Proton capture resonant state of O 15 at 7556 keV

The slowest reaction in the CNO cycle $^{14}\mathrm{N}(p,\ensuremath{\gamma})^{15}\mathrm{O}$ has been studied by populating the ${E}_{p}^{\mathrm{lab}}=278$ keV (${E}_{\mathrm{c}.\mathrm{m}.}^{r}=259$ keV) proton capture resonant state of $^{15}\mathrm{O}$ at 7556 keV. The strength of the resonance ($\ensuremath{\omega}\ensuremath{\gamma}$) has been determined from the experimental data. The level lifetime of the subthreshold resonant state at ${E}_{x}=6792$ keV, as well as the lifetimes of the 5181 keV and 6172 keV states, have been measured using the Doppler shift attenuation method (DSAM). The structural properties of the nucleus $^{15}\mathrm{O}$, such as the level energies, transition strengths, level lifetimes, and spectroscopic factors, have been calculated theoretically by using the large basis shell model, which agrees reasonably well with the present as well as the previous experimental data.