Weak interaction rates in O-16 and O-18 - art. no. 045501

The weak interaction rates in O-16,O-18 are investigated in detail in a lar ge shell-model space. Special attention is given to the muon capture proces s, which populates the states in N-16,N-18. The best agreement with experim ental rate is obtained when unquenched weak-coupling constants are used. Th e roles of different multipoles are discussed, along with their strength di stributions. The extracted mean excitation energy in muon capture is 10.6 M eV in O-16 and 9.9 MeV in O-18, close to the dipole resonance. The isotope effect is also discussed.