120981543
UNIFIED DESCRIPTION OF (PSEUDO)RAPIDITY DISTRIBUTIONS OF FINAL-STATE PARTICLES PRODUCED IN COLLISIONS AT RELATIVISTIC ENERGIES
The paper presents a fit to rapidity distributions of various hadrons measured in heavy-ion experiments at different beam energies. As examples distributions of various identified hadron species measured at GSI SIS and at BNL RHIC are presented and very good agreement between the fit and the data is found. The basis of the fits is a simple Feynman gas model, namely the two-cylinder gas model, for secondary particle production. The model assumption is that there are projectile and target cylinders that are the sources of emitted particles. The conjecture is that at low and intermediate energies the cylinders overlap totally, at high energy the cylinders overlap partly, while at very high energy a gap appears between the two cylinders.
120712528
Alpha emission in krypton–emulsion collisions at 1.7A GeV
Abstract The multiplicity and transverse momentum distributions of alpha projectile fragments emitted in nucleus–nucleus collisions at high energies are investigated. The results calculated by the two-source model are in agreement with the experimental data of krypton–emulsion collisions at 1.7 A  GeV.
122076971
ANGULAR DISTRIBUTIONS OF TARGET BLACK FRAGMENTS IN NUCLEUS NUCLEUS COLLISIONS AT HIGH ENERGY
The experimental results of space, azimuthal, and projected angular distributions of target black fragments produced in silicon-emulsion collisions at 4.5A GeV/c (the Dubna energy) are reported. A multi-source ideal gas model is suggested to describe the experimental angular distributions. The Monte Carlo calculated results are in agreement with the experimental data.
118607664
Singly and Doubly Charged Projectile Fragments in Nucleus-Emulsion Collisions at Dubna Energy in the Framework of the Multi-Source Model *
The multiplicity distributions of projectile fragments emitted in interactions of different nuclei with emulsion are studied by using a multi-source model. Our calculated results show that the projectile fragments can be described by the model and each source contributes an exponential distribution. As the weighted sum of the folding result of many exponential distributions, a multi-component Erlang distribution is used to describe the experimental data. The relationship between the height (or width) of the distribution and the mass of the incident projectile, as well as the dependence of projectile fragments on target groups, are investigated too.
122540755
Particle production in Au–Au collisions at RHIC energies
Abstract An overlapping cylinder model (OCM) is introduced in this Letter which considers three components: the longitudinal flow, transverse flow and the temperature. A comparison of our model calculations in terms of pseudorapidity distributions with the most recent experiments is presented. To describe the experimental data at Relativistic Heavy Ion Collider (RHIC) energies ( s NN =130 and 200 GeV), a relative strong longitudinal flow and two partly overlapping cylinders are needed in the model. The difference between the different centrality events is described by the contribution of leading protons. The other parameter values do not depend on the centrality. The calculated results of the overlapping cylinder model are in agreement with the experimental data at the RHIC energies.
115903813
Angular Distributions of Target Fragments in Magnesium-Emulsion Collisions at High Energy
121546377
Dependences of charged particle pseudorapidity distributions on impact parameter and center-of-mass energy in nucleus–nucleus collisions at relativistic energies
The centrality and rapidity dependence of charged particles over a wide range of center-of-mass energy are analyzed. In this framework of participant-spectator model, the interacting system of nucleus–nucleus collisions at relativistic energies is divided into four parts (sources): target spectator, target participant, projectile participant and projectile spectator. Each source is treated by using a revised Landau model. The pseudorapidity distributions calculated by four-component Landau model are found to be in agreement with experimental data of the PHOBOS and ALICE collaborations. The distribution height is mainly determined by effective nucleon number and center-of-mass energy; and the distribution width being measured by the revised width in the Landau model and the sources rapidity shifts. Furthermore, we have found two empirical relations for projectile-participant and projectile-spectator (pseudo)rapidity as functions of the center-of-mass energy.
120089995
The large-scale organization of the hadron decay network
The standard model of particle physics predicts a complex structure of decay modes for hadrons, which opens up an avenue for observing the internal forces governing the decay dynamics. In this paper, we present the decay modes of hadrons as a network in which the nodes are particles and directed links are pointing from the mother particles to daughter particles. Using the database of decay modes collected from the Particle Data Group, we try to unveil the topological structure and possible intrinsic nature of hadron decays in the light of recent investigations of complex networks. We study distributions of the numbers of daughter and mother particles, and explore scaling laws that may govern the underlying decay structure of the system. We find that it is a small-world network with symmetrical structure. We also study the influence of constraints arising from conservation laws on the network structure, and our analysis suggests that the constraints of conservations of momentum-energy, charge, lepton number and baryon number play important roles in the topology of the decay network. Finally, we classify the hadrons into communities according to their quark component, and uncover the relationship between the particle roles and connection patterns in the communities.
1752055
On transverse momentum event–by–event fluctuations in string hadronic models
Abstract. Transverse momentum event–by–event fluctuations are studied within the string–hadronic model of high energy nuclear collisions, LUCIAE. Data on non–statistical $p_T$ fluctuations in p+p interactions are reproduced. Fluctuations of similar magnitude are predicted for nucleus–nucleus collisions, in contradiction to the preliminary NA49 results. The introduction of a string clustering mechanism (Firecracker Model) leads to a further, significant increase of $p_T$ fluctuations for nucleus–nucleus collisions. Secondary hadronic interactions, as implemented in LUCIAE, cause only a small reduction of $p_T$ fluctuations.
122934588
Multi-component Erlang distribution of final-state particles produced in high energy collisions
A unified formula on multiplicity distributions of final-state particles is studied in this paper to describe a variety of experimental data including multiplicity, mass, transverse mass, excitation energy, transverse energy, and transverse momentum distributions. It is assumed that the sources of final-state particles are subjected to the multi-source thermal model and the contributions of sources meet the Erlang distribution. Further the validity of the unified formula in descriptions of different distributions is tested. Experimental data of proton-antiproton $$(p\overline{p}),$$ positron–proton (e+p), electron-proton (e−p), and nucleus-nucleus (AA) collisions are analyzed and found that the distributions of mentioned quantities can be described by the multi-component Erlang distribution.
123192244
Orientation dependence of center baryon density in central 0.52 GeV/n U-U collisions
With a relativistic transport model, We performed simulation for deformed UU collision with vast different orientation at CSR energy area corresponding to the high net-baryon density region in QCD phase diagram. By investigating the centrality and initial collision orientation dependence of the baryon density form, we found that those tip-tip like UU collisions with extended high density phase, which is very important for studying the nuclear EoS of high baryon density matter and the possible end-point of the phase boundary, are those events with small orientations (< 20°) in reaction plane and small impact parameter (< 2.4 fm). We have developed a measurable quantity that allows us to select those most interesting events (i.e. tip-tip like) in the experiment.