Quasi-fission in fragment mass distribution of ²²⁵Pa

Quasi fission (QF) and fusion fission (FF) are two competing processes affecting the formation probability of Super Heavy Elements (SHE). To optimize the exploration of the super heavy element landscape, the key challenge is to understand the competition between QF and FF. Several experiments are being carried out worldwide to understand the dynamics of QF and FF, though there are scarcity of reliable theoretical models that efficiently predicts the amount of QF in a reaction. However, any new models that are being developed, needs to be tested from experimental data. The calculated yields of the events originated from quasi fission at different beam energies for ¹⁶O+²⁰⁹Bi and ²⁰Ne+²⁰⁵Tl reactions. It is interesting to observe that a significant amount of quasi-fission events is near the projectile mass region, though the yield drastically reduces in the symmetric mass region. Quasi-fission yields for both reaction w.r.t. mass number at different lab energies In the standard method of the measurement of the mass distributions, emphasize are given to get rid of the projectile like events using gas detectors operating at lower pressure. Since the width of the mass distributions are calculated only from the measured symmetric events, it deviates from the predication of model calculations that considers all the events. The present calculation indicates the need of detection of projectile like events in the experiment to test the reliability of the newly developed theoretical models to better understand the dynamics of quasi fission and fusion fission reaction mechanism