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Java > Open Source Codes > JSci > physics > particles > Positron


1 package JSci.physics.particles;
2
3 import JSci.physics.quantum.QuantumParticle;
4
5 /**
6 * A class representing positrons.
7 * @version 1.5
8 * @author Mark Hale
9 */
10 public final class Positron extends AntiLepton {
11         /**
12         * Constructs a positron.
13         */
14         public Positron() {}
15         /**
16         * Returns the rest mass (MeV).
17         * @return 0.510998902
18         */
19         public double restMass() {return 0.510998902;}
20         /**
21         * Returns the electric charge.
22         * @return 1
23         */
24         public int charge() {return 1;}
25         /**
26         * Returns the electron lepton number.
27         * @return -1
28         */
29         public int eLeptonQN() {return -1;}
30         /**
31         * Returns the muon lepton number.
32         * @return 0
33         */
34         public int muLeptonQN() {return 0;}
35         /**
36         * Returns the tau lepton number.
37         * @return 0
38         */
39         public int tauLeptonQN() {return 0;}
40         /**
41         * Returns the antiparticle of this particle.
42         */
43         public QuantumParticle anti() {
44                 return new Electron();
45         }
46         /**
47         * Returns true if qp is the antiparticle.
48         */
49         public boolean isAnti(QuantumParticle qp) {
50                 return (qp!=null) && (qp instanceof Electron);
51         }
52         /**
53         * Returns a string representing this class.
54         */
55         public String JavaDoc toString() {
56                 return new String JavaDoc("Positron");
57         }
58         /**
59         * Emits a photon.
60         */
61         public Positron emit(Photon y) {
62                 momentum=momentum.subtract(y.momentum);
63                 return this;
64         }
65         /**
66         * Absorbs a photon.
67         */
68         public Positron absorb(Photon y) {
69                 momentum=momentum.add(y.momentum);
70                 return this;
71         }
72         /**
73         * Emits a W+.
74         */
75         public AntiElectronNeutrino emit(WPlus w) {
76                 AntiElectronNeutrino n=new AntiElectronNeutrino();
77                 n.momentum=momentum.subtract(w.momentum);
78                 return n;
79         }
80         /**
81         * Absorbs a W-.
82         */
83         public AntiElectronNeutrino absorb(WMinus w) {
84                 AntiElectronNeutrino n=new AntiElectronNeutrino();
85                 n.momentum=momentum.add(w.momentum);
86                 return n;
87         }
88         /**
89         * Emits a Z0.
90         */
91         public Positron emit(ZZero z) {
92                 momentum=momentum.subtract(z.momentum);
93                 return this;
94         }
95         /**
96         * Absorbs a Z0.
97         */
98         public Positron absorb(ZZero z) {
99                 momentum=momentum.add(z.momentum);
100                 return this;
101         }
102 }
103
104
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