Isoscalar high-energy octupole resonance inZr92in inelastic electron scattering

Abstract

The giant-resonance region in $^{92}\mathrm{Zr}$ has been studied by inelastic electron scattering of the effective momentum transfer range $0.65\ensuremath{\le}{q}_{\mathrm{eff}}\ensuremath{\le}1.18$ ${\mathrm{fm}}^{\ensuremath{-}1}$. The high-energy octupole resonance was identified at ${E}_{x}=25\ifmmode\pm\else\textpm\fi{}0.3$ MeV with a width of 6.3\ifmmode\pm\else\textpm\fi{}0.3 MeV exhausting 39\ifmmode\pm\else\textpm\fi{}4% of the $T=0$ $E3$ energy weighted sum rule. This result is in good agreement with a recent ($^{3}\mathrm{He}$, $^{3}\mathrm{He}$') result and the recent random-phase approximation calculations, and its strength is inconsistent with the trend of low strength of the high-energy octupole resonances observed by inelastic proton scattering.NUCLEAR REACTIONS $^{92}\mathrm{Zr}$(e,e'), enriched target, ${E}_{0}=220$ MeV, $\ensuremath{\theta}=32\ifmmode^\circ\else\textdegree\fi{}\ensuremath{-}61\ifmmode^\circ\else\textdegree\fi{}$, $q=0.65\ensuremath{-}1.18$ ${\mathrm{fm}}^{\ensuremath{-}1}$. Measured $\frac{{d}^{2}\ensuremath{\sigma}}{d\ensuremath{\Omega}d{E}_{x}}$ up to 33 MeV in excitation energy; deduced excitation energy, width, sum rule exhaustion of isoscalar high-energy octupole resonance.