New aspect of intermediate energy heavy ion reactions. Large spin polarization of fragments

The spin polarization, P, of ¹²B ejectiles has been measured for projectile fragmentation reactions induced by a 40.6 MeV/u ¹⁴N beam. Large values of P were observed, showing a characteristic dependence on the outgoing momentum including a sign change occurring at a momentum corresponding to the beam velocity. This behavior corresponds well with simple kinematical arguments based on projectile fragmentation models.