AnalysisUtils.h File Reference

Collection of utility functions useful for analysis. More...

#include <cmath>
#include <map>
#include <unordered_map>
#include <vector>

Go to the source code of this file.

Functions
std::tuple< int, const ldmx::SimParticle * >	Analysis::getRecoil (const std::map< int, ldmx::SimParticle > &particleMap)
	Find and return the sim particle associated with the recoil electron.
bool	Analysis::doesParticleHavePNDaughters (const ldmx::SimParticle &gamma, const std::map< int, ldmx::SimParticle > &particleMap)
	Helper function to getPNGamma.
const ldmx::SimParticle *	Analysis::getPNGamma (const std::map< int, ldmx::SimParticle > &particleMap, const ldmx::SimParticle *recoil, const float &energyThreshold)
	Get a pointer to the sim particle associated with the photon that underwent a photo-nuclear reaction.

Detailed Description

Collection of utility functions useful for analysis.

Author

Omar Moreno, SLAC National Accelerator Laboratory

Definition in file AnalysisUtils.h.

Function Documentation

doesParticleHavePNDaughters()

bool Analysis::doesParticleHavePNDaughters	(	const ldmx::SimParticle &	gamma,
		const std::map< int, ldmx::SimParticle > &	particleMap
	)

Helper function to getPNGamma.

Checks if a particle has daughter particles produced by the photonNuclear process type that are present in the particle map.

Definition at line 48 of file AnalysisUtils.cxx.

                                                     {
  for (auto daughterID : gamma.getDaughters()) {
    if (particleMap.find(daughterID) != std::end(particleMap)) {
      const auto daughter{particleMap.at(daughterID)};
      const auto processType{daughter.getProcessType()};
      if (processType == ldmx::SimParticle::ProcessType::photonNuclear) {
        return true;
      }  // Was it PN?
    }    // Was it in the map?
  }
 
  return false;
}

References Analysis::doesParticleHavePNDaughters(), and ldmx::SimParticle::getDaughters().

Referenced by Analysis::doesParticleHavePNDaughters(), and Analysis::getPNGamma().

getPNGamma()

const ldmx::SimParticle * Analysis::getPNGamma	(	const std::map< int, ldmx::SimParticle > &	particleMap,
		const ldmx::SimParticle *	recoil,
		const float &	energyThreshold
	)

Get a pointer to the sim particle associated with the photon that underwent a photo-nuclear reaction.

Returns the first particle in the map that underwent a PN interaction and has an energy above the threshold. If more than one particle satisfied this condition, this will NOT notice.

Parameters

[in]	particleMap	Map of sim particles
[in]	recoil	The recoil electron
[in]	energyThreshold	The energy that the photon energy must be greater than.

Returns

[out] Pointer to sim particle labeled as PN Gamma photon (nullptr if not found)

Definition at line 64 of file AnalysisUtils.cxx.

                                                                 {
  auto recoilDaughters{recoil->getDaughters()};
  for (auto recoilDaughterID : recoilDaughters) {
    // Have we stored the recoil daughter?
    if (particleMap.find(recoilDaughterID) != std::end(particleMap)) {
      auto recoilDaughter{particleMap.at(recoilDaughterID)};
      // Is it a gamma?
      if (recoilDaughter.getPdgID() == 22) {
        // Does it have enough energy?
        if (recoilDaughter.getEnergy() >= energyThreshold) {
          // Are its daughters PN products?
          if (doesParticleHavePNDaughters(recoilDaughter, particleMap)) {
            return &particleMap.at(recoilDaughterID);
          }
        }
      }
    }
  }
  return nullptr;
}

References Analysis::doesParticleHavePNDaughters(), ldmx::SimParticle::getDaughters(), and Analysis::getPNGamma().

Referenced by Analysis::getPNGamma().

getRecoil()

std::tuple< int, const ldmx::SimParticle * > Analysis::getRecoil

(

const std::map< int, ldmx::SimParticle > &

particleMap

)

Find and return the sim particle associated with the recoil electron.

Parameters

[in]

particleMap

map of sim particles

Returns

[out] Pointer to sim particle labeled as recoil electron (nullptr if not found)

Definition at line 28 of file AnalysisUtils.cxx.

                                                     {
  // The recoil electron is "produced" in the dark brem geneartion
  for (const auto &[trackID, particle] : particleMap) {
    if (particle.getPdgID() == 11 and
        particle.getProcessType() ==
            ldmx::SimParticle::ProcessType::eDarkBrem) {
      return {trackID, &particle};
    }
  }
  // only get here if recoil electron was not "produced" by dark brem
  //   in this case (bkgd), we interpret the primary electron as also the recoil
  //   electron
  return {1, &(particleMap.at(1))};
}

References Analysis::getRecoil().

Referenced by Analysis::getRecoil().