cHNLdecay

This is an implementation of partial widths described in the arXiv paper arXiv:1805.08567v2 by Kyrylo Bondarenko, Alexey Boyarsky, Dmitry Gorbunov and Oleg Ruchayskiy. It uses the CERN scientific software toolkit ROOT and is written in C++ using the GNU Multiple Precision Arithmetic Library GMP.

Installation

It is necessary to have GMP and ROOT installed on the system. Adapt the library paths in Makefile accordingly to point to the location of the libraries for GMP. ROOT should take care of this by itself as root-config is used. Additionally, if debugging is wished you need to install gperftools or uncomment the parts -lprofiler -ltcmalloc in LDLIBS_DBG in the Makefile.

Then simply run make in order to build the project. A binary called cHNLdecay is produced as a result.

Usage

When running cHNLdecay you can parse various parameters to the program to configure the HNL.

The options are as follows:

--loglevel {debug,info,warning,error}

(one must be chosen, if omited info is the default)

--generations {11,13,15}

(multiple can be passed separated by a , and no whitespace. The leptons are identified by their PDG ID)

--angle FLOAT

(the value of the mixing angle |U_alpha|^2, NOTE the squared)

--mass INTEGER

(the mass of the HNL in MeV)

And an example would be:

./cHNLdecay --generations 11,13,15 --mass 20000 --angle 3.5e-6

Contributing

This project uses the LLVM coding standards which can be found here. Please make sure that your commits are adhering to them accordingly. For your convenience please consider installing a pre-commit hook as described here.

References

This implementation tries to correctly implement equations from arXiv:1805.08567v2 [hep-ph] without guarantee of its accuracy or endorsement of its authors. Details of the published paper can also be found in CITATION.

Paper list:

K. Bondarenko, A. Boyarsky, D. Gorbunov and O. Ruchayskiy, Phenomenology of GeV-scale Heavy Neutral Leptons, arXiv:1805.08567v2 [hep-ph]

How to cite this project?

Please cite this project as follows:

@misc{thiele_cHNLdecay_2018,
  author = {Thiele, Fabian A.J.},
  title = {cHNLdecay},
  year = {2018},
  publisher = {GitHub},
  journal = {GitHub repository},
  howpublished = {\url{https://github.com/f-thiele/cHNLdecay}},
}

License

This project is licensed under the terms of the GPL v3 or any later version (GPL-3.0-or-later).