Package madgraph :: Package fks :: Module fks_common
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Module fks_common

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Definitions of the objects needed both for MadFKS from real and MadFKS from born

Classes [hide private]
  FKSProcessError
Exception for MadFKS
  FKSDiagramTag
Modified diagram tags to be used to link born and real configurations.
  FKSLegList
list of FKSLegs
  FKSLeg
a class for FKS legs: it inherits from the ususal leg class, with two extra keys in the dictionary: -'fks', whose value can be 'i', 'j' or 'n' (for "normal" particles) -'color', which gives the color of the leg -'charge', which gives the charge of the leg -'massless', boolean, true if leg is massless -'spin' which gives the spin of leg -'is_part', boolean, true if leg is an particle -'self_antipart', boolean, true if leg is an self-conjugated particle
Functions [hide private]
 
link_rb_configs(born_amp, real_amp, i, j, ij)
finds the real configurations that match the born ones, i.e.
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find_orders(amp)
Takes an amplitude as input, and returns a dictionary with the orders of the couplings.
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find_splittings(leg, model, dict, pert='QCD')
Finds the possible splittings corresponding to leg
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split_leg(leg, parts, model)
Splits the leg into parts, and returns the two new legs.
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ij_final(pair)
given a pair of legs in the final state, assigns the i/j fks id NOTE: the j partons is always put before the i one
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insert_legs(leglist_orig, leg, split, pert='QCD')
Returns a new leglist with leg splitted into split.
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combine_ij(i, j, model, dict, pert='QCD')
checks whether FKSlegs i and j can be combined together in the given model and with given perturbation order and if so combines them into ij.
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find_pert_particles_interactions(model, pert_order='QCD')
given a model and pert_order, returns a dictionary with as entries: --interactions : the interactions of order pert_order --pert_particles : pdgs of particles taking part to interactions --soft_particles : pdgs of massless particles in pert_particles
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insert_color_links(col_basis, col_obj, links)
insert the color links in col_obj: returns a list of dictionaries (one for each link) with the following entries: --link: the numbers of the linked legs --link_basis: the linked color basis --link_matrix: the color matrix created from the original basis and the linked one
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find_color_links(leglist, symm=False, pert='QCD')
Finds all the possible color(charge) links between any two legs of the born.
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legs_to_color_link_string(leg1, leg2, pert='QCD')
given two FKSlegs, returns a dictionary containing:...
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sort_proc(process, pert='QCD')
Given a process, this function returns the same process but with sorted FKSLegs.
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to_leg(fksleg)
Given a FKSLeg, returns the original Leg.
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to_legs(fkslegs)
Given a FKSLegList, returns the corresponding LegList.
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to_fks_leg(leg, model)
Given a leg or a dict with Leg entries, adds color, spin and massless entries, according to model
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to_fks_legs(leglist, model)
given leglist, sets color and massless entries according to the model variable.
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Variables [hide private]
  __package__ = 'madgraph.fks'
Function Details [hide private]

link_rb_configs(born_amp, real_amp, i, j, ij)

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finds the real configurations that match the born ones, i.e. for each born configuration, the real configuration that has the ij -> i j splitting. i, j and ij are integers, and refer to the leg position in the real process (i, j) and in the born process (ij).

insert_legs(leglist_orig, leg, split, pert='QCD')

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Returns a new leglist with leg splitted into split. The convention is to remove leg ij, replace it with leg j, and put i at the end of the group of legs with the same color(charge) representation

combine_ij(i, j, model, dict, pert='QCD')

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checks whether FKSlegs i and j can be combined together in the given model and with given perturbation order and if so combines them into ij. If dict is empty it is initialized with find_pert_particles_interactions

find_color_links(leglist, symm=False, pert='QCD')

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Finds all the possible color(charge) links between any two legs of the born. If symm is true, only half of the color links are generated, those for which leg1['number'] <= leg2['number']

legs_to_color_link_string(leg1, leg2, pert='QCD')

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given two FKSlegs, returns a dictionary containing:
--string: the color link between the two particles, to be appended to
    the old color string
    extra minus or 1/2 factor are included as it was done in MadDipole
--replacements: a pair of lists containing the replacements of the color 
    indices in the old string to match the link 

to_fks_legs(leglist, model)

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given leglist, sets color and massless entries according to the model variable. return a FKSLeglist