Resonant states 0+ of the Boron isotope 8B from the Jost-matrix analysis of the partial cross-sections

Abstract

The available [Formula: see text]-matrix parametrization of experimental data on the excitation functions for the elastic and inelastic [Formula: see text] scattering at the collision energies up to 3.4[Formula: see text]MeV is used to generate the corresponding partial-wave cross-sections in the states with [Formula: see text]. Thus, obtained data are fitted using the semi-analytic two-channel Jost matrix with a proper analytic structure and some adjustable parameters. Then the spectral points are sought as zeros of the Jost matrix determinant (which correspond to the [Formula: see text]-matrix poles) at complex energies. The correct analytic structure makes it possible to calculate the fitted Jost matrix on any sheet of the Riemann surface whose topology involves not only the square-root but also the logarithmic branching caused by the Coulomb interaction. In this way, two overlapping [Formula: see text] resonances at the excitation energies [Formula: see text] and [Formula: see text][Formula: see text]MeV have been found.

Jost matrices for some analytically solvable potential models

“…It was found that indeed there is the shadow pole, but it is on the physical sheet. A similar analysis [9] of the system 8 B(0 + ) also revealed the shadow pole on the physical sheet.…”

“…Pseudo three-dimensional (3D) images of this surface can be found in Refs. [1,9], where it is explained why the interconnections are done in this way. When the coupling between the channels grows, some of the poles move from the other sheets to the physical one by crossing the threshold point E = 0.…”

Resonant states 3+ and 2− of the Boron isotope 8B

“…( 1), as described in Ref. 13. Such a residue determines the asymptotic normalization coefficient, A , of the radial part, u (E, r), of the wave function…”

“…This work is a continuation of our previous publications, [10][11][12][13][14]18,19 where the reader can find all the details of the method we use here. To avoid the unnecessary repetition, we therefore present it rather briefly.…”

“…Recently, it was suggested to complement the R-matrix approach by a new method based on the Jost-matrix parametrization, which offers an alternative way of analytic continuation of the scattering data to the domain of complex energies (see Refs. [10][11][12][13][14]. In particular, Ref.…”