NtupleReader/src/MyCollinearApproximation.cxx

//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
// 13.12.2006, AUTHOR: MANFRED GROH
//+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
//:: IMPLEMENTATION OF METHODS DEFINED IN THE CLASS MyCollinearApproximation ::
//:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

//*****************************************************************************
#include "NtupleReader/MyCollinearApproximation.h"

//:::::::::::::::::
//:: METHOD init ::
//:::::::::::::::::
void MyCollinearApproximation::init(MyParticle* vis_particle_1,
                                    MyParticle* vis_particle_2,
                                    TLorentzVector missing_et
                                    ){
        m_vis_particle_1 = vis_particle_1;
        m_vis_particle_2 = vis_particle_2;
        m_missing_et = missing_et;
        calculate_kinematics();
        return;
}
//*****************************************************************************



//:::::::::::::::::::
//:: METHOD get_x1 ::
//:::::::::::::::::::
double MyCollinearApproximation::get_x1(void){
        return m_x1;
}

//*****************************************************************************



//:::::::::::::::::::
//:: METHOD get_x2 ::
//:::::::::::::::::::
double MyCollinearApproximation::get_x2(void){
        return m_x2;
}

//*****************************************************************************



//:::::::::::::::::::
//:: METHOD get_M_ll ::
//:::::::::::::::::::
double MyCollinearApproximation::get_M_ll(void){
        return m_M_ll;
}

//*****************************************************************************



//::::::::::::::::::::::::::::
//:: METHOD get_M_comp_part ::
//::::::::::::::::::::::::::::
double MyCollinearApproximation::get_M_comp_part(void){
        return m_M_comp_part;
}

//*****************************************************************************



//::::::::::::::::::::::::::::::
//:: METHOD get_tlv_comp_part ::
//::::::::::::::::::::::::::::::
TLorentzVector MyCollinearApproximation::get_tlv_comp_part(void){
    return tlv_comp_part;
}

//*****************************************************************************



//::::::::::::::::::::::::::::::
//:: METHOD get_vis_particle1 ::
//::::::::::::::::::::::::::::::
MyParticle* MyCollinearApproximation::get_vis_particle1(void){
        return m_vis_particle_1;
}

//*****************************************************************************



//::::::::::::::::::::::::::::::
//:: METHOD get_vis_particle2 ::
//::::::::::::::::::::::::::::::
MyParticle* MyCollinearApproximation::get_vis_particle2(void){
        return m_vis_particle_2;
}

//*****************************************************************************



// //::::::::::::::::::::::::::
// //:: METHOD get_neutrino1 ::
// //::::::::::::::::::::::::::
// MyParticle MyCollinearApproximation::get_neutrino_1(void){
//      return m_neutrino_1;
// }
// 
// //*****************************************************************************
// 
// 
// 
// //::::::::::::::::::::::::::
// //:: METHOD get_neutrino2 ::
// //::::::::::::::::::::::::::
// MyParticle MyCollinearApproximation::get_neutrino_2(void){
//      return m_neutrino_2;
// }
// 
// //*****************************************************************************
// 
// 
// 
// //::::::::::::::::::::::::::
// //:: METHOD get_comp_part ::
// //::::::::::::::::::::::::::
// MyParticle MyCollinearApproximation::get_comp_part(void){
//      return m_comp_part;
// }
// 
// //*****************************************************************************



//:::::::::::::::::::::::::::
//:: METHOD get_missing_et ::
//:::::::::::::::::::::::::::
TLorentzVector MyCollinearApproximation::get_missing_et(void){
        return m_missing_et;
}

//*****************************************************************************



//:::::::::::::::::::::::::::::::::
//:: METHOD calculate_kinematics ::
//:::::::::::::::::::::::::::::::::
void MyCollinearApproximation::calculate_kinematics(void){
        
        //============================//
        // do collinear approximation //
        //============================//
        double p1x, p1y, p2x, p2y, MissingEx, MissingEy;
        p1x = m_vis_particle_1->tlv().Px();
        p1y = m_vis_particle_1->tlv().Py();
        p2x = m_vis_particle_2->tlv().Px();
        p2y = m_vis_particle_2->tlv().Py();
        MissingEx = m_missing_et.Px();
        MissingEy = m_missing_et.Py();
        //MissingEx = m_missing_et.missinget_x();
        //MissingEy = m_missing_et.missinget_y();
        //MissingEx = m_missing_et.truth_missinget_x_NonInt();
        //MissingEy = m_missing_et.truth_missinget_y_NonInt();
        // calculate fraction of momentum carried by the
        // reconstructed decay products
    m_x1 = (p1x*p2y-p1y*p2x)/
            (p2y*(p1x+MissingEx)-p2x*(p1y+MissingEy));
        m_x2 = (p1x*p2y-p1y*p2x)/
            (p1x*(p2y+MissingEy)-p1y*(p2x+MissingEx));
        
        // calculate the invariant mass of the leptonpair
        m_M_ll=((m_vis_particle_1->tlv())+(m_vis_particle_2->tlv())).M();
    // calculate the invariant mass of the Higgs
        m_M_comp_part=m_M_ll/(sqrt(m_x1*m_x2));
    //std::cout<<"Higgs Mass: "<<m_M_comp_part<<std::endl;
    
    TLorentzVector tlv1, tlv2;
    tlv1 = m_vis_particle_1->tlv();
    tlv2 = m_vis_particle_2->tlv();
    tlv1 *= 1./m_x1;
    tlv2 *= 1./m_x2;
    tlv_comp_part = tlv1+tlv2;
    
//     if(TMath::Abs(m_M_comp_part-tlv_comp_part.M())>0.05 ){
//         std::cout<<"Higgs Mass old: "<<m_M_comp_part<<std::endl;
//         std::cout<<"Higgs Mass new: "<< tlv_comp_part.M()<<std::endl;
//         std::cout<<"Numerical problem?!?"<<std::endl;
//     }
    
        return;
}

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