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0001 // -*- C++ -*-
0002 //
0003 // a1ThreePionCLEODecayer.h is a part of Herwig - A multi-purpose Monte Carlo event generator
0004 // Copyright (C) 2002-2019 The Herwig Collaboration
0005 //
0006 // Herwig is licenced under version 3 of the GPL, see COPYING for details.
0007 // Please respect the MCnet academic guidelines, see GUIDELINES for details.
0008 //
0009 #ifndef HERWIG_a1ThreePionCLEODecayer_H
0010 #define HERWIG_a1ThreePionCLEODecayer_H
0011 //
0012 // This is the declaration of the a1ThreePionCLEODecayer class.
0013 //
0014 #include "Herwig/Decay/DecayIntegrator.h"
0015 #include "Herwig/Decay/PhaseSpaceMode.h"
0016 #include "Herwig/Utilities/Kinematics.h"
0017 #include "ThePEG/Helicity/LorentzPolarizationVector.h"
0018 
0019 namespace Herwig {
0020 using namespace ThePEG;
0021 
0022 /** \ingroup Decay
0023  *
0024  *  The  <code>a1ThreePionCLEODecayer</code> class is designed to implement the decay
0025  *  of the \f$a_1\f$ to three pions using the model of Phys.Rev.D61:012002,2000,
0026  *  (hep-ex/9902022) (CLEO) which was fitted to the one charged and two neutral pion
0027  *  channel for the charged \f$a_1\f$ decay in \f$\tau \to a_1 -> \pi\pi\pi\f$.
0028  *  The other modes are infered from this using isospin. This is a sophisticated model
0029  *  including the coupling of the \f$a_1\f$ to the \f$\rho\f$, \f$\rho(1450)\f$, 
0030  *  \f$f(1370)\f$ and \f$\sigma\f$ sigma mesons.
0031  *
0032  *  In this case the current is given by
0033  *  \f[\mathcal{M} = \epsilon_\mu
0034  *     \left[F_1(p_2-p_3)^\mu+F_2(p_3-p_1)^\mu+F_3(p_1-p_2)^\mu\right].\f]
0035  *
0036  *
0037  * The form factors for the \f$a_1^0 \to \pi^0 \pi^0 \pi^0\f$ mode are
0038  * \f[F_1=
0039  * \phantom{-}\frac23\left(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3)\right)
0040  *     -\frac23\left(g_\sigma B^S_\sigma(s_2)+g_{f_0}B^S_{f_0}(s_2)\right)
0041  *         +g_{f_2}\left(\frac12(s_3-s_2)B^D_{f_2}(s_1)
0042  *   -\frac1{18}\frac{(4m_{\pi^0}^2-s_2)(q^2+s_2-m_{\pi^0}^2)}{s_2}B^D_{f_2}(s_2)
0043  *   +\frac1{18}\frac{(4m_{\pi^0}^2-s_3)(q^2-m_{\pi^0}^2+s_3)}{s_3}B^D_{f_2}(s_3)\right)
0044  *\f]
0045  *
0046  * \f[F_2=\phantom{-}\frac23(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3))
0047  *          -\frac23(g_\sigma B^S_\sigma(s_1)+g_{f_0}B^S_{f_0}(s_1))
