GAMOW-TELLER STRENGTH IN NA-23(N,P) AND A COMPARISON TO NA-23(MU(-),NU)

We report measurements of the Na-23(n,p) differential cross section at an incident energy of 198 MeV and angles from 0 degrees to 24 degrees using the TRIUMF Charge Exchange Facility. From these data we determine Gamow-Teller (GT) transition probabilities to low lying 1/2(+), 3/2(+), and 5/2(+) Ne-23 states and the GT(+) strength distribution up to 25 MeV excitation energy. The values of B-GT(+) to discrete states, and the GT(+) strength below 10 MeV, are found to be in reasonable agreement with a full Is-Od shell model calculation with a normalization factor of about 0.74. The GT(+) strength above 10 MeV suggests the removal of strength from lower to higher excitation energies. We also compare the Na-23(n,p) data with Na-23(mu(-),nu) data and find agreement between the values of B-GT(+) to discrete levels extracted from the (n,p) and (mu(-),nu) reactions. The general consistency of the (n,p) and (mu(-), nu) data, and the full 1s-Od shell model calculation, give confidence in a recent extraction of the weak pseudoscalar coupling from mu(-) capture on Na-23. Finally, using both beta(-)-decay and mu(-) capture data, we obtain unit cross sections from the Na-23(n,p) measurement.