Last updated: June 26, 1995 by BL.
diffVM is a Monte Carlo generator for diffractive processes in ep collisions based on the VDM. The main author is Benno List.
This file describes the diffVM steering banks for version 1.10 and later. The steering banks for version 1.05 are described here.
The values of all parameters are also stored by the generator in the GDIR and GDII banks for later reference. If the GDIF bank is not present in the input stream, then GDIR bank can be used (together with the GDII bank) to define all input parameters for diffVM.
This is the resulting LOOK figure.
The EXPS bank is a TABLE, therefore the user has to provide a miniheader with the number of columns (5), and rows (number of data points). Each row then contains the W value, for which the experimental data was measured, the minimum and maximum W values (needed to draw horizontal error bars), and the cross section (in pb) with its error. Here is an example, used to generate the LOOK figure referenced above:
EXPS 0 / ! Experimental cross section values * Values for elastic J/psi production: 5 10 ! NCOL, NROW * Wmean Wmin Wmax x-sect / pb error 14.0 10.6 17.3 9.8E3 2.9E3 ! E516, PRL 52:795 67.0 56.0 78.0 50.0E3 16.0E3 ! ZEUS, DESY 95-052 114.0 105.0 123.0 71.0E3 23.0E3 42.0 30.0 60.0 29.0E3 8.0E3 ! T. Jansen, ultra-preliminary 73.0 60.0 90.0 61.0E3 13.0E3 104.0 90.0 120.0 64.0E3 16.0E3 134.0 120.0 150.0 75.0E3 31.0E3 49.0 30.0 80.0 29.0E3 8.0E3 ! Schmidt/Schiek 75.0 80.0 130.0 61.0E3 13.0E3 ! ultra-preliminary 68.0 130.0 180.0 64.0E3 16.0E3
This is the resulting LOOK figure. The format is quite simple: just enter all W values you are interested in. Here is an example, used to generate the LOOK figure referenced above:
WVAL 0 / ! W values where gamma-p cross section is to be evaluated
4.0 6.3
10.0 16.0 25.0 40.0 63.0
100.0 160.0 250.0
This is the resulting LOOK figure.
The EXPB bank is a TABLE, therefore the user has to provide a miniheader with the number of columns (5), and rows (number of data points). Each row then contains the W value, for which the experimental data was measured, the minimum and maximum W values (needed to draw horizontal error bars), and the value of b (in GeV^-2) with its error. Here is an example, used to generate the LOOK figure referenced above:
EXPB 0 / ! Experimental b values
* Values for J/psi production:
5 9 ! NCOL, NROW
* Wmean Wmin Wmax b / GeV**-2 error
16.4 12.7 20.0 4.0 0.0 ! E87, PRL 34:1040
5.8 5.1 6.5 2.9 0.0 ! SLAC, PRL 48:73
4.55 4.2 4.9 1.3 0.2 ! Cornell, PRL 35:1616
10.3 7.9 12.7 1.8 0.4 ! E25, PRL 36:1233
16.8 10.7 23.7 5.6 1.2 ! E401, PRL 48:73
14.0 10.6 17.3 5.0 2.0 ! E516, PRL 52:795
14.1 14.1 14.1 2.5 0.2 ! NA14, ZP C33:505
16.8 10.6 21.2 5.0 1.1 ! NMC, PL 332:195
90.0 30.0 180.0 4.7 1.9 ! H1, DESY 94-153
The =RTX bank contains the name of the user who generates a file. It is a text bank, and used to provide the user name in the LOG file. Therefore, adding this line to the job:
=RTX 0 'Benno List'Results in this line in the LOG file:
Monte-Carlo User: Benno List
The =WRL is used to steer the book-keeping for official Monte Carlo files. It is a text bank, and used to provide the user name in the LOG file. When generating MC files which are to be simulated and reconstructed, and in particular if they are of possibly general interest, then you should turn on the book-keeping (i.e. use the H1 database) in order to get a unique run number (otherwise you always get run number 2).
Therefore, add something like this to the steering files, if you want to produce official files:
=WRL 2 'Benno List' 50620 * | | | | | * | | | | the day of job submittal, for example the 20th * | | | the month of job submittal, for example june * | | the year of job submittal, for example '95 * | replace by your user id * means book-keeping wanted, i.e. this is serious stuff, not a test. * WRL 0 ... no book-keeping wanted * 1 ... temporary book-keeping wanted (i.e. if after a certain time * no action is taken, the records will be discarded) * 2 ... permanent book-keeping wanted
!=> This is the new HEAD bank. (from Feb 92 cosmic run onwards)
! Older descriptions are found in HERA01.H1BANKS.CMZ, patch GENERAL
! Use the H1UTIL function JRDATA to acces the information!
! Additional information which used to be in the HEAD bank is now
! defered to the banks HEAR and ZRCT!
! The KEY of JRDATA is the ATT-name.
! BANKname BANKtype !Comments
!
BANK HEAD ! Bank HEAD
!COL ATT-name FMT Min Max !Comments
1 VERSION I 0 3 ! = 1 + LCONFG(setup configuration=1,2)
2 NRUN I 1 +INF ! run number
3 NEVENT I 0 +INF ! event number
4 EWEIGHT I 0 +INF ! Event weight = Min Prescale
! factor active in this event
! 5 TIME I 700000000 +INF ! Unix time
5 TIME I 0 +INF !
6 RUNTYPE I 0 3 ! Run type
! = 0 for H1 Data
! = 1 Monte Carlo
! = 2 for CERN Test Data
! = 3 for MC CERN Test Data
7 BRERROR I ! combined processing error code
! 1bit per branch: 0 if ok,
! to be filled by level 4
8 DETSTAT I -INF +INF ! Global detector status,
! single bits, 0 if ok
! 0-15 BBL3 alarm bits
! 16-31 HV bits
9 L1CLASS I ! Level 1 classification, bit coded
! 0:
! 1: LAr trigger
! 2: BEMC trigger
! 3: Track trigger
! 4: eTag trigger
! 5: Muon trigger
10 L2CLASS I ! Level 2 classification
11 L3CLASS I ! Level 3 classification
12 L4CLASS I ! Level 4 classification
13 L5CLASS I ! Level 5 classification
!
