kinematics

import ampform.kinematics

Classes and functions for relativistic four-momentum kinematics.

class HelicityAdapter(transitions: ReactionInfo | Iterable[Topology | FrozenTransition[State, InteractionProperties]])

Bases: object

Converter for four-momenta to kinematic variable data.

The create_expressions method forms the bridge between four-momentum data for the decay you are studying and the kinematic variables that are in the HelicityModel. These are invariant mass (see get_invariant_mass_symbol()) and the \(\theta\) and \(\phi\) helicity angles (see get_helicity_angle_symbols()).

register_transition(transition: FrozenTransition[State, InteractionProperties]) → None

register_topology(topology: Topology) → None

property registered_topologies: frozenset[Topology]

permutate_registered_topologies() → None

Register outgoing edge permutations of all registered_topologies.

See Extend kinematic variables.

create_expressions() → dict[Symbol, Expr]

Submodules and Subpackages

• angles
  • Phi
  • Theta
  • compute_helicity_angles()
  • compute_wigner_angles()
  • compute_wigner_rotation_matrix()
  • formulate_scattering_angle()
  • formulate_theta_hat_angle()
  • formulate_zeta_angle()
• lorentz
  • create_four_momentum_symbols()
  • create_four_momentum_symbol()
  • FourMomenta
  • FourMomentumSymbol
  • Energy
  • FourMomentumX
  • FourMomentumY
  • FourMomentumZ
  • ThreeMomentum
  • EuclideanNorm
  • EuclideanNormSquared
  • three_momentum_norm()
  • InvariantMass
  • NegativeMomentum
  • MinkowskiMetric
  • BoostZMatrix
  • BoostMatrix
  • RotationYMatrix
  • RotationZMatrix
  • ArraySize
  • compute_boost_chain()
  • get_four_momentum_sum()
  • compute_invariant_masses()
  • get_invariant_mass_symbol()
• phasespace
  • Kibble
  • Kallen
  • is_within_phasespace()
  • compute_third_mandelstam()