lips package¶
Submodules¶
lips.particle module¶
-
class
lips.particle.
Particle
(four_mom=None, real_momentum=False)¶ Describes the kinematics of a single particle.
-
angles_for_squares
()¶ Flips left and right spinors.
-
comp_twist_x
(other)¶
-
four_mom
¶ Four Momentum with upper index: P^μ
-
four_mom_d
¶ Four Momentum with lower index: P_μ
-
l_sp_d
¶ Left spinor with index down: λ̅_α̇ (row vector).
-
l_sp_u
¶ Left spinor with index up: λ̅^α̇ (column vector).
-
r2_sp
¶ Four Momentum Slashed with upper indices: P^{α̇α}
-
r2_sp_b
¶ Four Momentum Slashed with lower indices: P̅̅_{αα̇}
-
r_sp_d
¶ Right spinor with index down: λ_α (column vector).
-
r_sp_u
¶ Right spinor with index up: λ^α (row vector).
-
randomise
(real_momentum=False)¶ Randomises its momentum.
-
randomise_twist
()¶
-
twist_x_to_mom
(other)¶
-
lips.particles module¶
-
class
lips.particles.
Particles
(number_of_particles_or_particles=None, seed=None, real_momenta=False, fix_mom_cons=True)¶ Describes the kinematics of n particles. Base one list of Particle objects.
-
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)¶ Returns the image of self under a given permutation. Remember, this is a passive transformation.
-
insert
(index, *args)¶
-
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=u'')¶
-
total_mom
¶ Total momentum of the given phase space as a rank two spinor.
-
-
lips.particles.
indexing_decorator
(func)¶ Rebases a list to start from index 1.
lips.particles_compute module¶
-
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.
-
lips.particles_set module¶
lips.particles_set_pair module¶
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.
1 2 3 4 5 6 | oParticles = Particles(multiplicity)
oParticles.randomise_all()
oParticles.fix_mom_cons()
oParticles.compute(spinor_string)
oParticles.set(spinor_string, small_value)
oParticles.set_pair(spinor_string_1, small_value_1, spinor_string_2, small_value_2)
|