This is the declaration of the MEBase class.
The MEBase class is the base class of all objects
representing hard matrix elements in Pythia7. There are three
methods which must be overridden by a concrete subclass:
includedDiagrams(tcPDPair) should return a vector of DiagramBases describing the diagrams used for this matrix element for the given pair of incoming parton types. These DiagramBases are used to identify the incoming and outgoing partons which can be handled to the process generation scheme, and is also used to cnstruct a corresponding SubProcess object.
scale() should return the scale associated with the phase space point set with the last call to setKinematics(...) or generateKinematics(...).
double me() const should return the the matrix element squared using the the type and momentum of the incoming and outgoing partons, previously set by the setKinematics(...) or generateKinematics(...) member functions, accessible through the methods meMomenta() and mePartonData() inherited from LastXCombInfo, and/or from information stored by sub classes. The returned value should be dimensionless suitable scaled by the total invariant mass squared (accessible through the sHat() member function). Any user of this method must make sure that the setKinematics(...) member function has been appropriately called before.
colourGeometries() should return a Selector with the possible ColourLines' weighted by their relative probabilities given the information given by the last call to setKinematics(...) or generateKinematics(...).
There are other virtula functions which may be overridden as listed below.
CLASS
MEBase: