Resonant suppression of the above-barrier fusion cross-section in $^{19}$O + $^{12}$C

TL;DR

This study measures fusion cross-sections for oxygen and fluorine isotopes with carbon, revealing a suppression in fusion for $^{19}$O + $^{12}$C above the Coulomb barrier, possibly due to transient molecular complex formation.

Contribution

It provides the first simultaneous measurement of fusion excitation functions for $^{19}$O and $^{19}$F + $^{12}$C, highlighting a unique suppression phenomenon in $^{19}$O fusion.

Findings

Significant suppression of fusion for $^{19}$O + $^{12}$C at E$_{c.m.}$~12 MeV.

Suppression potentially caused by transient $^{18}$O-n-$^{12}$C molecular complex.

Mean-field models used as a reference to interpret the results.

Abstract

Fusion excitation functions for $^{19}$O and $^{19}$F + $^{12}$C were simultaneously measured along with $^{20}$O + $^{12}$C using the active-target detector MuSIC@Indiana. Examination of the cross-section just above the barrier reveals a significant suppression of fusion for the $^{19}$O + $^{12}$C system at E$_{c.m.}$~12 MeV. This suppression may be due to the formation of a transient $^{18}$O-n-$^{12}$C molecule-like complex favored at a particular angular momentum. Mean-field level models are used as a reference to understand the measured fusion excitation functions.