摘要:

The extension of the periodic system into various new areas is investigated. Experiments for the synthesis of superheavy elements and the predictions of magic numbers are reviewed. Different ways of nuclear decay are discussed like cluster radioactivity, cold fission and cold multifragmentation, including the recent discovery of the tripple fission of252Cf.Furtheron, investigations on hypernuclei and the possible production of antimatter-clusters in heavy-ion collisions are reported. Various versions of the meson field theory serve as effective field theories at the basis of modern nuclear structure and suggest structure in the vacuum which might be important for the production of hyper- and antimatter. A perspective for future research is given. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427442

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Nuclear equation of state plays an important role in the evolution of the Universe, in supernova explosions and, thus, in the production of heavy elements, and in stability of neutron stars. The equation constrains the two- and three-nucleon interactions and the quantum chromodynamics in nonperturbative regime. Despite the importance of the equation, though, its features had remained fairly obscure. The talk reviews new results on the equation of state from measurements of giant nuclear oscillations and from studies of particle emission in central collisions of heavy nuclei. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427443

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Hadron production in recent nucleus-nucleus collisions experiments at the SPS and at RHIC have been analyzed in various thermal model fits. Here it is shown that the fit cannot be unique: the chemical freeze-out close to the phase transition to a QGP should be accompanied by shifting baryon masses in medium, which can yield considerably smaller break-up temperatures. Also a simple microscopic quark molecular dynamics model yields hadron ratios in nice agreement with those data. Hence, additional information, e.g., from HBT, is needed to determine the freeze-out parameters from data. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427444

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

A novel state of matter has been hypothesized to exist during the early stage of relativistic heavy ion collisions, with normal hadrons not appearing until several fm/c after the start of the reaction. Radial flow of multi-strange baryons is shown to be a sensitive probe to the expansion of the deconfined phase prior to hadronization. Using a hybrid macroscopic/microscopic transport model we show that if at hadronization the system has been significantly out of chemical equilibrium, hadronic rescattering cannot drive the system towards full chemical equilibration. Furthermore, we suggest a novel model-independent observable, balance functions, to evaluate correlations between charges and their associated anti-charges It is shown that balance functions are extremely sensitive to the time-scale of hadronization: late-stage hadronization is characterized by tightly correlated charge/anti-charge pairs when measured as a function of relative rapidity. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427445

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The structure of a new dibaryon(&OHgr;&OHgr;)0+is predicted in the framework of the chiral SU(3) quark model by solving a resonating group method (RGM) equation. The binding energy of this dibaryon is around 100 MeV, the mean squared root of the distance between two &OHgr;s is 0.84 fm and the preliminary estimated mean life time is about10−10 sec.All these interesting properties, and also the two negative charge units it carries could make it to be easily identified experimentally in the heavy ion collision process. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427446

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

In terms of both kinetic and transport models, we discuss the chemical equilibration of strange particles in heavy ion collisions at both SIS, where their abundance is rare, and at SPS and RHIC, where the abundance is small for some strange particles but large for others. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427447

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The pion production by sigma decay and its relation with chiral symmetry restoration in a hot matter are investigated. It is pointed out that the nonthermal decay into pions of sigma mesons which are popularly produced in chiral symmetric phase leads to a peak in the pion spectra in relativistic heavy-ion collisions. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427448

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

By using the Furnstahl, Serot and Tang’s model, the effect of density dependence of the effective nucleon-nucleon-&rgr;-meson (NN&rgr;) coupling on the liquid-gas phase transition in hot asymmetric nuclear matter is investigated. A limit pressureplimhas been found. We found that the liquid-gas phase transition cannot take place ifp>plim.The binodal surface for density dependent NN&rgr; coupling situation is addressed. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427449

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

The strange hadronic matter with nucleon, &Lgr;-hyperon and &Ygr;-hyperon is studied by using the FST model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427450

出版商:AIP    

年代:1901

数据来源: AIP

摘要:

Using a hadron and string cascade model, JPCIAE, the experimental data of charged particle pseudorapidity density at mid-rapidity in both the relativisticp+p¯collisions and theAu+Aucollisions atsnn=130 GeVwere reproduced fairly well without retuning the model parameters. The predictions for full RHIC energyAu+Aucollisions and forPb+Pbcollisions at the LHC energy were given. Participant nucleon distributions were calculated based on different methods. It was found that the number of participant nucleons,⟨Npart⟩,is not a well defined variable both experimentally and theoretically. Thus, it is inappropriate to use charged particle pseudorapidity density per participant pair as a function of⟨Npart⟩for distinguishing various theoretical models. ©2001 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.1427451

出版商:AIP    

年代:1901

数据来源: AIP