Last modified 3 years ago Last modified on 06/24/14 15:01:28

Effective field theory for nTGC

Author : Celine Degrande

References :

  • C. Degrande, A basis of dimension-eight operators for anomalous neutral triple gauge boson interactions, arXiv:1308.6323


This !MadGraph5 model is the implementation of the dimension-eight operators inducing neutral triple gauge boson couplings (nTGC). Namely, the model contains all the four dimension-eight operators that modify the neutral triple gauge boson vertices. Their coefficients can be set in the param_card.dat. The parameters in the param_card are the full coefficients, i.e. $C_i/\Lambda^4$ and are in TeV$^-2$. The name are self-explanatory, $C_{\widetilde{B}W}/\Lambda^4$ is called CBtWL4, $C_{BW}/\Lambda^4$ is called CBWL4 and similarly for $C_{WW}$ and $C_{BB}$. The new interaction has also an order NP (for new physics) which is the power of ($1/\Lambda^4$) of the amplitude.

Operator Coefficient param_card name limit at 95% C.L.(TeV$^{-4}$)
$i H^\dagger \widetilde{B}_{\mu\nu}W^{\mu\rho}\{D_\rho,D^\nu\} H$ $C_{\widetilde{B}W}/\Lambda^4$ CBtWL4 [-47 , 47]
$i H^\dagger B_{\mu\nu}W^{\mu\rho}\{D_\rho,D^\nu\} H$ $C_{BW}/\Lambda^4$ CBWL4 [-114 , 113 ]
$i H^\dagger W_{\mu\nu}W^{\mu\rho}\{D_\rho,D^\nu\} H$ $C_{WW}/\Lambda^4$ CWWL4 [-45 , 48]
$i H^\dagger B_{\mu\nu}B^{\mu\rho}\{D_\rho,D^\nu\} H$ $C_{BB}/\Lambda^4$ CBBL4 [-99 , 101]

The limits have been obtained by inverting the values of the anomalous couplings from the PDG 2012 and JHEP 1301 (2013) 063.