| 1 |
#include <iostream>
|
| 2 |
#include "Angles.h"
|
| 3 |
#include "EventData.h"
|
| 4 |
|
| 5 |
void fillAngles( EventData &data, Angles &a ) {
|
| 6 |
|
| 7 |
LabVectors l;
|
| 8 |
|
| 9 |
if( data.Z1leptons[0].charge > 0 ) {
|
| 10 |
l.vecl1p = data.Z1leptons[0].vec;
|
| 11 |
l.vecl1m = data.Z1leptons[1].vec;
|
| 12 |
} else {
|
| 13 |
l.vecl1p = data.Z1leptons[1].vec;
|
| 14 |
l.vecl1m = data.Z1leptons[0].vec;
|
| 15 |
}
|
| 16 |
|
| 17 |
if( data.Z2leptons[0].charge > 0 ) {
|
| 18 |
l.vecl2p = data.Z2leptons[0].vec;
|
| 19 |
l.vecl2m = data.Z2leptons[1].vec;
|
| 20 |
} else {
|
| 21 |
l.vecl2p = data.Z2leptons[1].vec;
|
| 22 |
l.vecl2m = data.Z2leptons[0].vec;
|
| 23 |
}
|
| 24 |
|
| 25 |
l.vecz1 = (l.vecl1p+l.vecl1m);
|
| 26 |
l.vecz2 = (l.vecl2p+l.vecl2m);
|
| 27 |
l.vec4l = (l.vecz1+l.vecz2);
|
| 28 |
|
| 29 |
getAngles( l, a );
|
| 30 |
}
|
| 31 |
|
| 32 |
void getAngles( LabVectors &l,
|
| 33 |
Angles &a ) {
|
| 34 |
|
| 35 |
//
|
| 36 |
// define the frames
|
| 37 |
// --------------------------------------------------------------------------------------------------
|
| 38 |
TVector3 Xframe = l.vec4l.BoostVector();
|
| 39 |
TVector3 Z1frame = l.vecz1.BoostVector();
|
| 40 |
TVector3 Z2frame = l.vecz2.BoostVector();
|
| 41 |
|
| 42 |
//
|
| 43 |
// costheta(l1m,X) in Z1 frame
|
| 44 |
// --------------------------------------------------------------------------------------------------
|
| 45 |
TLorentzVector vecl1m_in_Z1frame( l.vecl1m ); // make a copies of the vectors
|
| 46 |
TLorentzVector vec4l_in_Z1frame( l.vec4l ); //
|
| 47 |
vecl1m_in_Z1frame.Boost( -1*Z1frame ); // now go to the Z1 rest frame
|
| 48 |
vec4l_in_Z1frame.Boost( -1*Z1frame ); //
|
| 49 |
a.costheta1
|
| 50 |
= vecl1m_in_Z1frame.Vect().Dot(-1*vec4l_in_Z1frame.Vect()) /
|
| 51 |
(vecl1m_in_Z1frame.Vect().Mag()*vec4l_in_Z1frame.Vect().Mag());
|
| 52 |
|
| 53 |
//
|
| 54 |
// costheta(l3,X) in Z2 frame
|
| 55 |
// --------------------------------------------------------------------------------------------------
|
| 56 |
TLorentzVector vecl2m_in_Z2frame( l.vecl2m ); // make copies of the vectors
|
| 57 |
TLorentzVector vec4l_in_Z2frame( l.vec4l ); //
|
| 58 |
vecl2m_in_Z2frame.Boost( -1*Z2frame ); // now go to the Z2 rest frame
|
| 59 |
vec4l_in_Z2frame.Boost( -1*Z2frame );
|
| 60 |
a.costheta2 =
|
| 61 |
vecl2m_in_Z2frame.Vect().Dot(-1*vec4l_in_Z2frame.Vect()) /
|
| 62 |
(vecl2m_in_Z2frame.Vect().Mag()*vec4l_in_Z2frame.Vect().Mag());
|
| 63 |
|
| 64 |
|
| 65 |
//
|
| 66 |
// Phi(Z1,Z2) in X frame
|
| 67 |
// --------------------------------------------------------------------------------------------------
|
| 68 |
|
| 69 |
// this is essentially what they do and it reproduces their numbers,
|
| 70 |
// it's the angle between l1 and the z2 decay plane in the Z1 frame
|
| 71 |
