lips.particle
- class lips.particle.Particle(four_mom=None, r2_sp=None, real_momentum=False, field=(mpc, 0, 300))
Describes the kinematics of a single particle.
- angles_for_squares()
Flips left and right spinors.
- comp_twist_x(other)
- property four_mom
Four Momentum with upper index: P^μ
- property four_mom_d
Four Momentum with lower index: P_μ
- property l_sp_d
Left spinor with index down: λ̅_α̇ (row vector).
- property l_sp_u
Left spinor with index up: λ̅^α̇ (column vector).
- lsq()
Lorentz dot product with itself: 2 trace(P^{α̇α}P̅̅_{αα̇}) = P^μ * η_μν * P^ν.
- property mass
- property r2_sp
Four Momentum Slashed with upper indices: P^{α̇α}
- property r2_sp_b
Four Momentum Slashed with lower indices: P̅̅_{αα̇}
- property r_sp_d
Right spinor with index down: λ_α (column vector).
- property r_sp_u
Right spinor with index up: λ^α (row vector).
- randomise(real_momentum=False)
- randomise_finite_field()
- randomise_mpc(real_momentum=False)
Randomises its momentum.
- randomise_padic()
- randomise_rational()
- randomise_twist()
- property spinors_are_in_field_extension
- twist_x_to_mom(other)
lips.particles
- class lips.particles.Particles(number_of_particles_or_particles=None, seed=None, real_momenta=False, field=(mpc, 0, 300), fix_mom_cons=True)
Describes the kinematics of n particles. Base one list of Particle objects.
- analytical_subs_d()
- angles_for_squares()
Switches all angle brackets for square brackets and viceversa.
- static check_consistency(temp_string)
- cluster(llIntegers)
Returns clustered particle objects according to lists of lists of integers (e.g. corners of one loop diagram).
- fix_mom_cons(A=0, B=0, real_momenta=False, axis=1)
Fixes momentum conservation using particles A and B.
- four_momenta_for_mathematica(as_spinors=False)
- ijk_to_3Ks(ijk)
- ijk_to_3NonOverlappingLists(ijk, mode=1)
- image(permutation_or_rule)
Returns the image of self under a given permutation or rule. Remember, this is a passive transformation.
- insert(index, *args)
Insert object before index.
- make_analytical_d(indepVars=None, symbols=('a', 'b', 'c', 'd'))
- property masses
Masses of all particles in phase space.
- momentum_conservation_check(silent=True)
Returns true if momentum is conserved.
- onshell_relation_check(silent=True)
Returns true if all on-shell relations are satisfied.
- phasespace_consistency_check(invariants=[], silent=True)
Runs momentum and onshell checks. Looks for outliers in phase space. Returns: mom_cons, on_shell, big_outliers, small_outliers.
- randomise_all(real_momenta=False)
Randomises all particles. Breaks momentum conservation.
- randomise_twistor()
- save_phase_space_point(invariant='')
- property spinors_are_in_field_extension
- property total_mom
Total momentum of the given phase space as a rank two spinor.
- class lips.particles_compute.Particles_Compute
- compute(temp_string)
Computes spinor strings.
Available variables: ⟨a|b⟩, [a|b], ⟨a|b+c|d], ⟨a|b+c|d+e|f], …, s_ijk, Δ_ijk, Ω_ijk, Π_ijk, tr5_ijkl
- ee(i, j)
Contraction of two polarization tensors. Requires .helconf property to be set.
- ep(i, j)
Contraction of polarization tensor with four momentum. Requires .helconf property to be set.
- ldot(A, B)
Lorentz dot product: 2 trace(P^{α̇α}P̅̅_{αα̇}) = P_A^μ * η_μν * P_B^ν.
- pe(i, j)
Contraction of four momentum with polarization tensor. Requires .helconf property to be set.
Module contents
Defines tools for phase space manipulations. Particles objects are base one lists of Particle objects.
Particles objects allow to:
Compute spinor strings, through .compute;
Construct single collinear limits, through .set;
Construct double collinear limits, through .set_pair.
1oParticles = Particles(multiplicity)
2oParticles.randomise_all()
3oParticles.fix_mom_cons()
4oParticles.compute(spinor_string)
5oParticles.set(spinor_string, small_value)
6oParticles.set_pair(spinor_string_1, small_value_1, spinor_string_2, small_value_2)