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feynlag
feynlag
  • Getting Started
  • 1. The Pipeline
  • 2. Declaration: Parameters, Fields, Groups
  • 3. Writing the Lagrangian
  • 4. Checking Invariance
  • 5. Spontaneous Symmetry Breaking
  • 6. Mass Matrices
  • 7. Diagonalization and the Physical Basis
  • 8. Extracting Vertices
  • 9. Export
  • 10. Verification Philosophy
  • 11. Suggesting Invariant Terms
  • 12. Gauge-Anomaly Cancellation
  • 13. Electric Charge and the Vertex Checks
  • 14. Quark Flavour Mixing (CKM)
  • 15. Decay Widths
  • 16. Extending the Decay Calculator
  • 17. Extending to 2→2 Scattering
  • Tutorials
    • How to compute a particle decay
    • 2→2 scattering in feynlag: from Mandelstam invariants to a forward–backward asymmetry
    • From Pauli matrices to any SU(N): gauge representations with feynlag
    • Discrete symmetries: representations, characters, and the construction of invariants
    • Feynman rules of the Standard Model with feynlag
    • Vector-like fermions in feynlag: SM + a vector-like lepton doublet
    • Extending the SM by a gauged U(1)\(_X\): a Z′ tutorial in feynlag
    • Model building with feynlag: suggest + anomaly cancellation
    • The type-I seesaw in feynlag: Majorana neutrino masses, step by step
    • 3HDM with S₃ flavor symmetry: forcing the vacuum, not tuning it
  • Examples Gallery
  • Validated against MadGraph
  • Roadmap: Status and Remaining Work
  • Conventions
  • API Reference
    • feynlag.parameters
      • feynlag.parameters.ExternalParameter
      • feynlag.parameters.InternalParameter
      • feynlag.parameters.Parameter
      • feynlag.parameters.ParameterSet
    • feynlag.fields
      • feynlag.fields.bar_partner
      • feynlag.fields.conjugate_pair
      • feynlag.fields.dag
      • feynlag.fields.hc
      • feynlag.fields.DiracFermion
      • feynlag.fields.Fermion
      • feynlag.fields.Field
      • feynlag.fields.GaugeBoson
      • feynlag.fields.MajoranaFermion
      • feynlag.fields.Scalar
      • feynlag.fields.WeylFermion
    • feynlag.groups.base
      • feynlag.groups.base.GaugeGroup
      • feynlag.groups.base.SymmetryGroup
    • feynlag.groups.gauge
      • feynlag.groups.gauge.SU2
      • feynlag.groups.gauge.SU3
      • feynlag.groups.gauge.SUN
      • feynlag.groups.gauge.U1
    • feynlag.groups.discrete
      • feynlag.groups.discrete.DiscreteSymmetry
      • feynlag.groups.discrete.S3
      • feynlag.groups.discrete.ZN
    • feynlag.lagrangian
      • feynlag.lagrangian.InvarianceReport
      • feynlag.lagrangian.Lagrangian
      • feynlag.lagrangian.LagrangianTerm
      • feynlag.lagrangian.Model
      • feynlag.lagrangian.ValidationReport
    • feynlag.operators
      • feynlag.operators.D_linear
      • feynlag.operators.Dmu
      • feynlag.operators.expand_derivatives
      • feynlag.operators.to_momentum_space
      • feynlag.operators.PartialMu
    • feynlag.invariance
      • feynlag.invariance.check_discrete_invariance
      • feynlag.invariance.check_gauge_invariance
      • feynlag.invariance.check_hermiticity
      • feynlag.invariance.check_mass_dimension
      • feynlag.invariance.gauge_variation
    • feynlag.models
      • feynlag.models.charged_current_rotation
      • feynlag.models.electroweak_gauge
      • feynlag.models.electroweak_scaffold
      • feynlag.models.higgs_doublet
      • feynlag.models.higgs_lagrangian
