[1] | 1 | // HiddenValleyFragmentation.h is a part of the PYTHIA event generator. |
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| 2 | // Copyright (C) 2012 Torbjorn Sjostrand. |
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| 3 | // PYTHIA is licenced under the GNU GPL version 2, see COPYING for details. |
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| 4 | // Please respect the MCnet Guidelines, see GUIDELINES for details. |
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| 5 | |
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| 6 | // This file contains the classes for Hidden-Valley fragmentation. |
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| 7 | |
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| 8 | #ifndef Pythia8_HiddenValleyFragmentation_H |
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| 9 | #define Pythia8_HiddenValleyFragmentation_H |
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| 10 | |
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| 11 | #include "Basics.h" |
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| 12 | #include "Event.h" |
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| 13 | #include "FragmentationFlavZpT.h" |
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| 14 | #include "FragmentationSystems.h" |
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| 15 | #include "Info.h" |
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| 16 | #include "MiniStringFragmentation.h" |
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| 17 | #include "ParticleData.h" |
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| 18 | #include "PythiaStdlib.h" |
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| 19 | #include "Settings.h" |
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| 20 | #include "StringFragmentation.h" |
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| 21 | |
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| 22 | namespace Pythia8 { |
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| 23 | |
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| 24 | //========================================================================== |
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| 25 | |
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| 26 | // The HVStringFlav class is used to select HV-quark and HV-hadron flavours. |
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| 27 | |
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| 28 | class HVStringFlav : public StringFlav { |
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| 29 | |
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| 30 | public: |
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| 31 | |
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| 32 | // Constructor. |
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| 33 | HVStringFlav() {} |
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| 34 | |
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| 35 | // Destructor. |
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| 36 | ~HVStringFlav() {} |
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| 37 | |
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| 38 | // Initialize data members. |
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| 39 | void init(Settings& settings, Rndm* rndmPtrIn); |
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| 40 | |
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| 41 | // Pick a new flavour (including diquarks) given an incoming one. |
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| 42 | FlavContainer pick(FlavContainer& flavOld); |
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| 43 | |
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| 44 | // Combine two flavours (including diquarks) to produce a hadron. |
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| 45 | int combine(FlavContainer& flav1, FlavContainer& flav2); |
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| 46 | |
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| 47 | private: |
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| 48 | |
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| 49 | // Initialization data, to be read from Settings. |
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| 50 | int nFlav; |
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| 51 | double probVector; |
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| 52 | |
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| 53 | }; |
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| 54 | |
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| 55 | //========================================================================== |
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| 56 | |
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| 57 | // The HVStringPT class is used to select select HV transverse momenta. |
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| 58 | |
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| 59 | class HVStringPT : public StringPT { |
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| 60 | |
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| 61 | public: |
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| 62 | |
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| 63 | // Constructor. |
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| 64 | HVStringPT() {} |
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| 65 | |
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| 66 | // Destructor. |
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| 67 | ~HVStringPT() {} |
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| 68 | |
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| 69 | // Initialize data members. |
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| 70 | void init(Settings& settings, ParticleData& particleData, Rndm* rndmPtrIn); |
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| 71 | |
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| 72 | }; |
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| 73 | |
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| 74 | //========================================================================== |
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| 75 | |
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| 76 | // The HVStringZ class is used to sample the HV fragmentation function f(z). |
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| 77 | |
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| 78 | class HVStringZ : public StringZ { |
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| 79 | |
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| 80 | public: |
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| 81 | |
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| 82 | // Constructor. |
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| 83 | HVStringZ() {} |
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| 84 | |
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| 85 | // Destructor. |
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| 86 | ~HVStringZ() {} |
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| 87 | |
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| 88 | // Initialize data members. |
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| 89 | void init(Settings& settings, ParticleData& particleData, Rndm* rndmPtrIn); |
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| 90 | |
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| 91 | // Fragmentation function: top-level to determine parameters. |
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| 92 | double zFrag( int idOld, int idNew = 0, double mT2 = 1.); |
