64 checkSpinParent(EvtSpinType::SCALAR);
66 checkSpinDaughter(0, EvtSpinType::SCALAR);
67 checkSpinDaughter(1, EvtSpinType::SCALAR);
68 checkSpinDaughter(2, EvtSpinType::SCALAR);
82 const double alpha = getArg(0);
84 p->initializePhaseSpace(getNDaug(), getDaugs());
86 EvtVector4R mompi0_0 = p->getDaug(0)->getP4();
87 EvtVector4R mompi0_1 = p->getDaug(1)->getP4();
88 EvtVector4R mompi0_2 = p->getDaug(2)->getP4();
90 double m_eta = p->mass();
91 double m_pi0 = p->getDaug(0)->mass();
92 double deltaM = m_eta - 3 * m_pi0;
95 double z0 = (3 * mompi0_0.get(0) - m_eta) / deltaM;
96 double z1 = (3 * mompi0_1.get(0) - m_eta) / deltaM;
97 double z2 = (3 * mompi0_2.get(0) - m_eta) / deltaM;
99 double z = (2. / 3.) * (z0 * z0 + z1 * z1 + z2 * z2) ;
101 double Amp2 = 1.0 + alpha * 2.0 * z;
105 EvtComplex amp(
sqrt(Amp2), 0.);