[Bubble] Calculable microscopic theory for 12C(α,γ)16O cross section near Gamow window

[Jay Benesch]

seems relevant

https://arxiv.org/abs/2011.06701


Calculable microscopic theory for 12C(α,γ)16O cross section near Gamow 
window
Y. Suzuki

     12C(α,γ)16O radiative-capture process is a key reaction to produce 
the element of oxygen in stars. Measuring the cross section near the 
Gamow window is extremely hard because it is too small. To make a 
theoretical contribution towards resolving the long-standing problem, I 
present a microscopic formulation that aims at providing all materials 
needed to calculate the cross section. The states of 12C and 16O 
relevant to the reaction are respectively described with fully 
microscopic 3 α-particle and 4 α-particle configurations, in which the 
relative motion among the α particles is expanded in terms of correlated 
Gaussian basis functions. The configuration space has the advantage of 
being able to well describe the reduced α-width amplitudes of the states 
of 16O. Both electric dipole and electric quadrupole transitions are 
responsible for the radiative-capture process. The α particle is 
described with a (0s)4 configuration admixed with a small amount of an 
isospin T=1 impurity component, which is crucially important to account 
for the isovector electric dipole transition. The isoscalar electric 
dipole operators are also taken into account up to the first order 
beyond the long-wavelength approximation. All the necessary ingredients 
are provided to make the paper self-contained and ready for numerical 
computations.

Comments: 	24 pages, accepted for publication in Few-Body Systems
Subjects: 	Nuclear Theory (nucl-th); Solar and Stellar Astrophysics 
(astro-ph.SR); Nuclear Experiment (nucl-ex)
Cite as: 	arXiv:2011.06701 [nucl-th]