user guide
Contents
1. 29 p p p p fo gt p p K K 3 p p p p a p p K K 4 T p gt N gt n fo gt n K K 5 Changes from version 1 3 to 1 3p1 A bug in the tabulated decay width of higher resonances led to an overpopulation of a0 Mesons at SIS energies This bug is fixed in version 1 3 patchlevel 1 C Appendix Kknown problems and inconsistencies in Ur QMD Discrepancies to 12 GeV pp data pions at mid rapidity are too low Proton stopping not perfect Hyperon meson production in pp not in line with data Meson meson cross sections are very ugly and have discontinuities at the meltpoint to sighera cross section 1 7 GeV They should better be treated in a similar way as the meson baryons Parametrisation of Q production is unknown For the total cross sections we should use the Regge parametrisation instead of sighera It is more common and valid at higher energies Phase space must be considered when resonance masses are generated This is an argument of J rn Knoll GSI see also nucl th 9811099 He attacked the Giessen transport group for doing it wrong but some inconsistencies also remain in UrQMD The spline routine can cause discontinuities in the widths and cross sections The angdis fix meson baryon channel is still only an ad hoc fix Furthermore we need to improve angular distributions also for decays Coherent scattering may become important at high energies I e modifies energy distribution for the2. nsrt number of ys values from srtmin to srtmax for which events shall be calculated excita tion function pbeam momentum of the beam particle in case of nuclei it is the nucleon pmin minimal value for p 44 for excitation functions pmax maximal value for pzas for excitation functions npbin number of pay values from pmin to pmax for which events shall be calculated excitation function For single momenta energies the definitions ene elb ecm and plo are used for excitation func tions ENE ELG PLB PLG are needed The binning of the excitation function is linear for ENE and PLB and logarithmic for ELG and PLG In the case of an excitation function the number of events nev refers to the full excitation function i e the number of events per bin would be nev nsrt or nev npbin respectively Only one of the above seven definitions is needed The priority of definition increases from ene and ENE to PLG Make sure to only use one of the above commands for the beam energy in order to avoid ambiguities in the input file define impact parameter imp bmax IMP bmin bmax bmin minimum impact parameter 0 for imp and CTOpt ion 5 0 bmax maximum impact parameter In case of imp the value of bmin is automatically set to 0 0 Two different methods of weighting the impact parameter distribution are accesible via CTOpt ion 5 A minimum bias calculation can be performed for bmin 0 bmax gt Rp RH and CTOption 5 0 In ca
3. xxx string O a e Eh e string should contain at least one blank xxx marks the end of the input file define projectile pro Ap Zp PRO ityp iso3 Ap mass of projectile Zp charge of projectile Instead of defining an ordinary nucleus with pro one can also define a special non composite projectile with PRO ityp ID of projectile see tables 2 and 3 for available itypes iso3 2 Isosping of particle define target tar Ap Zp TAR ityp iso3 Ap mass of target Zp charge of target Instead of defining an ordinary nucleus with tar one can also define a special non composite target with TAR ityp ID of target see tables 2 and 3 for available itypes iso3 2 Isosping of particle define number of events nev nevents nevents number of events to calculate define calculation time tim tottime outtime tottime total time span in fm c to calculate outtime time interval in fm c after which output is written to files 13 and 14 define incident beam energy ebeam ebeam srtmin srtmin srtmax nsrt srtmin srtmax nsri pbeam pmin pmax npbin pmin pmax npbin ebeam kinetic energy of the beam particle in case of nuclei it is the nucleon in the laboratory frame srtmin minimal value for ys between projectile and target particles in case of nuclei it is the nucleon srtmax maximal value for 4 s between projectile and target particles in case of nuclei it is the nucleon
4. The Ur QMD x user guide March 24 2004 Warning This document is updated regularly In its current form it describes the handling of UrQMD revision 1 3 If you are using a newer version of UrQMD please contact one of the authors in order to obtain the latest version of this document The authors give no warranty to the correct functioning of the UrQMDprogram Use this program at your own risk Please send all bug reports to the following e mail address urgmd th physik uni frankfurt de Contents 1 General Information 2 Copyright 3 Compiling and running the program 4 Theinput file 4 1 Input Parameters vos heo e ope x AR m IR IEA REIR I 5 Output files 5 1 Standard output files filel3 flel4 les 5 2 Collision history Mle el So uo vow PONG EN ee Sed ewe eoe eei 5 3 Decay output Tele lt s 1254 oes obi dae ERE oe okie ser te Eu hrs 5 4 OSC1997A output OSCAR 1997A format filel9 5 5 OSCI1999A output OSCAR 1999A format file20 A Appendix Changes from version 1 0 1 1 to 1 2 B Appendix Changes from version 1 2 to 1 3 C Appendix Kknown problems and inconsistencies in Ur QMD 17 17 17 19 21 23 26 29 30 List of Figures ANM RW DD Ke running the UrQMD program 2 ao de mox x a a ee ee 2 sample input file for UrQMD 2200 eee eee a 3 sample header of an UrQMDoutputfile ee ee 22 beginning of a sample bod