0048  *          +g_{f_2}\left( \frac12(s_3-s1)B^D_{f_2}(s_2)
0049  *   -\frac1{18}\frac{(4m_{\pi^0}^2-s_1)(q^2+s_1-m_{\pi^0}^2)}{s_1}B^D_{f_2}(s_1)
0050  *   +\frac1{18}\frac{(4m_{\pi^0}^2-s_3)(q^2-m_{\pi^0}^2+s_3)}{s_3}B^D_{f_2}(s_3)\right)
0051  *\f]
0052  * \f[F_3=-\frac23(g_\sigma B^S_\sigma(s_1)+g_{f_0}B^S_{f_0}(s_1))
0053  *          +\frac23(g_\sigma B^S_\sigma(s_2)+g_{f_0}B^S_{f_0}(s_2))
0054  *          +g_{f_2}\left( \frac12(s_1-s_2)B^D_{f_2}(s_3)
0055  *  -\frac1{18}\frac{(4m_{\pi^0}^2-s_1)(q^2+s_1-m_{\pi^0}^2)}{s_1}B^D_{f_2}(s_1)
0056  *  +\frac1{18}\frac{(4m_{\pi^0}^2-s_2)(q^2+s_2-m_{\pi^0}^2)}{s_2}B^D_{f_2}(s_2)\right)
0057  *\f]
0058  *
0059  * The form factors for the \f$a_1^+ \to \pi^0 \pi^0 \pi^+\f$ mode are
0060  *
0061  * \f[F_1=\sum_k\left\{-\frac{g^P_{\rho_k}}3B_{\rho_k}^P(s_1)
0062  *          -g^D_{\rho_k}B_{\rho_k}^P(s_2)
0063  *                        \left((s_3-m_{\pi^+}^2)-(s_1-m_{\pi^0}^2)\right)\right\}
0064  *     +\frac23\left(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3)\right)     
0065  * +\frac{g_{f_2}}{18s_3}(q^2-m_{\pi^+}^2+s_3)(4m_{\pi^0}^2-s_3)B^D_{f_2}(s_3)
0066  *\f]
0067  *
0068  * \f[F_2=\sum_k\left\{-\frac13g^P_{\rho_k}B_{\rho_k}^P(s_2)
0069  *         -g^D_{\rho_k}B_{\rho_k}^P(s_1)
0070  *                       \left((s_3-m_{\pi^+}^2)-(s_2-m_{\pi^0}^2)\right)\right\}
0071  *     +\frac23\left(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3)\right)
0072  * +\frac1{18s_3}g_{f_2}(q^2-m_{\pi^+}^2+s_3)(4m_{\pi^0}^2-s_3)B^D_{f_2}(s_3)
0073  *\f]
0074  *
0075  * \f[F_3=\sum_k g^D_{\rho_k}\left\{ 
0076  *     -\frac13B_{\rho_k}^P(s_1)\left((s_3-m_{\pi^+}^2)-(s_2-m_{\pi^0}^2)\right)
0077  *     +\frac13B_{\rho_k}^P(s_2)\left((s_3-m_{\pi^+}^2)-(s_1-m_{\pi^0}^2)\right)\right\}
0078  *  -\frac{g_{f_2}}2(s_1-s_2)B^D_{f_2}(s_3)\f]
0079  * 
0080  * The form factors for \f$a_1^0\to\pi^+\pi^-\pi^0\f$.
0081  *
0082  * \f[F_1=\sum_k\left\{g^P_{\rho_k}B_{\rho_k}^P(s_1)
0083  *    -\frac{g^D_{\rho_k}}3B_{\rho_k}^P(s_2)(s_3-m_{\pi^0}^2-s_1+m_{\pi^+}^2)\right\}
0084  * +\frac23\left(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3)\right)
0085  * +\frac{g_{f_2}}{18s_3}(q^2-m_{\pi^0}^2+s_3)(4m_{\pi^+}^2-s_3)B^D_{f_2}(s_3)\f]
0086  *
0087  * \f[F_2=\sum_k\left\{g^P_{\rho_k}B_{\rho_k}^P(s_2)
0088  *    -\frac{g^D_{\rho_k}}3B_{\rho_k}^P(s_1)(s_3-m_{\pi^0}^2-s_2+m_{\pi^+}^2)\right\}