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| 93 | |
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| 94 | // Parameters for stopping in the middle; for now hardcoded. |
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| 95 | virtual double stopMass() {return 1.5 * mhvMeson;} |
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| 96 | virtual double stopNewFlav() {return 2.0;} |
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| 97 | virtual double stopSmear() {return 0.2;} |
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| 98 | |
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| 99 | private: |
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| 100 | |
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| 101 | // Initialization data, to be read from Settings and ParticleData. |
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| 102 | double mqv2, bmqv2, rFactqv, mhvMeson; |
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| 103 | |
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| 104 | }; |
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| 105 | |
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| 106 | //========================================================================== |
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| 107 | |
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| 108 | // The HiddenValleyFragmentation class contains the routines |
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| 109 | // to fragment a Hidden Valley partonic system. |
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| 110 | |
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| 111 | class HiddenValleyFragmentation { |
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| 112 | |
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| 113 | public: |
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| 114 | |
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| 115 | // Constructor. |
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| 116 | HiddenValleyFragmentation() : hvFlavSelPtr(NULL), hvPTSelPtr(NULL), |
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| 117 | hvZSelPtr(NULL) {} |
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| 118 | |
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| 119 | // Destructor. |
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| 120 | ~HiddenValleyFragmentation() { if (doHVfrag) { |
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| 121 | if (hvZSelPtr) delete hvZSelPtr; if (hvPTSelPtr) delete hvPTSelPtr; |
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| 122 | if (hvFlavSelPtr) delete hvFlavSelPtr;} } |
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| 123 | |
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| 124 | // Initialize and save pointers. |
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| 125 | bool init(Info* infoPtrIn, Settings& settings, |
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| 126 | ParticleData* particleDataPtrIn, Rndm* rndmPtrIn); |
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| 127 | |
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| 128 | // Do the fragmentation: driver routine. |
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| 129 | bool fragment(Event& event); |
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| 130 | |
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| 131 | private: |
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| 132 | |
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| 133 | // Pointer to various information on the generation. |
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| 134 | Info* infoPtr; |
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| 135 | |
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| 136 | // Pointer to the particle data table. |
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| 137 | ParticleData* particleDataPtr; |
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| 138 | |
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| 139 | // Pointer to the random number generator. |
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| 140 | Rndm* rndmPtr; |
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| 141 | |
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| 142 | // Data mambers. |
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| 143 | bool doHVfrag; |
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| 144 | int nFlav, hvOldSize, hvNewSize; |
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| 145 | double mhvMeson, mSys; |
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| 146 | vector<int> ihvParton; |
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| 147 | |
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| 148 | // Configuration of colour-singlet systems. |
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| 149 | ColConfig hvColConfig; |
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| 150 | |
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| 151 | // Temporary event record for the Hidden Valley system. |
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| 152 | Event hvEvent; |
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| 153 | |
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| 154 | // The generator class for Hidden Valley string fragmentation. |
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| 155 | StringFragmentation hvStringFrag; |
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| 156 | |
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| 157 | // The generator class for special low-mass HV string fragmentation. |
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| 158 | MiniStringFragmentation hvMinistringFrag; |
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| 159 | |
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| 160 | // Pointers to classes for flavour, pT and z generation in HV sector. |
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| 161 | StringFlav* hvFlavSelPtr; |
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| 162 | StringPT* hvPTSelPtr; |
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| 163 | StringZ* hvZSelPtr; |
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| 164 | |
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| 165 | // Extract HV-particles from event to hvEvent. Assign HV-colours. |
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| 166 | bool extractHVevent(Event& event); |
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| 167 | |
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| 168 | // Collapse of low-mass system to one HV-meson. |
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| 169 | bool collapseToMeson(); |
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| 170 | |
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| 171 | // Insert HV particles from hvEvent to event. |
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| 172 | bool insertHVevent(Event& event); |
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| 173 | |
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| 174 | }; |
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| 175 | |
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| 176 | //========================================================================== |
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| 177 | |
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| 178 | } // end namespace Pythia8 |
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| 179 | |
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| 180 | #endif // Pythia8_HiddenValleyFragmentation_H |
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