Spin Excitations in Nuclei

ISBN-13: 9781468447088 / Angielski / Miękka / 2012 / 660 str.

Fred Petrovich

Opis

This volume contains the proceedings of the "International Conference on Spin Excitations in Nuclei" held in Telluride, Colo rado, March 25-27, 1982. The motivation for the conference was, in a large part due to the recent development of new variable energy accelerators which produce high quality beams of electrons, protons, and pions that are providing the first precise information on spin excitations in nuclei over a large range of spin and mass. In the past such data had been restricted primarily to light nuclei and were generally resolution limited. Perhaps, the most exciting new result has been the clear observation of the elusive spin-dipole strength (Gamow Teller and Ml) in medium and heavy mass nuclei through the use of the (p, n) and (p, p') reactions at or near zero degrees with 100-200 MeV incident protons. Energy dependence in the isovector parts of the nucleon-nucleon interaction make the 100-200 MeV energy region particularly appropriate for such studies. The clean data from (e, e'), ('IT, 'IT'), (p, p'), and (p, n) on high spin "stretched" states which have particularly simple structure has also been quite impor tant. The recent results contain important new information on the nature of the spin dependent forces in nuclei. These in turn are inherently related to the properties of the nuclear mesonic field and the underlying quantum chromodynamics."

Spis treści

Session I: Introduction and Overview.- Opening Remarks: Basic Quark Considerations.- Shell Model Picture of Nuclear Magnetic Moments.- Spin-Isospin Response Functions in Nuclei.- The Search for Ml Strength.- Charge Exchange Reactions and Spin Modes.- Observation of M1 Strength in Medium-Heavy Nuclei via the (p,p?) Reaction.- Session II: The Role of the Meson Field in Spin Excitations.- Nucleus as a Chiral Filter: The Role of the ? (1232).- Magnetic Moments Revisited.- The Experimental Evidence for Gamow-Teller Quenching.- Evidence for A-h Components From Pion Reactions.- Constraints on Pion Condensates and Precursors from Nuclear Spin-Isospin Excitations.- Renormalization of Axial Beta and Magnetic Gamma Transitions with ?l = 1 and the Related Giant Resonances.- Lorentz-Lorenz Quenching for the Gamow-Teller Sum Rules.- Session III: Reactions and Effective Interactions.- The Nucleon-Nucleon Interaction and Nucleon-Nucleus Scattering.- Meson Exchange Models for Effective Interactions.- Comments: ? Versus Core Polarization.- Implications of Density Dependence in the Effective Interaction for the Excitation of Spin Modes.- Models for Pion-Nucleus Reactions.- Spin Excitations in Pion Inelastic Scattering.- Spin Flip 1+ Excitations by Inelastic Hadron Scattering.- Session IV: High Spin States, Spin Observables, and Damping.- Studies of Spin Excitations with Electromagnetic and Hadronic Probes.- Spin Observables in Nucleon-Nucleus Scattering.- Studies of Spin Excitation Using Polarized Protons.- High-Spin States in the (p,n) Reaction.- Background Calculations for (p,n)-Reactions at Intermediate Energies.- Damping of Spin Resonances.- Spin Modes in the Low-Energy (p,n) Reaction.- Spin Flip 1+ Strength in N=28 Isotones by Proton Inelastic Scattering at 65 MeV.- Session V: Multipole Dependence, Currents, and Other Reactions.- Dynamical Theory of Spin Excitations.- Spin Excitations in 208Pb.- Transverse Contributions to Natural Parity Excitations.- Convection Current Contributions to Spin Excitations.- Can We Learn About the Spin Flip Giant Dipole Resonances with Pions?.- Future Possibilities for (n,p) Studies at Intermediate Energies.- Isovector Spin States Observed in Radiative Pion Capture in Flight and at Rest: Recent Results from SIN.- Session VI: Implications and Impact of New Results.- 0- to 0+ Beta Decay in ? = 16.- Gamow-Teller Strength Distributions in Astrophysics.- Gamow-Teller Strength Functions and Neutrino Problems.- Experimental Perspective.- Unresolved Theoretical Problems.- Participants.