Upper Limit on the molecular resonance strengths in the ${}^{12}$C+${}^{12}$C fusion reaction

TL;DR

This paper establishes an upper limit on molecular resonance strengths in the ${}^{12}$C+${}^{12}$C fusion reaction, crucial for understanding carbon burning in astrophysics, based on cross section comparisons of related fusion reactions.

Contribution

It introduces a novel method to constrain resonance strengths in ${}^{12}$C+${}^{12}$C fusion by comparing related carbon isotope fusion reactions.

Findings

Set an upper limit on molecular resonance strengths in ${}^{12}$C+${}^{12}$C fusion.

Provides preliminary results impacting astrophysical reaction rate estimates.

Highlights uncertainties in extrapolating reaction rates at astrophysical energies.

Abstract

Carbon burning is a crucial process for a number of important astrophysical scenarios. The lowest measured energy is around E$_{\rm c.m.}$=2.1 MeV, only partially overlapping with the energy range of astrophysical interest. The currently adopted reaction rates are based on an extrapolation which is highly uncertain because of potential resonances existing in the unmeasured energy range and the complication of the effective nuclear potential. By comparing the cross sections of the three carbon isotope fusion reactions, ${}^{12}$C+${}^{12}$C, ${}^{12}$C+${}^{13}$C and ${}^{13}$C+${}^{13}$C, we have established an upper limit on the molecular resonance strengths in ${}^{12}$C+${}^{12}$C fusion reaction. The preliminary results are presented and the impact on nuclear astrophysics is discussed.