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This code allows for the calculation of neutrino flavor changing probabilities in the presence of invisible or visible neutrino decay over cosmological distances. Every figure in the paper can be made via the functions in src/Figures.cpp. To run one of them uncomment the relevant line in src/main.cpp, compile, and execute ./main.
The main object governing the decay parameters is the struct decay_params found in include/Parameters.h as well as dp_bm which is defined with the benchmark parameters. The invisible decay probability is the sum of the SM and depletion components, so to calculate the invisible decay probability composed of the SM and the depletion contributions from νμ to νe where the relevant decay parameters including the final energy are all defined in the variable dp of type decay_params, PSM(m, e, dp) + Pdep(m, e, dp) and for the visible case one simply addes in the regeneration term, PSM(m, e, dp) + Pdep(m, e, dp) + Preg(m, e, dp). Note that the regeneration term is computationally slow.
There are several IceCube related functions. Rtc(dp, vis) calculates the track to cascade ratio for visible decay if vis is true and for invisible decay otherwise. The spectral indices at Earth over 100 TeV < Ef < 1 PeV can be calculated with IC_gamma(dp, vis, gamma_track, gamma_cascade) which calculates the spectral index of both tracks and cascades simultaneously. Note that changing Ef in dp does nothing here. The χ2 test statistic can be calculated with Chisq(dp, vis, m1min) where the boolean m1min determines if the function should minimize over m1 with a prior from cosmology or not. In either case, the m1 prior is calculated relative to the smallest allowed value by oscillations.
- Energy: GeV
- Mass: eV
- Distance: km
Oscillation data is set to the best fit parameters from nu-fit v4.1 in the normal mass ordering without Super-K data.
This depends on gsl which can be found in libgsl-dev on ubuntu. This code also uses openmp for the longer calculations
If any bugs are identified or any features suggested, please use the tools (issues, pull requests, etc.) on github.
If you use this code please reference arXiv:2005.07200 and doi:10.5281/zenodo.3826887.