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- Timestamp:
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Jan 21, 2009, 8:43:20 PM (16 years ago)
- Author:
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gallmei
- Comment:
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--
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v2
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1 | | = Annotated Jobcard "jobHarp" = |
2 | | |
3 | | The jobcard explained here in little bit more detail is the file "jobHarp" from Release 1.2. This jobcard may be used in order to calculate particle spectra in pion or proton induced reaction on nuclei. The designated energies are 3 upto 50 GeV, as e.g. possible within the HARP and NA61/Shine experiments. |
4 | | |
5 | | For more information we refer to our [http://theorie.physik.uni-giessen.de/~gibuu/Documentation/ online documentation] |
| 1 | = Annotated Jobcard "jobHARP" = |
| 2 | |
| 3 | The jobcard explained here in some detail is the file "jobHARP" from Release 1.2. This jobcard may be used in order to calculate particle spectra in pion or proton induced reaction on nuclei. The designated energies are 3 upto 50 GeV, as e.g. possible within the HARP and NA61/Shine experiments. |
| 4 | |
| 5 | The given jobcard is shrinked to a minimal set of parameters to give. There are many other possible namelists and also in the namelists given here many other possible parameters. All these are set to sensible default values. |
| 6 | |
| 7 | ''Please note:'' |
| 8 | * Text after an exclamation mark is considered as a remark. |
| 9 | * This file is not conform with fortran standard. Code compiled with some compilers complains about our convention starting and ending a namelist by "$!NameOfNamelist" and "$end$" |
| 10 | |
| 11 | For more information of the given switches and parameters we refer to our [http://theorie.physik.uni-giessen.de/~gibuu/Documentation/ online documentation]. |
6 | 12 | |
7 | 13 | |
… |
… |
|
52 | 58 | num_runs_SameEnergy=2 ! number of runs per energy |
53 | 59 | }}} |
54 | | (see above) |
| 60 | See above. The given value 2 is just for test purposes. Real production runs (approx 2 weeks CPU time) need values as the also given 10000. |
55 | 61 | {{{ |
56 | 62 | |
… |
… |
|
60 | 66 | {{{ |
61 | 67 | freezeRealParticles = .TRUE. |
| 68 | }}} |
| 69 | The testparticles for the nucleons are kept fix at their spatial position during the time evolution, albeit carrying Fermi momentum. |
| 70 | {{{ |
62 | 71 | |
63 | 72 | DoPrLevel(1) = .FALSE. |
64 | 73 | DoPrLevel(2) = .FALSE. |
| 74 | }}} |
| 75 | These lines reduce the verbosity of the code, necessary for long calculations. |
| 76 | {{{ |
65 | 77 | |
66 | 78 | path_To_Input = '~/WC/buuinput' |
67 | | |
| 79 | }}} |
| 80 | The path to the directory, where the code finds the directory "buuinput" in the local installation. |
| 81 | {{{ |
68 | 82 | $end |
69 | 83 | |
… |
… |
|
71 | 85 | ! LesHouchesFinalParticles_Pert=.true. ! if you want that output |
72 | 86 | $end |
73 | | |
| 87 | }}} |
| 88 | Setting this flag to true will print for every subsequent run a XML file according the |
| 89 | [http://arxiv.org/pdf/hep-ph/0609017 "Les Houches Event Files Standard"], holding the perturbative particle vector after the last time step and all particle decays. |
| 90 | {{{ |
74 | 91 | $initRandom |
75 | 92 | SEED=45678 ! Seed for the random number |
76 | 93 | $end |
77 | | |
| 94 | }}} |
| 95 | The seed for the random number generator. |
| 96 | {{{ |
78 | 97 | $initDensity |
79 | 98 | densitySwitch=2 ! 1=dynamic, 2=analytic |
80 | 99 | $end |
| 100 | }}} |
| 101 | This selects the kind of calculating the nuclear density during the run. Here we choose to have it via a Woods--Saxon--density profile. The other choice would recalculate the density in every timestep according the spatial distribution of the testparticles for the nucleons. |
| 102 | {{{ |
81 | 103 | |
82 | 104 | $initPauli |
83 | 105 | pauliSwitch=2 ! 1=dynamic, 2=analytic |
84 | 106 | $end |
85 | | |
| 107 | }}} |
| 108 | As for the density above we select the option that Pauli Blocking is based on a analytic description contrary to actual phase space densities of testparticles. |
| 109 | {{{ |
86 | 110 | $propagation |
87 | 111 | coulomb=.false. ! Whether to use coulomb in propagation |
… |
… |
|
117 | 141 | use_cutoff=.true. |
118 | 142 | $end |
119 | | |
| 143 | }}} |
| 144 | All definitions above are given in the context that we switch off potentials in these calculations. Has been tested to be a good approximation for the energies covered by this jobcard: several GeV upto tens of GeV. |
| 145 | {{{ |
120 | 146 | |
121 | 147 | !************************************************************ |
… |
… |
|
138 | 164 | ! target_Z= 82, target_A=208 ! Pb |
139 | 165 | $end |
| 166 | }}} |
| 167 | Here we provide a (not complete) list of possible target nuclei. Above A=12 all (A,Z) combinations are possible. The first line indicates the possibility to switch on/off Fermi motion of the nucleons. (In the case of A<2 this is a necessary option.) |
| 168 | {{{ |
140 | 169 | |
