1 | <!-- ******************************************************** --> |
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2 | <!-- --> |
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3 | <!-- [History] --> |
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4 | <!-- Changed by: Katsuya Amako, 21-Sep-1998 --> |
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5 | <!-- Proof read by: Joe Chuma, 29-Jun-1999 --> |
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6 | <!-- Changed by: Hisaya Kurashige, 28-Oct-2001 --> |
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7 | <!-- Changed by: Dennis Wright, 27-Nov-2001 --> |
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8 | <!-- Converted to DocBook: Katsuya Amako, Aug-2006 --> |
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9 | <!-- Changed by: Hisaya Kurashige, 02-Dec-2007 --> |
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10 | <!-- Changed by: Hisaya Kurashige, 01-Dec-2008 --> |
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11 | <!-- --> |
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12 | <!-- ******************************************************** --> |
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13 | |
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14 | |
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15 | <!-- ******************* Section (Level#1) ****************** --> |
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16 | <sect1 id="sect.Parti"> |
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17 | <title> |
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18 | Particles |
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19 | </title> |
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20 | |
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21 | |
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22 | <!-- ******************* Section (Level#2) ****************** --> |
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23 | <sect2 id="sect.Parti.Basic"> |
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24 | <title> |
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25 | Basic concepts |
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26 | </title> |
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27 | |
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28 | <para> |
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29 | There are three levels of classes to describe particles in Geant4. |
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30 | |
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31 | <variablelist> |
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32 | <varlistentry> |
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33 | <term> |
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34 | <emphasis>G4ParticleDefinition</emphasis> |
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35 | </term> |
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36 | <listitem> |
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37 | defines a particle |
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38 | </listitem> |
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39 | </varlistentry> |
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40 | <varlistentry> |
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41 | <term> |
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42 | <emphasis>G4DynamicParticle</emphasis> |
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43 | </term> |
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44 | <listitem> |
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45 | describes a particle interacting with materials |
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46 | </listitem> |
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47 | </varlistentry> |
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48 | <varlistentry> |
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49 | <term> |
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50 | <emphasis>G4Track</emphasis> |
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51 | </term> |
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52 | <listitem> |
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53 | describes a particle traveling in space and time |
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54 | </listitem> |
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55 | </varlistentry> |
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56 | </variablelist> |
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57 | </para> |
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58 | |
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59 | <para> |
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60 | <emphasis>G4ParticleDefinition</emphasis> aggregates information to |
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61 | characterize a particle's properties, such as name, mass, spin, |
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62 | life time, and decay modes. <emphasis>G4DynamicParticle</emphasis> aggregates |
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63 | information to describe the dynamics of particles, such as energy, |
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64 | momentum, polarization, and proper time, as well as ``particle |
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65 | definition'' information. <emphasis>G4Track</emphasis> includes all information |
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66 | necessary for tracking in a detector simulation, such as time, |
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67 | position, and step, as well as ``dynamic particle'' |
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68 | information. |
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69 | </para> |
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70 | |
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71 | <para> |
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72 | <emphasis>G4Track</emphasis> has all the information necessary for tracking in |
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73 | Geant4. It includes position, time, and step, as well as |
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74 | kinematics. Details of <emphasis>G4Track</emphasis> will be described in |
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75 | <xref linkend="sect.Track" />. |
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76 | </para> |
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77 | |
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78 | </sect2> |
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79 | |
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80 | |
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81 | <!-- ******************* Section (Level#2) ****************** --> |
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82 | <sect2 id="sect.Parti.Def"> |
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83 | <title> |
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84 | Definition of a particle |
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85 | </title> |
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86 | |
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87 | <para> |
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88 | There are a large number of elementary particles and nuclei. Geant4 |
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89 | provides the <emphasis>G4ParticleDefinition</emphasis> class to represent |
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90 | particles, and various particles, such as the electron, proton, and |
