lcsim/sandbox/Partridge
diff -N MultipleScatter.java
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ MultipleScatter.java 29 Nov 2007 19:42:16 -0000 1.1
@@ -0,0 +1,50 @@
+/*
+ * MultipleScatter.java
+ *
+ * Created on November 21, 2007, 1:12 PM
+ *
+ */
+
+package org.lcsim.fit.helicaltrack;
+
+/**
+ * Encapsulate multiple scattering errors for a hit.
+ * HelicalTrackFitter does a straight-line fit of z(s).
+ * This is a good choice for barrel detectors that
+ * measure z. For disk detectors, the z
+ * position is fixed and the measurement coordinate
+ * is r (which is the same as s in the high pT limit).
+ * In this case, taking dz as dr * z / r is suggested.
+ * @author Richard Partridge
+ * @version 1.0
+ */
+public class MultipleScatter {
+ private double _drphi;
+ private double _dz;
+
+ /**
+ * Creates a new instance of MultipleScatter
+ * @param drphi Multiple scattering error in the r-phi plane
+ * @param dz Multiple scattering error in z assuming fixed s
+ */
+ public MultipleScatter(double drphi, double dz) {
+ _drphi = drphi;
+ _dz = dz;
+ }
+
+ /**
+ * Return the multiple scattering error in the r-phi plane
+ * @return r-phi multiple scattering error (units are mm)
+ */
+ public double drphi() {
+ return _drphi;
+ }
+
+ /**
+ * Return the multiple scattering error in z
+ * @return z coordinate multiple scattering error (units are mm)
+ */
+ public double dz() {
+ return _dz;
+ }
+}