摘要:

A new concept, recently introduced, critical point symmetry, is briefly discussed and applied to the study of shape phase transitions in nuclei. Experimental examples are presented. Implications to other fields, especially molecular physics are mentioned. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517930

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Recent investigations of off‐yrast low‐spin states of94Mo yielded evidence for one quadrupole phonon and two‐phonon states with mixed proton‐neutron symmetry. The mixed‐symmetry assignments are based on the observation of strongM1 transitions and the measurement of their absoluteM1 matrix elements ≈ 1 &mgr;N. Corresponding structures were identified very recently in theN= 52 neighboring even‐even isotones,96Ru and92Zr, too. Progress on this topic is reviewed. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517931

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

A new generation of experiments studying nuclei in spherical‐deformed transition regions has been encouraged by the introduction of innovative theoretical approaches to the treatment of these nuclei, including the critical point modelsE(5) andX(5). Experiments and results in theA=100 andA=150 regions are discussed. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517932

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

We introduce a matrix formulation in a coherent state basis which can be applied to configuration mixing IBM Hamiltonians. The potential energy matrices give rise to eigenpotentials which may display the phenomenon of shape coexistence . Some examples are discussed. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517933

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

This work presents the first continuum shell‐model study of weakly bound neutron‐rich nuclei withseveralvalence nucleons. For the single‐particle basis, we take the complex‐energy Berggren ensemble representing the bound single‐particle states, narrow resonances (Gamow states), and the non‐resonant continuum. In our calculations, we consider the shell‐model Hamiltonian consisting of a one‐body finite Woods‐Saxon potential and a residual two‐body interaction. The proposed Gamow shell model, which is a straightforward extension of the traditional shell model based on a discrete basis, is shown to be an excellent tool for the microscopic description of weakly bound systems. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517934

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The comparison of the strengths of correspondingE2transitions inT=1isospin multiplets has been an important tool for understanding the isovector dependence ofE2transitions for many years. The development of radioactive beams and more sensitive detector technology has made this method much more powerful so that moreT=1multiplets can be studied in detail andT=2multiplets can be studied for the first time. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517935

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

This paper reports on a test experiment to investigate the viability of using in‐beam gamma‐ray spectroscopy with projectile fragmentation reactions to explore the structure of heavy, neutron‐rich nuclei. The experiment used a ‘thin target’ fragmentation reaction with a 30 MeV per nucleon12C beam on a 30 mg/cm2self‐supporting gold target. The initial analysis has identified a number of previously known discrete cascades in a variety of in‐beam reaction products. The decay of products has also been investigated and an initial comparison of their relative yields with predictions from the EPAX parameterisation begun. The relevance and future viability of this method as a complimentary technique to fragmentation‐isomer studies to investigate the near‐yrast properties of heavy, neutron‐rich nuclei is discussed. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517936

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

The importance of nuclear moments for understanding nuclear structure is discussed along with some new developments in moment measurement techniques. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517937

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Radioactive Nuclear Beams (RNBs) are opening new regions of the nuclear landscape to nuclear structure studies. Early experiments with RNBs rely on reactions with large cross sections, inverse kinematics, and very efficient detector geometries in order to measure observables that are very sensitive to structural features. A Coulomb excitation experiment extracted theB(E2;01+ → 21+) values of the neutron rich RNBs132,134Te at the HRIBF with the GRAFIK through‐well NaI(Tl) detector. In addition, other experiments with RNBs, such as Coulomb excitation of octupole states and reorientation experiments, inelastic scattering, and single‐particle transfer, will be discussed. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517938

出版商:AIP    

年代:1902

数据来源: AIP

摘要:

Level density parameters of the back‐shifted Fermi gas and of the constant temperature model were determined for 298 nuclei with a least squares fit to low energy levels and neutron resonances. The results are systematized with the valence correlation scheme and related to Casten’s triangle. © 2002 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1517939

出版商:AIP    

年代:1902

数据来源: AIP