ATGEN – Monte-Carlo interface using GENZ User's Guide Version
Contents
1. 7 a 5 and does not store I am working on it and user requests are welcome CARD NUM type Description Defaults TRIG 1 I The total number of events to be precessed D 100 In using ISAJET the number of events generated is 9 10 CARD NUM type Chapter 5 ATGEN data cards the minimum of this number and the corresponding one in the ISAJET command Description Defaults Random number seed Marsaglia number D 54217137 For PYTHIA and NJETS it has to be gt 0 and lt 900 000 000 Description Defaults 1 I 2 I 3 I Debug card similar to SLUG This controls the information output for each event Debug that must be done once each run controlled by the PTAB card bellow 0 No debug 1 3 print event listing using LULIST 1 3 D 0 11 14 print event using GNZPRINT 1 1 4 21 24 GNZPRINT 2 1 4 31 34 pint like in 11 14 and also like in 21 24 First event to debug D 0 Number of events to debug D 0 Example DEBU 1 10 2 Prints the LULIST 1 information for events 10 and 11 CARD NUM type Description Defaults Available energy in the given frame CM for NJETS D 14000 used in PYTHIA and NJETS Description Defaults Beam momentum of the two colliding particles D 7000 7000 used in HERWIG and GENCL momentum of particle traveling in the Z direction positive momentum of particle in opposite direction Description Defaults Frame of collision used by PYTHIA now D CMS Description Def2. gt CTEQ Collaboration 2 L 1994 OND of the distributions in the PDFLIB compilation De selected using STRU 1000 NGROUP NSET The structure function selected with STRU is used to compute the cross section SIGMA n jets and the contribution of each subprocesses to the final result given in the column CONT NUM type Description Defaults I QCD scale Q used to compute the strong constant coupling a D 5 This parameter is particularly important in the case of the production of multijet events because more powers of alpha strong are involved in the calculation 1 gt PT average 2 Total invariant mass 3 Average invariant mass of 2 outgoing particles 4 Mass of quarks 5 PTmax in the event NUM type Description Defaults R produce unweighted events 0 0 gt Weighted events gt 0 gt Weight used to produce unweighted sample must be the maximum weight WTMAX To find WTMAX it is necessary to run a first time NJETS t the end of the job WTMAX can be found in the output file see appendix By runing a second time NJETS with WMAX WTMAX unweighted events are this time produced NUM type Description Defaults R Maximum parton pseudorapidity to accept D 8 Allowed values gt 0 5 6 Card to give parameters to the user routines 15 CARD NUM type Description Defaults ETMA 1 R Cut on the sum of partons transverse momenta D NJET PTMI CARD NU
3. specific particle can be forced to decay to states containing another specified particle 1 PDG particle code to decaying particle Sensitive to sign ie particle antiparticle 2 PDG code for daughter particle Not sensitive to sign 10 Real Specify whole or part of a single decay channel s information See JETSET array MDME 1 ie PDG code for decaying particle 2 IDC index of decay mode in decay table This must be obtained by looking at the listing produced by a call to LULIST 12 3 MDME IDC 1 MDME IDC 2 5 BRAT IDC if 0 0 or absent take default 6 10 KFDK 1 5 if 0 0 or absent use default 0 Card to call the PYINIT routine before some datacards are fed Usefull for example if MDC1 MDC2 MDC3 cards are used Very nice idea from Simon Tardell ds 5 3 Cards relative to ISAJET and to the ISASUSY call 13 5 3 Cards relative to ISAJET and to the ISASUSY call The ISAJET generator has a very sophisticated user interface that is used by appending it to the input datacard file to the end of the input datacard for ATGEN after the END command The ISASUSY package is now fully contained inside ISAJET and is called if one of the MSSM1 55 2 MSSM3 cards is included in the ISAJET input The coupling and mass parameters that can be given to this routine are however quite limited and the following cards describe a complementary implementation that is included and that has more freedom in changing the parameters
4. 1 Flow Diagram ATGNZI ATHPCP ATHPFIX 1 ATHPSTA PYTVER 1 CC PYTVER 1 ISAVER HERVER ATNINIT ATNTAG 1 2 2 1 UINIT ATGGEVT ATJESEV 1 ATISAEV 1 ATHEREV ATHERCP UVAL ATHPSTA ATGWRIT 1 ATJETAN UA2CELL 1 ATCELL 1 ATNOUT ATGFIND CCCCFATJETOR 1 ATDETE UDETE 1 C UANAL ATEVDEB 1 ATGREAD ATHPCP gt ATNEND 1 ATGGEND 1 22 GENZ init Keep non dekeyed PYTHIA version ISAJET version HERWIG version ATGEN ntuple init Ntuple entry name Ntuple entry xxxtyyy User init Event generation Jetset event Isajet event Herwig event copy HEPEVT 1 8 gt 4 User event validation GENZ write event Jet analysis routines ATGEN NTUPLE event PART finding Jet finding Detector smearing User detector smear User Analysis Atgen evennt debug GENZ event read HEPEVT convert ATGEN ntuple end ATGEN generator end Node name gt NFPAR NFPAR User utility to find entry 24 Chapter 9 ATGEN program structure 9 2 Data Structures COMMON Blocks eoe oe ke ke ProCom aK ak akak ok ok oe oe oe oe Module names appear along x a
5. CARD NUM type Description Defaults STRE 1 I 0 all particles are kept in the primary event 0 diff 0 only non decayed particles are kept in main event 5 2 The cards relative to the PYTHIA and JETSET generators CARD NUM type Description Defaults LUEN 8 R the parameters after KINE 3 in slug for test beam kinematics See Appendix A CARD NUM type Description Defaults 11 12 Chapter 5 ATGEN data cards 1 I diff 0 LULIST 12 at initialization if PYTHIA used D 0 prints all ISASUSY output if it is used NUM type Description Defaults 1 I PYTHIA MSEL Pythia defaults 200 I PYTHIA MSUB Pythia defaults 200 I PYTHIA MSTP Pythia defaults 200 R PYTHIA CKIN Pythia defaults 2000 I PYTHIA MDME i 1 Pythia defaults 2000 I PYTHIA MDME i 2 Pythia defaults 500 I PYTHIA MDCY i 1 Pythia defaults 500 I PYTHIA MDCY i 2 Pythia defaults 500 I PYTHIA MDCY i 3 Pythia defaults 200 I PYTHIA KFPR i 2 Pythia defaults 200 I PYTHIA MSTJ Pythia defaults 200 I PYTHIA MSTU Pythia defaults 200 R PYTHIA PARJ Pythia defaults 200 R PYTHIA PARU Pythia defaults 500 R PYTHIA PMAS i 1 Pythia defaults 500 R PYTHIA PMAS i 2 Pythia defaults 500 R PYTHIA PMAS i 3 Pythia defaults 500 R PYTHIA PMAS i 4 Pythia defaults NUM type Description from slug please test Defaults 20 List in any order LUND particle codes for STABLE FORCE DMOD PYIN those particles you wish to set stable Sets both particle and anti particles stable 2
