What is wrong with my implementation of Yukawa Lagrangian using Feynrules?

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SUMMARY

The discussion centers on the implementation of the Yukawa Lagrangian using the Feynrules package in Mathematica. The user, identified as S, is attempting to define a new charged Higgs scalar, X, and its charge conjugate, Xbar, alongside Standard Model fermions. Despite correctly defining quark fields and Lagrangian parameters, the user encounters an issue where the command WriteUFO[LX] produces no vertices, indicating a potential error in the model setup or parameter definitions.

PREREQUISITES
  • Feynrules package for Mathematica
  • Understanding of Yukawa interactions in particle physics
  • Familiarity with quark field definitions and indices
  • Basic knowledge of Lagrangian mechanics
NEXT STEPS
  • Review Feynrules documentation for model implementation guidelines
  • Examine the syntax and structure of the Yukawa Lagrangian
  • Learn about the WriteUFO function and its requirements for generating vertices
  • Investigate common issues in defining parameters and fields in Feynrules
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Particle physicists, researchers working with theoretical models, and users of Feynrules looking to implement complex Lagrangians in Mathematica.

Safinaz
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Hi all,

I wonder if anyone here is familiar with Feynrules package to implement new model by Mathematica.
Actually I'm a new user for and try to implement Yukawa Lagrangian for new charged Higgs scalar called X and the charge conjugate Xbar with the SM fermions, I wrote the Lag. as :

LX := X ( - ProjP[s1, s2] (( 3 CKM[i, j] Md[j] + Ml IndexDelta[i, j] )/4 vev) tB + ProjM[s1, s2] CKM[i, j] ( Y4 cB - Y3 sB))
uqbar[s1,i,cc].dq[s2,j,cc] + Xbar ( - ProjM[s1, s2] (( 3 Md CKM[i, j] + Ml IndexDelta[i, j] )/4 vev) tB + ProjP[s1, s2] CKM[i, j] ( Y4 cB - Y3 sB)) dqbar[s1,i,cc].uq[s2,j,cc] ;

This is typically as the attached figure..

I took into account to define the quark fields by three indices : spin, generation, color, also all the Lag. parameters like Y4 and Y3 defined as External or Internal parameters . But when I run WriteUFO[LX], it gave me no vertices, so what's wrong here ..

Bests,
S.
 

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Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?