학술논문
Clarifying the Radiative Decay of the Hoyle State with Charged-Particle Spectroscopy
Document Type
Working Paper
Author
Dell'Aquila, D.; Lombardo, I.; Redigolo, L.; Vigilante, M.; Angelini, F.; Baldesi, L.; Barlini, S.; Best, A.; Camaiani, A.; Casini, G.; Ciampi, C.; Cicerchia, M.; D'Andrea, M.; Diklić, J.; Fabris, D.; Servin, B. Gongora; Gottardo, A.; Gramegna, F.; Imbriani, G.; Marchi, T.; Massara, A.; Mengoni, D.; Ordine, A.; Palada, L.; Pasquali, G.; Piantelli, S.; Pilotto, E.; Rapagnani, D.; Sigmund, M.; Stefanini, A.; Stramaccioni, D.; Tagnani, D.; Tišma, I.; Valdré, S.; Verde, G.; Vukman, N.
Source
Subject
Language
Abstract
A detailed knowledge of the decay properties of the so called Hoyle state in the $^{12}$C nucleus ($E_x=7.654$ MeV, $0^+$) is required to calculate the rate at which carbon is forged in typical red-giant stars. This paper reports on a new almost background-free measurement of the radiative decay branching ratio of the Hoyle state using advanced charged particle coincidence techniques. The exploitation, for the first time in a similar experiment, of a bidimensional map of the coincidence efficiency allows to reach an unitary value and, consequently, to strongly reduce sources of systematic uncertainties. The present results suggest a value of the radiative branching ratio of $\Gamma_{rad}/\Gamma_{tot}=4.2(6)\cdot10^{-4}$. This finding helps to resolve the tension between recent data published in the literature.