https://www.cns.s.u-tokyo.ac.jp/~shimoura/research/nuc_data/pdf/11.pdf

Energy levels of light nuclei A = 11-12

The intensity interferometry technique, commonly referred to as the Hanbury-Brown/Twiss effect, has been applied to nuclear and elementary-particle collisions as a method of investigating their space-time evolution. In this review the theoretical framework of the technique is presented, describing the formulations in common use. A survey is made of its application to subatomic collisions, ranging from high-energy elementary-particle reactions to low-energy nuclear reactions. Results derived from experimental data analysis are compiled and discussed. A critique is made of the interpretational difficulties associated with the use of the technique in reaction studies.

Intensity interferometry in subatomic physics

Pion degrees of freedom in nuclear matter

▪ Abstract We provide an overview of collective flow phenomena observed in heavy ion collisions from the Fermi energy range up to CERN Super Proton Synchrotron (SPS) energies. We summarize the experimental data in terms of the various observed aspects of flow, namely directed flow in the reaction plane, elliptic flow in- and out-of-plane, and azimuthally symmetric radial flow originating from the expansion of the hot and compressed reaction zone. Also reviewed are the theoretical concepts developed to simulate the complex reactions with the aim of extracting fundamental properties of hot and compressed nuclear matter.

Collective flow in heavy-ion collisions

Systematics of pion emission in heavy ion collisions in the 1 A GeV regime

Negative-pion production in relativistic heavy-ion collisions has been studied in a triggered streamer-chamber experiment with projectile nuclei /sup 12/C and /sup 40/Ar in the energy range 0.4-2.1 GeV/nucleon incident on targets LiH, NaF, BaI/sub 2/, and Pb/sub 3/O/sub 4/. Negative-pion yields, multiplicity distributions, and angular and momentum distributions are reported.

/pdf/negative-pion-production-in-relativistic-heavy-ion-3ru9zopze8.pdf

Negative Pion Production in Relativistic Heavy Ion Collisions

The space-time structure of the pion-emitting source for central collisions of Ar on KCl at 1.5 GeV/nucleon is studied. The fireball is found to be nearly spherical with a radius R = 4.9 +- 0.5 fm. No significant dependence on pion multiplicity is present. A dependence on pion energy is observed.

Pion source parameters in Ar on KCl collisions

Central nuclear collisions are studied with a 1.8-GeV/N /sup 40/Ar beam incident on a Pb target. Momentum and angular distributions of negative pions infer a pion temperature of 86.6 +- 3.9 MeV, and a pion-nucleon ratio of 0.21--0.24. The pion multiplicity suggests a suppression of high multiplicity events and a non-Poisson distribution. Pion interferometry analyses are performed; the relationship between pion multiplicity and the collision impact parameter is examined.

Exploratory Studies on Relativistic Heavy-Ion Central Collisions

The technique of pion interferometry is used to study the pion source for central collisions of 1.2 GeV/nucleon Ar on KCl. The data are described by a Gaussian source of radius 3.8 +- 0.5 fm, a lifetime of 5.4 +- 1.8 fm/c and a degree of coherence of 0.74 +- 0.17. The sensitivity of the analysis to the two-particle phase space is discussed. A comparison with previously reported results at 1.5 GeV/nucleon is presented.

Pion interferometry analysis for 1.2 GeV/nucleon Ar on KCl

High multiplicity collisions of 1.2 GeV/nucleon /sup 40/Ar on Kcl and on BaI/sub 2/ in the Bevalac streamer chamber are studied using the global transverse momentum analysis introduced by Danielewicz and Odyniec. For both systems, there is a sideward flow which is significantly larger than intranuclear cascade model predictions. The current results permit a study of trends in the multiplicity, mass and energy dependence of the observed flow signatures. Estimates of the stiffness of the nuclear equation of state at high density are discussed.

W. Gorn

Papers

Negative Pion Production in Relativistic Heavy Ion Collisions

Pion source parameters in Ar on KCl collisions

Exploratory Studies on Relativistic Heavy-Ion Central Collisions

Pion interferometry analysis for 1.2 GeV/nucleon Ar on KCl

Global transverse momentum analysis for Ar+KCl and Ar+ BaI 2 at 1.2 GeV/nucleon