END BANK
A HEAD bank provided by diffVM looks like this (printed out with H1PRNT in H1UTIL):
+++++ HEAD, 0 NO MINIHEADER.
0----------------------------------------------------------------------------------------------------------------------------------
VERS NRUN NEVT WEIGHT U-TIME RUNTYPE BRERROR DETSTAT L1-CLASS L2-CLASS L3-CLASS L4-CLASS L5-CLASS
----------------------------------------------------------------------------------------------------------------------------------
2 2 1 1 803310707 1 0 0 0 0 0 0 0
0----------------------------------------------------------------------------------------------------------------------------------
diffVM essentially fills only the words VERSION (always 2),
NRUN, NEVENT, EWEIGHT (always 1),
TIME, and RUNTYPE (always 1).
All other words are set to 0.
The HEAD bank should be accessed with the routine JRDATA in H1UTIL, i.e.:
NEVENT = JRDATA ('NEVENT', IRET)
IF (IRET .NE. 0) THEN
PRINT *, 'ERROR: Cannot access HEAR bank'
END IF
! Note from J. Olsson, April 3, 1995, and April 11,1995
! There have been some changes in bit assignments in HEAR words 9,
! 10 and 11, due to the introduction of new detector components. Below
! follows the new description of HEAR, valid for 1995 data taking.
!
! another update of April 11,1995 concerns word 10
!
! Use the H1UTIL function JRDATA to acces the information!
! The KEY of JRDATA is the ATT-name.
! a * in the comment indicates a variable set to 999999999
! if the corresponding measurement is not available.
!
! BANKname BANKtype !Comments
!
BANK HEAR ! Bank HEAR
!COL ATT-name FMT Min Max !Comments
1 IDATE I 910101 991231 ! date yymmdd
2 ITIME I 0 240000 ! time hhmmss including changes between
! summer and winter time,
! i.e. Hamburg local time
3 PLEPIN I -30000 0 !* plepin [MeV], negative
4 PPIN I 0 820000 !* ppin [MeV], positive
5 POLARI I 0 1000 !* polarisation [per mille]
! ...slow controls information...
6 BFIELD I 0 15000 !* Bfield [Gauss]
! Note: use the function GUFLD to get
! the field values!
7 BCURRENT I !* Main magnet current [ADC counts]
8 PRESSURE I !* Pressure [mbar]
9 BBL3 I ! BBL3 Status, (DETSTAT in bank HEAD)
10 SLOWSTA1 I ! Slow Controls status1, Bit ON = HV OFF
! Contains HV Status since 16.8.93
11 SLOWSTA2 I ! Slow Controls status2
! CAEN crate HV-Status bits (one HW level
! per crate). Bit ON means HW level set.
12 NEBUNCH I 0 14352603 ! Npbunch*2**16 + Nebunch
! (0..219) (0..219)
13 ECHARGE I !* current of the triggering e-bunch
! unit microAmp
14 ECURRENT I !* total e-current + LepCha*2**16
! unit 100 microAmp
! (independent msrmnt)
!* LepCha = 0 for e-
!* LepCha = 1 for e+
15 PCHARGE I !* current of the triggering p-bunch
! unit microAmp
16 PCURRENT I !* total p-current in ring + HadCha*2**16
! unit 100 microAmp
! (independent msrmnt)
!* HadCha = 0 for p
!* HadCha = 1 for pbar
17 ARTIFIST I 0 255 ! Artificial Subtriggers set for event:
18 COMPCURR I !* Compensating magnet current
19 TORCURR I !* Toroid magnet current
20 L3RAW I ! Level 3 raw triggers.
21 L3ARBITR I ! Level 3 arbitrated triggers.
22 L3ACTUAL I ! Level 3 actual triggers, ie
! after arbitration and prescaling.
END BANK
The HEAR bank should be accessed with the routine JRDATA in H1UTIL.
The $RTX bank contains comments the user wants to provide as additional information to the generated file. It is a text bank, and its contents are printed in the LOG file, and (for official jobs) added to the database.
Therefore: adding this to your job:
$RTX 0 / $TEXT ! GENERATOR COMMENT BANK (USER'S TEXT IN COLS. 1-72) USER: BENNO LIST DATE: COMPUTER: DICE2 FILENAME: STORAGE: FAST GENERATOR: DIFFVM 1.10 DIFFRACTIVE VECTOR MESON PRODUCTION END$
Results in this output to the LOG file:
Beginning of generator comments: ************************************* USER: BENNO LIST DATE: COMPUTER: DICE2 FILENAME: STORAGE: FAST GENERATOR: DIFFVM 1.10 DIFFRACTIVE VECTOR MESON PRODUCTION End of generator comments: *************************************
The GSTX bank contains all the text input used to steer the generator. Its contents are written to the LOG output, and (for official jobs) also to the database.
Therefore, adding the following to the steering file:
*-----------------------------------------------------------------------
GSTX 0 / $TEXTC ! GENERATOR STEERING TEXT BANK
*
GDIF 0 / ! parameters for diffVM, version >= 1.10/00
*-----------------------------------------------------------------------
* diffVM 1.1 parameters and steering variables available to the user
* are stored in the following commons and can be changed as indicated
* below.
*
* Changing variables:
* The order and the number of variables to be changed are arbitrary.
* In case of a one-dimensional array only the first index is used, the
* second index may have any value.