6. PARL I variable The included jet analysis routines are driven by the card JETA CARD NUM type Description Defaults JETA 5 I to apply a particle level jet algorithm D 0 1 I 0 do not apply jet algorithm 1 LUCELL in pythia 2 UA2CELL sorry for the name takes for jet coordinates the ones of the seed cell 3 ATCELL similar to LUCELL but the energies of cells belonging to more than 1 jet are distributed in proportion with the jet energies It computes the missing momenta pxmiss and pymiss available in uanal The ptmis and phimis entries are included in the ntuple 2 I 1 Keep cell data appended to LUJETS before jet data in ATCELL case 3 I not used NCELL used mainly for output to UANAL 5 I NJET used mainly for output to UANAL d H Comment in future several ALGORITHMS will be added to this list If the user wants to call a different jet reconstruction routine he may do it in the beginning of UANAL The cell data consists of P NC 1 eta P NC 2 phi and P NC 5 Pt in the cell The cell index is stored in K NC 3 as IETA MAX 1 MIN MSTU 51 14 INT MSTU 51 0 5 ETA PARU 51 1 IPHI MAX 1 MIN MSTU 52 1 INT MSTU 52 0 5 PHI PARU 1 1 K NC 3 MSTU 52 IETA IPHI When one selects the options to append the jets to the event record this is only performed after the event has been saved on ZEBRA O and therefore does not go on tape 17 18 Chapter 7 ATGEN Analysis and Associated
7. and its tenth value as 5 This can be followed by lines with the same CARD but with different assignments like CARD 1126 An CARD statement means that the variables are loaded and an appropriate routine in run In the following description of the ATGEN cards tables with the same format are used In these tables the col umn CARD gives the card name NUM the number of parameters TYPE the parameter type I integer A Character 4 R Real In the first line the generic card is described and the following lines refer to each of the parameters and options The NUM column for the lines bellow the first one refers to the number of the parameter being described 5 1 General Purpose Cards in ATGEN In this section the general purpose Cards that are independent of the specific generator used are introduced CARD NUM type Description Defaults TASK 1 I Controls the ATGEN TASK to be performed 0 1 0 Reads Events from ZEBRA P 1 Generates events using PYTHIA and stores in ZEBRA O 1 Generates using PYTHIA but does not store 2 Consider fragmented partons like SLUG KINE 0 stores 2 T does not store 3 Generates events using ISAJET and stores 3 d M does not store 4 CALLS ISASUSY followed by ISAJET and stores Sse y does not store 5 Uses Herwig and stores the events 5 does not store 6 Generates events using GENCL and stores 6 2 A amp as and does not store 7 Generates events using NJETS and stores
8. data cards For pratical reasons a short description of the PYTHIA parameters to tune the jet analysis routines is here included see Chapter 5 CARD NUM type Description Defaults PARU 200 R From PYTHIA 51 R Calorimeter pseudorapidity limit PARU 51 to PARU 51 52 R minimum Et for seed cells 53 R minimum Et for jets 54 R R of cone 58 R cells with Et bellow are disregarded CARD NUM type Description Defaults MSTU 200 I From PYPHIA 41 I whose particles are included 2 drop newtrinos and unknown 43 I Store jets in lujets 2 store at end of listing 51 I Number of pseudo rapidity bins 52 I Number of azimuthal bins 54 I Reconstructed jet 2 four vector of the Et weighted center The following cards inputa 10x50 matrix trough FFREAD As this package considers them as one dimensional vectors the input is done with vector 1 to 10 corresponding to the fist line vector 11 to 20 corresponding to the second line and so on The PART IDPA IDMO IDST cards implement an algorithm to find the particles to be analyzed in the event record CARD NUM type Description Defaults PART 10x50R Analysis card to find and write on ntuple the particle data the second index refers to dealing with successive particles that one wants to analyze The PART datacard is relative to the first particle from 1 to 50 second particle from 11 to 20 etc 1 R 0 No more particles to analyze gt 0 Analyze treat the particle codes differing
9. envisaged These libraries and executables may be obtained from the CERN software repository asis01 cern ch by anonymous FTP The program has been tested in the HP Unix IBM 6000 DEC osfl alpha PC linux and SUN workstations and the included scripts to build the executable for these machines are named atgen XXX ins where XXX is the machine type 21 Running using the ATLAS software release The ATLAS software is maintained by G Poulard and includes a series of CMZ macros which perform the in stallation of the different parts of the software The software is located at CERN on a directory pointed by the LHC ROOT variable The macros are located in the subdirectory macros and include the at Wb macro to com pile a library the bin macro to build the executables and the a build macro to build an executable including the user corrections mechanism for selecting different versions was developed to use with GEANT and will be extended to the different generators Different versions of the software may be located in the pro new and dev subdirectories 2 2 Running the program on the ATLAS farm All the libraries and executables are on the directory afs cern ch user a aamorim public atgentest available via AFS and accessible in the ALTAS1 ATLAS2 machines If one wants to use the libraries lo cated here but include corrections in the executable he must copy the atgen cmz atgen corr my cmz and at gen hpux ins files to his directo