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91 | gamma have their own classes derived from |
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92 | <emphasis>G4ParticleDefinition</emphasis>. |
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93 | </para> |
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94 | |
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95 | <para> |
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96 | We do not need to make a class in Geant4 for every kind of |
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97 | particle in the world. There are more than 100 types of particles |
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98 | defined in Geant4 by default. Which particles should be included, |
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99 | and how to implement them, is determined according to the following |
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100 | criteria. (Of course, the user can define any particles he wants. |
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101 | Please see the <emphasis role="bold">User's Guide: For ToolKit |
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102 | Developers</emphasis>). |
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103 | </para> |
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104 | |
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105 | |
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106 | <!-- ******************* Section (Level#3) ****************** --> |
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107 | <sect3 id="sect.Parti.Def.PartiList"> |
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108 | <title> |
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109 | Particle List in Geant4 |
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110 | </title> |
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111 | |
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112 | <para> |
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113 | This list includes all particles in Geant4 and you can see |
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114 | properties of particles such as |
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115 | |
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116 | <itemizedlist spacing="compact"> |
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117 | <listitem><para> |
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118 | PDG encoding |
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119 | </para></listitem> |
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120 | <listitem><para> |
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121 | mass and width |
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122 | </para></listitem> |
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123 | <listitem><para> |
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124 | electric charge |
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125 | </para></listitem> |
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126 | <listitem><para> |
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127 | spin, isospin and parity |
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128 | </para></listitem> |
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129 | <listitem><para> |
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130 | magnetic moment |
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131 | </para></listitem> |
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132 | <listitem><para> |
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133 | quark contents |
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134 | </para></listitem> |
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135 | <listitem><para> |
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136 | life time and decay modes |
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137 | </para></listitem> |
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138 | </itemizedlist> |
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139 | </para> |
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140 | |
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141 | <para> |
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142 | Here is a list of particles in Geant4. This list is generated |
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143 | automatically by using Geant4 functionality, so listed values are |
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144 | same as those in your Geant4 application (as far as you do not |
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145 | change source codes). |
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146 | </para> |
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147 | |
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148 | <!-- ******* Bridgehead ******* --> |
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149 | <bridgehead renderas='sect4'> |
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150 | Categories |
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151 | </bridgehead> |
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152 | |
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153 | <para> |
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154 | <itemizedlist spacing="compact"> |
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155 | <listitem><para> |
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156 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/quarks/index.html"> |
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157 | gluon / quarks / di-quarks |
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158 | </ulink> |
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159 | </para></listitem> |
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160 | <listitem><para> |
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161 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/leptons/index.html"> |
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162 | leptons |
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163 | </ulink> |
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164 | </para></listitem> |
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165 | <listitem><para> |
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166 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/mesons/index.html"> |
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167 | mesons |
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168 | </ulink> |
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169 | </para></listitem> |
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170 | <listitem><para> |
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171 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/baryons/index.html"> |
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172 | baryons |
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173 | </ulink> |
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174 | </para></listitem> |
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175 | <listitem><para> |
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176 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/ions/index.html"> |
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177 | ions |
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178 | </ulink> |
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179 | </para></listitem> |
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180 | <listitem><para> |
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181 | <ulink url="./AllResources/TrackingAndPhysics/particleList.src/others/index.html"> |
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182 | others |
