Emc_helix Class Reference

#include <Emc_helix.h>

Public Member Functions
	Emc_helix (void)
	~Emc_helix (void)
int	Emc_Get (double, int, double[])
void	debugOpt (int deb)
void	pathlCut (double pathl_max)
void	zemcCut (double zemc_min, double zemc_max)

Public Attributes
double	R_emc
double	Fi_emc
double	W_emc
double	Z_emc
double	theta_emc
double	phi_emc
double	Dr
double	Phi0
double	Kappa
double	Dz
double	Tanl
int	NTrk
double	Phi1

Detailed Description

Definition at line 15 of file Emc_helix.h.

Constructor & Destructor Documentation

Emc_helix()

Emc_helix::Emc_helix

(

void

)

Definition at line 58 of file Emc_helix.cxx.

                           {
  piby1      = 3.141593;
  pi2        = 2.0 * piby1;
  _debug     = 0;
  _pathl_cut = 1000.0;
}

~Emc_helix()

Emc_helix::~Emc_helix ( void )

inline

Definition at line 21 of file Emc_helix.h.

{};

Member Function Documentation

debugOpt()

void Emc_helix::debugOpt ( int deb )

inline

Definition at line 40 of file Emc_helix.h.

{ _debug = deb; }

Emc_Get()

int Emc_helix::Emc_Get	(	double	rEmc,
		int	id,
		double	fzisan[] )

Definition at line 65 of file Emc_helix.cxx.

                                                             {
  // crossing points of the helix on the Emc cylinder
  double xc, yc;       // center of the circle
  double rho;          // radius of emc  cyclinder
  double xx[2], yy[2]; // coordinates of hits
  double emcx, emcy;   // (x,y) on the radius of R_emc
  double nx, ny;       // direction cosines of mom vector at vertex
  double cosx, sinx;
  double aa, ca, cb, cc, detm;
 
  // fzisan track ID and EMC radius
  int Id_cdfztrk = id;
  R_emc          = rEmc;
 
  if ( Id_cdfztrk < 0 )
  {
    if ( _debug ) std::cout << " Emc_helix *** wrong id_cdfztrk =" << Id_cdfztrk << std::endl;
    return ( -1 );
  }
 
  // fzisan track
  /*    FTFinder * ftrk = FTFinder:: GetPointer();
  FTList<FTTrack *> & FsTrks = ftrk->tracks();
  NTrk = FsTrks.length();
 
  if (NTrk<=0)                                   return (-3);
 
  // get helix params for Id_cdfztrk
  FTTrack & trk = * FsTrks[Id_cdfztrk];
  const Helix hel = * trk.helix();
 
  const HepPoint3D pivot1(0.,0.,0.);
  HepVector  a(5,0);
  a[0] = hel.a()[0];
  a[1] = hel.a()[1];
  a[2] = hel.a()[2];
  a[3] = hel.a()[3];
  a[4] = hel.a()[4];
  */
  const HepPoint3D pivot1( 0., 0., 0. );
  HepVector        a( 5, 0 );
  a[0] = fzisan[0];
  a[1] = fzisan[1];
  a[2] = fzisan[2];
  a[3] = fzisan[3];
  a[4] = fzisan[4];
 
  // Ill-fitted track in fzisan (dz=tanl=-9999.)
  if ( abs( a[3] ) > 50.0 || abs( a[4] ) > 500.0 ) return ( -5 );
 
  // D e f i n e   h e l i x
  Helix helix1( pivot1, a );
  Dr    = helix1.a()[0];
  Phi0  = helix1.a()[1];
  Kappa = helix1.a()[2];
  Dz    = helix1.a()[3];
  Tanl  = helix1.a()[4];
 
  /* double detaphi=asin(0.5*0.81*0.3*fabs(Kappa));
     double phi=Phi0+detaphi+ piby1/2;
     */
 
  // check cdfztrk hit on Emc cyclinder
  rho = helix1.radius();
  // cout<<" Emc_helix:: rho  ="<<rho<<endl;  // radius of the circle in cm
  HepPoint3D xyz = helix1.center();
  xc             = xyz( 0 );
  yc             = xyz( 1 );
 
  Hep3Vector vxyz = helix1.direction();
  nx              = vxyz( 0 ); // direction of track at the vertex
  ny              = vxyz( 1 );
 
  // get hit on Emc cylinder at radius R_Emc;
  if ( xc == 0.0 && yc == 0.0 ) return ( -3 );
 