5. deltat timeinterval in fm c for the update of potentials and a full particle scan for the collision arrays In the CASCADE mode a regular full particle scan for the collision arrays is not necessary therefore this command should be only used in calculations including potentials infinite matter calculations or for debug purposes suppress output files The output to the respective files is omitted if the above command is used set particles stable stb ityp typ ID of particle see tables 2 and 3 for available itypes H Treat all particles with this ID as stable particles set special parameter ctp index value index index of CTParam array value value for CTParam index see tables 4 and 5 for available parameters set special option cto index value index index of CTOption array value value for CTOption index see table 6 for available options 2 3 A 5 6 7 8 9 Ra a e e 2 x QN UA A WN KF O Table 2 Baryon ID s used in UrQMD A particle is fully defined when its ityp and 2 73 are known Antibaryons carry a negative sign ID 1 Table 3 Meson ID s in UrQMD sorted with respect to spin and parity included into the UrQMD model Mesons with strangeness 1 carry a negative sign 10 Ciara 1 d0 scaling factor for resonance widths 0 52d0 minimal stringmass and el inel cut inmakestr 2 0d0 velocity exponent for modified AQM 0 3d0 transverse pion mass u
6. mass char 32 L6 transformation betas NN lab pro 0000000 7183285 7183285 impact parameter real min max fm 00 00 00 total cross section mbarn 00 equation of state 0 E lab GeV u 2000E 01 sqrt s GeV 2697E 01 p lab GeV u 2784E 01 eventi 1 random seed 1944955121 fixed total time fm c 60 Delta t O fm c 60 0 op 0 0 0 0 0 0 0 0 0 0 0 0 0 0 op 0 0 0 0 0 0 1 0 1 0 0 0 0 1 op 0 0 0 1 1 0 0 0 0 0 0 0 0 0 pa 1000E 01 5200E 00 5000E 00 3000E 00 0000E 00 3700E 00 0000E 00 9300E 01 3500E 00 2500E 00 0000E 00 5000E 00 pa 2700E 00 4900E 00 2700E 00 1000E 01 1600E 01 8500E 00 1550E 01 0000E 00 0000E 00 0000E 00 0000E 00 0000E 00 pa 9000E 00 5000E 02 1000E 01 1000E 01 4000E 00 1500E 01 1600E 01 0000E 00 2500E 01 1000E 00 3000E 01 2750E 00 pa 4200E 00 1080E 01 8000E 00 5000E 00 0000E 00 5500E 00 5000E 01 8000E 00 5000E 00 8000E 06 1000E 01 2000E 01 pvec r0 rx ry rz po px py pz m ityp 2i3 chg lcl start of event body Figure 3 sample header of an UrQMDoutput file 83 60 248 105 141 2 78 165 0 0 60000000E 02 35597252E 02 76801184E 01 30121505E 01 11839331E 01 70109432E 00 16633296E 00 51512840E 01 93800002E 00 l cab 60000000E 02 81996126E 01 19904670E 02 24104662E 02 11707300E 01 14606801E 00 47854791E 00 49032721E 00 93800002E 00 1 1 0 60000000E 02 54067910E 01 30092770E 02 35340946E 02 15291829E 01 14462310E 00 74024320E 00 94322867E 00 93800
7. M Bleicher E Zabrodin C Spieles S A Bass C Ernst S Soff H Weber H St cker and W Greiner J Phys G25 1999 1859 1896 2 Copyright UrOMD source and documentation are provided freely for the purpose of checking and reproducing published results of the authors The Open Standard Codes and Routines OSCAR Group has established for good reasons guide lines for reproducablity usage and quality control of simlulations codes for pA and AA collsions UrOMD is a complex model In order to ensure that it is used correctly that all results are repro ducible and that the proper credits are given we ask for your agreement to the following copyright and safeguard mechanisms in the OSCAR spirit The UrQMD collaboration favors cooperation and joint projects with outside researchers We encour age experimental collaborations to compare their results to UrQMD We support you and or cooperate on any sensible project related to UrQMD If you are interested in a project please contact us Projects without the participation of the UrQMD Collaboration are accepted if the project is not a current thesis topic of any UrQMD Collaboration member We expect that the code authors are informed about any changes and modifications made to the code Any changes to the official version must be documented The code or any fragments of it shall not be given away to third parties Similarily events generated with UrQMD shall not be given to third p
8. i e a serial number the particle gets at creation and which is retired from the event after the particle undergoes an interaction This ID is supposed to make the tracing of a particle through the collision file easier since it does not change dynamically as our particle slots numbers do due to the internal UrQMD memory management Most file modifi cations are due to the introduction of this new uid array As usual all output statements are found in output f Heavy quark clusters A mechanism to cluster strange quarks into di quarks is introduced This can explain the strangeness enhancement at SPS It can be switched on with CTOpt ion 37 1 Bug fi xes and improvements e In GNUmakefile there is a small modification for the code to run on Alpha machines e Complete rewrite of gnuranf gnuranf is now the default for Linux e A new angular distribution in the meson baryon channel is used Le isotropic resonance de cays below an inv mass of 6 GeV and a forward backward behavior above angdis f for collisions with sroot larger than 6 GeV zero degree scattering is enforced only deflection from string decay e A sign error in angdis f has been corrected This error led to a wrong symmetry in meson baryon collisions only visible when running UrQMD for elementary hadron hadron collisions e New environment variable UROMD TAB to find tables dat think of export URQMD_TAB tables uname e Higher meltpoint for resonant
9. 0 disabled b PF a Jo reference trame Tor clean N N equal speed frame target lab frame NS projectile frame ST CC isotropic isotropic baryon goes into forward hemisphere baryon goes into forward hemisphere p 0 o fi frowen Fermi approximation in CASCADE mode disabled fs 2 0 siria resonance masses according to mass dep Breit Wigner 0 enabled 1 disabled 15 NO Qj r2a lt2 c Ea CTOption X default description use table use table lookup for calculation of poms inpmean for use table lookup for calculation of poms inpmean of poms in pmean enabled i T l T M T a DPF formalism 5 i generate highavecision ables le tables dat disabled 2 36 o cores normalization or mas dependen Breit Wigner distributions 0 enabled E e EE Tea Quark Chee SSCS 0 disabled CO RENE a o see phar bbar with equal pub 0 disabled PE O EA o 0 compuso colision densities via callto Pauliblocker 0 enabled E a EE La 0 Tuse oldie as nial ate or calculation 0 disabled 22 ai 0 extended ela ouput needed forsto C0 0 disabled 1 enabled Ma different counting rules for origin p 0 color fuctatons in high energy hadron hadron collisions 0 disabled 1 enabled Table 6 available ptions in UrQMD of ji eh Cle 5 Output files The UrQMD program has several different output files The standard output files 11e13 and filel4 con