      • feynlag.models.standard_model
      • feynlag.models.to_physical_basis
      • feynlag.models.weinberg_rotation
      • feynlag.models.ElectroweakScaffold
      • feynlag.models.PhysicalBasis
      • feynlag.models.StandardModel
    • feynlag.suggest
      • feynlag.suggest.build_lagrangian
      • feynlag.suggest.reynolds_project
      • feynlag.suggest.suggest_kinetic
      • feynlag.suggest.suggest_potential
      • feynlag.suggest.suggest_yukawa
      • feynlag.suggest.SuggestedTerm
    • feynlag.dirac
      • feynlag.dirac.dirac_conjugate
      • feynlag.dirac.gamma_simplify
      • feynlag.dirac.majorana_symmetry_sign
      • feynlag.dirac.minkowski_metric
      • feynlag.dirac.DiracC
      • feynlag.dirac.DiracGamma
      • feynlag.dirac.DiracGammaLower
      • feynlag.dirac.DiracIdentity
      • feynlag.dirac.DiracLatexPrinter
      • feynlag.dirac.DiracZero
      • feynlag.dirac.PL
      • feynlag.dirac.PR
    • feynlag.vacuum.ewsb
      • feynlag.vacuum.ewsb.Vacuum
    • feynlag.vacuum.tadpoles
      • feynlag.vacuum.tadpoles.extract_tadpoles
      • feynlag.vacuum.tadpoles.solve_tadpoles
    • feynlag.vacuum.masses
      • feynlag.vacuum.masses.build_mass_matrix
      • feynlag.vacuum.masses.charged_mass_matrix
      • feynlag.vacuum.masses.gauge_mass_matrix
      • feynlag.vacuum.masses.scalar_mass_matrix
      • feynlag.vacuum.masses.seesaw_light_mass
      • feynlag.vacuum.masses.seesaw_mass_matrix
    • feynlag.vacuum.diagonalize
      • feynlag.vacuum.diagonalize.diagonalize_orthogonal_2x2
      • feynlag.vacuum.diagonalize.diagonalize_svd
      • feynlag.vacuum.diagonalize.diagonalize_svd_2x2
      • feynlag.vacuum.diagonalize.diagonalize_takagi
      • feynlag.vacuum.diagonalize.rotation_2x2
      • feynlag.vacuum.diagonalize.solve_mixing_angle_2x2
      • feynlag.vacuum.diagonalize.MajoranaRotation
      • feynlag.vacuum.diagonalize.Rotation
    • feynlag.vertices.extract
      • feynlag.vertices.extract.extract_interaction_coefficients
      • feynlag.vertices.extract.feynman_rule
      • feynlag.vertices.extract.vertex_multiplicity
    • feynlag.vertices.bilinear
      • feynlag.vertices.bilinear.expand_bilinear
      • feynlag.vertices.bilinear.extract_fermion_vertices
      • feynlag.vertices.bilinear.extract_majorana_vertices
      • feynlag.vertices.bilinear.fermion_feynman_rule
      • feynlag.vertices.bilinear.fermion_gauge_current
      • feynlag.vertices.bilinear.fermion_mass_matrix
      • feynlag.vertices.bilinear.four_fermion_feynman_rule
      • feynlag.vertices.bilinear.majorana_feynman_rule
      • feynlag.vertices.bilinear.majorana_mass_matrix
      • feynlag.vertices.bilinear.Bilinear
      • feynlag.vertices.bilinear.MajoranaBilinear
    • feynlag.vertices.vertex
      • feynlag.vertices.vertex.classify_spins
      • feynlag.vertices.vertex.Vertex
    • feynlag.vertices.yangmills
      • feynlag.vertices.yangmills.cubic_couplings
      • feynlag.vertices.yangmills.quartic_couplings
      • feynlag.vertices.yangmills.structure_constants
    • feynlag.export.latex
      • feynlag.export.latex.latex_feynman_table
    • feynlag.export.ufo.writer
      • feynlag.export.ufo.writer.write_ufo
      • feynlag.export.ufo.writer.UFOParticle
    • feynlag.export.ufo.vvvv
      • feynlag.export.ufo.vvvv.adjoint_vvv
      • feynlag.export.ufo.vvvv.adjoint_vvvv
      • feynlag.export.ufo.vvvv.assemble_vvvv
