Differential D34 Diff 135 EvtGenModels/EvtEtaLLPiPi.hh

Changeset View

Standalone View

EvtGenModels/EvtEtaLLPiPi.hh

This file was added.


				/***********************************************************************
				* Copyright 1998-2020 CERN for the benefit of the EvtGen authors *
				* *
				* This file is part of EvtGen. *
				* *
				* EvtGen is free software: you can redistribute it and/or modify *
				* it under the terms of the GNU General Public License as published by *
				* the Free Software Foundation, either version 3 of the License, or *
				* (at your option) any later version. *
				* *
				* EvtGen is distributed in the hope that it will be useful, *
				* but WITHOUT ANY WARRANTY; without even the implied warranty of *
				* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
				* GNU General Public License for more details. *
				* *
				* You should have received a copy of the GNU General Public License *
				* along with EvtGen. If not, see <https://www.gnu.org/licenses/>. *
				***********************************************************************/

				#ifndef EVT_ETALLPIPI_HH
				#define EVT_ETALLPIPI_HH

				#include "EvtGenBase/EvtConst.hh"
				#include "EvtGenBase/EvtDecayProb.hh"

				#include <string>

				class EvtParticle;

				// eta' -> mu+ mu- pi+ pi- or e+ e- pi+ pi-
				tlathamUnsubmitted Done Inline Actions Can you please run clang-format (preferably version 10.0.0) on these few files when submitting the next version? Will add mention of this in the CONTRIBUTING docs. tlatham: Can you please run clang-format (preferably version 10.0.0) on these few files when submitting…
				// From Zhang Zhen-Yu et al, Chinese Phys. C 36, p926, 2012

				class EvtEtaLLPiPi : public EvtDecayProb {
				public:
				EvtEtaLLPiPi() = default;

				void init() override;
				void initProbMax() override;

				std::string getName() override;
				EvtDecayBase* clone() override;

				void decay( EvtParticle* p ) override;

				private:
				void updateMassPars( double mLep, double mPi );

				double rhoWidth( double s, double m ) const;

				double F0( double sLL, double sPiPi ) const;

				double lambda( double a, double b, double c ) const;

				double ampSquared( EvtParticle* p ) const;

				double m_alpha{ 1.0 / 137.0 };
				double m_eSq{ 4.0 * EvtConst::pi * m_alpha };
				double m_fPi{ 0.0924 };
				double m_f8{ 1.3 * m_fPi };
				double m_f0{ 1.04 * m_fPi };
				double m_thetaMix{ 20.0 * EvtConst::pi / 180.0 };
				double m_mixSq{ 0.0 };
				double m_c1{ 1.0 };
				double m_c2{ 0.0 };
				double m_c3{ m_c1 - m_c2 }; // Eq 9
				double m_par1{ 1.0 - ( 3.0 * ( m_c1 - m_c2 + m_c3 ) / 4.0 ) };
				double m_parLL{ 3.0 * ( m_c1 - m_c2 - m_c3 ) / 4.0 };
				double m_parPiPi{ 3.0 * m_c3 / 2.0 };
				double m_rhoMass{ 0.775 }; // updated in init()
				double m_rhoMassSq{ m_rhoMass * m_rhoMass };
				double m_rhoGamma{ 0.149 }; // updated in init()
				double m_lepMass{ 0.106 }; // modified in updateMassPars()
				double m_lepMassSq{ m_lepMass * m_lepMass };
				double m_piMass{ 0.140 }; // modified in updateMassPars()
				double m_piMassSq{ m_piMass * m_piMass };
				double m_4LepMassSq{ 4.0 * m_lepMassSq };
				double m_4PiMassSq{ 4.0 * m_piMassSq };
				};

				#endif