diff -N ParticleTypeClassifier.java
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ ParticleTypeClassifier.java	29 Nov 2007 01:02:39 -0000	1.1
@@ -0,0 +1,422 @@

+package org.lcsim.event.util;
+
+import static java.lang.Math.abs;
+
+/**
+ * 
+ * This class provides static utility methods for determining the type of a particle based on the PDGID.  It based on the primary
+ * document on PDGIDs issued by the Particle Data Group and also on some
+ * code from the ATLAS LXR.
+ * 
+ * <h2>References</h2>
+ * <ul> 
+ * <li><a href="http://pdg.lbl.gov/2007/mcdata/mc_particle_id_contents.html">PDG Numbering Scheme</a></li>
+ * <li><a href="http://alxr.usatlas.bnl.gov/lxr/source/atlas/PhysicsAnalysis/MuonID/MuonIDValidation/MuonIDValidation/pdg.h">pdg.h</a></li>
+ * <li><a href="http://alxr.usatlas.bnl.gov/lxr/source/atlas/PhysicsAnalysis/MuonID/MuonIDValidation/src/pdg.cxx">pdg.cxx</a></li>
+ * </ul>
+ * 
+ * @author Jeremy McCormick <[log in to unmask]>
+ * @version $Id: ParticleTypeClassifier.java,v 1.1 2007/11/29 01:02:39 jeremy Exp $
+ *
+ */
+public final class ParticleTypeClassifier 
+{
+	/**
+	 * Class is 100% static utility methods
+	 * so it should not be instantiated.
+	 */
+	private ParticleTypeClassifier()
+	{}
+
+	/**
+	 * True if <code>p</code> is a lepton.
+	 * Checks that <code>p</code> is between 11 and 18.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a lepton.
+	 */
+	public static boolean isLepton(int p)
+	{
+		return p > 10 && p < 19;
+	}
+	
+	/**
+	 * True if <code>p</code> is a charged lepton.
+	 * Checks that particle is a lepton and that
+	 * <code>p</code> is even numbered. 
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a charged lepton.
+	 */
+	public static boolean isChargedLepton(int p)
+	{
+		return isLepton(p) && (abs(p) % 2) == 0;
+	}
+	
+	/**
+	 * True if <code>p</code> is a neutrino.
+	 * Checks that <code>p</code> is odd. 
+	 * @param p
+	 * @return
+	 */
+	public static boolean isNeutrino(int p)
+	{
+		return isLepton(p) && (abs(p) % 2) != 0;
+	}
+	
+	/**
+	 * True if <code>p</code> is an electron.
+	 * @param p
+	 * @return
+	 */
+	public static boolean isElectron(int p)
+	{
+		return p == 11;
+	}
+			
+	/**
+	 * True if <code>p</code> is a positron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a postitron.
+	 */
+	public static boolean isPositron(int p)
+	{
+		return p == -11;
+	}
+	
+	/**
+	 * True if <code>p</code> is a muon.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a muon.
+	 */
+	public static boolean isMuon(int p)
+	{
+		return abs(p) == 13;
+	}
+	
+	/**
+	 * True if <code>p</code> is a tau.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a tau.
+	 */
+	public static boolean isTau(int p)
+	{
+		return abs(p) == 15;
+	}
+	
+	/**
+	 * True if <code>p</code> is a photon.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a photon.
+	 */
+	public static boolean isPhoton(int p)
+	{
+		return p == 22;
+	}
+	 		
+	/**
+	 * True if <code>p</code> is an electron or photon.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an electron or photon.
+	 */
+	public static boolean isEM(int p)
+	{
+		return isElectron(p) || isPhoton(p);
+	}
+	
+	/**
+	 * True if <code>p</code> is a boson.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a boson.
+	 */
+	public static boolean isBoson(int p)
+	{
+		int pp = abs(p);
+		return pp > 20 && pp < 38;
+	}
+			
+	/**
+	 * True if <code>p</code> is a quark.
+	 * @param p
+	 * @return
+	 */
+	public static boolean isQuark(int p)
+	{
+		int pp = abs(p);
+		return pp > 0 && pp < 9;
+	}
+	
+	/**
+	 * True if <code>p</code> is a hadron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a hadron.
+	 * FIXME: May be incorrect.
+	 */
+	public static boolean isHadron(int p)
+	{
+		int pp = abs(p);
+		return pp > 100 && (pp < 1000000 || pp > 9000000) && (pp % 10 != 0);
+	}
+	
+	/**
+	 * True if <code>p</code> is a proton.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a proton.
+	 */
+	public static boolean isProton(int p)
+	{
+		return p == 2212;		
+	}
+
+	/**
+	 * True if <code>p</code> is an antiproton.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a antiproton.
+	 */
+	public static boolean isAntiProton(int p)
+	{
+		return p == -2212;
+	}
+	
+	/**
+	 * True if <code>p</code> is a neutron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a neutron.
+	 */
+	public static boolean isNeutron(int p)
+	{
+		return p == 2112;
+	}
+	
+	/**
+	 * True if <code>p</code> is an antineutron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an antineutron.
+	 */
+	public static boolean isAntiNeutron(int p)
+	{
+		return p == -2112;
+	}
+
+	/**
+	 * True if <code>p</code> is a kaon.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an antineutron.
