J Rapaport, D Wang, J Carr, F Petrovich, C Foster, C Goodman, C Gaarde, J Larsen, C Goulding, T Taddeucci, D Horen, E Sugarbaker
Differential cross-section and analyzing powers-+ for the (p,n) reaction on carbon isotopes have been measured for angles up to OL = 50" using 160 MeV protons. An excitation energy spectra for (p,n) reactions on carbon isotopes at OL = 0" is presented in Fig. 1. The angular distributions for the stronger transitions have been compared with the results of DWIA calculations which utilize transition densities from existing shell model calculations (Cohen and Kurath) and the free nucleon-nucleon
more » ... eraction strength as parameterized by Franey and Love at Ep = 175 MeV. The shapes of the calculated differential cross-section distributions are in reasonable quantitative agreement with the data for q G 1.2 fm-l and the qualitative differences in the distributions are well described even at higher q. The forward-angle cross sections for transitions with known B(GT) scale with the beta decay transition strengths, permitting the experimental determination of B(GT) for levels whose beta decay is energetically forbidden. The scale factor required for 13c is different from that for l2 914c. This effect has been noted in studies of other even and odd isotopes. The total observed B(GT) for 12c is in agreement with the predictions of CKWF. For 13C2 and 14c we obtain the missing strength fractions Q G ~ = 0.46 and 0.60 respectively, when comparing with CKWF. These results are consistent with global values of QGT presented elsewhere. The experimental and calculated