algorithms/reco/InclusiveKinematicsDA.cc

0001 // SPDX-License-Identifier: LGPL-3.0-or-later
0002 // Copyright (C) 2022 Wouter Deconinck
0003
0004 #include <edm4eic/EDM4eicVersion.h>
0005 #if EDM4EIC_VERSION_MAJOR >= 6
0006
0007 #include <Math/GenVector/LorentzVector.h>
0008 #include <Math/GenVector/PxPyPzE4D.h>
0009 #include <Math/Vector4Dfwd.h>
0010 #include <edm4eic/InclusiveKinematicsCollection.h>
0011 #include <edm4eic/ReconstructedParticleCollection.h>
0012 #include <edm4hep/MCParticleCollection.h>
0013 #include <edm4hep/Vector3f.h>
0014 #include <fmt/core.h>
0015 #include <cmath>
0016 #include <gsl/pointers>
0017
0018 #include "Beam.h"
0019 #include "Boost.h"
0020 #include "InclusiveKinematicsDA.h"
0021
0022 using ROOT::Math::PxPyPzEVector;
0023
0024 namespace eicrecon {
0025
0026   void InclusiveKinematicsDA::init() { }
0027
0028   void InclusiveKinematicsDA::process(
0029       const InclusiveKinematicsDA::Input& input,
0030       const InclusiveKinematicsDA::Output& output) const {
0031
0032     const auto [mcparts, escat, hfs] = input;
0033     auto [kinematics] = output;
0034
0035     // Get incoming electron beam
0036     const auto ei_coll = find_first_beam_electron(mcparts);
0037     if (ei_coll.size() == 0) {
0038       debug("No beam electron found");
0039       return;
0040     }
0041     const PxPyPzEVector ei(
0042       round_beam_four_momentum(
0043         ei_coll[0].getMomentum(),
0044         m_particleSvc.particle(ei_coll[0].getPDG()).mass,
0045         {-5.0, -10.0, -18.0},
0046         0.0)
0047       );
0048
0049     // Get incoming hadron beam
0050     const auto pi_coll = find_first_beam_hadron(mcparts);
0051     if (pi_coll.size() == 0) {
0052       debug("No beam hadron found");
0053       return;
0054     }
0055     const PxPyPzEVector pi(
0056       round_beam_four_momentum(
0057         pi_coll[0].getMomentum(),
0058         m_particleSvc.particle(pi_coll[0].getPDG()).mass,
0059         {41.0, 100.0, 275.0},
0060         m_crossingAngle)
0061       );
0062
0063     // Get boost to colinear frame
0064     auto boost = determine_boost(ei, pi);
0065
0066     // Get electron angle
0067     auto kf = escat->at(0);
0068     PxPyPzEVector e_lab(kf.getMomentum().x, kf.getMomentum().y, kf.getMomentum().z, kf.getEnergy());
0069     PxPyPzEVector e_boosted = apply_boost(boost, e_lab);
0070     auto theta_e = e_boosted.Theta();
0071
0072     // Get hadronic final state variables
0073     auto sigma_h = hfs->at(0).getSigma();
0074     auto ptsum = hfs->at(0).getPT();
0075     auto gamma_h = hfs->at(0).getGamma();
0076
0077     // Sigma zero or negative
0078     if (sigma_h <= 0) {
0079       debug("Sigma zero or negative");
0080       return;
0081     }
0082
0083     // Calculate kinematic variables
0084     static const auto m_proton = m_particleSvc.particle(2212).mass;
0085     const auto y_da = tan(gamma_h/2.) / ( tan(theta_e/2.) + tan(gamma_h/2.) );
0086     const auto Q2_da = 4.*ei.energy()*ei.energy() * ( 1. / tan(theta_e/2.) ) * ( 1. / (tan(theta_e/2.) + tan(gamma_h/2.)) );
0087     const auto x_da = Q2_da / (4.*ei.energy()*pi.energy()*y_da);
0088     const auto nu_da = Q2_da / (2.*m_proton*x_da);
0089     const auto W_da = sqrt(m_proton*m_proton + 2*m_proton*nu_da - Q2_da);
0090     auto kin = kinematics->create(x_da, Q2_da, W_da, y_da, nu_da);
0091     kin.setScat(kf);
0092
0093     debug("x,Q2,W,y,nu = {},{},{},{},{}", kin.getX(),
0094             kin.getQ2(), kin.getW(), kin.getY(), kin.getNu());
0095   }
0096
0097 }
0098 #endif