A perturbative calculation is reported for the mixing of Gamow-Teller strength with two-particle two-hole configurations at high excitation energies. We find that roughly 50% of the Gamow-Teller strength is shifted into the region of 10-45 MeV excitation for the nucleus ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$. This would explain a substantial part of the continuum background seen in the 200 MeV ($p, n$) reaction.

NUCLEAR STRUCTURE ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, Gamow-Teller strength function, $E_{\mathrm{ex}}=10-45\mathrm{}$ MeV, theory.

• Received 14 May 1982

DOI:https://doi.org/10.1103/PhysRevC.26.1323