7operator

Last update: April 22, 2024

Intro

It’s recommended to read this post about nuclear shell model code BIGSTICK first.

BIGSTICK outputs density matrix (.dres), which basically includes everything. This post will demonstrate how to convert density matrix to nuclear response and scattering cross section

The steps are the following

  • Run res2den.py to convert to .dat
  • Open the mathematica notebook and input the .dat file
  • Run the mathematica notebook

Each of the steps will be explained in the next sections

Python conversion

res2den.py converts density matrix from BIGSTICK output (.dres) to mathematica input (.dat). The script does nothing special but merely reformat the data to be compatible with the mathematica notebook.

Mathematica package - 7operator

inelastic_nu_multipole.nb and inelastic_DM_multipole.nb in C12_YSOX folder show examples of inelastic neutrino-C12 scattering and inelastic dark matter-C12 scattering. In the notebooks, the scattering cross section is expressed by multipole operators, which are made of nuclear response functions. The mathematica package 7operator is used to calculate nuclear response function from density matrix. The instructions and details are included in the notebooks. I recommend to start with the neutrino, because it’s closer to the Standard Model.

Reference and further reading