void setp(double e, double px, double py, double pz)
void setpart_num(EvtId particle_number)
EvtSpinDensity rotateToHelicityBasis() const
void init(EvtId id, const EvtVector4R &p4)
void initPartons(int npartons, EvtVector4R *p4partons, EvtId *idpartons)