  // coefficients of quadratic equation
  ca = xc * xc + yc * yc;
  aa = 0.5 * ( ca - rho * rho + R_emc * R_emc );
 
  if ( xc != 0.0 )
  {
    cb = aa * yc;
    cc = aa * aa - R_emc * R_emc * xc * xc;
    // determinant
    detm = cb * cb - ca * cc;
    if ( detm > 0.0 )
    {
      yy[0] = ( cb + sqrt( detm ) ) / ca;
      xx[0] = ( aa - yy[0] * yc ) / xc;
      yy[1] = ( cb - sqrt( detm ) ) / ca;
      xx[1] = ( aa - yy[1] * yc ) / xc;
    }
    else return ( -1 );
  }
  else
  {
    cb = aa * xc;
    cc = aa * aa - R_emc * R_emc * yc * yc;
    // determinant
    detm = cb * cb - ca * cc;
    if ( detm > 0.0 )
    {
      xx[0] = ( cb + sqrt( detm ) ) / ca;
      yy[0] = ( aa - xx[0] * xc ) / yc;
      xx[1] = ( cb - sqrt( detm ) ) / ca;
      yy[1] = ( aa - xx[1] * xc ) / yc;
    }
    else return ( -2 );
  }
 
  // choose one of hits according to track direction at the vertex.
 
  if ( xx[0] * nx + yy[0] * ny > 0.0 )
  {
    emcx = xx[0];
    emcy = yy[0];
  }
  else
  {
    emcx = xx[1];
    emcy = yy[1];
  }
 
  double fi = atan2( emcy, emcx ); // atna2 from -pi to pi
 
  if ( fi < 0.0 ) fi = pi2 + fi;
  Fi_emc = fi;
 
  // get phi and z on the emc counter
  const HepPoint3D pivot2( emcx, emcy, 0.0 );
  helix1.pivot( pivot2 );
 
  // corrected by Ozaki san to avoid negative path length on Aug.10,99
  Phi1  = helix1.a()[1];
  Z_emc = helix1.a()[3];
 
  // get(thepa,phi)from the intersection (x,y,z)
  Hep3Vector intersec( emcx, emcy, Z_emc );
  theta_emc = intersec.getTheta();
  phi_emc   = intersec.getPhi();
 
  return ( 1 );
}

Referenced by EsTimeAlg::execute().

pathlCut()

void Emc_helix::pathlCut ( double pathl_max )

inline

Definition at line 42 of file Emc_helix.h.

{ _pathl_cut = pathl_max; }

Referenced by EsTimeAlg::execute().

zemcCut()

void Emc_helix::zemcCut ( double zemc_min, double zemc_max )

inline

Definition at line 44 of file Emc_helix.h.

                                                   {
    _zemc_cutm = zemc_min;
    _zemc_cutx = zemc_max;
  }

Member Data Documentation

Dr

double Emc_helix::Dr

Definition at line 33 of file Emc_helix.h.

Referenced by Emc_Get().

Dz

double Emc_helix::Dz

Definition at line 33 of file Emc_helix.h.

Referenced by Emc_Get().

Fi_emc

double Emc_helix::Fi_emc

Definition at line 26 of file Emc_helix.h.

Referenced by Emc_Get().

Kappa

double Emc_helix::Kappa

Definition at line 33 of file Emc_helix.h.

Referenced by Emc_Get().

NTrk

int Emc_helix::NTrk

Definition at line 34 of file Emc_helix.h.

Phi0

double Emc_helix::Phi0

Definition at line 33 of file Emc_helix.h.

Referenced by Emc_Get().

Phi1

double Emc_helix::Phi1

Definition at line 35 of file Emc_helix.h.

Referenced by Emc_Get().

phi_emc

double Emc_helix::phi_emc

Definition at line 30 of file Emc_helix.h.

Referenced by Emc_Get(), and EsTimeAlg::execute().

R_emc

double Emc_helix::R_emc

Definition at line 25 of file Emc_helix.h.

Referenced by Emc_Get().

Tanl

double Emc_helix::Tanl

Definition at line 33 of file Emc_helix.h.

Referenced by Emc_Get().

theta_emc

double Emc_helix::theta_emc

Definition at line 29 of file Emc_helix.h.

Referenced by Emc_Get(), and EsTimeAlg::execute().

W_emc

double Emc_helix::W_emc

Definition at line 27 of file Emc_helix.h.

Z_emc

double Emc_helix::Z_emc

Definition at line 28 of file Emc_helix.h.

Referenced by Emc_Get(), and EsTimeAlg::execute().

---

The documentation for this class was generated from the following files:

• Emc_helix.h
• Emc_helix.cxx