TLorentzVector vecz2_in_Z1frame( l.vecz2 ); //
|
| 72 |
TLorentzVector vecl2m_in_Z1frame( l.vecl2m ); //
|
| 73 |
TLorentzVector vecl2p_in_Z1frame( l.vecl2p ); //
|
| 74 |
vecz2_in_Z1frame.Boost( -1*Z1frame ); //
|
| 75 |
vecl2m_in_Z1frame.Boost( -1*Z1frame ); //
|
| 76 |
vecl2p_in_Z1frame.Boost( -1*Z1frame ); //
|
| 77 |
|
| 78 |
//
|
| 79 |
// define the Z2 coordinate system in the Z1 frame
|
| 80 |
// x : opposite the Z2 dir, lies in the Z2 decay plane
|
| 81 |
// z : orthogonal to the Z2 decay plane
|
| 82 |
// y : orthogonal to x&z, lies in the Z2 decay plane
|
| 83 |
TVector3 nnewX = ( -1*vecz2_in_Z1frame.Vect()).Unit();
|
| 84 |
TVector3 nnewZ = (vecl2m_in_Z1frame.Vect().Cross(vecl2p_in_Z1frame.Vect())).Unit();
|
| 85 |
TVector3 nnewY = nnewZ.Cross(nnewX).Unit();
|
| 86 |
TRotation rotation2;
|
| 87 |
rotation2 = (rotation2.RotateAxes( nnewX, nnewY, nnewZ )).Inverse();
|
| 88 |
TVector3 vecl1m_in_Z2coords_Z1frame = vecl1m_in_Z1frame.Vect().Transform(rotation2);
|
| 89 |
|
| 90 |
//
|
| 91 |
// axes are redfined so that Phi is the angle between the Z1 orthogonal
|
| 92 |
// and the Z2 decay plane as given by y
|
| 93 |
//
|
| 94 |
TRotation rotation3;
|
| 95 |
TVector3 nnnewX( 0,1,0 );
|
| 96 |
TVector3 nnnewY( 0,0,1 );
|
| 97 |
TVector3 nnnewZ( 1,0,0 );
|
| 98 |
rotation3 = (rotation3.RotateAxes( nnnewX, nnnewY, nnnewZ )).Inverse();
|
| 99 |
TVector3 vecl1m_in_Z2coords_redefined_Z1frame = vecl1m_in_Z2coords_Z1frame.Transform(rotation3);
|
| 100 |
a.Phi = vecl1m_in_Z2coords_redefined_Z1frame.Phi();
|
| 101 |
|
| 102 |
|
| 103 |
//
|
| 104 |
// rather, I'd expect something like this ...
|
| 105 |
//
|
| 106 |
TLorentzVector vecl1p_in_Xframe( l.vecl1p ); // make a copies of the vectors
|
| 107 |
TLorentzVector vecl1m_in_Xframe( l.vecl1m ); //
|
| 108 |
TLorentzVector vecl2p_in_Xframe( l.vecl2p ); //
|
| 109 |
TLorentzVector vecl2m_in_Xframe( l.vecl2m ); //
|
| 110 |
|
| 111 |
vecl1p_in_Xframe.Boost( -1*Xframe ); // go to the X rest frame
|
| 112 |
vecl1m_in_Xframe.Boost( -1*Xframe ); //
|
| 113 |
vecl2p_in_Xframe.Boost( -1*Xframe ); //
|
| 114 |
vecl2m_in_Xframe.Boost( -1*Xframe ); //
|
| 115 |
|
| 116 |
/*
|
| 117 |
// sanity check ...
|
| 118 |
TLorentzVector z1inX = vecl1p_in_Xframe+vecl1m_in_Xframe;
|
| 119 |
TLorentzVector z2inX = vecl2p_in_Xframe+vecl2m_in_Xframe;
|
| 120 |
float dotz1z2 = z1inX.Vect().Dot(z2inX.Vect()) / (z1inX.Vect().Mag()*z2inX.Vect().Mag());
|
| 121 |
std::cout << "dotz1z2: " << dotz1z2 << std::endl;
|
| 122 |
*/
|
| 123 |
|
| 124 |
TVector3 Z1ortho_in_Xframe = // define the decay planes via the orthogonals
|
| 125 |
vecl1m_in_Xframe.Vect().Cross(vecl1p_in_Xframe.Vect());
|
| 126 |
TVector3 Z2ortho_in_Xframe =
|
| 127 |
vecl2m_in_Xframe.Vect().Cross(vecl2p_in_Xframe.Vect());
|
| 128 |
|
| 129 |
/*
|
| 130 |
// sanity check ... why are these small but not exactly zero ???
