Sensitive search for near-symmetric and super-asymmetric fusion-fission of the superheavy element Flerovium (Z=114)

Measurements of mass and angular distributions have been made for fission-like outcomes in reactions forming isotopes flerovium (Z=114), using 48Ca, 50Ti, 54Cr projectiles. The dominant fast quasifission process, which masks the presence fusion-fission, has minimum yield at most backward angles, where sensitivity to fusion-fission is thus highest. In fitting angle spectra, only weak evidence a component super-asymmetric fission was found, but near-symmetric consistently required 48Ca + 244Pu reaction, giving upper limit fusion probabilities PCN ?10?2, ?5 times lower than previous results. 50Ti reaction whilst no found reaction.