Experimental study of resonant states in P-27 via elastic scattering of Si-26+p

Abstract

Proton resonant states in P-27 were studied by the resonant elastic scattering of Si-26 + p with a Si-26 radioactive ion beam bombarding a thick H-2 gas target with the inverse kinematics method. The properties of these resonance states are important to better constrain the production rates of the Si-26( p, gamma)P-27 reaction. This is one of the astrophysically important reactions needed to understand proton-rich nucleosynthesis such as the galactic production of Al-26 and energy generation in explosive stellar environments. Although there are recent studies on the resonant structure in P-27, large uncertainties remain, and only a few levels are known. In this work, resonant states were observed over the excitation energies range of 2.3 to 3.8 MeV with high statistics and without background contamination within the target. The resonance parameters were extracted by an R-matrix analysis of the excitation function. The Si-26( p,gamma)P-27 stellar reaction rate has been evaluated, including high-lying resonances found in this work.