Isospin transport effects in nuclear reactions at 25 MeV/nucleon

Abstract

Isotopic effects are studied in reactions induced by $^{40}\mathrm{Ca}$ projectiles at 25 MeV/nucleon on $^{40}\mathrm{Ca}$, $^{48}\mathrm{Ca}$, and $^{46}\mathrm{Ti}$ targets. The $N/Z$ contents of projectilelike and midvelocity (MV) sources are probed by means of isotopic ($^{7}\mathrm{Li}/^{6}\mathrm{Li}$ and $^{9}\mathrm{Be}/^{7}\mathrm{Be}$) and isobaric ($^{7}\mathrm{Li}/^{7}\mathrm{Be}$) yield ratios, for semiperipheral events. In particular, information about isospin transport phenomena will be discussed. Isospin diffusion processes involving nuclei, which have noticeable differences in $N/Z$ have been investigated. Signals of isospin drift, which are related to the gradient of density in the participant region, have also been observed for fragments emitted at MV.