Status of the Nuclear Shell Model

1 . INTRODUCTION....................................................................................................... 29 2. MODEL SPACES AND EFFECTIVE HAMILTONIANS ......................................................... 32 2.1 Model-Independent Eff ective HamiltoniansThe W Interaction/or sd-Shell Nuclei ........................................... .................................................... ..... 35 2.2 Potential Models/or Effective Shell-Model Interactions................................... 39 3. GAMOW-TELLER AND MAGNETIC DIPOLE MATRIX ELEMENTS ................................. ..... 40 3.1 Free-Nucleon and Effective Operators ..... ............................... .......................... 42 3.2 Gamow-Teller Results ...................................................................................... 43 3.3 Magnetic Dipole Results . . . . . . . . . . . . . ......... . . . . . . . . . . . . . . . . . . . . . . . . ............... . . . . . . ....... . . . . . . . . 46 3.4 Empirical versus Theoretical Correctionsjor Excluded Configurations ............. 49 4. ELECTRIC QUADRUPOLE MATRIX ELEMENTS............................................................... 52 5. HIGHER-MULTIPOLE MATRIX ELEMENTS AND ELECTRON SCATTERING FORM FACTORS.. 54 6. STUDIES IN OTHER MASS REGIONS.................. ........ ...... ............................................. 59 7. PROSPECTS FOR THE FUTURE.................................................................................... 61