diff -u -r1.3 -r1.4
--- MCHiggs.java	19 Dec 2012 17:37:12 -0000	1.3
+++ MCHiggs.java	19 Dec 2012 17:52:21 -0000	1.4
@@ -72,12 +72,29 @@

                 //aida.cloud1D("b transverse momentum").fill(pt);
                 aida.histogram1D("b transverse momentum hist", 100,0,63).fill(pt);
                 //aida.cloud1D("b_bar transverse momentum").fill(pt_bar);

-                aida.histogram1D("b transverse momentum hist", 100,0,63).fill(pt_bar);

+                aida.histogram1D("b_bar transverse momentum hist", 100,0,63).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.histogram1D("H inv mass hist",100,124.990,124.995).fill(inv_mass);

+                aida.histogram1D("H inv mass hist big",200,100,130).fill(inv_mass);
+            }
+            if (particle.getPDGID() == 22) {
+                double mass = particle.getMass();
+                double ener = particle.getEnergy();
+                Hep3Vector p = particle.getMomentum();
+                double p_m = p.magnitude();
+                
+                Hep3Vector z_unit = new BasicHep3Vector(0,0,1.);
+                
+                double pt = VecOp.dot(p, z_unit);
+                double cos_theta = VecOp.cosTheta(p);
+                double inv_mass = 2*p_m*p_m*(1-cos_theta);
+                
+                aida.cloud1D("gamma momentum").fill(p_m);
+                aida.cloud1D("gamma transverse momentum").fill(pt);
+                aida.cloud1D("gamma higgs inv mass").fill(inv_mass);

             }
         }
         aida.cloud1D("num children").fill(children.size());