10. charge of projectile and tar get the reference frame of the calculation the incident beam energy and the number of test particles used per nucleon OSCAR further recommends that additional information be provided in subsequent comment lines e g Initial Condition Au Au 200 GeV c Cascade Time Ordering Center of Mass additional parameters supplied for the run The remaining file after the comments contains the full history of each event in blocks of data Each block describes one interaction and has the following format block header one line particle list one or more lines 23 vc OSC1997A final_id_p_x UrQMD NOP WN EF FP 14 0 83 2212 ATETZ 2212 2212 2212 2212 32 16 4 32 16 eqsp 2000E 01 1 000 000 701094E 00 166333E 00 515128E 01 118393E 146068E 00 478548E 00 490327E 00 117073E 144623E 00 740243E 00 943229E 00 152918E 471067E 02 606154E 01 224088E 00 966311E 225070E 01 148103E 01 231440E 00 966506E 241272E 00 159999E 00 574162E 00 113724E Figure 6 Sample output in the OSC1997A format 01 01 01 00 00 01 938000 938000 9380001 938000 938000 9380001 EL G Ed EJ El El FOO FOO FOO FOO FOO FOO 24399 97 31 8199611 540679 729536 8663361 1261231 E pump p E E 02 01 01 00 00 02 The block header contains nin nout
11. different binary collisions see Nexus K Werner Perturbative QCD effects need to be included from RHIC energies on This enhances particle production at RHIC energies by at least 15 Detailed balance is violated due to string decays and other multi particle n gt 3 decays e g w gt 3r for which no inverse reactions are implemented The frame dependence of the code target vs projectile vs CMS frame leads to asymmetric distributions and different yields in forward backward hemispheres at RHIC 30
12. gz amp Figure 1 running the UrQMD program 4 The input file Figure 2 shows a typical input file for UrQMD The general format of the inputfile is 143 1A77 This means that every input line consists of two sections First a three character flag followed by a 77 character string the contents of which varies according to the flag specified this is a sample input file for uqmd projectile Ap Zp pro 197 79 optional special projectile ityp iso3 PRO 101 2 target At Zt tar 197 79 number of events nev 1 time to propagate and output time interval in fm c tim 40 40 incident beam energy in AGeV ene 10 7 imp 3 0 equation of state eos 0 CASCADE mode some options and parameters cto 4 1 output of initialization ctp 1 1 d0 scaling for decay width of Resonances f15 no output to filel5 f end of file XXX Figure 2 sample input file for UrOMD The input file does not have a predefined sequence However it is mandatory that the input contains definitions for projectile target impact parameter and incident beam energy Table 1 shows a quick summary of all possible flags with their respective parameters comment line last line of input file Ap Zp define projectile ityp 1303 define special projectile TAE define target ityp iso3 define special target nevents number of events to calculate tottime outtime define time of calculat
13. meson absorption on baryons only eta rho omega and all hy peron channels 26 LC OSC1999A full event history 4 UrQMD 1 2 4 2 4 0 8 I 2212 2 2212 3 2112 4 2112 5 2212 6 2212 7 2112 8 2112 2 4 4 2412 5 2212 9 2114 10 2212 deL 3112 12 3114 2 2 14 2112 7 2112 18 2112 19 2112 1 2 26 1212 32 2214 33 211 26 0 39 2112 28 2212 35 2112 46 2112 21 2212 29 2212 0 0 1 15 19 20 2 nncm 0 200 0 O O O GOG OOG TMA O O OGO G O O ooo JJ OOOO UW O O OOOO 0 5000E 0 0 00 5212961 723310 596589 6480171 442186l 3859911 489669 1317841 0 118 648017E 442186 oooo 376577 311133 235318 280179 0 290 425527 489669 845839 999780 14257 163056 352471 189415 207591 362984 130921 321851 234665 746550 E pd Bd Ed Dd E Ej Ej Hd fd O Ej E o Ed Di Dd D Dd Dd F P P P P F P Pu F Bi F Pu 0 01 01 01 01 01 01 01 00 9420 01 01 00 00 00 00 9240 01 01 02 01 1687 00 00 00 00 00 00 744360E ooo 714333E E 01 0 3 0 0 0 oo E 01 0 E 01 0 525298E 239309E 202471E 180513E 383077E 150743E 744360E 180513E 473402 221868 485507 112439 836121 150743 167264 265951 E Dd d d w 115806 203853 954203 He HO 539088 210145 811300 147599 39853
14. 002E 00 lo lo X 37 60000000E 02 72953637E 00 35051235E 01 14941324E 02 96631053E 00 47106723E 02 60615381E 01 22408834E 00 93800002E 00 1 1 1 13 Figure 4 beginning of a sample body of an UrQMDstandard output file 2 2 X 1 398 2650E 01 4565E 02 1834E 02 1742E 01 3l 39812730E 00 10071119E 01 11882873E 01 10408219E 00 13016664E 01 64792705E 01 13898806E 01 91198600E 00 92640464E 00 1 1 0 64 39812730E 00 28051872E 00 15413296E 01 10408219E 00 13490995E 01 11074780E 00 15481079E 01 97761791E 00 92294520E 00 1 1 0 Sd 39812730E 00 10071119E 01 11882873E 01 10408219E 00 15827584E 01 15319538E 00 62127758E 01 53196784E 00 14814876E 01 17 3 1 64 39812730E 00 28051872E 00 15413296E 01 10408219E 00 10680074E 01 19915048E 00 60545484E 01 46633592E 00 93800002E 00 IM T 2 2 5 2 143 2791E 01 4448E 02 8529E 00 1857E 01 25 74262809E 00 11192341E 01 13384231E 01 25707630E 01 14261601E 01 32413590E 01 82195855E 01 10840402E 01 92248724E 00 1 1 0 50 74262809E 00 97716182E 00 18394695E 01 25707630E 01 13692160E 01 13287008E 01 56741371E 01 10054827E 01 92755640E 00 Pet p 25 74262809E 00 11192341E 01 13384231E 01 25707630E 01 14831149E 01 14886580E 00 27346802E 00 36638117E 00 14030142E 01 2 Ii 0 50 74262809E 00 97716182E 00 18394695E 01 25707630E 01 13122612E 01 12973922E 00 13453079E 00 44493867E 00 12202985E 01 F 0 1 2 20 4 858 1481E 01 0000E 00 1718
