Constrained_Top.h

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//
//
// File: hitfit/Constrained_Top.h
// Purpose: Do kinematic fitting for a ttbar -> ljets event.
// Created: Jul, 2000, sss, based on run 1 mass analysis code.
//
// CMSSW File      : interface/Constrained_Top.h
// Original Author : Scott Stuart Snyder <snyder@bnl.gov> for D0
// Imported to CMSSW by Haryo Sumowidagdo <Suharyo.Sumowidagdo@cern.ch>

#ifndef HITFIT_CONSTRAINED_TOP_H
#define HITFIT_CONSTRAINED_TOP_H

#include "TopQuarkAnalysis/TopHitFit/interface/Fourvec_Constrainer.h"
#include "TopQuarkAnalysis/TopHitFit/interface/matutil.h"
#include <iosfwd>

namespace hitfit {

  class Defaults;
  class Lepjets_Event;

  class Constrained_Top_Args
  //
  // Purpose: Hold on to parameters for the Constrained_Top class.
  //
  // Parameters controlling the operation of the fitter:
  //   float bmass        - The mass to which b jets should be fixed.
  //
  {
  public:
    // Constructor.  Initialize from a Defaults object.
    Constrained_Top_Args(const Defaults& defs);

    // Retrieve parameter values.
    double bmass() const;

    // Arguments for subobjects.
    const Fourvec_Constrainer_Args& fourvec_constrainer_args() const;

    // Retrieve requirement for equal mass on both sides
    bool equal_side() const;

  private:
    // Hold on to parameter values.

    double _bmass;

    Fourvec_Constrainer_Args _fourvec_constrainer_args;

    bool _equal_side;
  };

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

  class Constrained_Top
  //
  // Purpose: Do kinematic fitting for a ttbar -> ljets event.
  //
  {
  public:
    // Constructor.
    // LEPW_MASS, HADW_MASS, and TOP_MASS are the masses to which
    // those objects should be constrained.  To remove a constraint,
    // set the mass to 0.
    Constrained_Top(const Constrained_Top_Args& args, double lepw_mass, double hadw_mass, double top_mass);

    // Do a constrained fit.
    double constrain(Lepjets_Event& ev, double& mt, double& sigmt, Column_Vector& pullx, Column_Vector& pully);

    // Dump out our state.
    friend std::ostream& operator<<(std::ostream& s, const Constrained_Top& ct);

  private:
    // Parameter settings.
    const Constrained_Top_Args _args;

    // The guy that actually does the work.
    Fourvec_Constrainer _constrainer;
  };

}  // namespace hitfit

#endif  // not HITFIT_CONSTRAINED_TOP_H