Peculiarities of quasifission reactions in heavy ion collisions

The probability of the formation and decay of a dinuclear system is investigated for a wide range of relative orbital angular momentum values. The mass and angular distributions of the quasifission fragments are studied to understand the reaction mechanisms of the heavy ion collision of ${}^{78}$Kr(10$A$ MeV) + ${}^{40}$Ca within dinuclear system model. The quasifission products are found to contribute to the mass-symmetric region of the mass distribution in collisions with a large orbital angular momentum. The analysis of mass and angular distributions of quasifission fragments shows the possibility of the ${180}^{\circ }$ rotation of the system so that projectile-like products can be observed in the forward hemisphere with large cross sections, which can explain the phenomenon observed recently in the ISODEC experiment.