15. 13 14 14 a12 a13 14 14 a1l t a36 3 10 7 t a36 3f6 2 a31 11f9 2 t a20 i13 a15 e10 4 a15 e10 4 a15 e610 4 a7 19 al 112 a9 a20 14 a20 f 7 3 5 13 a2 1 2 3 4 5 6 7 8 9 N Uo K Table 7 format for the standard event header contents of collisions of elastic collisions of inelastic collisions it of Pauli blocked collisions of decays of produced hard baryon resonances of produced soft baryon resonances of baryon resonances produced via a decay of another resonance Table 8 description of the collision decay counters in the standard output file 18 format 289 15 213 4 6 15 34 standard 11e14 and filel6 8 15 213 16 15 110 3e16 8 18 filel4 with CTOption 41 1 8 15 213 16 15 14 8el6 8 standard 11e13 TADO 2135 467 19 TA PTA filel6 with CTOption 13 format format format 9e 9e 2e 9e t t format Table 9 particle vector format for different output options in the standard output files The event header consists of a single line of the format format 11 18 14 17 8 3 4e12 4 The format is identical to the header line for the respective binary interactions and decays which follow in the the file In order to distinguish the beginning of an event from the beginning of a collision decay entry the first integer in the even
16. 5 257338 Ej mb on Dd eae E pd Dd Ed DH EH MEI 405082E 01 517619E 01 544394E 01 487618E 01 437103E 01 431142E 01 557163E 01 532665E 01 E 02 0 2506E 02 840 0 0 0 0 487618E 01 437103E 01 223060E 01 318752E 01 890289E 00 571773E 00 E 02 0 7584E 01 01 01 00 00 0001 0 0 366816E 01 557163E 01 366215E 01 556562E 01 E 00 0 5665 265 00 CC c 522476E 01 320625E 01 201851E 01 306519E 01 446340E 01 324282E 01 166698E 01 210678E 00 701843E 00 Figure 7 Sample output in the OSC1999A format D O O wT O O GO G D OT ES OOO O ooo DO O O OO 415387 525948 552250 496485 446873 441015 564798 540741 0 1508 496485 446873 261298 334457 158258 189345 0 1680 378736 564798 378408 565126 0 7609 549408 345977 203431 Ej Ed D Hd Dd Dd Fd pd eee a Dd d d EUM GE NETUS E Ed Dd Dd EH ji dapes e yug Ed Ed Ej Ed gs iE tem BEBEL Lu 321267E4 458015E4 337927E4 194526E4 106683E4 141279E4 O GCG OTO G OOGO CEO OWT G oooo ooo OQO OGOGO O 916548E 929208E 926260E 928902E 928092E 926336E 924068E 918942E 928902E 928092E 121909E 938000E 119200E 138400E 938000E 924068E 938000E 938000E 168722E 125111E 138000E 938000E 938000E 938000E 938000E 938000E 938000E L
17. E 02 1928E 01 31 85784130E 00 96261609E 00 12063324E 01 50428488E 01 15827584E 01 15319538E 00 62127758E 01 53196784E 00 14814876E 01 iy 3 L 31 85784130E 00 96261609E 00 12063324E 01 50428488E 01 11582730E 01 45590325E 00 19299762E 00 46546376E 00 93800002E 00 1 1 0 65 85784130E 00 96261609E 00 12063324E 01 50428488E 01 42448534E 00 30270787E 00 25512538E 00 66504080E 01 13800000E 00 101 2 1 Figure 5 excerpts of a sample body of an UrQMI Dcollision history file ncl or 64 31 50 25 64 31 31 20 20 30 I9 HR oOo ereo NB oooo ooo cue and contains first the model name and version followed by mass and charge of projectile and target the reference frame of the calculation the incident beam energy and the number of test particles used per nucleon The event header consists of one line with the format format 110 2x 110 2x f8 3 2x 1f8 3 This line lists the number of the event the number of particles in the event the impact parameter and an azimuthal angle with which the event plane might be rotated with respect to the xz plane The subsequent particle entries of the event body have the format format 110 2x 110 2x 9 e12 6 2x and contain first the particle number its ID then the four momentum vector of the particle Pz Dy Pz E followed by the mass of the particle and finally its freeze out location f yr Zf Tf The particle ID is given according to
18. arties without consent of the code authors 3 Compiling and running the program To compile UrQMD one needs a FORTRAN77 compiler and GNU make The GNU make programm is available on ftp gnu org note on many UNIX systems GNU make is called gmake Compi lation is initiated by issuing the make command at the command prompt in the Ur OMD subdirectory After successful compilation the binary has the name urqmd TYPE where TYPE is the machine type as given by the uname command In order to run UrQMD one needs to define the running parameters with an input file The input file is made accessible to UrQMD by attaching its name has to be to the environment variable ft n09 The output files are attached in the same fashion via the environment variables ftn14 and ftn15 Figure 1 shows how Ur QMD is started on a generic UNIX system here AIX using the Korn Shell Ur UN NY Ur NY UY Ur Ur expor j tfile expor 13 tfilewith freezeout expor 1 tfile expor isionfile export 1 tfile_with_decaying_resonances export 1 tfile for OSCAR97 export tfile for OSCAR99 urqmd AI or if you want to compress your files on line S urqmd AIX export ftn09 inputfile mknod outputfile p mknod collisionfile p export ftnl4 outputfile t ftnl5 2collisionfile Cal Cal outputfile gzip gt outputfile gz amp collisionfile gzip collisionfile
19. by the respective particle vectors in the body of the block OSCAR recommends optional information for the event header to include the event number impact parameter and azimuthal angle orientation of that event Thus the header of the first event block is very similar to the OSC1997A format format 3 17 2x 2 8 3 2x listing a zero the number of initial particles the number of the event the impact parameter and an azimuthal angle with which the event plane might be rotated with respect to the xz plane The very last block of each event describes the final freezeout configuration of all particles Here the header comes with nin as the number of final particles and nout 0 25 Figure 7 shows a sample output in the OSC1999A format A Appendix Changes from version 1 0 1 1 to 1 2 New OSCAR output The OSC1999A OSCAR intermediate file output format has been added Caution to remain con sistent with our input file convention you have to insert 20 into your urqmd inputfile in order not to get any file20 output If you forget this you will get a fort 20 which will surely explode your quota since the output on this file is huge This format is similar to our collision file output format but adheres to the new OSCAR OSC1999A output convention Output is written to Fortran unit 20 New features include particle ID according to the PDG Monte Carlo ID scheme and a new global quantum number uid stands for Unique Particle ID