0089  * +\frac23\left(g_\sigma B^S_\sigma(s_3)+g_{f_0}B^S_{f_0}(s_3)\right)
0090  * +\frac{g_{f_2}}{18s_3}(q^2-m_{\pi^0}^2+s_3)(4m_{\pi^+}^2-s_3)B^D_{f_2}(s_3)\f]
0091  *
0092  * \f[F_3=\sum_k
0093  *   g^D_{\rho_k}\left\{-\frac13B_{\rho_k}^P(s_1)(s_3-m_{\pi^0}^2-s_2+m_{\pi^+}^2)
0094  *                       +\frac13B_{\rho_k}^P(s_2)(s_3-m_{\pi^0}^2-s_1+m_{\pi^+}^2)
0095  *          \right\}
0096  * -\frac{g_{f_2}}2(s_1-s_2)B^D_{f_2}(s_3)\f]
0097  * 
0098  *  The form factors for  \f$a_1^+\to \pi^+ \pi^+ \pi^-\f$ mode
0099  *
0100  * \f[F_1=\sum_k\left\{-g^P_{\rho_k}B_{\rho_k}^P(s_1)
0101  *                       -\frac{g^D_{\rho_k}}3B_{\rho_k}^P(s_2)(s_1-s_3)\right\}
0102  *    -\frac23\left(g_\sigma B^S_\sigma(s_2)+g_{f_0} B^S_{f_0}(s_2)\right) 
0103  *    +g_{f_2}\left(\frac12(s_3-s_2)B^D_{f_2}(s_1)
0104  *    -\frac1{18s_2}(4m_{\pi^+}^2-s_2)(q^2+s_2-m_{\pi^+}^2)B^D_{f_2}(s_2)\right)\f]
0105  *
0106  * \f[F_2=\sum_k\left\{-g^P_{\rho_k}B_{\rho_k}^P(s_2)
0107  *                       -\frac{g^D_{\rho_k}}3B_{\rho_k}^P(s_1)(s_2-s_3)\right\}
0108  *    -\frac23\left(g_\sigma B^S_\sigma(s_1)+g_{f_0} B^S_{f_0}(s_1)\right)
0109  *    +g_{f_2}\left(\frac12(s_3-s_1)B^D_{f_2}(s_2)
0110  *    -\frac1{18s_1}(4m_{\pi^+}^2-s_1)(q^2+s_1-m_{\pi^+}^2)B^D_{f_2}(s_1)\right)\f]
0111  *
0112  * \f[F_3=\sum_k
0113  *     -g^D_{\rho_k}\left( \frac13(s_2-s_3)B_{\rho_k}^P(s_1)
0114  *                        -\frac13(s_1-s_3)B_{\rho_k}^P(s_2)\right)
0115  *   -\frac23\left(g_\sigma B^S_\sigma(s_1)+g_{f_0}B^S_{f_0}(s_1)\right)
0116  *   +\frac23\left(g_\sigma B^S_\sigma(s_2)+g_{f_0}B^S_{f_0}(s_2)\right)\f]
0117  *\f[
0118  *   +g_{f_2}\left(-\frac1{18s_1}(4m_{\pi^+}^2-s_1)(q^2+s_1-m_{\pi^+}^2)B^D_{f_2}(s_1)
0119  *            +\frac1{18s_2}(4m_{\pi^+}^2-s_2)(q^2+s_2-m_{\pi^+}^2)B^D_{f_2}(s_2)\right)\f]
0120  *
0121  * where
0122  *
0123  * - \f$g_{f_2}\f$ is the coupling of the \f$f_2\f$ to the \f$a_1\f$
0124  * - \f$g_{f_0}\f$ is the coupling of the \f$f_0(1370)\f$ to the \f$a_1\f$
0125  * - \f$g_{\sigma}\f$ is the coupling of the \f$\sigma\f$ to the \f$a_1\f$
0126  * - \f$g^P_{\rho_k}\f$ is the \f$p\f$-wave coupling of the \f$\rho_k\f$ multiplet
0127  *     to the \f$a_1\f$.
0128  * - \f$g^D_{\rho_k}\f$ is the \f$d\f$-wave coupling of the \f$\rho_k\f$ multiplet
0129  *     to the \f$a_1\f$.