10. 3 2 the jets are appended to the LUJETS common Their particle code is 98 so one can fetch them The way to identify a jet is normally a hard procedure that involves jet tagging and the definition of angular regions relative to other partons see the IDST cards Chapter 8 Interfacing with SLUG The output file generated by ATGEN can be red back by the DICE program by renaming it to ZEBRA P and in cluding in the DICE data card the following lines C organize the output outp 1 zebra output on OUTP 1 C BKIO 0 KINE BKIO 0 HITS BKIO P EVNT BKIO RUNT BKIO 0 EVNT BKIO 0 RUNT C C KINE 1 note the documentation on SLUG both on WWW and on the CERNVM is not updated since it mentions the GENP bank that has been replaced in GENZ by the RUNT and EVNT banks Ihave included a pick kumac utility that builds a series of PICK cards for SLUG to simulate only the events which survive the cut 1 applied to the at hbook ntuples Using Dice to simulate the detector response for the complete events may be a time and memory consuming task if the events contain a large number of particles If one uses carefully the track filter option of SLUG TFLT ETA MIN EIA MAX one may save a lot of time and memory in this process The event generation can also be done inside SLUG in the GENSLUG package see the SLUG manual Ap pendix on GENSLUG 1Tt is assumed that the ntuple number 1 exit
11. 87 6 The World Wide Web WWW for details telnet info cern ch 7 GEANT CERN Program Library 8 FFREAD CERN Program Library 9 CMZ User s Guide amp Reference Manual available from the CERN Program Library office CN division 10 HBOOK User s Guide amp Reference Manual CERN Program Library Long Writeup 11 PAW User s Guide amp Reference Manual CERN Program Library Long Writeup Q121 12 Julian J Bunn FLOPPY User s Guide amp Reference Manual CERN Program Library 13 H Grote FLOW User s Guide amp Reference Manual CERN Program Library Long Write Up Q902 1988 14 CERN library short writeups CERN Program Library 15 The ATLAS software manual ATLAS software group 16 The SLUG manual ATLAS software group 17 The DICE manual ATLAS software group 18 The ATRECON manual ATLAS software group 19 In preparation The GENSLUG appendix to the SLUG manual ATLAS software group 20 Torbj rn Sj strand CERN TH 7112 93 Related work is on T Sj strand Computer Physics Commun 39 1986 347 T Sj strand and M Bengtsson Computer Physics Commun 43 1987 367 See the files upgrade notes in the ATGEN distribution 21 All the ones in the previous plus H U Bengtsson and T Sj strand Computer Physics Commun 46 1987 43 22 Frank E Paige Serban D Protopopescu ISAJET Manual Brookaven National Laboratory USA copy is in the isajet CMZ file 23 Howard Baer Frank E Paige S
12. AMHL AMHH AMHA AMHC ALFAH AAT THETAT These replace the subroutine call SUBROUTINE SSMSSM XMG XMS XMTL XMTR XMLL XMLR XMNL XTANB XMHA XMU XMT XAT XMBR XAB IALLOW With C C Calculate MSSM masses and decays using parameters C XMG gluino mass C XMS common squark mass C XMTL m stop left C XMTR m stop right C XMBR m sbot right C XMLL left slepton mass C XMLR right slepton mass C XMNL left sneutrino mass C XTANB v v ratio of vev s C XMU 2 m 1 SUSY Higgs mass C XMHA m pseudo scalar Higgs C XMT m top C XAT stop trilinear coupling C XAB sbottom trilinear coupling with C AMGLSS XMG AMQKSS XMS AMLLSS XMLL AMLRSS XMLR AMNLSS XMNL TWOM1 XMU RV2Vi XR21 AMTLSS XMTL AMTRSS XMTR AMBLSS XMTL AMBRSS XMBR AMHA XMHA AAT XAT AAB XAB Bibliography 1 R DeWolf GENZ User Manual available from WWW of from the Atlas Software Group 2 ZEBRA User s Guide 3 53 R Brun M Goossens J Zoll CERN PROGRAM LIBRARY 0100 1987 3 T Sjostrand et al in Z Physics at LEP 1 ed G Altarelli R Kleiss and C Verzegnassi CERN Yellow Report 89 08 v 3 p 327 4 F Bruyant Skeleton Logic for Analysis Chains 5 Trippe Lynch Particle I D Numbers Decay Tables and Other Possible Contributions of the Particle Data Group to Monte Carlo Standards LBL 24287 in Proceedings of the Workshop on Detector Simulation for the SSC August 19
13. ATGEN Monte Carlo interface using GENZ ATGEN User s Guide Version 1 00 June 6 1995 A Amorim ATLAS Software Group 1LIP and CFNUL Lisbon Portugal About this guide I apologize to the reader who is an expert in the standard packages of high energy physics for the sometimes trivial matters that are here included The ATLAS software has by now become an impressive accomplishment and to deal with most of the packages one has to understand the basic mechanisms at a level that makes this guide look naive My only justification to include the well known material is to ease the life of the non expert to get into the main concepts used in our packages One has to start somewhere and I tried to make the way in simple even the less familiar user Acknowledgments The author would like to thank all his colleagues who by their encouragement have made this a pleasant task I am particularly graceful to A Pereira for his suggestions for a non expert manual and to P Ferreira for having tested the code The constant help of G Poulard and the guidance and encouragement of M Nessi P Nevski D Froidevaux are deeply acknowledged Related Manuals The PYTHIA JETSET manual 20 The ISAJET manual 22 The HERWIG manual 24 The GENCL reference paper 25 The NJETS reference notes Stephane BASA 26 The ZEBRA manual 2 The SLUG manual 16 The GENZ manual 1 The FFREAD manual 8 The HBOOK manual 10 Table of Contents 1 Introduct