* The basic rules (for details see the BOS manual) for writing card
* images are:
* 1) columns 1-4 are free
* 2) items (names, indices, values) without inside blanks
* 3) blank(s) between items
* 4) the array names in VAR-NAM have to be shortened to four
* characters if necessay
* 5) comment cards start with '*'
* 6) space behind "!" in each line reserved for comment
*
* VAR-NAM 1.INDX 2.INDX NEW-VALUE ! COMMENT IF NEEDED
* ------- ------ ------ -------- ---------------------------------
*-----------------------------------------------------------------------
************* Beam particles and momenta *******************************
*
* PE: electron beam momentum in GeV/c (positive)
'RPAR' 1 0 27.55 ! (D=30.0) 1995 value (D=design)
*
* PP: proton beam momentum in GeV/c (positive)
* 'RPAR' 2 0 820.0 ! (D=820.0)
*
* IBEAME: PDG code of beam electron
'IPAR' 1 0 -11 ! (D=11) positrons (D=e-)
*
* IBEAMP: PDG code of beam proton
* 'IPAR' 2 0 2212 ! (D=2212)
*
* ----------------------------------------------------------------------
* ************ Vector meson to be generated, decay mode ****************
*
* ITYPVM: PDG Code of generated vector meson
'IPAR' 3 0 443 ! (D=113) J/psi (D: rho)
* possible values:
* 113=rho, 223=omega, 333=phi, 443=J/psi, 20443=psi',
* 553=Upsilon, 20553=Upsilon', 30553=Upsilon''
* special value: 22 for diffr. gamma dissoc.
*
* ITYPEL: PDG code of vector meson decay product
'IPAR' 4 0 11 ! (D=0) decay to e+e- (D:all)
* possible values:
* 11=e+ e-, 13=mu+ mu-, 15=tau+ tau-,
* 211=pi+ pi-, 321+K+ K-, 130=K0L K0S
*
* ----------------------------------------------------------------------
* ************ Cuts on final state particles ***************************
*
* MUCUTS: determines if cuts on the VM particles are to be made
'IPAR' 5 0 1 ! (D=0) apply cuts (D: no)
* Use MUCUTS=1 only for ITYPEL <> -0!
*
* The following cuts must be fulfilled by all charged decay particles,
* if MUCUTS > 0:
*
* EMUMIN: minimum energy of decay particles to get accepted
* 'RPAR' 3 0 0.0 ! (D=0.0)
* CTHMUF: maximal cos(theta) of decay particles
'RPAR' 4 0 0.9962 ! (D=1.0) theta > 5 deg
* CTHMUB: minimal cos(theta) of decay particles
'RPAR' 5 0 -0.9962 ! (D=-1.0) theta < 175 deg
*
* The following cuts must be fulfilled by at least 1 charged decay part.
* if MUCUTS > 0:
*
* EMUMIN2: minimum energy of decay particles to get accepted
* 'RPAR' 6 0 0.0 ! (D=0.0)
* CTHMUF2: maximal cos(theta) of decay particles
'RPAR' 7 0 1.0 ! (D=1.0)
* CTHMUB2: minimal cos(theta) of decay particles
'RPAR' 8 0 -1.0 ! (D=-1.0)
*
* The following cuts must be fulfilled by the scattered electron
*
* CTHELB: minimal cos(theta) of scattered electron
'RPAR' 9 0 -0.9962 ! (D=-1.0) theta < 175 deg
* EELMIN: minimal energy of scattered electron in GeV
'RPAR' 10 0 8.0 ! (D=0.0)
*
* ----------------------------------------------------------------------
* ************ Choice of elastic or inelastic proton vertex
*
* IFRAGP: Fragmentation mode for diffractive proton state *************
* 'IPAR' 6 0 0 ! (D=0)
* possible values:
* 0=Elastic scattering of proton
* 1=Fragmentation by JETSET 7.3
* 2=Isotropic phase space decay into nucleon and pions
* 12212=Elastic N(1440)+ production at p vertex
* (for other N* states, insert respective PDG code)
*
* DEMINP: minimal energy released in decay of diffractive proton state
* 'RPAR' 11 0 0.236 ! (D=0.236)
* If value is too small (smaller than m_pi0),
* diffVM sets value to 0.236 = m_n+m_pi0+0.10 - m_p
* Value is only meaningful for IFRAGP= 1 or 2.
*
* ----------------------------------------------------------------------
* ************ Choice of elastic or inelastic gamma-pomeron vertex *****
*
* IFRAGV: Fragmentation mode for diffractive vector meson state
* 'IPAR' 7 0 0 ! (D=0)
* possible values:
* 0=Elastic vector meson production
* 1=Fragmentation by JETSET 7.3
* 2 =Isotropic phase space decay into VM+pions
* 995=diffractive pomeron-VM scattering
* (glueball production)
* see P.E.SCHLEIN (1994): Phys. Lett. B332, 136-140.
*
* AMASSV: Minimal mass of diffractive VM state
* 'RPAR' 12 0 0.0 ! (D=0.0)
* If value is too small (smaller than m_pi0),
* diffVM sets value to m_VM+ some offset
* Value is only meaningful for IFRAGV= 1 or 2 or 955.
*
* ----------------------------------------------------------------------
* ************ Photon generator mode ***********************************
*
* IGAMMD: Photon generator mode
* 'IPAR' 8 0 1 ! (D=1)
* possible values:
* -1=Fixed photon energy EGAMMA
* 0=1/k spectrum
* 1=WWA spectrum (recommended)
* 2=Full transverse spectrum a la ABT & SMITH
* 3=Full transverse & longitudinal spectrum a la A&S
* 4=As 3, but in proton rest frame
*
* EGAMMA: Energy of photon in GeV for IGAMMD = -1
* 'RPAR' 13 0 3.0 ! (D=3.0)
* Value is only meaningful for IGAMMD=-1.
*
* WMIN: Minimal CM energy of gamma-proton system.
'RPAR' 14 0 20.0 ! (D=0.0)
* If WMIN is too low, it is set by DIFFVM.
*
* WMAX: Maximal CM energy of gamma-proton system.
* 'RPAR' 15 0 0.0 ! (D=0.0)
* If WMIN is too low, it is set by DIFFVM to sqrt (s).
