Absolute (, p0) and (, p1) cross sections and angular distributions for the closed-neutron shell nucleus Y89

Absolute (, p0) and (, p1) differential cross sections for Y89 were measured at seven angles in the energy interval between 13 and 24.6 MeV, from which the angular distribution coefficients were deduced by fitting a sum of Legendre polynomials. In these cross sections we observe a number of isolated resonances which can be identified as the isobaric analogs of known 12+ and 32+ excited states in the Sr89 parent nucleus. The appearance of a maximum around 21 MeV excitation energy in both total cross sections may indicate the existence of the T> coherent dipole state. From the angular distribution coefficients in the (, p0) channel, an upper and lower limit for the E2 photon absorption were estimated as being equal to 22% and 6%, respectively, of the total E2 energy-weighted sum rule. NUCLEAR REACTIONS Y89(, p0), (, p1), E=13.0-24.6 MeV, =37-143°; measured (E;) absolutely. Deduced (E; p0), (E; p1); E1, E2 strengths, isobaric analog states, isospin splitting. Natural target.