0130  * - \f$s_3=m^2_{12}\f$ is the invariant mass squared of particles 1 and 2.
0131  * - \f$s_2=m^2_{13}\f$ is the invariant mass squared of particles 1 and 3.
0132  * - \f$s_1=m^2_{23}\f$ is the invariant mass squared of particles 2 and 3.
0133  *
0134  * The Breit-Wigner factors are given by
0135     \f$B^L_Y(s_i) = \frac{m^2_Y}{m^2_Y-s_i)+im_Y\Gamma^{Y,L}(s_i)}\f$
0136  * where
0137  * \f$\Gamma^{Y,L}(s_i) = \Gamma^Y\left(\frac{p(s_i)}{p(M_Y}\right)^{2L+1}\frac{m_Y}{\sqrt{s_i}}\f$
0138  * \f$m_Y\f$ and \f$\Gamma^Y\f$ are the mass and width of the particle \f$Y\f$ 
0139  * respectively. \f$p(s_i)\f$ is the momentum of the outgoing pion in the 
0140  * rest frame of the resonanc \f$Y\f$.
0141  *
0142  * @see ThreePionCLEOCurrent
0143  * @see DecayIntegrator
0144  *
0145  */
0146 class a1ThreePionCLEODecayer: public DecayIntegrator {
0147   
0148 public:
0149   
0150   /**
0151    * Default constructor.
0152    */
0153   a1ThreePionCLEODecayer();
0154 
0155   /**
0156    * Which of the possible decays is required
0157    * @param cc Is this mode the charge conjugate
0158    * @param parent The decaying particle
0159    * @param children The decay products
0160    */
0161   virtual int modeNumber(bool & cc, tcPDPtr parent, 
0162              const tPDVector & children) const;
0163 
0164   /**
0165    * Return the matrix element squared for a given mode and phase-space channel.
0166    * @param ichan The channel we are calculating the matrix element for. 
0167    * @param part The decaying Particle.
0168    * @param outgoing The particles produced in the decay
0169    * @param momenta  The momenta of the particles produced in the decay
0170    * @param meopt Option for the calculation of the matrix element
0171    * @return The matrix element squared for the phase-space configuration.
0172    */
0173   double me2(const int ichan,const Particle & part,
0174          const tPDVector & outgoing,
0175          const vector<Lorentz5Momentum> & momenta,
0176          MEOption meopt) const;
0177 
0178   /**
0179    *   Construct the SpinInfos for the particles produced in the decay
0180    */
0181   virtual void constructSpinInfo(const Particle & part,
0182                  ParticleVector outgoing) const;
0183 
0184   /**
0185    * Method to return an object to calculate the 3 body partial width.
0186    * @param dm The DecayMode
0187    * @return A pointer to a WidthCalculatorBase object capable of calculating the width
0188    */
0189   virtual WidthCalculatorBasePtr threeBodyMEIntegrator(const DecayMode & dm) const;
0190 
0191   /**
0192    * The matrix element to be integrated for the three-body decays as a function
0193    * of the invariant masses of pairs of the outgoing particles.
0194    * @param imode The mode for which the matrix element is needed.
0195    * @param q2 The scale, \e i.e. the mass squared of the decaying particle.
0196    * @param s3 The invariant mass squared of particles 1 and 2, \f$s_3=m^2_{12}\f$.
0197    * @param s2 The invariant mass squared of particles 1 and 3, \f$s_2=m^2_{13}\f$.
0198    * @param s1 The invariant mass squared of particles 2 and 3, \f$s_1=m^2_{23}\f$.
0199    * @param m1 The mass of the first  outgoing particle.
0200    * @param m2 The mass of the second outgoing particle.
0201    * @param m3 The mass of the third  outgoing particle.
