Primaryγ-ray spectra in44Ti of astrophysical interest

Abstract

Primary $\ensuremath{\gamma}$-ray spectra for a wide excitation-energy range have been extracted for ${}^{44}$Ti from particle-$\ensuremath{\gamma}$ coincidence data of the ${}^{46}$Ti($p,t\ensuremath{\gamma}$)${}^{44}$Ti reaction. These spectra reveal information on the $\ensuremath{\gamma}$-decay pattern of the nucleus and may be used to extract the level density and radiative strength function applying the Oslo method. Models of the level density and radiative strength function are used as input for cross-section calculations of the ${}^{40}$Ca($\ensuremath{\alpha},\ensuremath{\gamma}$)${}^{44}$Ti reaction. Acceptable models should reproduce data on the ${}^{40}$Ca($\ensuremath{\alpha},\ensuremath{\gamma}$)${}^{44}$Ti reaction cross section as well as the measured primary $\ensuremath{\gamma}$-ray spectra. This is only achieved when a coherent normalization of the slope of the level density and radiative strength function is performed. Thus, the overall shape of the experimental primary $\ensuremath{\gamma}$-ray spectra puts a constraint on the input models for the rate calculations.