20. c 11e13 only T5 f freeze out x coordinate in fm fi1e13 only Ty fr freeze out y coordinate in fm fi1e13 only T fr freeze out z coordinate in fm 116e13 only E fr freeze out energy of particle in GeV fi1e13 only Pz fr freeze out x momentum component in GeV file Py fr freeze out y momentum component in GeV file Pz fr freeze out z momentum component in GeV filel Tdec decay time of particle file14 with CTOpt ion 41 1 Tform formation time of particle 11e14 with CTOption 41 1 R cross section reduction factor 11e14 with CTOption 41 1 unique particle number not ID ile14 with CTOption 41 1 ityPoid 1 particle ID of parent particle 1 11e16 with CTOption 1 ityPoid 2 particle ID of parent particle 2 11e16 with CTOption 1 Table 10 contents of the particle vector in the standard output files 20 ind index of particle t eigentime of particle in fm c T4 X coordinate in fm Ty y coordinate in fm T Z coordinate in fm E energy of particle in GeV p X momentum component in GeV Py y momentum component in GeV 1 2 3 4 5 6 7 8 9 Pz z momentum component in GeV m mass of particle in GeV oS ityp particle ID N 2 3 isospin z projection doubled Uo ch charge of particle K index of last collision partner Nn Neco number of collisio
21. der of the decay output file is identical to that of the standard output files see figure 3 and table 7 The body of the decay file contains entries for each particle which has decayed during the event as well as a list of all stable particles after the final timestep of the event Since the number of decays and particles listed in the event body is not determined at the point where the first output is written to file the event body directly starts with particle vector entries see tables 9 and 10 The end of the event is marked with a line of the format format a1 818 which contains an E as a marker in the first column followed by the collision counters listed in table 8 For CTOption 13 1 all outgoing particles of all collisions and decays are listed instead of the decaying particles alone The decay output file provides additional information about the produced 19 t eigentime of particle in fm c T X coordinate in fm ry y coordinate in fm T Z coordinate in fm E energy of particle in GeV Px X momentum component in GeV Py y nomentum component in GeV Pz z momentum component in GeV VD o00 10 g RA WN Mm m mass of particle in GeV ityp particle ID pui ye O 2 3 isospin z projection doubled N ch charge of particle o index of last collision partner K Necou number of collisions Nn history information parent process tfr freeze out time of particle in fm
22. generators indicating the status of the particular entry The optional information can be anything useful or relevant to the particular model but has to fit into the same output line Thus each par ticle entry line contains first the particle number its ID the 2nd ID tag then the four momentum vector of the particle Pz Py Pz E followed by the mass of the particle all in GeV and finally its production vertex x y z T in fm and fm c The minimal format for this line is format 3 110 2x 9 612 6 2x It should be noted that the particle number ipart is a unique particle identifier not equivalent to the memory slot information used in OSC1997A which is created for a particle at its production point and is retired for the duration of the event at the destruction scattering vertex of the respective particle It thus can be used to track trajectories of particles in the course of the reaction The particle ID is given according to the definitions of the Review of Particle Properties Monte Carlo naming scheme Composite clusters nuclei are marked with 7AAAZZZ AAA mass ZZZ charge of cluster If other objects than nuclei are used as projectile or target then a 1 is listed in the mass slot followed by the PDG ID in the charge slot The very first block of each event describes the initial distribution of the nucleons partons or other species In this case the header contains nin 0 and nout is the number of initial particles followed
23. he number of particles Npart to follow there are as many lines to follow as there are particles and the time in fm c of the output two un formatted integers The next line contains counters for the number of collisions decays and produced resonances per event format 818 it is described in table 8 The subsequent Npart lines then contain the information on the individual particles The exact format of the particle vector depends on the chosen output file and the selected options Table 9 lists the different possibilities Figure 4 shows the beginning of a sample event body for file14 The standard output files should suffice for most types of analysis They provide the event information at a given timestep mostly the final timestep The contents of the particle vectors is described in table 10 All reference frame dependent values are given in the computational frame which has been fixed by CTOption 27 5 2 Collision history file file15 The collision file 11e15 contains each binary interaction resonance decay and string excitation which occurred in the course of the heavy ion reaction It can be used to reconstruct the entire space time evolution of the event Each entry collision decay or annihilation consists of a header line followed by 3 to N lines three lines for annihilations decays four lines for scattering more lines for string decays with the individual particle information 17 mat a20 317 a15 12 t a13 a