*
* Q2MIN: Minimal Q**2 of photon in GeV**2
'RPAR' 16 0 4.0 ! (D=0.0)
* If Q2MIN is 0, the respective kinematical limit is used
*
* Q2MAX: Maximal Q**2 of photon in GeV**2
'RPAR' 17 0 100.0 ! (D=0.0)
* If Q2MAX is 0, it is set by DIFFVM to s_ep
*
* YMIN: Minimal value of scaling variable y
* 'RPAR' 18 0 0.0 ! (D=0.0)
*
* YMAX: Maximal value of scaling variable y
* 'RPAR' 19 0 1.0 ! (D=1.0)
*
* ----------------------------------------------------------------------
* ************ VMD model parameters ************************************
*
* LAMBDA: Parameter for Q2-dependence of cross section in GeV:
* sigma (Q2) / sigma (0) = 1 / (1 + Q2/Lambda**2)**EPROP
* 'RPAR' 20 0 0.0 ! (D=0.0)
* For lambda=0, lambda is set to VM mass
*
* EPROP: Propagator term exponent
'RPAR' 21 0 2.5 ! (D=2.0)
*
* XI: Parameter for Q**2-dependence of sigma_L/sigma_T:
* 'RPAR' 22 0 1.0 ! (D=1.0)
*
* sigma_L (Q**2) xi Q**2/m**2
* -------------- = --------------------
* sigma_T (Q**2) 1 + xi chi Q**2/m**2
*
* sigma_L/sigma_T -> xi Q**2/m**2 for low Q**2
* sigma_L/sigma_T -> 1 / chi for high Q**2
*
* XI is assumed to be less than 4
* (more precisely: it is assumed that sigma_L(Q**2)
* is always less than sigma_T (0).)
*
* CHI: See above. chi is a purely phenomenological parameter
* with no theoretical justification!
'RPAR' 23 0 1.0 ! (D=0.0)
*
* ----------------------------------------------------------------------
* ************ Parameters for the pomeron ******************************
*
* EPSILW: Intercept of pomeron trajectory minus 1
* controls rise of sigma_gammap with W
'RPAR' 24 0 0.225 ! (D=0.0808)
*
* EPSILM: Intercept of pomeron trajectory minus 1
* controls Mx spectrum (not yet implemented)
* 'RPAR' 25 0 0.0808 ! (D=0.0808)
*
* ALPHA1: slope alpha' of pomeron trajectory in GeV**-2
* controls shrinkkage of b slope
'RPAR' 26 0 0.0 ! (D=0.25)
*
* ----------------------------------------------------------------------
* ************ Parameters for t spectrum *******************************
*
* B0: slope parameter b of t distribution (must be positive!)
* in GeV^-2 at CM energy WB0 and (for diffractive
* dissociation) mass AMXB0
'RPAR' 27 0 4.0 ! (D=10.0) in GeV^-2
*
* WB0: CM energy of gamma-p system at which B0 was measured in GeV
'RPAR' 28 0 95.0 ! (D=14.0)
*
* AMXB0: Mass of diffractively dissociating hadronic system
* for which B0 was measured
* 'RPAR' 29 0 14.0 ! (D=0.0)
* For AMXB0=0.0, AMXB0 is set by diffVM according to
* production mode
* Value is not meaningful for elastic VM production
*
* ----------------------------------------------------------------------
* ************ Parameters for cross section calculation ****************
*
* SIGGP: Total gamma-N x-section of the simulated process
* in pb without cuts for W=WSIG0
'RPAR' 30 0 61.0E3 ! (D=10.0E6)
*
* DSIGGP: Error of total x-section in pb without cuts
'RPAR' 31 0 0.0E3 ! (D=0.0)
*
* WSIG0: gamma-p CM energy at which SIGGP was measured
'RPAR' 32 0 95.0 ! (D=14.0)
*
* BR: Branching ratio of the chosen decay channel
'RPAR' 33 0 0.0598 ! (D=1.0)
* Useful values:
* 1.000 for ITYPEL = 0
* 0.99 for rho0 -> pi+ pi-
* 0.0221 for omega -> pi+ pi-
* 0.491 for phi -> K+ k-
* 0.344 for phi -> K0_L K0_S
* 0.0598 for J/psi -> e+ e-, mu+ mu-
* 0.0396 for psi' -> l+ l- X (including cascade decays)
* 0.0250 for Upsilon (1S) -> l+ l-
* 0.0200 for Upsilon (2S) -> l+ l- X (incl.casc.decays)
* 0.0217 for Upsilon (3S) -> l+ l- X (incl.casc.decays)
*
*-----------------------------------------------------------------------
* ************ Parameters for cross section calculation ****************
* ISCPLT: Generate scatterplots (1) or 2D-histos (0)
'IPAR' 9 0 1 ! (D=0)
* Possible values:
* 1 = Scatterplots for various quantities
* 0 = 2D-Histograms instead of scatterplots
* -1 = No scatterplots/2d-histos
*
*-----------------------------------------------------------------------
************************************************************************
*-----------------------------------------------------------------------
GJET 0 / ! JETSET 7.404 PARAMETERS
*-----------------------------------------------------------------------
* JETSET 7.4 parameters and steering variables available to the user
* are stored in the following commons and can be changed as indicated
* below. They are explained in the JETSET manual.
*
* COMMON /LUDAT1/ MSTU(200),PARU(200),MSTJ(200),PARJ(200)
* COMMON /LUDAT2/ KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4)
* COMMON /LUDAT3/ MDCY(500,3),MDME(2000,2),BRAT(2000),KFDP(2000,5)
* CHARACTER CHAF*8
* COMMON /LUDAT4/ CHAF(500)
*
* Changing variables:
* The order and the number of variables to be changed are arbitrary.
* In case of a one-dimensional array only the first index is used, the
* second index may have any value. In case of the variable CHAF, the
* second index and new-value are used to set the character*8 string.
* The basic rules (for details see the BOS manual) for writing card
* images are:
* 1) columns 1-4 are free
* 2) items (names, indices, values) without inside blanks
* 3) blank(s) between items
* 4) the array names in VAR-NAM have to be shortened to four
* characters if necessay
* 5) comment cards start with '*'
* 6) space behind "!" in each line reserved for comment
*
* VAR-NAM 1.INDX 2.INDX NEW-VALUE ! COMMENT IF NEEDED
* ------- ------ ------ -------- ---------------------------------
* 'MSTJ' 1 0 2 ! (D=1)
* choice of fragmentation scheme.
* 0 = no jet fragmentation at all.
