SMITH, Robin, GAI, Moshe, AHMED, Mohammad, FREER, Martin, FYNBO, Hans, SCHWEITZER, Deran and STERN, Sarah (2020). Stringent upper limit on the direct 3α decay of the Hoyle state in 12C. Physical Review C: Nuclear Physics, 101, 021302(R).
|
PDF
HoyleBR_PRL_HIGS_Submission.pdf - Accepted Version All rights reserved. Download (646kB) | Preview |
Abstract
We investigate an implication of the most recent observation of a second Jπ=2+ state in 12C, which was measured using the 12C(γ,α)8Be(g.s.) reaction. In addition to the dissociation of 12C to an α-particle and 8Be in its ground state, a small fraction of events (2%) were identified as direct decays and decays to excited states in 8Be. This allowed a limit on the direct 3α partial decay width to be determined as Γ3α<32(4) keV. Since this 2+ state is predicted by all theoretical models to be a collective excitation of the Hoyle state, the 3α partial width of the Hoyle state is calculable from the ratio of 3α decay penetrabilities of the Hoyle and 2+ states. This was calculated by using the semiclassical Wenzel-Kramers-Brillouin approach and we deduce a stringent upper limit for the direct decay branching ratio of the Hoyle state of Γ3α Γ <5.7×10−6, over an order of magnitude lower than previously reported. This result places the direct measurement of this rare decay mode beyond current experimental capabilities.
Item Type: | Article |
---|---|
Uncontrolled Keywords: | Materials and Engineering Research Institute; Department of Engineering and Mathematics; 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics; Nuclear & Particles Physics |
Identification Number: | https://doi.org/10.1103/PhysRevC.101.021302 |
Page Range: | 021302(R) |
SWORD Depositor: | Symplectic Elements |
Depositing User: | Symplectic Elements |
Date Deposited: | 05 Feb 2020 10:10 |
Last Modified: | 18 Mar 2021 02:17 |
URI: | https://shura.shu.ac.uk/id/eprint/25801 |
Actions (login required)
View Item |
Downloads
Downloads per month over past year