# Changes between Version 4 and Version 5 of HiggsPheno

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Timestamp:
04/19/12 09:08:36 (7 years ago)
Comment:

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Unmodified
 v4 In the large top mass limit, the gluon fusion production of a Higgs boson can be described by an effective field theory where the Higgs couples directly to the gluons, %$\begin{cal}L\end{cal}=C_H\, H\, G_{\mu\nu}^a\, G_a^{\mu\nu}$, $\begin{cal}L\end{cal}=C_H\, H\, G_{\mu\nu}^a\, G_a^{\mu\nu}$, where $C_H$ is an effective (dimensionful) coupling constant and $G_{\mu\nu}^a$ denotes the gluon field strength tensor. Exercise (DIFFICULT but interesting!!): Use the all the material above to derive the EFT description of a pseudo-scalar Higgs, A, %$\begin{cal}L\end{cal}=C_A\, A\, G_{\mu\nu}^a\, {\tilde G}_a^{\mu\nu}$, $\begin{cal}L\end{cal}=C_A\, A\, G_{\mu\nu}^a\, {\tilde G}_a^{\mu\nu}$, where $C_A$ is an effective (dimensionful) coupling constant and $G_{\mu\nu}^a$ denotes the gluon field strength tensor and %${\tilde G}''a^{\mu\nu}=\frac12 \epsilon^{\mu\nu\rho\sigma} G''a^{\rho\sigma}$  is its dual. Compute the loop amplitude, derive  the Feynman rules ${\tilde G}''a^{\mu\nu}=\frac12 \epsilon^{\mu\nu\rho\sigma} G''a^{\rho\sigma}$  is its dual. Compute the loop amplitude, derive  the Feynman rules in the large top mass limit and calculate the LO and NLO cross sections at the LHC.