0202    * @return The matrix element
0203    */
0204   virtual double threeBodyMatrixElement(const int imode , const Energy2 q2,
0205                     const Energy2 s3, const Energy2 s2,
0206                     const Energy2 s1, const Energy  m1,
0207                     const Energy  m2, const Energy m3) const;
0208 
0209   /**
0210    * Output the setup information for the particle database
0211    * @param os The stream to output the information to
0212    * @param header Whether or not to output the information for MySQL
0213    */
0214   virtual void dataBaseOutput(ofstream & os,bool header) const;
0215   
0216 public:
0217   
0218   /** @name Functions used by the persistent I/O system. */
0219   //@{
0220   /**
0221    * Function used to write out object persistently.
0222    * @param os the persistent output stream written to.
0223    */
0224   void persistentOutput(PersistentOStream & os) const;
0225 
0226   /**
0227    * Function used to read in object persistently.
0228    * @param is the persistent input stream read from.
0229    * @param version the version number of the object when written.
0230    */
0231   void persistentInput(PersistentIStream & is, int version);
0232   //@}
0233   
0234   /**
0235    * Standard Init function used to initialize the interfaces.
0236    */
0237   static void Init();
0238   
0239 protected:
0240   
0241   /** @name Clone Methods. */
0242   //@{
0243   /**
0244    * Make a simple clone of this object.
0245    * @return a pointer to the new object.
0246    */
0247   virtual IBPtr clone() const { return new_ptr(*this);}
0248 
0249   /** Make a clone of this object, possibly modifying the cloned object
0250    * to make it sane.
0251    * @return a pointer to the new object.
0252    */
0253   virtual IBPtr fullclone() const { return new_ptr(*this);}
0254   //@}
0255   
0256 protected:
0257   
0258   /** @name Standard Interfaced functions. */
0259   //@{
0260   /**
0261    * Initialize this object after the setup phase before saving and
0262    * EventGenerator to disk.
0263    * @throws InitException if object could not be initialized properly.
0264    */
0265   virtual void doinit();
0266 
0267   /**
0268    * Initialize this object to the begining of the run phase.
0269    */
0270   virtual void doinitrun();
0271   //@}
0272   
0273 private:
0274   
0275   /**
0276    * Private and non-existent assignment operator.
0277    */
0278   a1ThreePionCLEODecayer & operator=(const a1ThreePionCLEODecayer &) = delete;
0279   
0280 private:
0281 
0282   /**
0283    * Breit wigner for the \f$\rho\f$, \f$B^P_{\rho_k}(q^2)\f$.
0284    * @param ires The \f$\rho\f$ multiplet to used.
0285    * @param q2 The scale, \f$q^2\f$.
0286    * @param icharge Which pion masses to use for the momentum calculation
0287    * @return The Breit-Wigner
0288    */
0289   Complex rhoBreitWigner(int ires, Energy2 q2,int icharge) const {
0290     Energy q=sqrt(q2);
0291     Complex ii(0.,1.);
0292     double ratio = icharge==0 ? 
0293       Kinematics::pstarTwoBodyDecay(q,_mpic,_mpic)/_prhocc[ires] :
0294       Kinematics::pstarTwoBodyDecay(q,_mpic,_mpi0)/_prhoc0[ires];
0295     Energy gamrun=_rhowidth[ires]*pow(ratio,3)*_rhomass[ires]/q;
0296     return sqr(_rhomass[ires])
0297       /(sqr(_rhomass[ires])-q2-ii*_rhomass[ires]*gamrun);
0298   }
0299 
0300   /**
0301    * Breit wigner for the \f$\sigma\f$, \f$B^S_\sigma(q^2)\f$.
0302    * @param q2 The scale, \f$q^2\f$.
0303    * @param icharge Which pion masses to use for the momentum calculation
0304    * @return The Breit-Wigner
0305    */
0306   Complex sigmaBreitWigner(Energy2 q2,int icharge) const {
0307     Energy q=sqrt(q2);
0308     Complex ii(0.,1.);
0309     double ratio = icharge==0 ? 
