Isovector and Gamow-Teller Strength from Small-Angle (<span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>n</mi><mo>,</mo><mi> </mi><mi>p</mi></math></span>) Reactions at 60 MeV

F. P. Brady; C. M. Castaneda; G. A. Needham; J. L. Ullmann; J. L. Romero; T. Ford; M. L. Johnson; N. S. P. King; C. M. Morris; F. Petrovich; R. H. Howell

doi:10.1103/PhysRevLett.48.860

Isovector and Gamow-Teller Strength from Small-Angle ( $n, p$ ) Reactions at 60 MeV

F. P. Brady, C. M. Castaneda, G. A. Needham, J. L. Ullmann, J. L. Romero, T. Ford, M. L. Johnson, N. S. P. King, C. M. Morris, F. Petrovich, and R. H. Howell

Phys. Rev. Lett. 48, 860 – Published 29 March 1982

Abstract

The ( $n, p$ ) reactions to the analog giant magnetic dipole states, the inverse of the transitions in allowed Gamow-Teller $β$ decay, have been measured for ${}^{6}{Li}$ , ${}^{12}C$ , and ${}^{28}{Si}$ for forward angles using 59.6-MeV neutrons. With use of a relation between $σ (0 °)$ and the $β$ -decay matrix elements, there results ${v_{σ τ}}^{c} (0) = 157 \pm 11$ MeV ${fm}^{3}$ for the $l = 0$ , isovector part of the effective spin-flip nucleon-nucleon interaction. Comparison with 120-MeV ( $p, n$ ) reactions indicates that ${v_{σ τ}}^{c}$ has a small energy dependence in the range 60 to 120 MeV.

Received 20 August 1981

DOI:https://doi.org/10.1103/PhysRevLett.48.860

Authors & Affiliations

F. P. Brady, C. M. Castaneda, G. A. Needham^*, J. L. Ullmann^†, J. L. Romero, T. Ford, and M. L. Johnson

Department of Physics and Crocker Nuclear Laboratory, University of California, Devis, California 95616

N. S. P. King and C. M. Morris

Los Alamos National Laboratory, Los Alamos, New Mexico 87545

F. Petrovich

Florida State University, Tallahassee, Florida 32306

R. H. Howell

Lawrence Livermore Laboratory, Livermore, California 94550

^*Present address: Rockwell International, Canoga Park, Cal. 91304.
^†Present address: Nuclear Physics Laboratory, University of Colorado, Boulder, Colo. 80309.