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#### Track lengths distributions #####
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A. Celentano, L. Darme, L. Marsicano, E. Nardi
16-06-2020


## --- General description --- ##

This is the companion dataset to the publication "New production channels for light dark matter in hadronic showers" by the same authors.
It includes the track-lengths for electrons and positrons for MiniBooNE, SHiP, NOvA and DUNE. It further includes the event files for light mesons
pi0 and eta generated from the same shower (including their secondary production).

An example card for Maddump and a simple dark matter UFO are further provided.

## --- Practical implementation  --- ##

The track-lengths are provided in two files, designed to be used via the Maddump plugin to MadGraph@NLO. Typically for each experiments
we provide files for the various material present in the target (or only the dominant one). Two files are used:
 - out.1E7.FTFP_BERT_HP.root_<materialname>_<particletype>.pdf : The normalised track-length distribution as function of energy, the corresponding normalisations
   can be found in the file "normalization.txt" (the differential track lengths are normalised in GeV.cm)
- out.1E7.FTFP_BERT_HP.root_<materialname>_<particletype>.lhe : An event files containing a distribution a particle from the shower. It is typically used
   by Maddump to sample the angular distributions

Both files need to be referenced in the Maddump card, acting together as a PDF for the process considered (e.g. e+ e- > chi chi~).

The events file for the light mesons can be additional directly sample to generate the any new physics process based on meson decay. The overall
normalisation (in number of mesons per Proton-on-Target) is further included in the file "normalization.txt".

We provide  an example process card for Maddump (for production at SHiP), as well as a UFO file for a dark photon model with a complex scalar dark matter.
The final cross-section has to be multiplied with the corresponding normalisation (trackE*nAtoms for bremsstrahlung and trackE*nPositron for resonant production for instance)
to obtain the overall number of events.
Note that the UFO file contains the form factor for e+/e- bremsstrahlung off a nucleus, and implements a regularisation cut as described in the paper.

## --- Additional details  --- ##

The track-length distributions include a lower-energy cut on the electrons and positrons from the shower:
- DUNE : Electron and positron kinetic energy E_e > 50 MeV, sin(theta) between 0 and 0.2
- MiniBooNE : Electron and positron kinetic  energy E_e > 10 MeV, sin(theta) between 0 and 0.2
- NOvA : Electron and positron kinetic  energy E_e > 50 MeV, sin(theta) between 0 and 0.2
- SHiP : Electron and positron kinetic energy E_e > 100 MeV, sin(theta) between 0 and 0.2

For the mesons (pi0 and eta)
- DUNE : kinetic energy E_e > 50 MeV, sin(theta) between 0 and 0.2
- MiniBooNE : kinetic energy E_e > 10 MeV, sin(theta) between 0 and 0.2
- NOvA : kinetic energy E_e > 50 MeV, sin(theta) between 0 and 0.2
- SHiP : kinetic energy E_e > 100 MeV, sin(theta) between 0 and 0.2


## --- Version history  --- ##

- 1.0.0: Public release alongside the ArXiV Publication New production channels for light dark matter in hadronic showers