Momentum Transfer Dependence of Spin Isospin Modes in the Quasielastic Region.

Authors :: Wakasa, T.
Sakai, H.
Ichimura, M.
Hatanaka, K.
Greenfield, M.B.
Okamura, H.
Kawahigashi, K.
Tamii, A.
Otsu, H.
Nakaoka, Y.
Ohnishi, T.
Yako, K.
Sekiguchi, K.
Yagita, T.
Kamiya, J.
Sakoda, S.
Suda, K.
Kato, H.
Hatano, M.
Source :: AIP Conference Proceedings. 2003, Vol. 675 Issue 1, p734. 7p.
Publication Year :: 2003
Abstract: A complete set of polarization transfer coefficients has been measured for the quasi-elastic 12C(pvector ,nvector ) reaction at a bombarding energy of 345 MeV and laboratory scattering angles of 16°, 22°, and 27°. The spin-longitudinal IDq and spin-transverse IDp polarized cross sections are deduced. The theoretically expected enhancement in the spin-longitudinal mode is observed. The observed IDq is consistent with the pionic enhanced IDq evaluated in a distorted wave impulse approximation (DWIA) calculation employing a random phase approximation (RPA) response function. On the contrary, the theoretically predicted quenching in the spin-transverse mode is not observed. The observed IDp is not quenched, but rather enhanced in comparison with the DWIA+RPA calculation. Two-step contributions are responsible in part for the enhancement of ID p. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]