14. After the ISAJET initialization is performed a modified version of SSMSSM is call to compute the supersymmetric parameters CARD NUM type Description Defaults SSSM 18 R The SSSM common in SSMSSM routine See Appendix B CARD NUM type Description Defaults 55 33 R The 55 common in SSMSSM including the input parameters See Appendix B 5 4 Cards to drive the Herwig generator This is realy very preliminary and incomplete It needs further improvement CARD NUM type Description Defaults see atgen general cards 5 5 Cards to drive the NJETS generator The library PDFLIB 27 which is a compilation by H Plothow Besch Is used by NJETS to incorporate further Parton Density Functions see also atgen general cards CARD NUM type Description Defaults NJET 1 I Number of Jets in the Final State 2 CARD NUM type Description Defaults STRU 1 I Structure functions avalaible of them are directly D 1 incorporated in NJETS and the other call the library PDFLIB 14 Chapter 5 ATGEN data cards Function incorporated 1 Duke Owens set 1 1984 2 gt Duke Owens set 2 1984 3 Eichten Hinchliffe Lane and Quigg set 1 1984 4 Martin Roberts and Sterling E 1988 5 Martin Roberts and Sterling B 1988 Function defined with PDFLIB gt Martin Roberts and Sterling 50 1993 Kwiecinski Martin Roberts and Setrling B 1990 gt Martin Roberts and Sterling 0 135 1991
15. M type Description Defaults COST 1 R Cosine of minimum opening angle allowed between D 0 99 partons This parameter requires that the outgoing partons are well separated in the phase space and assure the validity of perturbative QCD avoiding collinear divergencies Allowed values are 0 995 COST 1 0 CARD NUM type Description Defaults COMP 1 I Compare different structure functions sets 0 0 gt No 1 gt Yes If comparison between several functions is made the functions incorporated in NJETS are automatically selected and only one defined with PDFLIB by default CTEQ 221 is selected 5 6 Card to give parameters to the user routines This is a card to allow the user to pass parameters to its analysis routines CARD NUM type Description Defaults UCAR 100 R User parameters for UINIT UANAL UVAL UDETE routines 0 Chapter 6 User and User Tailoring In the directory ATUSER in TAGEN CMZ there are 4 dummy routines that must be changed if the user wants to do specific jobs UINIT Define NTUPLES and call HBOOKN It is called in the beginning of the run The Ntuple 1 is already used by ATGEN if the PART analysis data card is used Hbook file at hbook is already open UANAL called for each event The user can for example fill his ntuple ATGEN provides some utility routines that can be used inside UANAL function NFPAR TAG Return the line in LUJETS common block corresponding to the particle found by at
16. N the generator codes are included after being converted to a set of CMZ files The corresponding correction files include the very few changes applied to the respective generators Following the SLUG conventions the zebra files have the names of ZEBRA O for output ZEBRA P to read the primary stream and ZEBRA B for the secondary stream to add minimum bias events to the main event The program is driven via data cards using the FFREAD 8 package In the case of ISAJET the specific input commands must be appended to the data card file after the END statement 1 Diversity is a system radio system in which different antennas are scanned in order to peek the most clear signal This program is meant to integrate different physics Monte Carlos to achieve the most clear signatures from ATLAS Chapter 2 Installing ATGEN The program should be put on the ATLAS area see Sec 2 1 as soon as there are not to many obvious bugs Mean while one can either use the executable and libraries as mentioned in Sec 2 2 or one can do a complete installation following the steps described in Sec 2 3 To construct ATGEN as user friendly as possible I have included in the stand alone installation all source files of both the program and used libraries The only external libraries that are required to be present on your computer are the CERN libraries PACKLIB MATHLIB and KERNLIB 14 Extensive use of the CERNLIB executables PAWL 11 and the CMZ 9 code manager must also be
17. VT common block 16 Chapter 7 The ATGEN Analysis and Associated data cards The analysis routines are called both for the generation task and for the read back task is a completely similar way All the HBOOK activity in ATGEN including the user histograms and ntuples goes onto the file at hbook which is already open and closed by ATGEN For very specific problems the user analysis can be performed in the user routines according to Chap 6 In the UANAL routine that is called for each event all kinds of jet finding algorithms should be included and user ntuples should be filled For analysis of a more general nature the user does not have to write these routines but instead he can use the ATGEN intrinsic analysis routines This analysis creates an ntuple number 1 that contains variables relative to the chosen particles in the event record and variables relative to pairs of particles These variables are named EO to E9 PHIO to PHI9 PHIO to ETAO for each selected particle and FMOTI ROT1 to FM8T9 R8T9 for the invariant mass and distance in 7 of particles 0 1 to 8 9 etc The particles number 0 up to 9 are chosen in the event record by a series of conditions defined using the cards PART IDPA IDMO IDST defined bellow as 10x50 matrices in which line 1 correspond to variables 1 and line 50 to variables E50 50 etc This variable names for particle I can be customized by assigning a label to each paticle trough the