0310       Kinematics::pstarTwoBodyDecay(q,_mpic,_mpic)/_psigmacc :
0311       Kinematics::pstarTwoBodyDecay(q,_mpi0,_mpi0)/_psigma00;
0312     Energy gamrun=_sigmawidth*ratio*_sigmamass/q;
0313     return sqr(_sigmamass)/(sqr(_sigmamass)-q2-ii*_sigmamass*gamrun);
0314   }
0315   
0316   /**
0317    * Breit wigner for the \f$f_0(1370)\f$, \f$B^S_{f_0}(q^2)\f$.
0318    * @param q2 The scale, \f$q^2\f$.
0319    * @param icharge Which pion masses to use for the momentum calculation
0320    * @return The Breit-Wigner
0321    */
0322   Complex f0BreitWigner(Energy2 q2,int icharge) const {
0323     Energy q=sqrt(q2);
0324     Complex ii(0.,1.);
0325     double ratio = icharge==0 ? 
0326       Kinematics::pstarTwoBodyDecay(q,_mpic,_mpic)/_pf0cc :
0327       Kinematics::pstarTwoBodyDecay(q,_mpi0,_mpi0)/_pf000;
0328     Energy gamrun=_f0width*ratio*_f0mass/q;
0329     return sqr(_f0mass)/(sqr(_f0mass)-q2-ii*_f0mass*gamrun);
0330   }
0331   
0332   /**
0333    * Breit wigner for the \f$f_2\f$, \f$B^D_{f_2}(q^2)\f$.
0334    * @param q2 The scale, \f$q^2\f$.
0335    * @param icharge Which pion masses to use for the momentum calculation
0336    * @return The Breit-Wigner
0337    */
0338   Complex f2BreitWigner(Energy2 q2,int icharge) const {
0339     Energy q=sqrt(q2);
0340     Complex ii(0.,1.);
0341     double ratio = icharge==0 ?
0342       Kinematics::pstarTwoBodyDecay(q,_mpic,_mpic)/_pf2cc :
0343       Kinematics::pstarTwoBodyDecay(q,_mpi0,_mpi0)/_pf200;
0344     Energy gamrun=_f2width*pow(ratio,5)*_f2mass/q;
0345     return sqr(_f2mass)/(sqr(_f2mass)-q2-ii*_f2mass*gamrun);
0346   }
0347   
0348   /**
0349    * Calculate the form factors
0350    * @param iopt The mode being calculated in the order given above
0351    * @param ichan The phase space channel in the order given in the doinit member.
0352    * @param q2 The sacale \f$q^2\f$.
0353    * @param s1 The invariant mass squared of particles 2 and 3, \f$s_1=m^2_{23}\f$.
0354    * @param s2 The invariant mass squared of particles 1 and 3, \f$s_2=m^2_{13}\f$.
0355    * @param s3 The invariant mass squared of particles 1 and 2, \f$s_3=m^2_{12}\f$.
0356    * @param F1 The form factor \f$F_1\f$.
0357    * @param F2 The form factor \f$F_2\f$.
0358    * @param F3 The form factor \f$F_3\f$.
0359    * 
0360    */
0361   void formFactors(int iopt,int ichan,Energy2 q2,Energy2 s1,Energy2 s2,
0362            Energy2 s3,
0363            complex<InvEnergy> & F1,
0364            complex<InvEnergy> & F2,
0365            complex<InvEnergy> & F3) const;
0366 
0367 private:
0368 
0369   /**
0370    * Masses of the rho resonaces
0371    */
0372   vector<Energy> _rhomass;
0373 
0374   /**
0375    * Widths of the rho resonaces
0376    */
0377   vector<Energy> _rhowidth;
0378 
0379   /**
0380    * Momentum of the particles produced in charged rho decay
0381    */
0382   vector<Energy> _prhocc;
0383 
0384   /**
0385    * Momentum of the particles produced in neutral rho decay
0386    */
0387   vector<Energy> _prhoc0;
0388 
0389   /**
0390    * Mass of the \f$f_2\f$.
