Fine-tunings in radiative $alpha$-particle capture on $^{12}$C at astrophysical energies

Fine-tunings in radiative $alpha$-particle capture on $^{12}$C at astrophysical energies
Ulf-G. Mei{ss}ner, Bernard Ch. Metsch, Helen Meyer
arXiv:2601.11180v2 Announce Type: replace-cross
Abstract: We investigate the fine-tuning of radiative alpha-particle capture on carbon, $alpha(^{12}{rm C},^{16}{rm O})gamma$, at astrophysical energies. Utilizing results from cluster effective field theory for this reaction, we find that the low-energy data of the astrophysical S-factor allow for only very small variations in the electromagnetic fine-structure constant $alpha$, namely $|delta alpha/alpha| leq 0.2,$ per mille, in both the $E1$ and the $E2$ radiative capture.arXiv:2601.11180v2 Announce Type: replace-cross
Abstract: We investigate the fine-tuning of radiative alpha-particle capture on carbon, $alpha(^{12}{rm C},^{16}{rm O})gamma$, at astrophysical energies. Utilizing results from cluster effective field theory for this reaction, we find that the low-energy data of the astrophysical S-factor allow for only very small variations in the electromagnetic fine-structure constant $alpha$, namely $|delta alpha/alpha| leq 0.2,$ per mille, in both the $E1$ and the $E2$ radiative capture.