* 1 = string fragmentation according to the Lund model.
* 2 = independent fragmentation, according to specification
* in MSTJ(2) and MSTJ(3).
*
'MSTJ' 22 0 2 ! (D=1) cutoff on decay length
* cut-off on decay length for a particle that is allowed to
* decay according to MSTJ(21) and the MDCY value.
* 2 = a particle is decayed only if its average invariant
* lifetime is larger than PARJ(71); i.e. K0s, Lambda,
* Sigma-+, Sigma+, Xi-, Xi0, and Omega- do not decay
* (H1 standard).
*
* 'PARJ' 71 0 10.0 ! (D=10.0) maximum average proper
* lifetime for particles allowed to decay in the MSTJ(22)=2
* option. With the default value, K0S, Lambda, Sigma-, Sigma+,
* Xi-, Xi0 and Omega- are stable (in addition to those normally
* taken to be stable), but charm and bottom do still decay.
*
'MSTU' 13 0 0 ! (D=1) writing of information
* on values changed by a LUGIVE call.
* 0 = no information is provided
* 1 = information is written to standard output.
*
'MSTU' 21 0 1 ! (D=2) check on possible errors
* during program execution. Obviously no guarantee can be given
* that all errors will be caught, but some of the most trivial
* user-caused errors may be found.
* 0 = errors do not cause any immediate action, rather the
* program will try to cope, which may mean e.g. that it
* runs into an infinite loop.
* 1 = parton/particle configurations are checked for possible
* errors. In case of problem, an exit is made from the
* misbehaving subprogram, but the generation of the event
* is continued from there on. For the first MSTU(22) errors
* a message is printed; after that no messages appear.
* 2 = parton/particle configurations are checked for possible
* errors. In case of problem, an exit is made from the
* misbehaving subprogram, and subsequently from LUEXEC. You
* may then choose to correct the error, and continue the
* execution by another LUEXEC call. For the first MSTU(22)
* errors a message is printed; after that no messages appear.
*
'MSTU' 22 0 100 ! (D=10) maximum number of errors
* that are printed.
*
'PARU' 11 0 0.01 ! (D=0.001) relative error, i.e.
* nonconservation of momentum and energy divided by total
* energy, that may be attributable to machine precision
* problems before a physical error is suspected (see
* MSTU(24)=5).
*
*-----------------------------------------------------------------------
************************************************************************
END$
Results in this output to the LOG file:
Beginning of generator steering:
*************************************
*
GDIF 0 / ! parameters for diffVM, version >= 1.10/00
*-----------------------------------------------------------------------
* diffVM 1.1 parameters and steering variables available to the user
* are stored in the following commons and can be changed as indicated
* below.
*
* Changing variables:
* The order and the number of variables to be changed are arbitrary.
* In case of a one-dimensional array only the first index is used, the
* second index may have any value.
* The basic rules (for details see the BOS manual) for writing card
* images are:
* 1) columns 1-4 are free
* 2) items (names, indices, values) without inside blanks
* 3) blank(s) between items
* 4) the array names in VAR-NAM have to be shortened to four
* characters if necessay
* 5) comment cards start with '*'
* 6) space behind "!" in each line reserved for comment
*
* VAR-NAM 1.INDX 2.INDX NEW-VALUE ! COMMENT IF NEEDED
* ------- ------ ------ -------- ---------------------------------
*-----------------------------------------------------------------------
************* Beam particles and momenta *******************************
*
* PE: electron beam momentum in GeV/c (positive)
'RPAR' 1 0 27.55 ! (D=30.0) 1995 value (D=design)
*
* PP: proton beam momentum in GeV/c (positive)
* 'RPAR' 2 0 820.0 ! (D=820.0)
*
* IBEAME: PDG code of beam electron
'IPAR' 1 0 -11 ! (D=11) positrons (D=e-)
*
* IBEAMP: PDG code of beam proton
* 'IPAR' 2 0 2212 ! (D=2212)
*
* ----------------------------------------------------------------------
* ************ Vector meson to be generated, decay mode ****************
*
* ITYPVM: PDG Code of generated vector meson
'IPAR' 3 0 443 ! (D=113) J/psi (D: rho)
* possible values:
* 113=rho, 223=omega, 333=phi, 443=J/psi, 20443=psi',
* 553=Upsilon, 20553=Upsilon', 30553=Upsilon''
* special value: 22 for diffr. gamma dissoc.
*
* ITYPEL: PDG code of vector meson decay product
'IPAR' 4 0 11 ! (D=0) decay to e+e- (D:all)
* possible values:
* 11=e+ e-, 13=mu+ mu-, 15=tau+ tau-,
* 211=pi+ pi-, 321+K+ K-, 130=K0L K0S
*
* ----------------------------------------------------------------------
* ************ Cuts on final state particles ***************************
*
* MUCUTS: determines if cuts on the VM particles are to be made
'IPAR' 5 0 1 ! (D=0) apply cuts (D: no)
* Use MUCUTS=1 only for ITYPEL <> -0!
*
* The following cuts must be fulfilled by all charged decay particles,
* if MUCUTS > 0:
*
* EMUMIN: minimum energy of decay particles to get accepted
* 'RPAR' 3 0 0.0 ! (D=0.0)
* CTHMUF: maximal cos(theta) of decay particles
'RPAR' 4 0 0.9962 ! (D=1.0) theta > 5 deg
* CTHMUB: minimal cos(theta) of decay particles
'RPAR' 5 0 -0.9962 ! (D=-1.0) theta < 175 deg
*
* The following cuts must be fulfilled by at least 1 charged decay part.
