Ab-initio calculation of the photonuclear cross section of ¹⁰B

Original · EN

We present for the first-time the photonuclear cross section of ¹⁰B calculated within the ab-initio No Core Shell Model framework. Realistic two-nucleon (NN) chiral forces up to next-to-next-to-next-order (N3LO), which have been softened by the similarity renormalization group method (SRG) to λ=2.02 fm⁻¹, were utilized. The electric-dipole response function is calculated using the Lanczos method. The effects of the continuum were accounted for by including neutron escape widths derived from R-matrix theory. The calculated cross section agrees well with experimental data in terms of structure as well as in absolute peak height, σ max=4.85 mb at photon energy ω=23.61 MeV, and integrated cross section 85.36 MeV mb. We test the Brink hypothesis by calculating the electric-dipole response for the first five positive-parity states in ¹⁰B and verify that dipole excitations built upon the ground- and excited states have similar characteristics.