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183 | </ulink> |
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184 | </para></listitem> |
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185 | </itemizedlist> |
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186 | </para> |
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187 | |
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188 | </sect3> |
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189 | |
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190 | <!-- ******************* Section (Level#3) ****************** --> |
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191 | <sect3 id="sect.Parti.Def.Classif"> |
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192 | <title> |
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193 | Classification of particles |
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194 | </title> |
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195 | |
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196 | <para> |
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197 | <orderedlist spacing="compact"> |
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198 | <listitem><para> |
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199 | <para> |
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200 | elementary particles which should be tracked in Geant4 volumes |
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201 | </para> |
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202 | <para> |
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203 | All particles that can fly a finite length and interact with |
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204 | materials in detectors are included in this category. In addition, |
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205 | some particles with a very short lifetime are included |
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206 | for user's convenience. |
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207 | |
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208 | <orderedlist spacing="compact"> |
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209 | <listitem><para> |
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210 | stable particles |
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211 | <para> |
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212 | Stable means that the particle can not decay, or has a very small |
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213 | possibility to decay in detectors, e.g., gamma, electron, proton, |
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214 | and neutron. |
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215 | </para> |
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216 | </para></listitem> |
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217 | <listitem><para> |
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218 | long life (>10<superscript>-14</superscript>sec) particles |
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219 | <para> |
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220 | Particles which may travel a finite length, e.g., muon, charged |
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221 | pions. |
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222 | </para> |
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223 | </para></listitem> |
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224 | <listitem><para> |
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225 | short life particles that decay immediately in Geant4 |
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226 | <para> |
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227 | For example, pi<superscript>0</superscript>, eta |
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228 | </para> |
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229 | </para></listitem> |
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230 | <listitem><para> |
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231 | K<superscript>0</superscript> system |
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232 | <para> |
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233 | K<superscript>0</superscript> "decays" immediately into |
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234 | K<superscript>0</superscript><subscript>S</subscript> |
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235 | or K<superscript>0</superscript><subscript>L</subscript>, and then |
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236 | K<superscript>0</superscript><subscript>S</subscript>/ |
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237 | K<superscript>0</superscript><subscript>L</subscript> decays |
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238 | according to its life time and decay modes. |
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239 | </para> |
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240 | </para></listitem> |
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241 | <listitem><para> |
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242 | optical photon |
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243 | <para> |
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244 | Gamma and optical photon are distinguished in the simulation |
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245 | view, though both are the same particle (photons with different |
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246 | energies). For example, optical photon is used for Cerenkov light |
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247 | and scintillation light. |
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248 | </para> |
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249 | </para></listitem> |
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250 | <listitem><para> |
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251 | geantino/charged geantino |
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252 | <para> |
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253 | Geantino and charged geantino are virtual particles for |
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254 | simulation which do not interact with materials and undertake |
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255 | transportation processes only. |
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256 | </para> |
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257 | </para></listitem> |
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258 | </orderedlist> |
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259 | </para> |
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260 | </para></listitem> |
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261 | <listitem><para> |
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262 | nuclei |
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263 | <para> |
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264 | Any kinds of nucleus can be used in Geant4, such as alpha(He-4), |
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265 | uranium-238 and excited states of carbon-14. In addition, |
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266 | Geant4 provides hyper-nuclei. Nuclei in Geant4 are |
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267 | divided into two groups from the viewpoint of implementation. |
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268 | <orderedlist spacing="compact"> |
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269 | <listitem><para> |
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270 | light nuclei |