141 | 170 | !************************************************************ |
142 | 171 | |
143 | 172 | $HiPionNucleus ! EVENTTYPE = 12 |
| 173 | }}} |
| 174 | Here we start the namelist directly connected with the event type we selected at the very top: High energetic pions/protons on a nucleus. This steers the initialization of the testparticles. |
| 175 | {{{ |
144 | 176 | distance=10. ! distance of pions to nucleus |
| 177 | }}} |
| 178 | All projectile testparticles are initialized 10 fm apart from the nucleus in (negative) beam direction. |
| 179 | {{{ |
145 | 180 | impact_parameter=-99 ! impact-parameter<0: impact-parameter integration |
| 181 | }}} |
| 182 | This selects the impact parameter. A negative value indicates, that we average over all impact parameters; the beam test particles are initialized in a disk around the beam direction. |
| 183 | {{{ |
146 | 184 | DoProton=.TRUE. |
| 185 | }}} |
| 186 | Since historically this kind of init was for ''pions'' on nuclei, this flag tells the code that the "pion" is indeed a nucleon. |
| 187 | {{{ |
147 | 188 | charge=1 ! charge of pions |
| 189 | }}} |
| 190 | This selects the charge of the beam particle (being a pion or a proton, as selected above). |
| 191 | {{{ |
148 | 192 | numberPions= 25 ! number of pions per ensemble |
| 193 | }}} |
| 194 | For every real pion we initialize 25 testparticles. |
| 195 | {{{ |
149 | 196 | |
150 | 197 | ! ekin_lab=515. ! kinetic energy in system where nucleus rests |
151 | 198 | |
152 | 199 | ! ekin_lab = 2.205 ! p= 3GeV |
153 | | ! ekin_lab = 4.149 ! p= 5GeV |
| 200 | ekin_lab = 4.149 ! p= 5GeV |
154 | 201 | ! ekin_lab = 7.117 ! p= 8GeV |
155 | 202 | ! ekin_lab =11.099 ! p=12GeV |
156 | | ekin_lab = 30.000 ! T2K |
| 203 | |
| 204 | |
| 205 | }}} |
| 206 | This gives a selection of beam energies (e.g. 3,5,8,12 GeV beam momentum for HARP) |
| 207 | {{{ |
157 | 208 | |
158 | 209 | |
159 | 210 | doPerturbativeInit=.TRUE. ! Do perturbative init |
| 211 | }}} |
| 212 | In this special initialization type ("HiPion") we have the possibility to not only initialize the beam (test)particles (pions or nucleons) in some distance from the nucleus, which then have to propagate in every time step towards the nucleus until they first interact with some specific nucleon, but also run this in some "fast motion" mode and to hit the beam particle already to this nucleon. This means, we first start at time 0 with a bunch of beam particles at some distance, then also at time 0 hit a selected nucleon, and also at time 0, the beam test particles are replaced by the particles produced in this interaction. |
| 213 | {{{ |
160 | 214 | DoOnlyOne = .TRUE. |
| 215 | }}} |
| 216 | For some processes the cross section has been proven to follow a A^1^ dependence, instead of A^2/3^ as given by this transport approach. Setting the above flag to .false. attends for this possibility by allowing the beam particle to interact with many nucleons in beam direction. |
| 217 | {{{ |
161 | 218 | minimumMomentum=0.1 ! minimum momentum for particles to propagate |
| 219 | }}} |
| 220 | Particles with momenta smaller the given value are simply erased from the particle vector in order to speed up the calculation. |
| 221 | {{{ |
162 | 222 | $end |
163 | 223 | |
… |
… |
|
176 | 236 | ! threeBodyProcesses=.false. |
177 | 237 | $end |
| 238 | }}} |
| 239 | In this namelist one has the possibility to switch on/off particle decays, 2-Body collisions and 3-Body collisions in the propagation. The chosen values here represent a sensible choice for these kind of processes. |
| 240 | {{{ |
178 | 241 | |
179 | 242 | $insertion |
180 | 243 | minimumEnergy=0.100 ! minimal kinetic energy of produced nucleons (GeV) |
181 | 244 | $end |
| 245 | }}} |
| 246 | Here we decide, that protons and neutrons coming as outgoing particle from some collision during the propagation are erased from the particle vector, if their momenta are below 100 MeV. This is one very essential speed up of the calculations, not changing particle spectra above some hundreds of MeV in energy or momentum. |
| 247 | {{{ |
182 | 248 | |
183 | 249 | $master_2Body |
184 | 250 | correctEnergy_message=.false. |
185 | 251 | $end |
186 | | |
| 252 | }}} |
| 253 | Reducing the verbosity. |
| 254 | {{{ |
187 | 255 | |
188 | 256 | !************************************************************ |
… |
… |
|
192 | 260 | temperatureSwitch=1 ! 1=groundstate calculations (T=0,mu=E_F) |
193 | 261 | $end |
194 | | |
| 262 | }}} |
| 263 | Setting a default (do not touch). |
| 264 | {{{ |
195 | 265 | |
196 | 266 | !************************************************************ |
… |
… |
|
203 | 273 | |
204 | 274 | }}} |
| 275 | Here one sets steering parameters for the included PYTHIA implementation. Many of the common block parameters there are tunable here. We refer to the Pythia manual for the description of all of this bunch. |
| 276 | |
| 277 | The above parameters select the value of intrinsic transverse momentum, and while compiled against a Pythia version 6.4 switches the handling of the collisions to the most recent behavior. |
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