Determination of the Gamow-Teller Quenching Factor via the90Zr(n, p) Reaction at 293 MeV.

The double differential cross sections at 0°–12° were measured for the 90Zr(n,p) reaction at 293 MeV in a wide excitation energy region of 0–70 MeV. The experiment was performed by using the (n,p) facility at the Research Center for Nuclear Physics. The multipole decomposition (MD) technique was applied to the measured cross sections to extract the GT component in the continuum. After subtracting the contribution of the isovector spin-monopole excitation we obtained the GT strength of Sβ+ = 3.0 ± 0.3 ± 0.8 ± 0.5 up to 31.4 MeV excitation. The quenching factor Q was deduced by using the present result and the Sβ- value obtained from the MD analysis of the 90Zr(p,n) spectra. The result is Q = 0.83 ± 0.06 in regards to Ikeda’s sum rule value of 3(N - Z) = 30. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]