18. XXX is the generator and version Following the choices for the ATLAS software maintenance the separate correction files are kept for each li brary To upgrade a specific page one has to copy the correction file edit the specific kumac that builds that library adding the USE directive for that file and execute this kumac A new library will be built that will be used when linking atgen If required a copy of the old library can be kept to check the compatibility of results In the case of ATGEN corrections one just needs to include the USE file in the atgen X XX ins script that builds the executable and run it The new correction files will be available in the ATLAS software directories but for the time being they can be picked form the mentioned directory in the ATLAS farm 2 An utility to dump ZEBRA files is included in atgen tar The zebdump f file is a modified copy of the ATLAS utility with the same name available on CERNVM The executable can be obtained using the enclosed zebdump XXX ins where XXX is the machine type Chapter 3 Running ATGEN In this Chapter the simple procedures to run ATGEN are described The Unix syntax is used which has to be changed in the case to VM CMS of VMS syntax in non Unix machines 31 Generating Events with ATGEN The ATGEN program reads the data cards from the standard input and writes all messages to the standard output To run the program one has just to give the input data card and if wanted t
19. aults Beam type used in PYTHIA HERWIG and GENCL Particle 1 type D P 2 Particle 2 type D P 3 Description Defaults IPROC process number Herwig and in njets D 3 PROC 1 I NJETS PROCESS 1 gt EXACT calculation 2 gt Leading Order of multigluon scattering processes 5 2 The cards relative to the PYTHIA JETSET generators Special Helicity Approximation SPHEL gt MAXWELL ESFAG gt ESFAQ gt MCHEL gt M 2 1 o NoNe 1 WM CARD NUM type Description Defaults PTMI 1 R PTMIN in Herwig and in NJETS D 100 for njets NJETS Minimal value of the transverse momenta of each partons GeV Allowed values are PTMI gt 0 CARD NUM type Description Defaults PTMA 1 R PTMAX in Hervig CARD NUM type Description Defaults BACK 2 R Add min bias READ OPERATION ONLY to avoid double counting in SLUG 1 R Poisson mean of the number of min bias events to add D 0 2 R 0 Only non decayed particles in min bias are added to HEPEVT D 0 1 Events added directly from the GENCL generator 2 events red with all particles kept Example BACK 20 0 a random number of events generated using a Poisson distribution with average 20 is added to HEPEVT and LUJETS Only the stable particles in these events red from the secondary stream are kept BACK 41 a random number of events generated using a Poisson distribution with average 4 is added to HEPEVT and LUJETS These events are generated using GENCL
20. ding the libraries Inthis step you compile all the libraries inside your directory by running the script INSTALL This installation will leave in your directory besides the libraries themselves the following files e installation kumacs to compile all libraries e The directories XXX src with the Fortran source files of the routines corresponding to the library XXX e The Unix scripts to compile the executable on each different type of machine e The data card file examples with extension datacard e The atgenman tex file containing this manual that must be processed by LaTeX e The pick kumac and pick f files that are to be used in PAW to produce a PICK datacard for SLUG see Chapter 8 4 Building the executable file 6 Chapter 2 Installing ATGEN An executable file atgen exe must be created by using the appropriate Unix script file On HP workstations this file is named atgen hpux ins and for the other tested environments a similar file is included The gener alization to other UNIX machines where the CERN library is available is very simple and correspond only to change the compilation statement in these files 24 Getting the new correction files for ATGEN Some not very deep corrections to both ATGEN and the generator libraries will become available very often This makes is rather cumbersome to always repeat the installation procedure The alternative choice is to copy the cor rection files atgen corr or XXX corr where
21. erban D Protopopescu and Xerxes Tata ISASUSY Manual a copy is in the isajet CMZ file 29 30 BIBLIOGRAPHY 24 G Marchesini B R Webber G Abbiendi I G Knowles M H Seymour and L Stanco HERWIG Manual a copy is in the herwig CMZ file The main reference is G Marchesini B R Webber G Abbiendi I G Knowles M H Seymour and L Stanco Computer Physics Communications 67 1992 465 25 The UAS High Energy pp Simulation Program UAS Collaboration Nuc Phys B291 1987 445 502 26 Jets at LHC F A Brends and H Kuijf Nucl Phys B353 1991 59 Muilti Jets Event Generator for LHC H Kuijf et al Proceedings of the Large Hadron Collider Workshop CERN 90 10 and ECFA 90 133 27 H Plothow Besch CERN PPE 92 123 1992 PDFLIB a library of all available parton density functions of the nucleon the pion and the photon and the corresponding alpha s calculations H Plothow Besch Comp Phys Comm 75 1993 396 416
22. fault Values AMUP 0 0099 AMDN 0 0056 5 0 199 AMCH 1 35 AMBT 5 0 AME 0 511E 3 AMMU 0 105 AMTAU 1 784 AMW 80 0 AMTRSS XMTR AMBLSS XMTL AMBRSS XMBR AMHA XMHA AAT XAT AAB XAB AMGLSS XMG TWOM1 XMU RV2V1 XR21 AMTLSS XMTL AMZ 91 17 GAMW 2 12 GAMZ 2 487 ALFAEM 1 128 SN2THW 0 23 ALQCD4 0 177 ALFA3 0 12 IF ALF2 EQ 0 and for SSPA SUSY parameters AMGLSS AMQKSS AMLLSS AMLRSS AMNLSS TWOM1 RV2V1 AMTLSS AMTRSS AMT1SS AMT2SS AMBLSS AMBRSS AMB1SS AMB2SS AMZiSS ZMIXSS AMWiSS GAMMAL GAMMAR AMHL AMHH AMHA AMHC ALFAH AAT THETAT AAB CO CO OO CO OO OO OO CO OO OO CO CO OO OO CO OO OO CO OO CO CO ALF2 ALFAEM SN2THW gluino mass squark mass left slepton mass right slepton mass sneutrino mass Higgsino mass mu ratio 2 of vev s left right stop masses light heavy stop masses left right sbottom masses light heavy sbottom masses signed mass of Zi Zi mixing matrix signed Wi mass Wi left right mixing angles neutral Higgs 0 HO AO masses charged Higgs mass Higgs mixing angle stop trilinear term stop mixing angle sbottom trilinear term sbottom mixing angle COMMON SSPAR AMGLSS AMQKSS AMLLSS AMLRSS AMNLSS TWOM1 RV2V1 AMTLSS AMTRSS AMT1SS AMT2SS AMBLSS AMBRSS 27 28 Appendix common block contents associated with the cards SSSM and SSPA AMB1SS AMB2SS AMZ1SS AMZ2SS AMZ3SS AMZASS ZMIXSS 4 4 AMW1SS AMW2SS GAMMAL GAMMAR