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271 | <para> |
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272 | Light nuclei frequently used in simulation, e.g., alpha, deuteron, |
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273 | He3, triton. |
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274 | </para> |
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275 | </para></listitem> |
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276 | <listitem><para> |
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277 | heavy nuclei (including hyper-nuclei) |
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278 | <para> |
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279 | Nuclei other than those defined in the previous category. |
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280 | </para> |
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281 | </para></listitem> |
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282 | </orderedlist> |
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283 | |
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284 | Note that G4ParticleDefinition represents nucleus state and |
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285 | G4DynamicParticle represents atomic state with some nucleus. Both |
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286 | alpha particle with charge of +2e and helium atom with no charge |
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287 | aggregates the same "particle definition" of G4Alpha, but different |
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288 | G4DynamicParticle objects should be assigned to them. (Details can |
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289 | be found below) |
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290 | </para> |
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291 | </para></listitem> |
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292 | <listitem><para> |
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293 | short-lived particles |
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294 | <para> |
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295 | Particles with very short life time decay immediately and are never |
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296 | tracked in the detector geometry. These particles are usually used |
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297 | only inside physics processes to implement some models of |
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298 | interactions. <emphasis>G4VShortLivedParticle</emphasis> is provided as |
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299 | the base class for these particles. All classes related to particles in |
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300 | this category can be found in <literal>shortlived</literal> sub-directory |
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301 | under the <literal>particles</literal> directory. |
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302 | |
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303 | <orderedlist spacing="compact"> |
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304 | <listitem><para> |
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305 | quarks/di-quarks |
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306 | <para> |
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307 | For example, all 6 quarks. |
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308 | </para> |
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309 | </para></listitem> |
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310 | <listitem><para> |
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311 | gluon |
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312 | </para></listitem> |
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313 | <listitem><para> |
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314 | baryon excited states with very short life |
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315 | <para> |
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316 | For example, spin 3/2 baryons and anti-baryons |
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317 | </para> |
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318 | </para></listitem> |
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319 | <listitem><para> |
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320 | meson excited states with very short life |
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321 | <para> |
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322 | For example, spin 1 vector bosons |
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323 | </para> |
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324 | </para></listitem> |
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325 | </orderedlist> |
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326 | </para> |
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327 | </para></listitem> |
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328 | </orderedlist> |
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329 | </para> |
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330 | |
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331 | </sect3> |
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332 | |
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333 | |
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334 | <!-- ******************* Section (Level#3) ****************** --> |
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335 | <sect3 id="sect.Parti.Def.Imple"> |
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336 | <title> |
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337 | Implementation of particles |
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338 | </title> |
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339 | |
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340 | <para> |
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341 | <emphasis>Single object created in the initialization :</emphasis> |
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342 | Categories a, b-1 |
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343 | </para> |
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344 | |
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345 | <para> |
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346 | These particles are frequently used for tracking in |
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347 | Geant4. An individual class is defined for each particle in these |
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348 | categories. The object in each class is unique. |
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349 | The user can get pointers to these objects by using static methods |
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350 | in their own classes. The unique object for each class is created |
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351 | when its static method is called in the ``initialization phase''. |
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352 | </para> |
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353 | |
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354 | <para> |
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355 | <emphasis>On-the-fly creation:</emphasis> Category b-2 |
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356 | </para> |
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357 | |
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358 | <para> |
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359 | Ions will travel in a detector geometry and should |
