Fission fragment mass distributions in reactions populating 200Pb

TL;DR

This study measures fission fragment mass distributions in reactions leading to 200Pb, revealing a monotonic increase in width with excitation energy and providing evidence against the presence of quasi-fission in these reactions.

Contribution

It provides the first detailed comparison of mass distributions in reactions populating 200Pb, challenging recent claims of quasi-fission presence.

Findings

Mass distribution widths increase with excitation energy

No evidence of quasi-fission in the studied reactions

Supports the compound nucleus formation hypothesis

Abstract

The fission fragment mass distributions have been measured in the reactions 16O + 184W and 19F+ 181Ta populating the same compound nucleus 200Pb? at similar excitation energies. It is found that the widths of the mass distribution increases monotonically with excitation energy, indicating the absence of quasi-fission for both reactions. This is contrary to two recent claims of the presence of quasi-fission in the above mentioned reactions.