23. gen analysis routines with PARL TAG Ex npar NFPAR j1 gives the LUJETS line of the particle corresponding to PARL 11 UVAL IRET if the user sets IRET different from 0 the event is dropped not written called for each event UDETE LIRET a user routine to apply some detector effect to the particle index I of the ATGEN analysis rou tines Called from the ATGEN analysis routine associated with the card PART for each particle in the events specified in the PART card It is called before UANAL t any moment in UANAL the user has available to do the analysis the GENZ routines that fetch information from the zebra banks the HEPEVT standard event common block the LUJETS pythia common block regardless of the specific generator used the UKEEP vector with the real parameters fed by the UCAR card Besides these specific routines the user has an almost infinite freedom to change the program by using the MY CMZ file In fact all the routines that that were copied from ATGEN CMZ to the MY CMZ file and then changed will be recompiled and linked with ATGEN when the script atgen X X X ins is executed If a change in one of the external libraries is to be included one may use the same procedure by copying it from the library CMZ file to MY CMZ This routine will then be compiled and loaded to the object file preventing the old one with the same name to be used 1 The event number can be picked from the NEVHEP variable in HEPE
24. ion 2 2 Installing ATGEN 3 2 Running using the ATLAS software release 3 2 2 Running the program the ATLAS farm es 3 2 3 Installing the program as 0 2 2 3 2 4 Getting the new correction files for ATGEN 2 3 Running ATGEN 6 31 Generating Bvents wit ATGEN orase t NN 6 32 Reading Events From the ZEBRA 6 4 Interfacing with the Physics Generators 7 5 ATGEN data cards 8 5 1 General Purpose Cards 8 5 2 The cards relative to the PYTHIA JETSET 10 5 3 Cards relative to ISAJET to the ISASUSY call 12 5 4 Cards to drive the Herwig generator 12 5 5 Cards to drive the NJETS generator 12 5 6 Card to give parameters to the user routines 14 6 User Routines and User Tailoring 15 7 The ATGEN Analysis and Associated data cards 16 8 Interfacing with SLUG 20 9 The ATGEN program structure 21 91 Plow Diagram s sess deve ete a ee EN Gg eene mds 21 92 Data Structures COMMON 5 23 A Description of the LUEN card for test beam kinematics 25 The common block contents associated with the cards SSSM and SSPA 26 Bibliograph
25. isajet713 isajet713 bnluxi bnl gov pub isajet 30 9 94 24 11 94 NJETS 2 1 njets sbasa atlas cern ch public njets 4 4 95 05 20 94 The generator source files were converted using the CMZ code manager the following changes are intro duced in the corresponding correction files The HEPEVT common block that had 2000 lines in GENZ and HERWIG and 4000 line in ISAJET PYTHIA JETSET was set to 10000 in all codes consistently This is a choice which has some advantages it allows the inclusion of a reasonable number of min bias events the non decayed particles only and allows this common block to be used to do particle level analysis including pile up Since most generators have special input to include minimum bias events a large enough common block is required to use this option This option had not to done in SLUG because the minimum bias events are added at the level of the KINE bank In PYTHIA and JETSET I also set the length of the LUJETS common to 10000 in order to be able to copy events to this format at any time In ISAJET I had to remove a EOD line of all routines in the file In HERWIGI had to change the name of the internal routine iucomp due to a conflict with the standard cernlib routine with the same name In GENCL I added user control on beam target type and momentum The change on the common block size force a similar change in SLUG before linking these libraries with SLUG The output ZEBRA O file i
26. o redirect the output to a listing file Some examples of data card files are created during the installation procedure These data cards are described in detail in Chap 5 in particular the TASK card controls the program task as event generation using a specific generator or reading back the events to do a new analysis TASK 0 The command atgen exe lt wjjpyt datacard gt listfile for example runs ATGEN using the wjjpyt datacard file that generates events using PYTHIA and writes them on the ZEBRA O output file The ATGEN program creates the following output files e at hbook This hbook file may contains an ntuple 1 automatically generated by ATGEN using the PART card Chap 7 and all histogram and ntuple allocation performed in the user routines see Chap 6 e ZEBRA O The ZEBRA file is a binary file written in the machine independent format that contains the ZEBRA banks RUNT and EVNT that contain the full event information 3 20 Reading Events From the ZEBRA File The FZ file written by ATGEN contains information on all particles in each event The output file ZEBRA O can be used for input by renaming it to file ZEBRA P and running ATGEN with a data card including TASK 0 card This is a fast procedure to perform a new analysis on the already generated events This can be done for example by issuing the command atgen exe lt wjjread datacard gt newlisting The wjjread datacard is a demo file created by the INSTALL proced