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360 | be tracked, however, the number of ions which may be used for |
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361 | hadronic processes is so huge that ions are dynamically |
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362 | created by requests from processes (and users). |
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363 | Each ion corresponds to one object of the <emphasis>G4Ions</emphasis> |
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364 | class. |
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365 | <emphasis>G4IonTable</emphasis> class is a dictionary for ions. |
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366 | <literal>G4ParticleTable::GetIon()</literal> method invokes |
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367 | <literal>G4IonTable::GetIon()</literal> method to create ions |
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368 | on the fly. |
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369 | </para> |
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370 | |
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371 | <para> |
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372 | Users can register a <emphasis>G4IsotopeTable</emphasis> to the |
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373 | <emphasis>G4IonTable</emphasis>. <emphasis>G4IsotopeTable</emphasis> |
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374 | describes properties of ions (exited energy, decay modes, life time |
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375 | and magnetic moments), which are used to create ions. |
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376 | </para> |
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377 | |
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378 | <para> |
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379 | Processes attached to heavy ions are same as those for |
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380 | <emphasis>G4GenericIon</emphasis> class. In other words, you need to |
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381 | create <emphasis>G4GenericIon</emphasis> and attach processes to it |
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382 | if you want to use heavy ions. |
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383 | </para> |
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384 | |
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385 | <para> |
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386 | <emphasis>G4ParticleGun</emphasis> can shoot any heavy ions |
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387 | with /gun/ions command after ``ion'' is selected by /gun/particle command. |
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388 | </para> |
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389 | |
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390 | <para> |
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391 | <emphasis>Dynamic creation by processes:</emphasis> Category c |
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392 | </para> |
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393 | |
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394 | <para> |
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395 | Particle types in this category are are not created |
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396 | by default, but will only be created by request from processes or |
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397 | directly by users. Each shortlived particle corresponds to one |
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398 | object of a class derived from <emphasis>G4VshortLivedParticle</emphasis>, |
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399 | and it will be created dynamically during the ``initialization |
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400 | phase''. |
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401 | </para> |
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402 | |
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403 | </sect3> |
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404 | |
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405 | |
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406 | <!-- ******************* Section (Level#3) ****************** --> |
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407 | <sect3 id="sect.Parti.Def.G4Parti"> |
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408 | <title> |
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409 | G4ParticleDefinition |
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410 | </title> |
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411 | |
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412 | <para> |
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413 | The <emphasis>G4ParticleDefinition</emphasis> class has ``read-only'' properties |
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414 | to characterize individual particles, such as name, mass, charge, |
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415 | spin, and so on. These properties are set during initialization of |
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416 | each particle. Methods to get these properties are listed in |
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417 | <xref linkend="table.Parti_1" />. |
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418 | |
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419 | <table id="table.Parti_1"> |
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420 | <title> |
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421 | Methods to get particle properties. |
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422 | </title> |
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423 | |
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424 | <tgroup cols="2"> |
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425 | <tbody> |
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426 | <row> |
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427 | <entry> |
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428 | <literal>G4String GetParticleName()</literal> |
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429 | </entry> |
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430 | <entry> |
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431 | particle name |
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432 | </entry> |
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433 | </row> |
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434 | <row> |
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435 | <entry> |
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436 | <literal>G4double GetPDGMass()</literal> |
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437 | </entry> |
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438 | <entry> |
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439 | mass |
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440 | </entry> |
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441 | </row> |
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442 | <row> |
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443 | <entry> |
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444 | <literal>G4double GetPDGWidth()</literal> |
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445 | </entry> |
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446 | <entry> |
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447 | decay width |
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448 | </entry> |
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449 | </row> |