      • feynlag.export.ufo.vvvv.metric_pair_coefficients
      • feynlag.export.ufo.vvvv.permute_vvvv
      • feynlag.export.ufo.vvvv.structures_from_metric_pairs
    • feynlag.export.ufo.lorentz_map
      • feynlag.export.ufo.lorentz_map.structures_for
    • feynlag.pheno.lorentz
      • feynlag.pheno.lorentz.contract_to_dots
      • feynlag.pheno.lorentz.dirac_trace
      • feynlag.pheno.lorentz.index
      • feynlag.pheno.lorentz.momentum
      • feynlag.pheno.lorentz.reduce_projectors
      • feynlag.pheno.lorentz.slashed
    • feynlag.pheno.kinematics
      • feynlag.pheno.kinematics.is_allowed
      • feynlag.pheno.kinematics.kallen
      • feynlag.pheno.kinematics.two_body_momentum
      • feynlag.pheno.kinematics.two_body_phase_space
      • feynlag.pheno.kinematics.ThreeBodyKinematics
      • feynlag.pheno.kinematics.TwoBodyKinematics
      • feynlag.pheno.kinematics.TwoToTwoKinematics
    • feynlag.pheno.amplitudes
      • feynlag.pheno.amplitudes.amplitude_squared
      • feynlag.pheno.amplitudes.ffs_squared
      • feynlag.pheno.amplitudes.ffv_squared
      • feynlag.pheno.amplitudes.polarization_sum
      • feynlag.pheno.amplitudes.spin_sum
      • feynlag.pheno.amplitudes.sss_squared
      • feynlag.pheno.amplitudes.vvs_squared
    • feynlag.pheno.vertices
      • feynlag.pheno.vertices.classify_gamma
      • feynlag.pheno.vertices.collect_decay_vertices
      • feynlag.pheno.vertices.fermion_decay_vertices
      • feynlag.pheno.vertices.resolve_leg
      • feynlag.pheno.vertices.DecayVertex
    • feynlag.pheno.particles
      • feynlag.pheno.particles.expand_particles
      • feynlag.pheno.particles.DiracParticle
      • feynlag.pheno.particles.ExternalState
    • feynlag.pheno.propagator
      • feynlag.pheno.propagator.breit_wigner
      • feynlag.pheno.propagator.propagator_denominator
      • feynlag.pheno.propagator.scalar_propagator
      • feynlag.pheno.propagator.vector_propagator
      • feynlag.pheno.propagator.vector_propagator_numerator
    • feynlag.pheno.integrate
      • feynlag.pheno.integrate.dalitz_integral
      • feynlag.pheno.integrate.have_scipy
    • feynlag.pheno.offshell
      • feynlag.pheno.offshell.offshell_scalar_vv_width
      • feynlag.pheno.offshell.scalar_offshell_vv_width
      • feynlag.pheno.offshell.scalar_vv_s12_integral
      • feynlag.pheno.offshell.scalar_vv_squared
    • feynlag.pheno.loop
      • feynlag.pheno.loop.A_half
      • feynlag.pheno.loop.A_half_zgamma
      • feynlag.pheno.loop.A_one
      • feynlag.pheno.loop.A_one_zgamma
      • feynlag.pheno.loop.f_function
      • feynlag.pheno.loop.g_function
      • feynlag.pheno.loop.higgs_gammagamma_width
      • feynlag.pheno.loop.higgs_gg_width
      • feynlag.pheno.loop.higgs_zgamma_width
    • feynlag.pheno.calculator
      • feynlag.pheno.calculator.partial_width
      • feynlag.pheno.calculator.DecayCalculator
      • feynlag.pheno.calculator.DecayChannel
    • feynlag.verify.checks
      • feynlag.verify.checks.check_dimension
      • feynlag.verify.checks.decoupling_limit
      • feynlag.verify.checks.diagonalize_hermitian
      • feynlag.verify.checks.is_hermitian
      • feynlag.verify.checks.is_symmetric
      • feynlag.verify.checks.numeric_equal
      • feynlag.verify.checks.round_trip_reconstruct
      • feynlag.verify.checks.seesaw_light_mass
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