+	 */
+	public static boolean isKaon(int p)
+	{
+		return p == 130 || p == 310 || p == 311 || abs(p) == 321;
+	}
+	
+	/**
+	 * True if <code>p</code> is a charged kaon.
+	 * @param p The PDGID.
+	 * @return True if particle is a charged kaon.
+	 */
+	public static boolean isChargedKaon(int p)
+	{
+		return abs(p) == 321;
+	}
+			
+	/**
+	 * True if <code>p</code> is an UD hadron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an UD hadron.
+	 */
+	public static boolean isUDHadron(int p)
+	{
+		int flavor = flavor(p);
+		return isHadron(p) && (flavor == 1 || flavor == 2);
+	}
+	
+	/**
+	 * True if <code>p</code> is an S hadron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an S hadron.
+	 */
+	public static boolean isSHadron(int p)
+	{
+		return isHadron(p) && flavor(p) == 3;
+	}
+	
+	/**
+	 * True if <code>p</code> is a C hadron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a C hadron.
+	 */
+	public static boolean isCHadron(int p)
+	{
+		return isHadron(p) && flavor(p) == 4;
+	}
+	
+	/**
+	 * True if <code>p</code> is a B hadron.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a B hadron.
+	 */
+	public static boolean isBHadron(int p)
+	{
+		return isHadron(p) && flavor(p) == 5;
+	}
+	
+	/**
+	 * True if <code>p</code> is a down quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a down quark.
+	 */
+	public static boolean isDownQuark(int p)
+	{
+		return abs(p) == 1;
+	}
+	
+	/**
+	 * True if <code>p</code> is an up quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a up quark.
+	 */
+	public static boolean isUpQuark(int p)
+	{
+		return abs(p) == 2;
+	}
+	
+	/**
+	 * True if <code>p</code> is a strange quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a strange quark.
+	 */
+	public static boolean isStrangeQuark(int p)
+	{
+		return abs(p) == 3;
+	}
+	
+	/**
+	 * True if <code>p</code> is a charm quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a charm quark.
+	 */
+	public static boolean isCharmQuark(int p)
+	{
+		return abs(p) == 4;
+	}
+	
+	/**
+	 * True if <code>p</code> is a bottom quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a bottom quark.
+	 */
+	public static boolean isBottomQuark(int p)
+	{
+		return abs(p) == 5;
+	}
+		
+	/**
+	 * True if <code>p</code> is a top quark.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a top quark.
+	 */
+	public static boolean isTopQuark(int p)
+	{
+		return abs(p) == 6;
+	}		
+	
+	/**
+	 * True if particle is a K0L or a K0S.
+	 * @param p
+	 * @return
+	 */
+	public static boolean isNeutralKaon(int p)
+	{
+		return p == 130 || p == 310;
+	}
+	
+	/**
+	 * True if <code>p</code> is an ion or nucleus.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is an ion or nucleus.
+	 * FIXME: This relies on the PDGID of ions and nuclei being 0, which may 
+	 *        not be completely accurate.  For instance, geantinos have a PDGID
+	 *        of 0 also.
+	 */
+	public static boolean isIon(int p)
+	{
+		return p == 0;
+	}		
+	
+	/**
+	 * True if <code>p</code> is a Z boson.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a Z boson.
+	 */
+	public static boolean isZBoson(int p)
+	{
+		return p == 23;
+	}
+	
+	/**
+	 * True if <code>p</code> is a W boson.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a W boson.
+	 */
+	public static boolean isWBoson(int p)
+	{
+		return abs(p) == 24;
+	}	
+	
+	/**
+	 * True if <code>p</code> is a Higgs boson.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a Higgs boson.
+	 */
+	public static boolean isHiggs(int p)
+	{
+		int pp = abs(p);
+		return pp == 25 || pp == 35 || pp == 36 || pp == 37; 
+	}
+	
+	/**
+	 * True if <code>p</code> is a SUSY particle.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a SUSY particle.
+	 */
+	public static boolean isSUSY(int p)
+	{
+		return p > 1000000 && p < 2000015;
+	}
+	
+	/**
+	 * True if <code>p</code> is a Technicolor particle.
+	 * @param p The PDGID.
+	 * @return True if <code>p</code> is a Technicolor particle.
+	 */
+	public static boolean isTechnicolor(int p)
+	{
+		int pp = abs(p);
+		return pp > 3000110 && pp < 3000224;
+	}
+	
+	/**
+	 * Get the flavor of a hadron indicating its quark content.
+	 * This method is only used internally to this class.
+	 * @param p The PDGID.
+	 * @return The flavor of the particle.
+	 */
+	static int flavor(int p)
+	{
+		int rid = abs(p) % 10000;
+		int flavor = 0;
+		if (rid > 999)
+		{
+			flavor = rid / 1000;
+		}
+		else
+		{
+			int flavor1 = rid / 100;
+			int flavor2 = (rid % 100) / 10;
+			flavor = flavor1;
+			if (flavor1 == flavor2 && flavor1 < 4)
+			{
+				flavor = 1;
+			}
+			if (p == 130) flavor = 3;
+		}
+		return flavor;
+	}	
+}