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450 | <row> |
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451 | <entry> |
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452 | <literal>G4double GetPDGCharge()</literal> |
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453 | </entry> |
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454 | <entry> |
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455 | electric charge |
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456 | </entry> |
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457 | </row> |
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458 | <row> |
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459 | <entry> |
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460 | <literal>G4double GetPDGSpin()</literal> |
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461 | </entry> |
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462 | <entry> |
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463 | spin |
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464 | </entry> |
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465 | </row> |
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466 | <row> |
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467 | <entry> |
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468 | <literal>G4double GetPDGMagneticMoment()</literal> |
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469 | </entry> |
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470 | <entry> |
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471 | magnetic moment (0: not defined or no magnetic moment) |
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472 | </entry> |
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473 | </row> |
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474 | <row> |
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475 | <entry> |
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476 | <literal>G4int GetPDGiParity()</literal> |
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477 | </entry> |
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478 | <entry> |
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479 | parity (0:not defined) |
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480 | </entry> |
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481 | </row> |
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482 | <row> |
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483 | <entry> |
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484 | <literal>G4int GetPDGiConjugation()</literal> |
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485 | </entry> |
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486 | <entry> |
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487 | charge conjugation (0:not defined) |
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488 | </entry> |
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489 | </row> |
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490 | <row> |
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491 | <entry> |
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492 | <literal>G4double GetPDGIsospin()</literal> |
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493 | </entry> |
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494 | <entry> |
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495 | iso-spin |
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496 | </entry> |
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497 | </row> |
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498 | <row> |
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499 | <entry> |
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500 | <literal>G4double GetPDGIsospin3()</literal> |
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501 | </entry> |
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502 | <entry> |
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503 | 3<superscript>rd</superscript>-component of iso-spin |
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504 | </entry> |
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505 | </row> |
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506 | <row> |
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507 | <entry> |
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508 | <literal>G4int GetPDGiGParity()</literal> |
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509 | </entry> |
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510 | <entry> |
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511 | G-parity (0:not defined) |
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512 | </entry> |
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513 | </row> |
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514 | <row> |
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515 | <entry> |
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516 | <literal>G4String GetParticleType()</literal> |
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517 | </entry> |
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518 | <entry> |
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519 | particle type |
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520 | </entry> |
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521 | </row> |
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522 | <row> |
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523 | <entry> |
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524 | <literal>G4String GetParticleSubType()</literal> |
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525 | </entry> |
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526 | <entry> |
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527 | particle sub-type |
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528 | </entry> |
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529 | </row> |
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530 | <row> |
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531 | <entry> |
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532 | <literal>G4int GetLeptonNumber()</literal> |
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533 | </entry> |
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534 | <entry> |
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535 | lepton number |
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536 | </entry> |
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537 | </row> |
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538 | <row> |
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539 | <entry> |
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540 | <literal>G4int GetBaryonNumber()</literal> |
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541 | </entry> |
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542 | <entry> |
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543 | baryon number |
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544 | </entry> |
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545 | </row> |
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546 | <row> |
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547 | <entry> |
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548 | <literal>G4int GetPDGEncoding()</literal> |
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549 | </entry> |
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550 | <entry> |
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551 | particle encoding number by PDG |
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552 | </entry> |
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553 | </row> |