* if MUCUTS > 0:
*
* EMUMIN2: minimum energy of decay particles to get accepted
* 'RPAR' 6 0 0.0 ! (D=0.0)
* CTHMUF2: maximal cos(theta) of decay particles
'RPAR' 7 0 1.0 ! (D=1.0)
* CTHMUB2: minimal cos(theta) of decay particles
'RPAR' 8 0 -1.0 ! (D=-1.0)
*
* The following cuts must be fulfilled by the scattered electron
*
* CTHELB: minimal cos(theta) of scattered electron
'RPAR' 9 0 -0.9962 ! (D=-1.0) theta < 175 deg
* EELMIN: minimal energy of scattered electron in GeV
'RPAR' 10 0 8.0 ! (D=0.0)
*
* ----------------------------------------------------------------------
* ************ Choice of elastic or inelastic proton vertex
*
* IFRAGP: Fragmentation mode for diffractive proton state *************
* 'IPAR' 6 0 0 ! (D=0)
* possible values:
* 0=Elastic scattering of proton
* 1=Fragmentation by JETSET 7.3
* 2=Isotropic phase space decay into nucleon and pions
* 12212=Elastic N(1440)+ production at p vertex
* (for other N* states, insert respective PDG code)
*
* DEMINP: minimal energy released in decay of diffractive proton state
* 'RPAR' 11 0 0.236 ! (D=0.236)
* If value is too small (smaller than m_pi0),
* diffVM sets value to 0.236 = m_n+m_pi0+0.10 - m_p
* Value is only meaningful for IFRAGP= 1 or 2.
*
* ----------------------------------------------------------------------
* ************ Choice of elastic or inelastic gamma-pomeron vertex *****
*
* IFRAGV: Fragmentation mode for diffractive vector meson state
* 'IPAR' 7 0 0 ! (D=0)
* possible values:
* 0=Elastic vector meson production
* 1=Fragmentation by JETSET 7.3
* 2 =Isotropic phase space decay into VM+pions
* 995=diffractive pomeron-VM scattering
* (glueball production)
* see P.E.SCHLEIN (1994): Phys. Lett. B332, 136-140.
*
* AMASSV: Minimal mass of diffractive VM state
* 'RPAR' 12 0 0.0 ! (D=0.0)
* If value is too small (smaller than m_pi0),
* diffVM sets value to m_VM+ some offset
* Value is only meaningful for IFRAGV= 1 or 2 or 955.
*
* ----------------------------------------------------------------------
* ************ Photon generator mode ***********************************
*
* IGAMMD: Photon generator mode
* 'IPAR' 8 0 1 ! (D=1)
* possible values:
* -1=Fixed photon energy EGAMMA
* 0=1/k spectrum
* 1=WWA spectrum (recommended)
* 2=Full transverse spectrum a la ABT & SMITH
* 3=Full transverse & longitudinal spectrum a la A&S
* 4=As 3, but in proton rest frame
*
* EGAMMA: Energy of photon in GeV for IGAMMD = -1
* 'RPAR' 13 0 3.0 ! (D=3.0)
* Value is only meaningful for IGAMMD=-1.
*
* WMIN: Minimal CM energy of gamma-proton system.
'RPAR' 14 0 20.0 ! (D=0.0)
* If WMIN is too low, it is set by DIFFVM.
*
* WMAX: Maximal CM energy of gamma-proton system.
* 'RPAR' 15 0 0.0 ! (D=0.0)
* If WMIN is too low, it is set by DIFFVM to sqrt (s).
*
* Q2MIN: Minimal Q**2 of photon in GeV**2
'RPAR' 16 0 4.0 ! (D=0.0)
* If Q2MIN is 0, the respective kinematical limit is used
*
* Q2MAX: Maximal Q**2 of photon in GeV**2
'RPAR' 17 0 100.0 ! (D=0.0)
* If Q2MAX is 0, it is set by DIFFVM to s_ep
*
* YMIN: Minimal value of scaling variable y
* 'RPAR' 18 0 0.0 ! (D=0.0)
*
* YMAX: Maximal value of scaling variable y
* 'RPAR' 19 0 1.0 ! (D=1.0)
*
* ----------------------------------------------------------------------
* ************ VMD model parameters ************************************
*
* LAMBDA: Parameter for Q2-dependence of cross section in GeV:
* sigma (Q2) / sigma (0) = 1 / (1 + Q2/Lambda**2)**EPROP
* 'RPAR' 20 0 0.0 ! (D=0.0)
* For lambda=0, lambda is set to VM mass
*
* EPROP: Propagator term exponent
'RPAR' 21 0 2.5 ! (D=2.0)
*
* XI: Parameter for Q**2-dependence of sigma_L/sigma_T:
* 'RPAR' 22 0 1.0 ! (D=1.0)
*
* sigma_L (Q**2) xi Q**2/m**2
* -------------- = --------------------
* sigma_T (Q**2) 1 + xi chi Q**2/m**2
*
* sigma_L/sigma_T -> xi Q**2/m**2 for low Q**2
* sigma_L/sigma_T -> 1 / chi for high Q**2
*
* XI is assumed to be less than 4
* (more precisely: it is assumed that sigma_L(Q**2)
* is always less than sigma_T (0).)
*
* CHI: See above. chi is a purely phenomenological parameter
* with no theoretical justification!
'RPAR' 23 0 1.0 ! (D=0.0)
*
* ----------------------------------------------------------------------
* ************ Parameters for the pomeron ******************************
*
* EPSILW: Intercept of pomeron trajectory minus 1
* controls rise of sigma_gammap with W
'RPAR' 24 0 0.225 ! (D=0.0808)
*
* EPSILM: Intercept of pomeron trajectory minus 1
* controls Mx spectrum (not yet implemented)
* 'RPAR' 25 0 0.0808 ! (D=0.0808)
*
* ALPHA1: slope alpha' of pomeron trajectory in GeV**-2
* controls shrinkkage of b slope
'RPAR' 26 0 0.0 ! (D=0.25)
*
* ----------------------------------------------------------------------
* ************ Parameters for t spectrum *******************************
*
* B0: slope parameter b of t distribution (must be positive!)
