Neutron capture on $$^{16}$$O within the framework of RMF + ACCC + BCS for astrophysical simulations

Impact of the decay width in Breit-Wigner formula on Maxwellian-averaged cross section for neutron capture on 16O

“…The cross section of neutron capture on 16 O mainly consists of three parts: direct capture, resonance, and the interference between the direct capture and the resonance. We have estimated these terms separately and found that the contribution from low-lying resonance to Maxwellian-averaged cross section (MACS) progressively increases as the energy goes beyond 70 keV, in which the resonant cross section takes the form of Breit-Wigner formula with an energy-dependent decay width [2,3].…”

“…Usually, the decay width of a resonant state is defined as a constant in textbooks and some references [4,5]. Except for a constant width, an energy-dependent width is also utilized in some works [6][7][8], including our former attempts [2,3]. There are two ways commonly used to obtain an energy-dependent width.…”

“…One way is to calculate the penetration factor by using semi-classical WKB approximation, then decay width as a function of energy can be evaluated. The other way is to express penetration factor by the asymptotic solution (AS) of Bessel function, which is adopted in our former work [3]. Here, we aim at clarifying the effectiveness and rationality among these three kinds of decay widths, and showing their impacts on resonant cross sections and MACS.…”