27. re set to have this mother particle If IDST 2 the jets are the non picked pair of JETS with invariant mass closest to the value of PICK 1 I The following is forced to store the other JET in the pair If IDST 1 the JETS in the same hemicircle of the mother in the x y plane are all set to have this mother particle The search mechanism consists in finding a particle such that its particle code is IDPA with the mother found previously in line IDMO of PART and with IDST status All values that are zero do not enter the condition OR is done along the 10 columns of these cards I realize that an example is HIGHLY recommended Lets consider that one want to find a W in an event This card would do it PART 10 10 0 PARL Wp IDPA 24 IDMO 0 IDST O then lets try to find the quarks in which the W decayed The following would do it PART 11 1 0 20 0 20 Chapter 7 ATGEN Analysis Associated data cards PARL 2 741 IDPA 11 1 12 2 13 3 14 4 15 5 IDMO 11 1 12 1 13 1 14 1 15 1 IDST 11 0 PART 21 1 26 2 30 0 PARL 3 2 q2 IDPA 21 1 22 2 23 3 24 4 25 5 IDMO 21 1 22 1 23 1 24 1 25 1 IDST 21 0 where 1 2 3 4 5 are the ID codes of the quarks in LUJETS The mother of the quarks is always the W that was found in line 1 of PART Setting PART 26 2 includes in the ntuple the quantities relative to the pair of quarks 3 2 like the invariant mass and so on It is also possible to find JETS since with the option MSTU 4
28. ry and modify the script atgen hpux ins by including in the compilation statement the above library directory L afs cern ch user a aamorim public atgentest The atgen hpux ins script will then be able to create a new executable file in his directory 2 3 Installing the program as stand alone The ATGEN program is stand alone which allows is to be installed independently of other packages except CERN LIB which is assumed to be present The sequence of procedures necessary to build the libraries and the executables in your machine is described in the steps bellow 1 Copying the file previous registration may be required To register one can send a mail to cernlib cern ch 4 2 3 Installing the program as stand alone 5 You must open subdirectory in your machine and copy there the atgen tar file This file is on afs cern ch user a aamorim publ on AFS in particular on the ATLAS cluster ATLAS1 2 or on the csf farm on u zp morimzp atgen tar 2 Open the tar file This Unix backup file should be opened using the command tar xvf atgen tar that will put in your directory all the source and script files necessary to do the installation among which are the files MAKETAR INSTALL GENERATOR HISTORY atgen cmz my cmz pythia57 cmz jetset74 cmz isajet7 cmz herwig57 cmz gencl cmz njets cmz genz cmz atgen corr genz corr isajet709 corr jetset7402 corr pythia5704 corr herwig corr gencl corr genz corr 3 Buil
29. s however perfectly compatible with SLUG since all information is contained in data banks changes from the original programs kept separately one correction file for each generator Generator upgrades that do not involve a change in the version will also be included in separate correction files This makes it easy to choose among different patches at compilation time and also avoids keeping many versions of the same code Chapter 5 ATGEN data cards Some example of very simple data cards are on the ATGEN CMZ file under the directory DATA CARD also copied to datacard files on the installation procedure They are examples of DRELL YAN production of W s de caying into jets using the different physics generators Example cards for the top hadronic events are also included I would greatly appreciate if people could send me the data cards that they have built to be included as examples The datacard choice follows as close as possible the SLUG conventions and namely the PYTHIA data cards are directly compatible with SLUG The changes that are being made in SLUG GENSLUG will make the data cards compatible in all cases The FFREAD 8 package reads input from a file in a very intuitive way values until the END statement is reached are red at once and the assigned variables to each defined card are loaded The syntax follows the example CARD 1 2 1025 in which the vector assigned to CARD inputs its first value as 1 second as 2
30. s with first entry giving the event number This is automatic if the PART analysis is used and must otherwise be included in the user routines 21 Chapter 9 ATGEN program structure The flow diagram of ATGEN and the used data blocks COMMON blocks are presented They were obtained using the FLOPPY 12 and FLOW 13 programs of CERN library 9 1 Flow Diagram of Symbols terminal node in the tree external procedure subtree node expanded below multiply called terminal node procedure calling only externals module is in IF clause module is in DO loop aK ak ak ak 3k ke ok ok ok ok ok oe oe o ok ok ok oe oe oe oe ke oe oe oe oe oe oe oe ke 2 2k koe EXTERNAL procedure names will not appear Node name gt ATGMAIN ATGGINI ATGFFU PYTFFU PYFORC PYSTAB 1 PYDMOD 1 ATPYINI 1 ATPYKEY ATISKEY ATHEKEY ATPYINI 1 ATISAI 1 SUSYLOA ATHERI 1 SUSYDEB l ISASUSY 1 SSPRT SSID 22 Main Program Force linker loading FFREAD routines Generator part PYTHIA part gt FORC CHFLAV 1 STAB DMOD DEPYIN ATGEN INIT Load atgen keys Load pythia keys Load Isajet Keys Load Herwig keys Generator init PYTHIA init ISAJET init ISASUSY init ISASUSY debug HERWIG init 9
31. see IDPA For jet analysis with IDST 2 this is the central mass value 0 Analyze treat particle codes for as the same see IDPA 2 diff 0 Call UDETE I IRET after finding this particle detector smearing type to apply to particle 4 gt 0 and 3 gt 0 gt E resolution with a sampling on PART 3 and a constant term in PART 4 R include the ntuple quantities that correlate this particle with one to which a previous card refers to number of w 19 that particle in PART 6 7 8 9 10 R particle line in LUJETS lt 0 the particle is always taken as the one appearing in the line whose absolute value is given here else the particle finding mechanism is activated CARD NUM type Description Defaults PARL 50 first two letters are the Particle label for ntuple entries if the particle order in PART will be used CARD NUM type Description Defaults IDPA 10x50 I Particle code in LUJETS to be searched IDMO 10x50 I Particle order in PART of the already found particle that is its mother In the case of Finding the Mother of jets the jets are related to the partons in IDMO trough somei conditions that depend on IDST See bellow IDST 10x50 I Particle Status of the particle to be found In the case of JETS If IDST 0 the jets are the non picked JETS closest to the mother IDMO particle in R phi eta If IDST 1 the JETS in the opposite hemicircle to the mother in the x y plane a