* in GeV^-2 at CM energy WB0 and (for diffractive
* dissociation) mass AMXB0
'RPAR' 27 0 4.0 ! (D=10.0) in GeV^-2
*
* WB0: CM energy of gamma-p system at which B0 was measured in GeV
'RPAR' 28 0 95.0 ! (D=14.0)
*
* AMXB0: Mass of diffractively dissociating hadronic system
* for which B0 was measured
* 'RPAR' 29 0 14.0 ! (D=0.0)
* For AMXB0=0.0, AMXB0 is set by diffVM according to
* production mode
* Value is not meaningful for elastic VM production
*
* ----------------------------------------------------------------------
* ************ Parameters for cross section calculation ****************
*
* SIGGP: Total gamma-N x-section of the simulated process
* in pb without cuts for W=WSIG0
'RPAR' 30 0 61.0E3 ! (D=10.0E6)
*
* DSIGGP: Error of total x-section in pb without cuts
'RPAR' 31 0 0.0E3 ! (D=0.0)
*
* WSIG0: gamma-p CM energy at which SIGGP was measured
'RPAR' 32 0 95.0 ! (D=14.0)
*
* BR: Branching ratio of the chosen decay channel
'RPAR' 33 0 0.0598 ! (D=1.0)
* Useful values:
* 1.000 for ITYPEL = 0
* 0.99 for rho0 -> pi+ pi-
* 0.0221 for omega -> pi+ pi-
* 0.491 for phi -> K+ k-
* 0.344 for phi -> K0_L K0_S
* 0.0598 for J/psi -> e+ e-, mu+ mu-
* 0.0396 for psi' -> l+ l- X (including cascade decays)
* 0.0250 for Upsilon (1S) -> l+ l-
* 0.0200 for Upsilon (2S) -> l+ l- X (incl.casc.decays)
* 0.0217 for Upsilon (3S) -> l+ l- X (incl.casc.decays)
*
*-----------------------------------------------------------------------
* ************ Parameters for cross section calculation ****************
* ISCPLT: Generate scatterplots (1) or 2D-histos (0)
'IPAR' 9 0 1 ! (D=0)
* Possible values:
* 1 = Scatterplots for various quantities
* 0 = 2D-Histograms instead of scatterplots
* -1 = No scatterplots/2d-histos
*
*-----------------------------------------------------------------------
************************************************************************
*-----------------------------------------------------------------------
GJET 0 / ! JETSET 7.404 PARAMETERS
*-----------------------------------------------------------------------
* JETSET 7.4 parameters and steering variables available to the user
* are stored in the following commons and can be changed as indicated
* below. They are explained in the JETSET manual.
*
* COMMON /LUDAT1/ MSTU(200),PARU(200),MSTJ(200),PARJ(200)
* COMMON /LUDAT2/ KCHG(500,3),PMAS(500,4),PARF(2000),VCKM(4,4)
* COMMON /LUDAT3/ MDCY(500,3),MDME(2000,2),BRAT(2000),KFDP(2000,5)
* CHARACTER CHAF*8
* COMMON /LUDAT4/ CHAF(500)
*
* Changing variables:
* The order and the number of variables to be changed are arbitrary.
* In case of a one-dimensional array only the first index is used, the
* second index may have any value. In case of the variable CHAF, the
* second index and new-value are used to set the character*8 string.
* The basic rules (for details see the BOS manual) for writing card
* images are:
* 1) columns 1-4 are free
* 2) items (names, indices, values) without inside blanks
* 3) blank(s) between items
* 4) the array names in VAR-NAM have to be shortened to four
* characters if necessay
* 5) comment cards start with '*'
* 6) space behind "!" in each line reserved for comment
*
* VAR-NAM 1.INDX 2.INDX NEW-VALUE ! COMMENT IF NEEDED
* ------- ------ ------ -------- ---------------------------------
* 'MSTJ' 1 0 2 ! (D=1)
* choice of fragmentation scheme.
* 0 = no jet fragmentation at all.
* 1 = string fragmentation according to the Lund model.
* 2 = independent fragmentation, according to specification
* in MSTJ(2) and MSTJ(3).
*
'MSTJ' 22 0 2 ! (D=1) cutoff on decay length
* cut-off on decay length for a particle that is allowed to
* decay according to MSTJ(21) and the MDCY value.
* 2 = a particle is decayed only if its average invariant
* lifetime is larger than PARJ(71); i.e. K0s, Lambda,
* Sigma-+, Sigma+, Xi-, Xi0, and Omega- do not decay
* (H1 standard).
*
* 'PARJ' 71 0 10.0 ! (D=10.0) maximum average proper
* lifetime for particles allowed to decay in the MSTJ(22)=2
* option. With the default value, K0S, Lambda, Sigma-, Sigma+,
* Xi-, Xi0 and Omega- are stable (in addition to those normally
* taken to be stable), but charm and bottom do still decay.
*
'MSTU' 13 0 0 ! (D=1) writing of information
* on values changed by a LUGIVE call.
* 0 = no information is provided
* 1 = information is written to standard output.
*
'MSTU' 21 0 1 ! (D=2) check on possible errors
* during program execution. Obviously no guarantee can be given
* that all errors will be caught, but some of the most trivial
* user-caused errors may be found.
* 0 = errors do not cause any immediate action, rather the
* program will try to cope, which may mean e.g. that it
* runs into an infinite loop.
* 1 = parton/particle configurations are checked for possible
* errors. In case of problem, an exit is made from the
* misbehaving subprogram, but the generation of the event
* is continued from there on. For the first MSTU(22) errors
* a message is printed; after that no messages appear.
* 2 = parton/particle configurations are checked for possible
* errors. In case of problem, an exit is made from the
* misbehaving subprogram, and subsequently from LUEXEC. You
* may then choose to correct the error, and continue the
* execution by another LUEXEC call. For the first MSTU(22)
* errors a message is printed; after that no messages appea
*
'MSTU' 22 0 100 ! (D=10) maximum number of errors
* that are printed.
*
'PARU' 11 0 0.01 ! (D=0.001) relative error, i.e.
* nonconservation of momentum and energy divided by total
* energy, that may be attributable to machine precision
* problems before a physical error is suspected (see
* MSTU(24)=5).
*
*-----------------------------------------------------------------------
************************************************************************
End of generator steering:
*************************************
The GDIR bank contains the steering parameters of diffVM that have floating point format. Here is its DDL description:
! BANKname BANKtype !Comments
!
BANK GDIR ! diffVM real valued parameters
!
