29
29
from madgraph import InvalidCmd
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30
logger = logging.getLogger('madgraph.diagram_generation')
33
class NoDiagramException(InvalidCmd): pass
32
35
#===============================================================================
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# DiagramTag mother class
34
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#===============================================================================
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"""Exception for any problems in DiagramTags"""
62
def __init__(self, diagram, model = None, ninitial = 2):
65
def __init__(self, diagram, model=None, ninitial=2):
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"""Initialize with a diagram. Create DiagramTagChainLinks according to
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67
the diagram, and figure out if we need to shift the central vertex."""
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def vertices_from_link(cls, link, model, first_vertex = False):
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"""Recursively return the leg corresponding to this link and
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the list of all vertices from all previous links"""
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the list of all vertices from all previous links"""
143
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if link.end_link:
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# This is an end link and doesn't correspond to a vertex
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# First recursively find all daughter legs and vertices
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leg_vertices = [cls.vertices_from_link(l, model) for l in link.links]
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# The daughter legs are in the first entry
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legs = base_objects.LegList(sorted([l for l,v in leg_vertices],
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lambda l1,l2: l2.get('number') - \
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if not first_vertex:
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# This corresponds to a wavefunction with a resulting leg
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# Need to create the resulting leg from legs and vertex id
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last_leg = cls.leg_from_legs(legs,
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cls.id_from_vertex_id(link.vertex_id),
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last_leg = cls.leg_from_legs(legs,link.vertex_id,model)
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legs.append(last_leg)
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# Now create and append this vertex
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vertices.append(cls.vertex_from_link(legs,
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# Return list of vertices
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# Return leg and list of vertices
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return last_leg, vertices
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def leg_from_legs(legs, vertex_id, model):
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def legPDGs_from_vertex_id(cls, vertex_id,model):
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"""Returns the list of external PDGs of the interaction corresponding
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to this vertex_id."""
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# In case we have to deal with a regular vertex, we return the list
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# external PDGs as given by the model information on that integer
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if (len(vertex_id)>=3 and 'PDGs' in vertex_id[2]):
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return vertex_id[2]['PDGs']
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return [part.get_pdg_code() for part in model.get_interaction(
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cls.id_from_vertex_id(vertex_id)).get('particles')]
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def leg_from_legs(cls,legs, vertex_id, model):
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"""Return a leg from a leg list and the model info"""
182
pdgs = [part.get_pdg_code() for part in \
183
model.get_interaction(vertex_id).get('particles')]
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pdgs = list(cls.legPDGs_from_vertex_id(vertex_id, model))
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# Extract the resulting pdg code from the interaction pdgs
185
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for pdg in [leg.get('id') for leg in legs]:
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def vertex_from_link(cls, legs, vertex_id, model):
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"""Return a vertex given a leg list and a vertex id"""
206
return base_objects.Vertex({'legs': legs,
207
'id': cls.id_from_vertex_id(vertex_id)})
219
vert_ID = cls.id_from_vertex_id(vertex_id)
221
return base_objects.Vertex({'legs': legs,
224
contracted_vert = base_objects.ContractedVertex({'legs': legs,'id': -2})
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for key, value in cls.loop_info_from_vertex_id(vertex_id):
226
if key in contracted_vert:
227
contracted_vert.set(key,value)
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def leg_from_link(link):
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"""Return a leg from a link"""
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def id_from_vertex_id(vertex_id):
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"""Return the numerical vertex id from a link.vertex_id"""
247
return vertex_id[0][0]
250
def loop_info_from_vertex_id(vertex_id):
251
"""Return the loop_info stored in this vertex id. Notice that the
252
IdentifyME tag does not store the loop_info, but should normally never
253
need access to it."""
229
258
def reorder_permutation(perm, start_perm):
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281
"""Returns the default vertex id: just the interaction id
253
282
Note that in the vertex id, like the leg, only the first entry is
254
283
taken into account in the tag comparison, while the second is for
255
storing information that is not to be used in comparisons."""
284
storing information that is not to be used in comparisons and the
285
third for additional info regarding the shrunk loop vertex."""
257
return (vertex.get('id'),)
287
if isinstance(vertex,base_objects.ContractedVertex):
288
# return (vertex.get('id'),(),{'PDGs':vertex.get('PDGs')})
289
return ((vertex.get('id'),vertex.get('loop_tag')),(),
290
{'PDGs':vertex.get('PDGs')})
292
return ((vertex.get('id'),()),(),{})
260
295
def flip_vertex(new_vertex, old_vertex, links):
534
570
self['diagrams'] = res
535
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raise InvalidCmd, 'The number of fermion is odd'
537
raise InvalidCmd, 'The number of fermion is odd'
540
575
# Then check same number of incoming and outgoing fermions (if
541
576
# no Majorana particles in model)
546
581
self['diagrams'] = res
547
582
raise InvalidCmd, 'The number of of incoming/outcoming fermions are different'
549
raise InvalidCmd, 'The number of of incoming/outcoming fermions are different'
551
586
# Finally check that charge (conserve by all interactions) of the process
552
587
#is globally conserve for this process.
553
588
for charge in model.get('conserved_charge'):
1662
1697
# Setup process
1663
process = base_objects.Process({\
1665
'model':process_definition.get('model'),
1666
'id': process_definition.get('id'),
1667
'orders': process_definition.get('orders'),
1668
'required_s_channels': \
1669
process_definition.get('required_s_channels'),
1670
'forbidden_onsh_s_channels': \
1671
process_definition.get('forbidden_onsh_s_channels'),
1672
'forbidden_s_channels': \
1673
process_definition.get('forbidden_s_channels'),
1674
'forbidden_particles': \
1675
process_definition.get('forbidden_particles'),
1677
process_definition.get('is_decay_chain'),
1678
'perturbation_couplings': \
1679
process_definition.get('perturbation_couplings'),
1681
process_definition.get('squared_orders'),
1683
process_definition.get('sqorders_types'),
1685
process_definition.get('overall_orders'),
1687
process_definition.get('has_born'),
1689
process_definition.get('split_orders')
1698
process = process_definition.get_process_with_legs(legs)
1692
1701
array.array('i',[leg.get('id') for leg in legs])
1693
1702
if collect_mirror_procs and \
1718
1727
not process.get('is_decay_chain'):
1720
1729
crossed_index = success_procs.index(sorted_legs)
1730
# The relabeling of legs for loop amplitudes is cumbersome
1731
# and does not save so much time. It is disable here and
1732
# we use the key 'loop_diagrams' to decide whether
1733
# it is an instance of LoopAmplitude.
1734
if 'loop_diagrams' in amplitudes[crossed_index]:
1721
1736
except ValueError:
1722
1737
# No crossing found, just continue
1759
1774
if len(failed_procs) == 1 and 'error' in locals():
1777
raise NoDiagramException, \
1763
1778
"No amplitudes generated from process %s. Please enter a valid process" % \
1764
1779
process_definition.nice_string()
added
removed
madgraph/core/diagram_generation.py
