Isospin splitting of giant resonances inC13andO17

Abstract

The two-particle, one-hole shell model with a harmonic oscillator basis is employed for a calculation of isospin-split giant resonance states in $^{13}\mathrm{C}$ and $^{17}\mathrm{O}$ that can be reached from the ground state by $\ensuremath{\Delta}T=0,1$ transitions of type $E1$ or $M2$. Residual forces used were a zero-range Soper mixture as well as the separable Tabakin potential. We calculate photoabsorption strengths which for $^{13}\mathrm{C}$ agree with the available data and with a previous calculation of Easlea using the Soper force; for the Tabakin force, this agreement is achieved without Easlea's ad hoc modification of the interaction. We also evaluate the inelastic form factors for electroexcitation of the $^{13}\mathrm{C}$ resonance levels, thereby identifying isospin and spin-isospin collective states.NUCLEAR REACTIONS $^{13}\mathrm{C}$ calculated photonuclear cross sections, electron scattering form factors of giant and pygmy resonances (${T}_{>},{T}_{<}$); $^{17}\mathrm{O}$ calculated photonuclear cross sections. Used two-particle, one-hole shell model.