wiki:B-L-SM

Version 17 (modified by WeiLiu, 2 weeks ago) (diff)

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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- ucl.ac.uk
      • 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- physik.uni-freiburg.de
      • (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.

References


Model files

See attachments


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 http://arxiv.org/abs/arXiv:0812.4313.
  • Please set the decay width of the heavy neutrino, two Higgs and Z' to auto (in MadGraph5 param_card.dat)

Attachments (7)

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