High energy octupole resonance in Sn-116

Journals published by the American Physical Society can be found at http://publish.aps.org/The region of excitation energy from 7 less than or equal to E(x) less than or equal to 38 MeV in Sn-116 was studied with inelastic scattering of 240 MeV alpha particles. Parameters obtained for the isoscalar giant monopole resonance and the isoscalar giant quadrupole resonance are in agreement with accepted values. A peak exhausting (67 +/- 10)% of the E3 energy-weighted sum rule at E(x)= 21.8 +/- 0.5 MeV with width r = 7.1 +/- 0.5 MeV was identified as the isoscalar high energy octupole resonance (HEOR). The energy and width are consistent with previous measurements made with proton, He-3, and alpha particle projectiles. The observed strength of the HEOR is in agreement with measurements made with He-3 inelastic scattering, but is roughly three to four times larger than measurements made with alpha particle and proton inelastic scattering