Data on photoproton and photoneutron 90Zr disintegration decay channels defined main parameters of giant dipolew resonance (GDR) isospin splitting are investigated in details. New data on photoneutron reaction 90Zr($\gamma$,n)89Zr and 90Zr($\gamma$,2n)88Zr cross sections obtained as results of combined joint correction of two experiments carried out with quasimonoenergetic annihilation photons at Livermore (USA) and Saclay (France) were analyzed. An information on energy positions of states with various values of isospin in 90Zr and neighbouring nuclei - members of the correspondent isospin multiplet - were included in analysis additionally. New data on 90Zr GDR isospin splitting parameters were obtained on the base of joint analysis of data on GDR states appeared as resonances in photoproton and photoneutron reaction cross sections and possible channels of their decay via states with various isospin values in neighbouring nuclei.
Document number: 2003-25/738
Authors: I.N.Boboshin, V.V.Varlamov, I.V.Safonov, M.E.Stepanov, M.G.Urin
Email: varlamov@depni.sinp.msu.ru