24. ic cross sections 0 enable table lookup O JE rre A Pauli Pauli blocker enable Pauli blocker disable Pauli blocker 13 CTOption X default description m o mass reduction binding energy in CASCADE mode 0 enable mass reduction according to binding energy ENIM EN m fo ring production SS 0 enable string production a eee P30 erene 0 disabled ae REN ig o angular disdain in binary sanering 0 enable angular distribution a a disable distribution cos 0 1 forward peak Hs 0 mesonmesonand meson bayjonsatering 0 enable MM and MB scattering a NM disable MM and MB scattering ie Jo molecular dynamics switch 0 enable collision term Le ere 7 o _ collsion ubie update mode 0 update only collision partners after interaction reer s 0 decay of unstable particles arend ofevent 0 perform decay after final timestep Do E een ms o BBawWhim O O 0 enabled A fis o Jo ee aninion instead of BB annihilation 0 disabled normal BB mode 1 enabled ete mode 14 CTOption X default description options E a string fragmentation function field Feynman fragmentation function Lund fragmentation function QGSM fragmentation function 1 simple 1 M excitation 1 FRITIOF ansatz 2 QGSM ansatz 5 o Lorenz contacto of projectile adag 0 enabled E RR 0 hard sphere used for EOS0 1 Woods Saxon used for CASCASE mode a o T prase space correction tor resonance masses
25. ion and output ebeam incident kinetic beam energy lab frame ebeam incident kinetic beam energy lab frame pbeam incident beam momentum lab frame pmin pmax npbin incident min max beam momentum for excitation function pmin pmax npbin like PLB log weighted srt v s for two particle collision srtmin srtmax nsrt incident min max 4 s for excitation function srtmin srtmax nsrt incident min max 4 5 for excitation function log weighted bmax define impact parameter bmin 0 bmin bmax define impact parameter Eos define equation of state dim edens solid para define box for infinite matter calculation ityp iso3 npart pmax define particle population for box mode ityp iso3 npart like bpt for given energy density seed seed for random number generator ityp keep particle stable deltat At between full collision load suppress output to unit 13 suppress output to unit 14 suppress output to unit 15 suppress output to unit 16 suppress output to unit 19 suppress output to unit 20 index val set optional parameter in CTParam array index val set option in CTOption array Table 1 possible flags in the input file with their respective arguments 4 4 1 Input Parameters In this section all input labels with their respective arguments are explained A complete sample input file can be seen in figure 2 e S B e a string string can be used to insert comments into the input file
26. ns nN S strangeness N history information parent process Table 11 contents of the particle vector in the collision file baryon and meson resonances when compared to the standard output file Since it contains particle output at different times during the event however one has to be very careful when extracting cross sections All reference frame dependent values are given in the computational frame which has been set by CTOption 27 5 4 OSC1997A output OSCAR 1997A format file19 The OSC output format has been defined by the OSCAR group in order to create a well defined easily accessible output format which is supported by all OSCAR compliant transport models event genera tors and other heavy ion related models For a full overview of the goals of the OSCAR collaboration please consult the web site http rhic phys columbia edu oscar index html UrQMD supports the OSC1997A output format The file header consists of three lines The first two lines have the format format a12 and specify the format e g OSC1997A and the file contents Currently this is final_id_p_x ie the final event output including particle ID the momentum space information and the freeze out coordinates in configuration space The third line has the format format 2 a8 2x 13 210 13 1 6 2x 234 2x 6010 4 2x 18 21 CT UQMD version 10000 1000 10001 output_file 14 projectile mass char 32 16 target
27. o Gl Fl FI 1 FI E E El E El El JDB 0 Fl E El EE EE Cl Dp Fl FI E E FOO FOO FOO FOO FOO FOO FOO FOO FOO 00 01 FOO HO 1 01 00 FOO FOO FOO HO 1 HO 1 FOO FOO FOO FOO FOO FOO FOO O O GOOG OG GOG Bugfix in meson meson annihilation cross section string f subroutine ityp2id case of u quark anti u quark quark ids corrected from 2 and 2 to l and 1 string f subroutine gausspt comment with respect to the calculated distribution is cor rected make22 f sighera warning only active if new logical variable warn is true analogously defined as variables check and info in tt coms f As default the variable warn is set as false to avoid countless warnings coms f new logical variable warn nmax maximum number of particles increased from 5000 to 40000 input f Due to the enhancement of nmax in coms f a warning is added if calculations are performed for energies smaller than 200 A GeV Ej or pias or sroot smaller 20 A GeV parameter nmax in coms f may be decreased colltab f ncollmax maximum number of entries in collision table is increased from 5000 to 10000 28 B Appendix Changes from version 1 2 to 1 3 Initialization In UrQMD version 1 3 a new initialization method for cascade mode has been implemented The initialization method used in UrQMD 1 0 1 2 led to an increased nucleon density on the surface of the nucleus and a too small total collision cr
