Version 19 (modified by WeiLiu, 22 months ago) (diff)


The B-L model

as a U(1) extension of the SM with 3 RH neutrinos and a singlet scalar.

This is an update to the previous minimal Zprime model.

Implementation authors

  • This version
    • Wei Liu
      • Department of Physics & Astronomy, University College London
      • wei.liu.16 -at-
      • update based on Lorenzo Basso's model with availability to FeynRules 2.3 with the help of Dr. Frank Deppisch.
  • Previous version
    • Lorenzo Basso
      • Physikalisches Institut, Albert-Ludwigs-Universität Freiburg (Germany)
      • lorenzo.basso -at-
      • (formerly at University of Southampton, UK & RAL-PPD, Didcot, UK)
      • Based upon the minimal B-L model implementation, done in collaboration with Giovanni Marco Pruna (TU Dresden, Institut für Kern- und Teilchenphysik, Dresden, Germany, formerly at University of Southampton, UK & RAL-PPD, Didcot, UK).

Model description

The model describe a U(1) extension of the SM, related to the B-L (baryon minus lepton) charge. 3 RH neutrinos are required to cancel the anomalies, thus providing neutrino masses via the type-I see-saw. A Z' boson is also present, together with a further scalar for the spontaneous symmetry breaking of the further U(1) factor, at TeV scale.

  • Minimal B-L model: gt = 0. This is the "Minimal" version of the model, where the mixing between Z and Z' is set to zero. This choice is set for the .fr and UFO file.


Model files

See attachments

*Please use BL_N_UFO when use display modellist at MadGraph5, otherwise it would not be a valid path name.

Parameter description and user guide

The choice of benchmark model within the class is done by choosing the free parameters below.

Free parameters

  • Scalar sector
    • Higgs mixing angle, sa
    • The mass of the Higgs, mh1 and mh2, where mh1 is usually the mass of the SM model Higgs.
  • Gauge boson sector
    • The Z' boson mass, mzp
    • The coupling constant of B-L group, g1p
  • Neutrino sector
    • The heavy neutrino mass, mnh1, mnh2 and mnh3
    • The light neutrino mass, mnl1, mnl2 and mnl3
    • The neutrino mixing matrix are internal parameter set by Type-I seesaw, please read
  • Please set the decay width of the heavy neutrino, two Higgs and Z' to auto (in MadGraph5 param_card.dat)

Attachments (8)

Download all attachments as: .zip