32. than 6 digits The first particle carries the sign In the 2 jet case the jets are produced back to back with jet 1 taking direction and momentum given by the rest of the cards Note that defaults are the same as above so that giving no parameters except parameter 1 will just give an electron which does not fragment LUEN 1 R Encodes particle codes for jet initiators D 11 electrons if we call this parameter N then SIGN N MOD ABS N 10000 ID2 ABS INT N 10000 C C C C C C C C C C C C C C C C C C C C If ID2 is zero then a 1 event is generated C C C C C C 2 R minimum momentum GeV c of jet 40 3 R maximum momentum GeV c of jet 40 4 R minimum pseudorapidity of jet St 5 R maximum pseudorapidity of jet 1 6 R minimum phi in radians of jet 0 7 R maximum phi in radians of jet 2 pi 26 Appendix B The common block contents associated with the cards SSSM and SSPA The SSSM common block fed by the card SSSM has the following contents a real vector 18 is mapped to the SSSM common block Standard model parameters AMUP AMTP AME AMMU AMTAU 2 ALFAEM SN2THW ALFA3 ALQCDA quark masses lepton masses W Z masses W Z widths SM couplings 4 flavor lambda COMMON SSSM AMUP AMDN AMST AMCH AMBT AMTP AMTAU AMW AMZ GAMW GAMZ ALFAEM SII2THW ALFA2 ALFA3 ALQCD4 C C C C C GAMW GANZ C C C C De
33. ure that differs form the event generation data card by the TASK 0 line All CARDS to steer the generator options are irrelevant The zebdump utility included in the ATGEN release provides a simple way to exam the BANK headers in this file 1 Since the ZEBRA O file is opened by GENZ with status new if it already exist an error is reported and the file is not overwritten In the HP machines a file with name ftn23 will contain the ZEBRA output Chapter 4 Interfacing with the Physics Generators log file of the generator source files that were picked for ATLAS is kept updated in file GENERATOR HISTORY In the present version it contains GENERATOR Int ver cmz file corr SOURCE Last Change DATE PYTHIA 5 7 pythia57 pythia5704 Sjostrand torsjo 1920CERNVM 7 4 94 25 5 94 JETSET 7 4 jetset74 jetset7402 Sjostrand torsjo 1920CERNVM 7 4 94 25 5 94 ISAJET 7 09 isajet7 isajet709 bnluxi bnl gov pub isajet 23 4 94 14 6 94 GENCL 1 gencl gencl Hawkings pubzp 197 CERNVM 18 6 94 ISAJET 7 10 isajet710 isajet710 bnluxi bnl gov pub isajet 29 7 94 22 8 94 JETSET 7 4 jetset74 jetset7403 Sjostrand torsjo 1920CERNVM 15 7 94 24 8 94 PYTHIA 5 7 pythia57 pythia5705 Sjostrand torsjo 1920CERNVM 15 7 94 24 8 94 PYTHIA 5 7 pythia57 pythiab705a Sjostrand mail bug on WtW BRatio 05 9 94 JETSET 7 4 jetset74 jetset7404 Sjostrand torsjo 1920CERNVM 26 8 94 24 11 94 PYTHIA 5 7 pythia57 pythia5709 Sjostrand torsjo 1920CERNVM 26 10 94 24 11 94 ISAJET 7 13
34. xis COMMON block names along y axis Y gt COMMON used in module lt N gt gt COMMON not used but is DECLARED lt gt gt COMMON not DECLARED aK ak ak ak 3k Kok 2g k oko oko ok oe oe oke ok oke ok oe oe oe oe Kok oko ok oe ok ok ok ok ok oke oe ok 9 9 oK oe oe oe oe ok oe oe oe oe oe oe 2 2 2 2 ke oe ke ok ATGKEEP EPEVT PART CFREAD PAWC GI CSTO UKEEP PYCA LUDA LUDA LUEN SSMODE SSPA SSSM QLMASS DHEPEVT LUDAT1 GNCCON GNCCPA GNCEVT GNCIPA GNCRPA t B5 C0 r read Mox AM ox LS 55 4 NJETSKEY1 H NJETSKEY 2 N 25 9 2 Data Structures COMMON Blocks Figure 9 1 The Flow diagram of ATGEN Appendix A Description of the LUEN card for test beam kinematics The cards and routines to generate particles in a test beam like kinematics were pick with slight modifications from the implementation of R DeWolf in SLUG The LUEN card in particular follows exactly the KINE 3 arguments in SLUG with the 0 for the first parameter removed gt LUEN Test beam 1 jet or 2 jet events can also be generated in here The second parameter of the KINE card encodes for the PDG codes of the jet initiators Single jets are produced if parameter 2 has an absolute value less than 10 000 Otherwise the 5th and 6th decimal digits are used to encode the second jet s initiator The routine is not guaranteed to work if the floating point precision is less
35. y 27 Chapter 1 Introduction ATGEN DIVERSITY is a system for integrating particle physics generators into a common framework The main purpose is to provide a simple particle level simulation tool for ATLAS that generates output compatible with the input format of the full detector simulator package of SLUG DICE 17 16 In the interest of user friendliness itis kept as a stand alone program with a simple installing procedure described in Chap 2 A similar interface is also maintained inside the SLUG package 19 In that case an different approach is used which is suitable for advanced users It consists mainly of favoring the use of routines to deal directly with the ZEBRA banks instead of event COMMON blocks and keeping the use of only one generator at the time by defining the appropriate SELECTS in CMZ 9 This mechanism of conditional compilation also exists in ATGEN but the program is designed such that all generators can be available at the same time Presently the ATGEN program is an interface to the PYTHIA 20 JETSET 21 ISAJET 22 ISASUSY 23 HERWIG 24 GENCL 25 and NJETS 26 generators and is planned to include several other generators namely of the matrix element type The program can write and read zebra sequential files and is suitable to perform particle level analysis which are preliminary to the more complex and time consuming full event simulation by DICE and its reconstruction by ATRECON 18 In the distribution of ATGE
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