28. on of nuclei AB 1 0d0 Field Feynman fragmentation func parameter a prod part AB oo 2 0d0 Field Feynman fragmentation func parameter b prod part Table 4 Optional parameters used in UrQMD 11 CT Param enhancement factor for 07 mesons enhancement factor for 1 mesons enhancement factor for 0 mesons enhancement factor for 1 mesons enhancement factor for 27 mesons enhancement factor for 1 mesons enhancement factor for 1 mesons enhancement factor for 1 mesons scaling factor for DPF time delay Table 5 Optional parameters used in UrQMD 12 CTOption X default description options 1 mass dependent resonance decay widths disabled LN CNN 0 panicle sanering plane Do stochastic selection of y 1 2 conserve plane ETA 0 take finite resonance widths into account BER a o init configuration output to HTA 0 output according to t im statement O aen 5 0 impact parameter weighting 0 use bmax as fixed impact parameter 1 random b from bmin to bmax bdb weighted NS random 5 from bmin to bmax flat distribution e 0 ts colisins within tareeVprojectile 0 block first collisions within proj target eer RN HE Jo suppress elastic N N collisions 0 elastic collisions are allowed 1 no elastic NN collisions Cin Otot 8 fs mass dependent partial decay widths 0 enabled ENIM RN S fo tabulated prp inelast
29. optional information with nin and tt nout being integers denoting the number of ingoing and outgoing particles of that particular reac tion e g 2 2 for two particles scattering into two particles or 1 2 for a resonance decaying into two particles Optional information can be anything that fits on one line For example one could put g q gt g qto characterize the block as describing elastic quark gluon scattering Thus the min imum format for that line is format 2 i7 2x In UrQMD additional information is supplied analogously to the file15 output after nin and nout the ID of the respective process e g elastic scattering decay string excitation is listed followed by the number of the collision in the respec tive event the collision time in fm c the the total CM energy ys in GeV the total cross section cto in mbarn the partial cross section c in mbarn for the respective exit channel and finally the baryon density at the collision point in units of nuclear ground state density Note that the cross sections are ill defined in the case of a decay The next nin lines are incoming particles followed by nout lines of outgoing particles the format of these lines is ipart id ist px py pz pO mass x y z t optional information This format is identical to the particle entries of the OSC1997A format with two additions ist is an integer containing additional information related to the particle ID this is needed in some event
30. ossection For calculations with Skryme equation of state eos lt gt 1 the old initialization method is still the recommended one Caution Due to the new initialization method calculations made with UrQMD version 1 3 may give results deviating from the results published with earlier versions of UrQMD To reproduce old results you can set cto 24 0 to get the old initialization New Options New parameter ctp 21 allows the initialization of deformed nuclei The parameter 25 gives the deformation parameter default is 0 0 New option stb ityp prevents the decay of a particle type ityp Multiple definitions of stb in the input file are allowed Phasespace correction for upper mass limit of resonances This feature is important for correct dilepton spectra To enable this feature set cto 25 to 1 Default is 0 Alternate parametrisation of the p pbar annihilation crosssection You can switch with cto 38 For a detailed description of the two parametrizations see Phys Rev C66 054903 2002 New option cto 41 2 origin i modified elastic collisions no longer overwrite the production process Instead elastic collisions increment the 3rd digit of origin origin 100 A process with iline 27 and no color exchange is treated as an elastic collision New Channels To improve the description of Kaon production at low energies the following channels have been implemented p p p Et K 1 p p pc 3X K 2
31. se of negative values of bmax in the imp command a calculation from b 0 fm to b bmax fm with quadratic weighting CTOpt ion 5 1 is performed infinite matter box calculations box dim edens solid para bpt ityp iso3 npart pmax bpe ityp iso3 npart dim width of cubic box edens total energy content of box in GeV solid 1 reflecting walls 0 periodic boundary conditions para 0 standard 1 use old periodic boundary conditions ityp ID of species see tables 2 and 3 for available itypes iso3 2 Isosping of species npart number of particles for species pmax maximum momentum for fermi sphere in momentum space define equation of state EoS equation of state for the calculation Currently only CASCADE mode EoS 0 or a hard Skyrme equation of state EoS 1 are available The default mode is CASCADE the hard Skyrme equation of state is limited to incident beam energies below 4 0 GeV nucleon Important This option also changes the initialization mode see CTOpt ion 24 set random number generator seed seed integer seed for random number generator Depending on the computer system the omission of the rsd command or the value seed 0 cause the generation of an automated supposedly unique seed for each calculated event This feature is sofar only implemented for IBM RISC 6000 running AIX For all other systems the definition of a seed is mandatory set forces collision load update interval cdt deltat
32. sed in st rexct and make22 0 0d0 probability for quark rearrangement in cluster 0 37d0 strangeness probability inmakestr 0 d0 charm probability not yet implemented in Ur OM 0 093d0 probability to create a diquark 0 35d0 kinetic energy cut off for last string break O 00 10 tA FW NY 0 25d0 min kinetic energy for hadron in string 0 0d0 percentage of non groundstate resonances in string N 0 d0 deformation parameter 0 9d0 probability for diquark not to break 1 d0 scaling factor for transverse fermi motion N N WN WO 00 tA 0 4d0 strange di quark suppression factor o2 1 5d0 radius offset for initialization U 1 6d0 o of Gaussian for transverse momentum transfer o N 0 d0 a 1 for valence quark distribution Oo Oo 2 5d0 B for valence quark distribution W R 0 1d0 minimal z multiplied with E m 3 0d0 offset for cut for the FSM 0 275d0 fragmentation function parameter a nucleons UD W WwW NNN 0 42d0 fragmentation function parameter b nucleons o2 oo 1 08d0 diquark p scaling factor U O 0 8d0 strange quark p scaling factor AB 0 5d0 Bs 1 for valence quark distribution A 0 d0 distance between nuclei at initialization EN N 0 55d0 width of Gaussian for p distribution in string fragmentation h W 5 0d0 maximum kinetic energy in mesonic cluster AB nN 8 0d5 maximum number of rejections during initializati
