Package madgraph :: Package core :: Module helas_objects :: Class HelasAmplitude

Class HelasAmplitude

            object --+        
                     |        
                  dict --+    
                         |    
base_objects.PhysicsObject --+
                             |
                            HelasAmplitude

HelasAmplitude object, has the information necessary for writing a call to a HELAS amplitude routine:a list of mother wavefunctions, interaction id, amplitude number

Nested Classes

[hide private]

Inherited from base_objects.PhysicsObject: PhysicsObjectError

Instance Methods

[hide private]

default_setup(self)
Default values for all properties

source code

new empty dictionary

__init__(self, *arguments)
Allow generating a HelasAmplitude from a Vertex

source code

filter(self, name, value)
Filter for valid property values.

source code

__str__(self)
practicle way to represent an HelasAmplitude

source code

D[k] if k in D, else d

get(self, name)
Get the value of the property name.

source code

set(self, *arguments)
When setting interaction_id, if model is given (in tuple), set all other interaction properties.

source code

get_sorted_keys(self)
Return particle property names as a nicely sorted list.

source code

check_and_fix_fermion_flow(self, wavefunctions, diagram_wavefunctions, external_wavefunctions, wf_number)
Check for clashing fermion flow (N(incoming) != N(outgoing)) in mothers.

source code

needs_hermitian_conjugate(self)
Returns true if any of the mothers have negative fermionflow

source code

get_call_key(self)
Generate the (spin, state) tuples used as key for the helas call dictionaries in HelasModel

source code

calculate_fermionfactor(self)
Calculate the fermion factor for the diagram corresponding to this amplitude

source code

get_base_diagram(self, wf_dict, vx_list=[], optimization=1)
Return the base_objects.Diagram which corresponds to this amplitude, using a recursive method for the wavefunctions. source code

get_base_vertex(self, wf_dict, vx_list=[], optimization=1)
Get a base_objects.Vertex corresponding to this amplitude. source code

get_s_and_t_channels(self, ninitial, new_pdg)
Returns two lists of vertices corresponding to the s- and t-channels of this amplitude/diagram, ordered from the outermost s-channel and in/down towards the highest number initial state leg.

source code

get_color_indices(self)
Get the color indices corresponding to this amplitude and its mothers, using a recursive function.

source code

find_outgoing_number(self)
Return 0.

source code

get_conjugate_index(self)
Return the index of the particle that should be conjugated.

source code

get_vertex_leg_numbers(self)
Get a list of the number of legs in vertices in this diagram

source code

set_coupling_color_factor(self)
Check if there is a mismatch between order of fermions w.r.t.

source code

__eq__(self, other)
Comparison between different amplitudes, to allow check for identical processes.

source code

__ne__(self, other)
Overloading the nonequality operator, to make comparison easy

source code

Inherited from base_objects.PhysicsObject: __getitem__, __repr__, is_valid_prop

Inherited from dict: __cmp__, __contains__, __delitem__, __ge__, __getattribute__, __gt__, __iter__, __le__, __len__, __lt__, __new__, __setitem__, __sizeof__, clear, copy, fromkeys, has_key, items, iteritems, iterkeys, itervalues, keys, pop, popitem, setdefault, update, values

Inherited from object: __delattr__, __format__, __reduce__, __reduce_ex__, __setattr__, __subclasshook__

Static Methods

[hide private]

sign_flips_to_order(fermions)
Gives the sign corresponding to the number of flips needed to place the fermion numbers in order

source code

Class Variables

[hide private]

Inherited from dict: __hash__

Properties

[hide private]

Inherited from object: __class__

Method Details

[hide private]

default_setup(self)

source code

Default values for all properties

Overrides: base_objects.PhysicsObject.default_setup

init(self, arguments)
(Constructor)*

source code

Allow generating a HelasAmplitude from a Vertex

Returns: new empty dictionary
Overrides: object.__init__

filter(self, name, value)

source code

Filter for valid property values.

Overrides: base_objects.PhysicsObject.filter

str(self)
(Informal representation operator)

source code

practicle way to represent an HelasAmplitude

Overrides: object.__str__

get(self, name)

source code

Get the value of the property name.

Returns: D[k] if k in D, else d
Overrides: dict.get

set(self, *arguments)

source code

When setting interaction_id, if model is given (in tuple), set all other interaction properties. When setting pdg_code, if model is given, set all other particle properties.