4-fermion EFT with FCNC implementation

Authors:

Yoav Afik, Jonathan Cohen, Eitan Gozani, Enrique Kajomovitz, Yoram Rozen
Department of Physics, Technion: Israel Institute of Technology Haifa, Israel

E-mails: yoavafik@…, jcohen@…, gozani@…, enrique@…, rozen@…

Description of the model:

This is a Contact Interaction (CI) model.

The lagrangian of the model is described by:
$\mathcal{L}_{eff} = \frac{C_{ij}^{{U \mu}}{v}2} (\bar{u}_{L}^{{i} \gamma_{\mu} u_{L}}{j}) (\bar{\mu}_{L} \gamma_{\mu} \mu_{L}) + \frac{C_{ij}^{{D \mu}}{v}2} (\bar{d}_{L}^{{i} \gamma_{\mu} d_{L}}{j}) (\bar{\mu}_{L} \gamma_{\mu} \mu_{L})$

$C_{ij}^{{U \mu} = \begin{pmatrix} C_{u \mu} & 0 & 0
0 & C_{c \mu} & 0
0 & 0 & C_{t \mu} \end{pmatrix} , C_{ij}}{D \mu} = \begin{pmatrix} C_{d \mu} & 0 & 0
0 & C_{s \mu} & C_{b s \mu}^{{*}
0 & C_{b s \mu} & C_{t \mu} \end{pmatrix} $}

See more details in: ​https://link.springer.com/article/10.1007/JHEP08(2018)056

Sample commands for MadGraph5_aMC@NLO:

define p = g u c d s b u~ c~ d~ s~ b~ 
define j = g u c d s b u~ c~ d~ s~ b~ 
generate p p > mu+ mu- 
add process p p > mu+ mu- j 
add process p p > mu+ mu- j j