|
| 131 |
float z1odot = Z1ortho_in_Xframe.Dot(z1inX.Vect())/(Z1ortho_in_Xframe.Mag()*z1inX.Vect().Mag());
|
| 132 |
float z2odot = Z2ortho_in_Xframe.Dot(z2inX.Vect())/(Z2ortho_in_Xframe.Mag()*z2inX.Vect().Mag());
|
| 133 |
float l1podot = Z1ortho_in_Xframe.Dot(vecl1p_in_Xframe.Vect())/(Z1ortho_in_Xframe.Mag()*vecl1p_in_Xframe.Vect().Mag());
|
| 134 |
float l1modot = Z1ortho_in_Xframe.Dot(vecl1m_in_Xframe.Vect())/(Z1ortho_in_Xframe.Mag()*vecl1m_in_Xframe.Vect().Mag());
|
| 135 |
std::cout << "Z1ortho_in_Xframe.Dot(z1inX): " << z1odot << "\t"
|
| 136 |
<< "Z2ortho_in_Xframe.Dot(z2inX): " << z2odot << "\t"
|
| 137 |
<< "Z1ortho_in_Xframe.Dot(veclp1_in_Xframe) : " << l1podot << "\t"
|
| 138 |
<< "Z1ortho_in_Xframe.Dot(veclm1_in_Xframe) : " << l1modot << "\t"
|
| 139 |
<< std::endl;
|
| 140 |
*/
|
| 141 |
|
| 142 |
|
| 143 |
// a.Phi = Z1ortho_in_Xframe.DeltaPhi(Z2ortho_in_Xframe);
|
| 144 |
//a.Phi = Z1ortho_in_Xframe.Angle(Z2ortho_in_Xframe);
|
| 145 |
|
| 146 |
|
| 147 |
|
| 148 |
//
|
| 149 |
// costheta*(Z1,pp) in X frame
|
| 150 |
// --------------------------------------------------------------------------------------------------
|
| 151 |
TLorentzVector vecz1_in_Xframe( l.vecz1 ); // make a copies of the vectors
|
| 152 |
TLorentzVector vecpp_in_Xframe( 0., 0., 1., 0. ); // define pp axis
|
| 153 |
|
| 154 |
vecz1_in_Xframe.Boost( -1*Xframe ); // go to the X rest frame
|
| 155 |
vecpp_in_Xframe.Boost( -1*Xframe ); //
|
| 156 |
|
| 157 |
a.costhetastar =
|
| 158 |
vecz1_in_Xframe.Vect().Dot(vecpp_in_Xframe.Vect()) /
|
| 159 |
(vecz1_in_Xframe.Vect().Mag()*vecpp_in_Xframe.Vect().Mag());
|
| 160 |
|
| 161 |
|
| 162 |
//
|
| 163 |
// Phi1(Z1,pp) in X frame
|
| 164 |
// --------------------------------------------------------------------------------------------------
|
| 165 |
|
| 166 |
// define the Z1 decay plane in the Xframe
|
| 167 |
// y: orthogonal to the Z1 decay plane
|
| 168 |
// x: lies in the Z1 decay plane, but orthogonal to Z1
|
| 169 |
// z: z1 in Xframe
|
| 170 |
TVector3 newY = (vecl1p_in_Xframe.Vect().Unit().Cross(vecl1m_in_Xframe.Vect().Unit())).Unit();
|
| 171 |
TVector3 newX = (newY.Cross(vecz1_in_Xframe.Vect().Unit())).Unit();
|
| 172 |
TVector3 newZ( (vecz1_in_Xframe.Vect()).Unit() );
|
| 173 |
|
| 174 |
TRotation rotation;
|
| 175 |
rotation = (rotation.RotateAxes( newX, newY, newZ )).Inverse();
|
| 176 |
TVector3 vecpp( 0., 0., 1. );
|
| 177 |
TVector3 vecpp_in_Z1coords_Xframe = vecpp.Transform(rotation);
|
| 178 |
a.Phi1 = vecpp_in_Z1coords_Xframe.Phi();
|
| 179 |
|
| 180 |
// a.mz1 = (l.vecl1m+l.vecl1p).M();
|
| 181 |
// a.mz2 = (l.vecl2m+l.vecl2p).M();
|
| 182 |
// a.m4l = (l.vec4l).M();
|
| 183 |
|
| 184 |
};
|
| 185 |
|
| 186 |
|
