1212.2884 (Peter Mohr)

Direct capture in the $^{130}$Sn(n,$γ$)$^{131}$Sn and
$^{132}$Sn(n,$γ$)$^{133}$Sn reactions under $r$-process conditions    [PDF]

Peter Mohr

The cross sections of the $^{130}$Sn(n,$\gamma$)$^{131}$Sn and $^{132}$Sn(n,$\gamma$)$^{133}$Sn reactions are calculated in the direct capture model at low energies below 1.5\,MeV. Using recent data from (d,p) transfer experiments on $^{130}$Sn and $^{132}$Sn, it is possible to avoid global input parameters with their inherent uncertainties and to determine all input to the direct capture model by local adjustments. The calculated direct capture cross sections of $^{130}$Sn and $^{132}$Sn are almost identical and have uncertainties of less than a factor of two. The stellar reaction rates $N_A < \sigma v >$ show a slight increase with temperature. Finally an estimate for the influence of low-lying resonances to the stellar reaction rates is given.

View original: http://arxiv.org/abs/1212.2884