Package org.jlab.rec.cvt.trajectory

Class Helix

java.lang.Object
org.jlab.rec.cvt.trajectory.Helix
public class Helix extends Object
A class describing a helix; the helix parameters are field of the track object These parameters are private and accessed by getters: _dca; // distance of closest approach to the z-axis in the lab frame _phi_at_dca; // azimuth at the DOCA _curvature; // track curvature = 1/R, where R is the radius of the circle _Z0; // intersect of the helix axis with the z-axis _tandip; // tangent of the dip angle = pz/pt Has a method getPointAtRadius(double r) which returns the point position along the helix at a given radial distance from the lab origin. This method is used to estimate the intersection of the helix with a plane or a cylinder.

  • Field Details

    • B

      public double B

  • Constructor Details

    • Helix

      public Helix(double dca, double phi_at_doca, double curvature, double Z0, double tandip, double xb, double yb, double[][] covmatrix)

    • Helix

      public Helix(double dca, double phi_at_doca, double curvature, double Z0, double tandip, double xb, double yb)

    • Helix

      public Helix(double pt, double d0, double phi0, double Z0, double tandip, int q, double xb, double yb)

    • Helix

      public Helix(Helix helix, double[][] matrix)

  • Method Details

    • getXb

      public double getXb()

    • setXb

      public final void setXb(double xb)

    • getYb

      public double getYb()

    • setYb

      public final void setYb(double yb)

    • getDCA

      public double getDCA()

    • setDCA

      public final void setDCA(double dca)

    • getPhiAtDCA

      public double getPhiAtDCA()

    • setPhiAtDCA

      public final void setPhiAtDCA(double phi_at_dca)

    • getCurvature

      public double getCurvature()

    • setCurvature

      public final void setCurvature(double curvature)

    • getZ0

      public double getZ0()

    • setZ0

      public final void setZ0(double Z0)

    • getTanDip

      public double getTanDip()

    • setTanDip

      public final void setTanDip(double tandip)

    • getCovMatrix

      public double[][] getCovMatrix()

    • setCovMatrix

      public final void setCovMatrix(double[][] covmatrix)

    • cosTheta

      public double cosTheta()

    • sinTheta

      public double sinTheta()

    • radius

      public double radius()

    • xCen

      public double xCen()

    • yCen

      public double yCen()

    • xDCA

      public double xDCA()

    • yDCA

      public double yDCA()

    • getVertex

      public Point3D getVertex()

    • getPt

      public double getPt(double solenoidMag)

    • getPXYZ

      public Vector3D getPXYZ(double solenoidMag)

    • getArcLengthDCA

      public double getArcLengthDCA(Point3D refpoint)

    • getCharge

      public int getCharge()

    • getPointAtRadius

      public Point3D getPointAtRadius(double r)

    • getTrackDirectionAtRadius

      public Vector3D getTrackDirectionAtRadius(double r)

    • toString

      public String toString()
      Overrides:
      toString in class Object