1 package org.lcsim.mc.fast.util;
2
3 import java.util.List;
4 import org.lcsim.event.MCParticle;
5
6 /**
7 * MCParticleClassifier has a single method, getClassification(MCParticle), that returns an enum classifying the particle.
8 *
9 * Possible return values are:
10 *
11 * GEN_INITIAL -> Generator particle the simulator never saw
12 *
13 * GEN_PREDECAY -> Generator particle passed to the simulator along with a predecay, and the simulator generated the decay products.
14 *
15 * GEN_FINAL_STATE -> Generator final state particle: either FinalState in the input file, or intermediate passed to the Simulator with a predecay that never happened.
16 *
17 * SIM_BACKSCATTER -> Simulator particle produced as a result of backscatter from a non-tracking region.
18 *
19 * SIM_VERTEX_NOT_PARENT_ENDPOINT -> Simulator particle produced without destroying parent.
20 *
21 * SIM_INTERACTED_OR_DECAYED -> Simulator particle produced as a result of an interaction or decay in a tracking region.
22 * @version $Id: MCParticleClassifier.java,v 1.5 2006/06/28 04:48:33 jstrube Exp $
23 */
24 public class MCParticleClassifier {
25 public enum MCPClass {
26 GEN_INITIAL, GEN_PREDECAY, GEN_FINAL_STATE, SIM_BACKSCATTER, SIM_VERTEX_NOT_PARENT_ENDPOINT, SIM_INTERACTED_OR_DECAYED
27 };
28
29 public static MCPClass getClassification(MCParticle p) {
30 //
31 // Check if particle existed in Generator
32 //
33 if (p.getGeneratorStatus() > 0) {
34 //
35 // Remove the documentation particles in case the generator left them floating
36 //
37 if (p.getGeneratorStatus() == MCParticle.DOCUMENTATION)
38 return MCPClass.GEN_INITIAL;
39 //
40 // Check if the generator particle has daughters in the generator
41 //
42 boolean hasGeneratorDaughters = false;
43 List<MCParticle> daughters = p.getDaughters();
44 for (MCParticle d : daughters) {
45 if (d.getGeneratorStatus() > 0)
46 hasGeneratorDaughters = true;
47 }
48 //
49 // If no generator daughters return final state
50 //
51 if (!hasGeneratorDaughters) {
52 //
53 // Trap for strange generator problem: Hanging quark with INTERMEDIATE status
54 // Therefore must check that Simulator saw this particle, otherwise return
55 // GEN_INITIAL
56 //
57 boolean inSim = p.getSimulatorStatus().isDecayedInTracker() || p.getSimulatorStatus().isDecayedInCalorimeter() || p.getSimulatorStatus().hasLeftDetector() || p.getSimulatorStatus().isStopped();
58 if (inSim) {
59 return MCPClass.GEN_FINAL_STATE;
60 } else {
61 return MCPClass.GEN_INITIAL;
62 }
63 }
64 //
65 // A generator particle with gerenrator daughters:
66 // if the simulator saw it must be a predecay
67 //
68 if (p.getSimulatorStatus().isDecayedInTracker() | p.getSimulatorStatus().isDecayedInCalorimeter()) {
69 return MCPClass.GEN_PREDECAY;
70 }
71 //
72 // simulator never saw it: initial
73 //
74 return MCPClass.GEN_INITIAL;
75 } else {
76 //
77 // Particle didn't exist in generator: choices are backscatter, production without killing parent,
78 // or the result of an interaction or decay( killing parent)
79 //
80 if (p.getSimulatorStatus().isBackscatter()) {
81 return MCPClass.SIM_BACKSCATTER;
82 }
83
84 if (p.getSimulatorStatus().vertexIsNotEndpointOfParent()) {
85 return MCPClass.SIM_VERTEX_NOT_PARENT_ENDPOINT;
86 }
87
88 return MCPClass.SIM_INTERACTED_OR_DECAYED;
89 }
90 }
91 }