| Geant4 Cross Reference |
1 // -*- C++ -*- 1
2 // -------------------------------------------
3 //
4 // This file is a part of the CLHEP - a Class
5 //
6 // This is the implementation of the HepLorent
7 // Those methods originating in ZOOM dealing w
8 // Use of one of these methods will not force
9 // HepLorentzRotation class.
10 //
11
12 #include "CLHEP/Vector/LorentzVector.h"
13
14 #include <cmath>
15 #include <iostream>
16
17 namespace CLHEP {
18
19 //-*********
20 // rotationOf()
21 //-*********
22
23 // Each of these is a shell over a rotate meth
24
25 HepLorentzVector rotationXOf
26 (const HepLorentzVector & vec, double phi){
27 HepLorentzVector vv (vec);
28 return vv.rotateX (phi);
29 }
30
31 HepLorentzVector rotationYOf
32 (const HepLorentzVector & vec, double phi){
33 HepLorentzVector vv (vec);
34 return vv.rotateY (phi);
35 }
36
37 HepLorentzVector rotationZOf
38 (const HepLorentzVector & vec, double phi){
39 HepLorentzVector vv (vec);
40 return vv.rotateZ (phi);
41 }
42
43 //-********
44 // boost
45 //-********
46
47 HepLorentzVector & HepLorentzVector::boost
48 ( const Hep3Vector & aaxis, double bbet
49 if (bbeta==0) {
50 return *this; // do nothing for a 0 boost
51 }
52 double r2 = aaxis.mag2();
53 if ( r2 == 0 ) {
54 std::cerr << "HepLorentzVector::boost() -
55 << "A zero vector used as axis defining
56 << std::endl;
57 return *this;
58 }
59 double b2 = bbeta*bbeta;
60 if (b2 >= 1) {
61 std::cerr << "HepLorentzVector::boost() -
62 << "LorentzVector boosted with beta >= 1
63 << "no boost done" << std::endl;
64 } else {
65 Hep3Vector u = aaxis.unit();
66 double ggamma = std::sqrt(1./(1.-b2));
67 double betaDotV = u.dot(pp)*bbeta;
68 double tt = ee;
69
70 ee = ggamma * (tt + betaDotV);
71 pp += ( ((ggamma-1)/b2)*betaDotV*bbeta + g
72 // Note: I have verified the behavior of
73 // small -- (gamma-1)/b2 becomes in
74 // multiplied by O(beta**2) and add
75 // inaccuracy does not affect the f
76 }
77 return *this;
78 } /* boost (axis, beta) */
79
80 } // namespace CLHEP
81