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554 | <row> |
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555 | <entry> |
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556 | <literal>G4int GetAntiPDGEncoding()</literal> |
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557 | </entry> |
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558 | <entry> |
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559 | encoding for anti-particle of this particle |
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560 | </entry> |
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561 | </row> |
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562 | </tbody> |
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563 | </tgroup> |
---|
564 | </table> |
---|
565 | </para> |
---|
566 | |
---|
567 | <para> |
---|
568 | <xref linkend="table.Parti_2" /> shows the methods of |
---|
569 | <emphasis>G4ParticleDefinition</emphasis> for |
---|
570 | getting information about decay modes and the life time of the |
---|
571 | particle. |
---|
572 | |
---|
573 | <table id="table.Parti_2"> |
---|
574 | <title> |
---|
575 | Methods to get particle decay modes and life time. |
---|
576 | </title> |
---|
577 | |
---|
578 | <tgroup cols="2"> |
---|
579 | <tbody> |
---|
580 | <row> |
---|
581 | <entry> |
---|
582 | <literal>G4bool GetPDGStable()</literal> |
---|
583 | </entry> |
---|
584 | <entry> |
---|
585 | stable flag |
---|
586 | </entry> |
---|
587 | </row> |
---|
588 | <row> |
---|
589 | <entry> |
---|
590 | <literal>G4double GetPDGLifeTime()</literal> |
---|
591 | </entry> |
---|
592 | <entry> |
---|
593 | life time |
---|
594 | </entry> |
---|
595 | </row> |
---|
596 | <row> |
---|
597 | <entry> |
---|
598 | <literal>G4DecayTable* GetDecayTable()</literal> |
---|
599 | </entry> |
---|
600 | <entry> |
---|
601 | decay table |
---|
602 | </entry> |
---|
603 | </row> |
---|
604 | </tbody> |
---|
605 | </tgroup> |
---|
606 | </table> |
---|
607 | </para> |
---|
608 | |
---|
609 | <para> |
---|
610 | Users can modify these properties, though the other properties |
---|
611 | listed above can not be change without rebuilding the |
---|
612 | libraries. |
---|
613 | </para> |
---|
614 | |
---|
615 | <para> |
---|
616 | Each particle has its own <emphasis>G4ProcessManger</emphasis> |
---|
617 | object that manages a list of processes applicable to the |
---|
618 | particle.(see <xref linkend="sect.HowToSpecPhysProc.ManagingProc"/> ) |
---|
619 | </para> |
---|
620 | |
---|
621 | |
---|
622 | </sect3> |
---|
623 | </sect2> |
---|
624 | |
---|
625 | |
---|
626 | <!-- ******************* Section (Level#2) ****************** --> |
---|
627 | <sect2 id="sect.Parti.Dynam"> |
---|
628 | <title> |
---|
629 | Dynamic particle |
---|
630 | </title> |
---|
631 | |
---|
632 | <para> |
---|
633 | The <emphasis>G4DynamicParticle</emphasis> class has kinematics information for |
---|
634 | the particle and is used for describing the dynamics of physics |
---|
635 | processes. The properties in <emphasis>G4DynamicParticle</emphasis> are listed in |
---|
636 | <xref linkend="table.Parti_4" />. |
---|
637 | |
---|
638 | <table id="table.Parti_4"> |
---|
639 | <title> |
---|
640 | Methods to set/get cut off values. |
---|
641 | </title> |
---|
642 | |
---|
643 | <tgroup cols="2"> |
---|
644 | <tbody> |
---|
645 | <row> |
---|
646 | <entry> |
---|
647 | <literal>G4double theDynamicalMass</literal> |
---|
648 | </entry> |
---|
649 | <entry> |
---|
650 | dynamical mass |
---|
651 | </entry> |
---|
652 | </row> |
---|
653 | <row> |
---|
654 | <entry> |
---|
655 | <literal>G4ThreeVector theMomentumDirection</literal> |
---|
656 | </entry> |
---|
657 | <entry> |
---|
658 | normalized momentum vector |
---|
659 | </entry> |
---|
660 | </row> |
---|
661 | <row> |
---|
662 | <entry> |
---|
663 | <literal>G4ParticleDefinition* theParticleDefinition</literal> |
---|
664 | </entry> |
---|
665 | <entry> |
---|
666 | definition of particle |
---|
667 | </entry> |
---|
668 | </row> |
---|
669 | <row> |
---|
670 | <entry> |
---|
671 | <literal>G4double theDynamicalSpin</literal> |
---|
672 | </entry> |
---|
673 | <entry> |
---|
674 | dynamical spin |
---|
675 | (i.e. total angular momentum as a ion/atom ) |
---|
676 | </entry> |
---|
677 | </row> |
---|
678 | <row> |
---|
679 | <entry> |
---|
680 | <literal>G4ThreeVector thePolarization</literal> |
---|
681 | </entry> |
---|
682 | <entry> |
---|
683 | polarization vector |
---|
684 | </entry> |
---|
685 | </row> |
---|
686 | <row> |
---|
687 | <entry> |
---|
688 | <literal>G4double theMagneticMoment</literal> |
---|
689 | </entry> |
---|
690 | <entry> |
---|
691 | dynamical magnetic moment |
---|
692 | (i.e. total magnetic moment as a ion/atom ) |
---|
693 | </entry> |
---|
694 | </row> |
---|
695 | <row> |
---|
696 | <entry> |
---|
697 | <literal>G4double theKineticEnergy</literal> |
---|
698 | </entry> |
---|
699 | <entry> |
---|
700 | kinetic energy |
---|
701 | </entry> |
---|
702 | </row> |
---|
703 | <row> |
---|
704 | <entry> |
---|
705 | <literal>G4double theProperTime</literal> |
---|
706 | </entry> |
---|
707 | <entry> |
---|
708 | proper time |
---|
709 | </entry> |
---|
710 | </row> |
---|
711 | <row> |
---|
712 | <entry> |
---|
713 | <literal>G4double theDynamicalCharge</literal> |
---|
714 | </entry> |
---|
715 | <entry> |
---|
716 | dynamical electric charge |
---|
717 | (i.e. total electric charge as a ion/atom ) |
---|
718 | </entry> |
---|
719 | </row> |
---|
720 | <row> |
---|
721 | <entry> |
---|
722 | <literal>G4ElectronOccupancy* theElectronOccupancy</literal> |
---|
723 | </entry> |
---|
724 | <entry> |
---|
725 | electron orbits for ions |
---|
726 | </entry> |
---|
727 | </row> |
---|
728 | </tbody> |
---|
729 | </tgroup> |
---|
730 | </table> |
---|
731 | </para> |
---|
732 | |
---|
733 | <para> |
---|
734 | Here, the dynamical mass is defined as the mass for the dynamic |
---|
735 | particle. For most cases, it is same as the mass defined in |
---|
736 | <emphasis>G4ParticleDefinition</emphasis> class ( i.e. mass value given by |
---|
737 | <literal>GetPDGMass()</literal> method). However, there are two |
---|
738 | exceptions. |
---|
739 | |
---|
740 | <itemizedlist spacing="compact"> |
---|
741 | <listitem><para> |
---|
742 | resonance particle |
---|
743 | </para></listitem> |
---|
744 | <listitem><para> |
---|
745 | ions |
---|
746 | </para></listitem> |
---|
747 | </itemizedlist> |
---|
748 | </para> |
---|
749 | |
---|
750 | <para> |
---|
751 | Resonance particles have large mass width and the total energy of |
---|
752 | decay products at the center of mass system can be different event |
---|
753 | by event. |
---|
754 | </para> |
---|
755 | |
---|
756 | <para> |
---|
757 | As for ions, <emphasis>G4ParticleDefintion</emphasis> defines a nucleus and |
---|
758 | <emphasis>G4DynamicParticle</emphasis> defines an atom. |
---|
759 | <emphasis>G4ElectronOccupancy</emphasis> describes state of orbital electrons. |
---|
760 | So, the dynamic mass can be different from the PDG mass by the mass |
---|
761 | of electrons (and their binding energy). In addition, the dynamical |
---|
762 | charge, spin and magnetic moment are those of the atom/ion |
---|
763 | (i.e. including nucleus and orbit electrons). |
---|
764 | </para> |
---|
765 | |
---|
766 | <para> |
---|
767 | Decay products of heavy flavor particles are given in many event |
---|
768 | generators. In such cases, <emphasis>G4VPrimaryGenerator</emphasis> sets this |
---|
769 | information in <literal>*thePreAssignedDecayProducts</literal>. In addition, |
---|
770 | decay time of the particle can be set arbitrarily time by using |
---|
771 | <literal>PreAssignedDecayProperTime</literal>. |
---|
772 | </para> |
---|
773 | |
---|
774 | |
---|
775 | </sect2> |
---|
776 | </sect1> |
---|