mcd-analysis/src/main/java/org/lcsim/mcd/analysis
diff -N MCHiggs.java
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ MCHiggs.java 19 Dec 2012 17:14:06 -0000 1.1
@@ -0,0 +1,81 @@
+package org.lcsim.mcd.analysis;
+
+import java.util.List;
+import java.util.ArrayList;
+import org.lcsim.event.EventHeader;
+import org.lcsim.event.MCParticle;
+import org.lcsim.event.ReconstructedParticle;
+import org.lcsim.util.Driver;
+import org.lcsim.util.aida.AIDA;
+import hep.physics.vec.Hep3Vector;
+import hep.physics.vec.BasicHep3Vector;
+import hep.physics.vec.VecOp;
+
+/**
+ *
+ * @author agias
+ */
+public class MCHiggs extends Driver{
+
+ public MCHiggs()
+ {
+ }
+
+ private AIDA aida = AIDA.defaultInstance();
+
+ protected String mcParticlesSkimmedName = "MCParticle";
+
+ public void process(EventHeader event) {
+ List<MCParticle> particles = event.get(MCParticle.class,mcParticlesSkimmedName);
+ List<MCParticle> children = new ArrayList<MCParticle>();
+
+ boolean hfound = false;
+ for (MCParticle particle : particles) {
+ // 25 == h0/H01
+ if ((particle.getPDGID()==25)&&(!hfound)) {
+ children.addAll(particle.getDaughters());
+ hfound=true;
+ }
+ }
+
+ for (MCParticle particle : children) {
+ /*
+ * Only count positive PDGID's because negatives
+ * are just antiparticles
+ * 4 == c
+ * 5 == b
+ * 15 == tau-
+ * 21 == gluon
+ * 23 == Zo
+ * 24 == W
+ */
+ if (particle.getPDGID() > 0) {
+ aida.cloud1D("decay modes").fill(particle.getPDGID());
+ }
+ if (particle.getPDGID() == 5) {
+ Hep3Vector p = particle.getMomentum();
+ Hep3Vector p_bar = VecOp.neg(p);
+
+ double mass = particle.getMass();
+ double en = particle.getEnergy();
+
+ Hep3Vector z_unit = new BasicHep3Vector(0,0,1.);
+
+ double p_m = p.magnitude();
+
+ double pt = VecOp.dot(p, z_unit);
+ double pt_bar = VecOp.dot(p_bar, z_unit);
+
+ aida.cloud1D("b momentum").fill(p_m);
+ aida.cloud1D("b transverse momentum").fill(pt);
+ aida.cloud1D("b_bar transverse momentum").fill(pt_bar);
+
+ // b and b_bar are produced with equal energy, opposite momenta
+ double inv_mass = Math.sqrt(2.*mass*mass + 2.*(en*en-VecOp.dot(p, p_bar)));
+ aida.cloud1D("H invariant mass").fill(inv_mass);
+ }
+ }
+ aida.cloud1D("num children").fill(children.size());
+ }
+
+}