0391    */
0392   Energy _f2mass;
0393 
0394   /**
0395    * Width of the \f$f_2\f$.
0396    */
0397   Energy _f2width;
0398 
0399   /**
0400    * Momentum for the decay of the \f$f_2\f$ to two charged pions.
0401    */
0402   Energy _pf2cc;
0403 
0404   /**
0405    * Momentum for the decay of the \f$f_2\f$ to two neutral pions.
0406    */
0407   Energy _pf200;
0408 
0409   /**
0410    * Mass of the \f$f_0(1370)\f$.
0411    */
0412   Energy _f0mass;
0413 
0414   /**
0415    * Width of the \f$f_0(1370)\f$.
0416    */
0417   Energy _f0width;
0418 
0419   /**
0420    * Momentum for the decay of the \f$f_0(1370)\f$ to two charged pions.
0421    */
0422   Energy _pf0cc;
0423 
0424   /**
0425    * Momentum for the decay of the \f$f_0(1370)\f$ to two neutral pions.
0426    */
0427   Energy _pf000;
0428 
0429   /**
0430    * Mass of the \f$\sigma\f$ meson.
0431    */
0432   Energy _sigmamass;
0433 
0434   /**
0435    * Width of the \f$\sigma\f$ meson.
0436    */
0437   Energy _sigmawidth;
0438 
0439   /**
0440    * Momentum for the decay of the \f$\sigma\f$ to two charged pions.
0441    */
0442   Energy _psigmacc;
0443 
0444   /**
0445    * Momentum for the decay of the \f$\sigma\f$ to two neutral pions.
0446    */
0447   Energy _psigma00;
0448 
0449   /**
0450    * Mass of the neutral pion
0451    */
0452   Energy _mpi0;
0453 
0454   /**
0455    * Mass of the charged pion
0456    */
0457   Energy _mpic;
0458 
0459   /**
0460    * overall coupling for the decay
0461    */
0462   InvEnergy _coupling;
0463 
0464   /**
0465    * Magnitude of the \f$p\f$-wave couplings of the rho resonance, \f$g^P_{\rho_k}\f$, 
0466    * (\f$\beta_{1,2}\f$ in the CLEO paper.)
0467    */
0468   vector<double> _rhomagP;
0469 
0470   /**
0471    * Phase of the \f$p\f$-wave couplings of the rho resonance, \f$g^P_{\rho_k}\f$,
0472    * (\f$\beta_{1,2}\f$ in the CLEO paper.)
0473    */
0474   vector<double> _rhophaseP;
0475 
0476   /**
0477    *\f$p\f$-wave couplings of the rho resonance, \f$g^P_{\rho_k}\f$, 
0478    * (\f$\beta_{1,2}\f$ in the CLEO paper.)
0479    */
0480   vector<Complex> _rhocoupP;
0481 
0482   /**
0483    * Magnitude of the \f$d\f$-wave couplings of the rho resonance, \f$g^D_{\rho_k}\f$,
0484    * (\f$\beta_{3,4}\f$ in the CLEO paper.)
0485    */
0486   vector<InvEnergy2> _rhomagD;
0487 
0488   /**
0489    * Phase of the \f$d\f$-wave couplings of the rho resonance, \f$g^D_{\rho_k}\f$, 
0490    * (\f$\beta_{3,4}\f$ in the CLEO paper.)
0491    */
0492   vector<double>_rhophaseD;
0493 
0494   /**
0495    * \f$d\f$-wave couplings of the rho resonance, \f$g^D_{\rho_k}\f$,
0496    * (\f$\beta_{3,4}\f$ in the CLEO paper.)
