diff -N DileptonAnalysis.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ DileptonAnalysis.java	8 Feb 2010 22:14:45 -0000	1.1
@@ -0,0 +1,90 @@

+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+package org.lcsim.contrib.Partridge.dilepton;
+
+import hep.physics.vec.BasicHep3Vector;
+import hep.physics.vec.Hep3Vector;
+import hep.physics.vec.VecOp;
+
+import java.util.Random;
+//import org.lcsim.util.aida.AIDA;
+
+/**
+ *
+ * @author richp
+ */
+public class DileptonAnalysis {
+
+    private double _elmax = 300.;
+    private double _elmin = 15.;
+    private double _metmax = 300.;
+    private double _metmin = 20.;
+    private double _mtmin = 100.;
+    private double _mW = 80.;
+    private double _gamW = 2.3;
+    private double _eps = 1.e-6;
+    private Random _rn = new Random();
+//    private AIDA _aida = AIDA.defaultInstance();
+
+    public DileptonAnalysis() {
+    }
+
+    public void Analyze() {
+
+        double el1 = _elmax * _rn.nextDouble();
+        double el2 = _elmax * _rn.nextDouble();
+        double met = _metmax * _rn.nextDouble();
+
+        if (el1 < _elmin || el2 < _elmin || met < _metmin) return;
+
+        System.out.println("Electron 1 energy: "+el1+" Electron 2 energy: "+el2+" MET: "+met);
+
+        Hep3Vector pl1 = newRandom(el1);
+        double pl1x = pl1.x();
+        Hep3Vector pl2 = newRandom(el2);
+        Hep3Vector umet = newRandom(1.);
+        double cth = umet.z();
+        double sth = Math.sqrt(1. - cth*cth);
+        double ptotmet = met / sth;
+        Hep3Vector pmet = VecOp.mult(ptotmet, umet);
+
+//        double mt1 = Math.sqrt(Math.sqrt(pl2. * (el1 * met )
+        double wgtmax = -1.e99;
+        for (int i=0; i<1000000; i++) {
+            Hep3Vector unu1 = newRandom(1.);
+            Hep3Vector unu2 = newRandom(1.);
+            double denom = unu2.x()*unu1.y() - unu2.y()*unu1.x();
+            if (Math.abs(denom) < _eps) continue;
+            double enu1 = (pmet.y()*unu2.x() - pmet.x()*unu2.y()) / denom;
+            double enu2 = (pmet.x()*unu1.y() - pmet.y()*unu1.x()) / denom;
+            Hep3Vector pnu1 = VecOp.mult(enu1, unu1);
+            Hep3Vector pnu2 = VecOp.mult(enu2, unu2);
+            double m1 = Math.sqrt(el1*enu1 - pl1.x()*pnu1.x() - pl1.y()*pnu1.y() - pl1.z()*pnu1.z());
+            double m2 = Math.sqrt(el2*enu2 - pl2.x()*pnu2.x() - pl2.y()*pnu2.y() - pl2.z()*pnu2.z());
+            double wgt1 = 0.25 * _gamW*_gamW / ((m1 - _mW)*(m1 - _mW) + 0.25 * _gamW*_gamW);
+            double wgt2 = 0.25 * _gamW*_gamW / ((m2 - _mW)*(m2 - _mW) + 0.25 * _gamW*_gamW);
+            double wgt = wgt1 * wgt2;
+            if (wgt > wgtmax) {
+                System.out.println("New weight: "+wgt+" for step "+i+" enu1: "+enu1+" enu2: "+enu2);
+                wgtmax = wgt;
+            }
+//            _aida.cloud1D("BW Weight").fill(wgt);
+        }
+
+    }
+
+    private Hep3Vector newRandom(double length) {
+
+        double phi = 2. * Math.PI * _rn.nextDouble();
+        double cth = 2. * _rn.nextDouble() - 1.;
+        double sth = Math.sqrt(1. - cth*cth);
+        double vx = length * Math.cos(phi) * sth;
+        double vy = length * Math.sin(phi) * sth;
+        double vz = length * cth;
+        Hep3Vector v = new BasicHep3Vector(vx, vy, vz);
+        return v;
+    }
+}

diff -N DileptonMain.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ DileptonMain.java	8 Feb 2010 22:14:45 -0000	1.1
@@ -0,0 +1,25 @@

+/*
+ * To change this template, choose Tools | Templates
+ * and open the template in the editor.
+ */
+
+package org.lcsim.contrib.Partridge.dilepton;
+
+/**
+ *
+ * @author richp
+ */
+public class DileptonMain {
+    
+
+    public static void main(String[] args) {
+
+        DileptonAnalysis dla = new DileptonAnalysis();
+
+        for (int i=0; i<100; i++) {
+            dla.Analyze();
+        }
+    }
+
+
+}