The Galactic 1.809-MeV γ-ray signature from the β decay of Al26g is a dominant target of γ-ray astronomy, of which a significant component is understood to originate from massive stars. The Al26g(p,γ)Si27 reaction is a major destruction pathway for Al26g at stellar temperatures, but the reaction rate is poorly constrained due to uncertainties in the strengths of low-lying resonances in Si27. The Al26g(d,p)Al27 reaction has been employed in inverse kinematics to determine the spectroscopic factors, and hence resonance strengths, of proton resonances in Si27 via mirror symmetry. The strength of the 127-keV resonance is found to be a factor of 4 higher than the previously adopted upper limit, and the upper limit for the 68-keV resonance has been reduced by an order of magnitude, considerably constraining the Al26g destruction rate at stellar temperatures.
Publication Source (Journal or Book title)
Physical Review Letters
Pain, S., Bardayan, D., Blackmon, J., Brown, S., Chae, K., Chipps, K., Cizewski, J., Jones, K., Kozub, R., Liang, J., Matei, C., Matos, M., Moazen, B., Nesaraja, C., Okołowicz, J., O'Malley, P., Peters, W., Pittman, S., Płoszajczak, M., Schmitt, K., Shriner, J., Shapira, D., Smith, M., Stracener, D., & Wilson, G. (2015). Constraint of the astrophysical Al 26g (p,γ) Si 27 destruction rate at stellar temperatures. Physical Review Letters, 114 (21) https://doi.org/10.1103/PhysRevLett.114.212501