Momentum transfer dependence of spin isospin modes in quasielastic (pvector ,nvector ) reactions.

A complete set of polarization transfer coefficients has been measured for quasielastic (&prarr;, ↛) reactions on ²H and [sup 12]C at a bombarding energy of 346 MeV and laboratory scattering angles of 16°, 22°, and 27°. The spin-longitudinal ID[sub q] and spin-transverse ID[sub p] polarized cross sections are deduced. The theoretically expected enhancement in the spin-longitudinal mode is observed. The observed ID[sub q] is consistent with the pionic enhanced ID[sub q] 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 ID[sub p] is not quenched, but rather enhanced in comparison with the DWIA+RPA calculation. [ABSTRACT FROM AUTHOR]