0497    */
0498   vector<complex<InvEnergy2> > _rhocoupD;
0499 
0500   /**
0501    * Magntiude of the coupling of the \f$f_2\f$ resonance, \f$g_{f_2}\f$,
0502    * (\f$\beta_5\f$ in the CLEO paper.)
0503    */
0504   InvEnergy2 _f2mag;
0505 
0506   /**
0507    * Phase of the coupling of the \f$f_2\f$ resonance, \f$g_{f_2}\f$,
0508    * (\f$\beta_5\f$ in the CLEO paper.)
0509    */
0510   double _f2phase;
0511 
0512   /**
0513    * Coupling of the \f$f_2\f$ resonance, \f$g_{f_2}\f$,
0514    * (\f$\beta_5\f$ in the CLEO paper.)
0515    */
0516   complex<InvEnergy2> _f2coup;
0517 
0518   /**
0519    * Magntiude of the coupling of the \f$f_0(1370)\f$ resonance, \f$g_{f_0}\f$,
0520    * (\f$\beta_6\f$ in the CLEO paper.)
0521    */
0522   double _f0mag;
0523 
0524   /**
0525    * Phase of the coupling of the \f$f_0(1370)\f$ resonance, \f$g_{f_0}\f$,
0526    * (\f$\beta_6\f$ in the CLEO paper.)
0527    */
0528   double _f0phase;
0529 
0530   /**
0531    * Coupling of the \f$f_0(1370)\f$ resonance, \f$g_{f_0}\f$,
0532    * (\f$\beta_6\f$ in the CLEO paper.)
0533    */
0534   Complex _f0coup;
0535 
0536   /**
0537    * Magntiude of the coupling of the \f$\sigma\f$ resonance, \f$g_\sigma\f$,
0538    * (\f$\beta_7\f$ in the CLEO paper.)
0539    */
0540   double _sigmamag;
0541 
0542   /**
0543    * Phase of the coupling of the \f$\sigma\f$ resonance, \f$g_\sigma\f$,
0544    * (\f$\beta_7\f$ in the CLEO paper.)
0545    */
0546   double _sigmaphase;
0547 
0548   /**
0549    * Coupling of the \f$\sigma\f$ resonance, \f$g_\sigma\f$,
0550    * (\f$\beta_7\f$ in the CLEO paper.)
0551    */
0552   Complex _sigmacoup;
0553 
0554   /**
0555    * Use local values of the mass parameters
0556    */
0557   bool _localparameters;
0558   
0559   /**
0560    * Weights for the channels for the zero charged pion channel.
0561    */
0562   mutable vector<double> _zerowgts;
0563   
0564   /**
0565    * Weights for the channels for the one charged pion channel.
0566    */
0567   mutable vector<double> _onewgts;
0568   
0569   /**
0570    * Weights for the channels for the two charged pion channel.
0571    */
0572   mutable vector<double> _twowgts;
0573   
0574   /**
0575    * Weights for the channels for the three charged pion channel.
0576    */
0577   mutable vector<double> _threewgts;
0578 
0579   /**
0580    * Maximum weight for the zero charged pion channel.
0581    */
0582   mutable double _zeromax;
0583 
0584   /**
0585    * Maximum weight for the one charged pion channel.
0586    */
0587   mutable double _onemax;
0588 
0589   /**
0590    * Maximum weight for the two charged pion channel.
0591    */
0592   mutable double _twomax;
0593 
0594   /**
0595    * Maximum weight for the three charged pion channel.
0596    */
0597   mutable double _threemax;
0598 
0599   /**
0600    *  Spin density matrix
0601    */
0602   mutable RhoDMatrix _rho;
0603 
0604   /**
0605    *  Polarization vectors
0606    */
0607   mutable vector<Helicity::LorentzPolarizationVector> _vectors;
0608 };
0609   
0610 }
0611 
0612 
0613 #endif /* HERWIG_a1ThreePionCLEODecayer_H */