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hitfit::Constrained_Top Class Reference

Do a constrained kinematic fitting for a $t\bar{t}\to\ell + \rm{jets}$ event. More...

#include <Constrained_Top.h>

Public Member Functions

double constrain (Lepjets_Event &ev, double &mt, double &sigmt, Column_Vector &pullx, Column_Vector &pully)
 Do a constrained fit of $t\bar{t}\to\ell + \rm{jets}$ events. Returns the top mass and its error in mt and sigmt, and the pull quantities in pullx and pully. Returns the $\chi^{2}$, this will be negative if the fit failed to converge. More...
 
 Constrained_Top (const Constrained_Top_Args &args, double lepw_mass, double hadw_mass, double top_mass)
 Constructor, create an instance of the Constrained_Top object from the arguments object and the mass constraints. More...
 

Private Attributes

const Constrained_Top_Args _args
 
Fourvec_Constrainer _constrainer
 

Friends

std::ostream & operator<< (std::ostream &s, const Constrained_Top &ct)
 Output stream operator, print the content of this Constrained_Top object to an output stream. More...
 

Detailed Description

Do a constrained kinematic fitting for a $t\bar{t}\to\ell + \rm{jets}$ event.

Definition at line 128 of file Constrained_Top.h.

Constructor & Destructor Documentation

hitfit::Constrained_Top::Constrained_Top ( const Constrained_Top_Args args,
double  lepw_mass,
double  hadw_mass,
double  top_mass 
)

Constructor, create an instance of the Constrained_Top object from the arguments object and the mass constraints.

Parameters
argsArgument for this instance of Constrained_Top object.
lepw_massThe mass to which the leptonic W should be constrained. If this parameter is set to 0, the constraint is skied.
hadw_massThe mass to which the hadronic W should be constrained. If this parameter is set to 0, the constraint is skied.
top_massThe mass to which the top quarks should be constrained. If this parameter is set to 0, the constraints is skied.

Definition at line 106 of file Constrained_Top.cc.

References _constrainer, hitfit::Fourvec_Constrainer::add_constraint(), hitfit::Constrained_Top_Args::equal_side(), hitfit::hadb_label, hitfit::hadw1_label, hitfit::hadw2_label, hitfit::lepb_label, hitfit::lepton_label, hitfit::Fourvec_Constrainer::mass_constraint(), and hitfit::nu_label.

122  : _args (args),
123  _constrainer (args.fourvec_constrainer_args())
124 {
125  char buf[256];
126  if (lepw_mass > 0) {
127  sprintf (buf, "(%d %d) = %f", nu_label, lepton_label, lepw_mass);
129  }
130 
131  if (hadw_mass > 0) {
132  sprintf (buf, "(%d %d) = %f", hadw1_label, hadw2_label, hadw_mass);
134  }
135 
136  if (args.equal_side()) {
137  sprintf (buf, "(%d %d %d) = (%d %d %d)",
141  }
142 
143  if (top_mass > 0) {
144  sprintf (buf, "(%d %d %d) = %f",
145  hadw1_label, hadw2_label, hadb_label, top_mass);
147  }
148  else {
149  sprintf (buf, "(%d %d %d) = 0", hadw1_label, hadw2_label, hadb_label);
151  }
152 }
const int nu_label
Fourvec_Constrainer _constrainer
dictionary args
const Constrained_Top_Args _args
void mass_constraint(std::string s)
Specify a combination of objects that will be returned by the constrain() method as mass...
void add_constraint(std::string s)
Specify an additional constraint s for the problem. The format for s is described in the class descri...

Member Function Documentation

double hitfit::Constrained_Top::constrain ( Lepjets_Event ev,
double &  mt,
double &  sigmt,
Column_Vector pullx,
Column_Vector pully 
)

Do a constrained fit of $t\bar{t}\to\ell + \rm{jets}$ events. Returns the top mass and its error in mt and sigmt, and the pull quantities in pullx and pully. Returns the $\chi^{2}$, this will be negative if the fit failed to converge.

Parameters
evThe event to be fitted (input), and the event after fitting (output).
mtThe fitted top mass.
sigmtThe uncertainty on the fitted top mass.
pullxPull quantities for the well-measured variables.
pullyPull quantities for the poorly-measured variables.
Input:
Output:
  • Lepjets_Event ev.
  • double mt.
  • double sigmt.
  • Column_Vector pullx.
  • Column_Vector pully.
Return:
The $\chi^{2}$ of the fit. Return a negative value if the fit didn't converge.

Definition at line 290 of file Constrained_Top.cc.

References _args, _constrainer, hitfit::Constrained_Top_Args::bmass(), and hitfit::Fourvec_Constrainer::constrain().

Referenced by hitfit::Top_Fit::fit_one_perm().

314 {
315  Fourvec_Event fe;
316  do_import (ev, _args.bmass (), fe);
317  double chisq = _constrainer.constrain (fe, mt, sigmt, pullx, pully);
318  do_export (fe, ev);
319 
320  return chisq;
321 }
Fourvec_Constrainer _constrainer
double constrain(Fourvec_Event &ev, double &m, double &sigm, Column_Vector &pullx, Column_Vector &pully)
Do a constrained fit for event ev. Returns the requested mass and its uncertainty in m and sigm...
const Constrained_Top_Args _args

Friends And Related Function Documentation

std::ostream& operator<< ( std::ostream &  s,
const Constrained_Top ct 
)
friend

Output stream operator, print the content of this Constrained_Top object to an output stream.

Parameters
sThe output stream to which to write.
ctThe instance of Constrained_Top to be printed.

Definition at line 333 of file Constrained_Top.cc.

344 {
345  return s << ct._constrainer;
346 }

Member Data Documentation

const Constrained_Top_Args hitfit::Constrained_Top::_args
private

Parameter settings for the $\chi^{2}$ constrainer.

Definition at line 208 of file Constrained_Top.h.

Referenced by Vispa.Main.Application.Application::_readCommandLineAttributes(), and constrain().

Fourvec_Constrainer hitfit::Constrained_Top::_constrainer
private

The guy that actually does the work.

Definition at line 214 of file Constrained_Top.h.

Referenced by constrain(), Constrained_Top(), and hitfit::operator<<().