33. t header is a 0 It is then followed by the number of the event the mass of projectile and target the impact parameter the two particle c m energy of the heavy ion reaction i e s for proton proton reactions the total cross section of the heavy ion reaction and the beam energy and momentum per particle in the laboratory frame Figure 5 shows a sample collision entry The header line contains first the number of in and outgoing particles scattering 2 2 decay 1 2 annihilation 2 1 Pauli blocked collision 2 0 Pauli blocked decay 1 0 and string decay with 5 outgoing particles 2 5 the ID of the respective process e g elastic scattering decay string excitation then the number of the collision in the respective event the collision time in fm c the the total CM energy ys in GeV the total cross section 0 5 in mbarn the partial cross section 6 in mbarn for the respective exit channel and finally the baryon density at the collision point in units of nuclear ground state density Note that the cross sections are ill defined in the case of a decay One of the purposes of the collision file is to have the possibility to track the trajectory of a single particle in the course of the reaction or the time evolution of the available CM energy per binary collision The contents of the particle vectors has the format format 15 e16 8 15 213 16 15 13 115 and is described in table 11 5 3 Decay output file16 The hea
34. tain all particles of a given event at a certain time step The collision history file i1e15 contains information on all collisions decays of a given event The decay file file16 contains information on all particle decays as well as information on all stable particles after the final timestep The OSC files file19 fi1 20 generates output compliant with the Open Standards And Codes OSCAR format Consecutive timesteps only file13 and filel4 and events are added sequentially to the files Each event consists of a header and a body The standard header is identical for 11e13 filel4 and filel6 and filel5 use an abbreviated header and the format of 11e19 and file20 is fixed by the OSCAR requirements 5 1 Standard output fi les file13 fi le14 The standard output files contain the phase space of the event at a given timestep e g final output after last timestep file13 contains the same information as file14 but additionally lists the freeze out coordinates in configuration and momentum space for all particles Figure 3 shows a standard header as used in file13 filel14 and filel16 Only one header per event is written to file Consecutive time steps of the same event are added body to body without additional headers between them The general format of the standard fileheader can be found in table 7 its contents is self explanatory please consult figure 3 The body of the standard output files contains in its first line t
35. the definitions of the Review of Particle Properties Monte Carlo naming scheme Composite clusters nuclei are marked with 7AAAZZZ AAA mass ZZ Z charge of cluster If other objects than nuclei are used as projectile or target then a 1 is listed in the mass slot followed by the PDG ID in the charge slot Figure 6 shows a sample output in the OSC format 5 5 OSC1999A output OSCAR 1999A format fi le20 The OSC1999A is an improvement to the OSC97A output and allows to write out the complete event history starting with the initial state including all binary collisions string fragmentations and hadronic decays In it s scope it is comparable to the UrQMD file15 collision output file but includes also the full initial configuration and final state information An abbreviated OSC1994A output format without the intermediate collision history can be used as replacement for the OSC97A output format The first three lines of the header are almost identical to the OSC97A format but are preceded by a comment marker and a blank space in each line The first two lines thus have the format format a20 and specify the format e g OSC1999A and the file contents Currently this can be full event history the final output tag final id p x referring to the OSC1997A format The third line has the format format k 33 16 39 7 7 yi36 2xX 84 2xX 010 41 2xX 18 and contains first the model name and version followed by mass and
36. y of an UrOMDstandard output file 22 excerpts of a sample body of an UrQMDcollision history file 22 Sample output in the OSC1997A format a 24 Sample output in the OSC1999A format a 27 1 General Information The Ultra Relativistic Quantum Molecular Dynamics UrQMD model is a transport model for simu lating heavy ion collisions in the energy range from SIS to RHIC It runs on various UNIX based com puting platforms Current implementations include IBM AIX xlf GNU Linux g77 ifc SGI IRIX DEC UNIX and Sun Solaris UrOMDis designed as multipurpose tool for studying a wide variety of heavy ion related effects rang ing from multifragmentation and collective flow to particle production and correlations This document is no introduction to the physics of UrQMD Its purpose is to serve as a short guide to the experienced physicist on how to run the program A detailed model description can be found in the following two articles 1 Microscopic Models for Ultrarelativistic Heavy Ion Collisions S A Bass M Belkacem M Bleicher M Brandstetter L Bravina C Ernst L Gerland M Hofmann S Hofmann J Konopka G Mao L Neise S Soff C Spieles H Weber L A Winckelmann H St cker W Greiner C Hartnack J Aichelin and N Amelin Prog Part Nucl Phys 41 1998 225 370 2 Relativistic Hadron Hadron Collisions and the Ultra Relativistic Quantum Molecular Dynam ics Model UrQMD
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