Kr84(t,p)Kr86andKr86(t,p)Kr88reactions

The ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ and ${}_{}{}^{88}{}_{}{}^{}\mathrm{Kr}$ nuclei have been studied by the ${}_{}{}^{84,86}{}_{}{}^{}\mathrm{Kr}\mathrm{}(t,p)\mathrm{}$ reactions at $E_t=17.0\mathrm{}$ MeV. Energy levels up to 6400 and 4400 keV excitation in ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ and ${}_{}{}^{88}{}_{}{}^{}\mathrm{Kr}$, respectively, were observed. Differential cross sections for many excited states have been extracted from 12° to 50° c.m. for ${}_{}{}^{88}{}_{}{}^{}\mathrm{Kr}$ and 12° to 55° c.m. for ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$. The data are compared with DWBA calculations in order to obtain the angular momentum ($L$) transfer as well as nuclear structure information. The excited $L=0\mathrm{}$ strength leading to ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ in the region where the pairing vibration is expected is found to be fractionated and about $\frac{2}{3}$ of the intensity of the ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ → ${}_{}{}^{88}{}_{}{}^{}\mathrm{Kr}$ (g.s.) transition strength. Strong $L=2\mathrm{}$ transitions are found above this excited $L=0\mathrm{}$ strength in ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ and appear to have their parentage in the pairing quadrupole states represented by the first $2^{+}$ level in ${}_{}{}^{88}{}_{}{}^{}\mathrm{Kr}$. The ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ spectrum and transition strengths as found in the ($t,p$) reaction are compared with the ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}(p,p^{\prime })$ and ${}_{}{}^{87}{}_{}{}^{}\mathrm{Rb}(t,\alpha )$ experiments.