Abstract
The thermonuclear P30(p,γ)S31 reaction rate is critical for modeling the final elemental and isotopic abundances of ONe nova nucleosynthesis, which affect the calibration of proposed nova thermometers and the identification of presolar nova grains, respectively. Unfortunately, the rate of this reaction is essentially unconstrained experimentally, because the strengths of key S31 proton capture resonance states are not known, largely due to uncertainties in their spins and parities. Using the β decay of Cl31, we have observed the β-delayed γ decay of a S31 state at Ex=6390.2(7) keV, with a P30(p,γ)S31 resonance energy of Er=259.3(8) keV, in the middle of the P30(p,γ)S31 Gamow window for peak nova temperatures. This state exhibits isospin mixing with the nearby isobaric analog state at Ex=6279.0(6) keV, giving it an unambiguous spin and parity of 3/2+ and making it an important l=0 resonance for proton capture on P30.
Original language | English |
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Article number | 102502 |
Journal | Physical Review Letters |
Volume | 116 |
Issue number | 10 |
DOIs | |
State | Published - Mar 8 2016 |