are shown to increase with increasing target size and with centrality. For central collisions the radii are larger than the geometrical sizes of the involved nuclei. 相似文献
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V. V. Ognivenko 《Journal of Experimental and Theoretical Physics》2016,122(1):203-208
An expression has been obtained for the diffusion tensor of particles in the momentum space on the basis of the dynamics of particles motion. The general equations have been used to determine the rms momentum spread at collisions of relativistic charged particles at times shorter than the time of randomization of particles motion and at greater times when motion is completely random. 相似文献
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Two-particle (two-fragment) azimuthal correlation functions are studied by using a simple formula which describes uniformly azimuthal distributions of final-state charged particles and nuclear fragments. This formula is obtained in the framework of a multi-source thermal model (or multi-source ideal gas model). The calculated results are compared and found to be in agreement with the experimental data of charged hadrons and nuclear fragments in nucleus-nucleus collisions at intermediate and high energies. 相似文献
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L. V. Chkhaidze T. D. Djobava L. L. Kharkhelauri E. N. Kladnitskaya 《Physics of Atomic Nuclei》2012,75(7):811-817
Multiparticle azimuthal correlations of ?? ? mesons have been studied in dC, HeC, CC, CNe, MgMg, (d, He)Ta, CCu, CTa, and OPb collisions at momentum of 4.2, 4.5 GeV/c per nucleon within the standard transverse momentum analysis method of P. Danielewicz and G. Odyniec. The data were obtained by SKM-200-GIBS and Propane Bubble Chamber Collaborations of JINR. The axis has been selected in the phase space and with respect to this axis ?? ? meson correlations were observed. The values of the coefficient of the correlations linearly depend on the mass numbers of projectile (A P ) and target (A T ) nuclei. The Quark-Gluon String Model satisfactorily describes the experimental results. 相似文献
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A. T. D’yachenko O. V. Lozhkin 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(6):880-883
The formation of kaon and pion spectra is considered within the relativistic hydrodynamic model of interaction of heavy nuclei. The terms describing the formation of quarks and gluons are included in the state equation of the hydrodynamic model. This approach allowed consideration of nucleus-nucleus collisions in the range from 4 to 160 GeV/nucleon and reproduce the increase in temperature of the kaons formed, which is not reproduced within the ultrarelativistic quantum molecular-dynamics model and other microscopic approaches. 相似文献