The Hoyle state in12C(Ex= 7.654MeV) is characterized by a pronounced 3Î± cluster configuration. It is involved in the so-called 3Î± process in stars, that is responsible of12C nucleosynthesis. We studied the decay path of the Hoyle state by using the14N(d, Î±2)12C(7.654) reaction at 10.5MeV incident energy. We found, with a precision higher of a factor 5 than any other previous experiment, an almost total absence of direct decays by-passing the ground state of8Be. A new upper limit of such a decay width is placed at 0.043% (95% C.L.). Astrophysical 3Î± process reaction rate calculations have to be consequently revised.
|Titolo:||A new high-precision upper limit of direct α-decays from the Hoyle state in 12C|
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|