Determination of the Gamow-Teller quenching factor from charge exchange reactions on 90Zr

Double differential cross sections between 0°-12° were measured for the 90Zr(n, p) reaction at 293 MeV over a wide excitation energy range of 0-70 MeV. A multipole decomposition technique was applied to the present data as well as the previously obtained 90Zr(p, n) data to extract the Gamow-Teller (GT) component from the continuum. The GT quenching factor Q was derived by using the obtained total GT strengths. The result is Q=0.88±0.06, not including an overall normalization uncertainty in the GT unit cross section of 16%.