Author

Richard Ruiz, University of Durham (IPPP) richard.ruiz[at]durham.ac.uk

Model Description

After electroweak symmetry breaking, the effective Type I Seesaw Lagrangian is given by [1]

$\mathcal{L}_{\rm Type~I} = \mathcal{L}_{\rm SM} + \mathcal{L}_{N} + \mathcal{L}_{N~\text{Int.}} $,

where { #!latex $\mathcal{L}_{\rm SM}$ } is the Standard Model Lagrangian, the heavy Majorana neutrino's kinetic and mass terms are given by

$\mathcal{L}_{N} = \frac{1}{2}\overline{N} i\!\not\!\partial N - \frac{1}{2}M_N \overline{N}N$,

and its interaction terms with the Weak gauge and Higgs bosons in the mass eigenbasis, i.e., after mixing with active neutrinos, by

\begin{eqnarray}
\mathcal{L}_{N~\text{Int.}} &=& -\frac{g}{\sqrt{2}}W_{\mu}^{+}\sum_{\ell=e}^{\tau} \overline{N^{c}}V_{\ell N}^{*}\gamma^{\mu}P_{L}\ell^{-}
\\
& &-\frac{g}{2\cos\theta_W}Z_{\mu}\sum_{\ell=e}^{\tau} \overline{N^{c}}V_{\ell N}^{*}\gamma^{\mu}P_{L}\nu_\ell
\\
& & -\frac{g m_N}{2 M_W} h \sum_{\ell=e}^{\tau} \overline{N^{c}}V_{\ell N}^{*}P_{L}\nu_\ell
+{\rm H.c.}
\end{eqnarray}

Model Files

Validation

References

[1] A. Atre, T. Han, S. Pascoli and B. Zhang, The Search for Heavy Majorana Neutrinos, JHEP 0905, 030 (2009) ​arXiv:0901.3589 [hep-ph]

[2] D. Alva, T. Han, R. Ruiz, Heavy Majorana neutrinos from #!latex $W\gamma$ fusion at hadron colliders, JHEP 1502, 072 (2015), ​arXiv:1411.7305 [hep-ph]