$\beta$-delayed proton-decay study of $^{20}\mathrm{Mg}$ and its implications for the breakout reaction in {X}-ray bursts
| Pub type: | Article |
| Citation: | Wallace201259 |
| Status: | Published |
| Journal: | Physics Letters B |
| Volume: | 712 |
| Year: | 2012 |
| Month: | May |
| Pages: | 59 - 62 |
| ISSN: | 0370-2693 |
| URL: | http://www.sciencedirect.com/s... |
| DOI: | 10.1016/j.physletb.2012.04.046 |
| Abstract: | Under astrophysical conditions of high temperature and density, such as for example found in X-ray bursts, breakout can occur from the hot \{CNO\} cycles into the rapid proton capture process. A key breakout route is via the sequence O 15 ( α , γ ) Ne 19 ( p , γ ) Na 20 . The Ne 19 ( p , γ ) Na 20 reaction rate is expected to be dominated by a single resonance at 457(3) keV. The identity of the resonance has been under discussion for a long time, with J π = 1 + and 3 + assignments suggested. In this study of the β-delayed proton decay of 20Mg we report a new, significantly more stringent, upper limit on the β-decay branch to this state of 0.02% with a confidence level of 90%. This makes a 1 + assignment highly unlikely and favours a 3 + assignment for which no branch is expected to be observed. The 3 + state is predicted to have a significantly higher resonance strength, and to produce a proportionately higher Ne 19 ( p , γ ) Na 20 reaction rate in X-ray burst conditions. |
| Month_val: | 5 |
| Userfields: | issue = {1-2} |
| Keywords: | Explosive nuclear astrophysics, Hot CNO breakout, Nuclear structure, X-ray bursts, β-p decay of 20Mg |
| Authors: | |
| Added by: | [DGM] |
| Total mark: | 0 |
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