! ATTributes:
! -----------
!COL ATT-name FMT Min Max !Comments
!
1 PE F ! electron beam momentum in GeV/c
2 PP F ! proton beam momentum in GeV/c
! Cuts that must be fullfilled by all particles
3 EMUMIN F ! mimimumm energy in GeV of decay particles to
! be accepted
4 CTHMUF F ! maximum cos(theta) for decay particles
5 CTHMUB F ! minimum cos(theta) for decay particles
! Cuts that must be fullfilled by at least 1 particle:
6 EMUMN2 F ! mimimumm energy in GeV of decay particles to
! be accepted
7 CTHMF2 F ! maximum cos(theta) for decay particles
8 CTHMB2 F ! minimum cos(theta) for decay particles
! Cuts for the scattered electron:
9 CTHELB F ! minimum cos(theta) for scattered electron
10 EELMIN F ! minimum energy of scattered electron in GeV
11 DEMINP F ! minimal energy [GeV] released in decay of
! proton state
12 AMASSV F ! minimal mass [GeV] of excited VM state
13 EGAMMA F ! Photon energy [GeV] for fixed photon mode
14 WMIN F ! Minimum CM energy of gamma-p system in GeV
15 WMAX F ! Maximum CM energy of gamma-p system in GeV
16 Q2MIN F ! Minimal Q2 of photon in GeV**2
17 Q2MAX F ! Maximal Q2 of photon in GeV**2
18 YMIN F ! Minimum value of scaling variable y
19 YMAX F ! Maximum value of scaling variable y
20 LAMBDA F ! Mass parameter for propagator term
21 EPROP F ! Exponent n for propagator term
! (1+Q^2/Lambda^2)**-n
22 XI F ! Parameter for Q**2 dependence of sig_L/sig_T
23 CHI F ! Parameter for Q**2 dependence of sig_L/sig_T
24 EPSILW F ! Intercept minus 1 of pomeron trajetory
! (affects W dependence of cross section)
25 EPSILM F ! Intercept minus 1 of pomeron trajetory
! (affects M_X spectrum)
26 ALPHA1 F ! Slope of pomeron trajetory in GeV**-2
27 B0 F ! momentum transfer (t) slope parameter [GeV^-2]
28 WB F ! CM energy at which B was measured
29 AMXB0 F ! M_x at which B was measured
30 SIGGP F ! Total x-section of simulated process in pb
! without cuts
31 DSIGGP F ! Error of total x-section in pb without cuts
32 WSIG0 F ! CM energy at which SIGTOT was measured
33 BR F ! Branching ration of chosen decay channel
!
END BANK
If the GDIF bank is not present in the input stream, then GDIR bank can be used (together with the GDII bank) to define all input parameters for diffVM.
diffVM prints out the contents of the GDIR bank to the standard output in a way that can be used as definition a a text bank:
GDIR 0 / diffVM parameter steering bank
27.55000 ! PE
820.00000 ! PP
0.00000 ! EMUMIN
0.99620 ! CTHMUF
-0.99620 ! CTHMUB
0.00000 ! EMUMN2
1.00000 ! CTHMF2
-1.00000 ! CTHMB2
-0.99620 ! CTHELB
8.00000 ! EELMIN
0.23600 ! DEMINP
4.00000 ! AMASSV
3.00000 ! EGAMMA
20.00000 ! WMIN
300.60751 ! WMAX
4.00000 ! Q2MIN
100.00000 ! Q2MAX
0.00000 ! YMIN
1.00000 ! YMAX
3.09688 ! LAMBDA
2.50000 ! EPROP
1.00000 ! XI
1.00000 ! CHI
0.22500 ! EPSILW
0.08080 ! EPSILM
0.00000 ! ALPHA1
4.00000 ! B0
95.00000 ! WB0
3.09688 ! AMXB0
61000.00000 ! SIGGP
0.00000 ! DSIGGP
95.00000 ! WSIG0
0.05980 ! BR
*
*-----------------------------------------------------------------------
The GDII bank contains the steering parameters of diffVM that have integer format. Here is its DDL description:
! BANKname BANKtype !Comments
!
BANK GDII ! diffVM integer valued parameters
!
! ATTributes:
! -----------
!COL ATT-name FMT Min Max !Comments
!
1 IBEAME I ! beam electron/positron PDG code
2 IBEAMP I ! beam proton PDG code
3 ITYPVM I ! PDG code for produced vector meson
4 ITYPEL I ! PDG code for particles produced by decaying VM
5 MUCUTS I ! Determines if cuts on decay particles are to
! be applied (MUCUTS > 0) or not (MUCUTS = 0).
6 IFRAGP I ! Fragmentation mode for diffractive proton state
! 0: Elastic scattering of the proton
! 1: Fragmentation by JETSET 7.3
! 2: Isotropic phase space decay into nucleon and pions
! >2: Elastic N* production at p vertex;
! IFRAGP gives PDG code of N*
7 IFRAGV I ! Fragmentation mode for diffractive vector
! meson state
! 0: Elastic production of the vector meson
! 1: Fragmentation by JETSET 7.3
! 2: Isotropic phase space decay into vector
! meson and pions
8 IGAMMOD I ! Photon generator mode:
!-1: Fixed photon energy EGAMMA
! 0: 1/k spectrum
! 1: WWA approximation
! 2: Full transverse spectrum after SMITH (H1-12/92-259)
! 3: Full transverse & longitudinal spectrum
! 4: As 3, but in proton rest frame
9 ISCPLT I ! Flag for scatterplots
! 1: Generate scatterplots
! 0: Generate 2d-histograms instead
!-1: No scatterplots/2d-histograms at all
!
END BANK
If the GDIF bank is not present in the input
stream, then GDIR bank can be used (together with the
GDII bank) to define all input parameters
for diffVM.
diffVM prints out the contents of the GDII bank to the standard output in a way that can be used as definition a a text bank:
GDII 0 / diffVM parameter steering bank
-11 ! IBEAME
2212 ! IBEAMP
443 ! ITYPVM
11 ! ITYPEL
1 ! MUCUTS
0 ! IFRAGP
0 ! IFRAGV
1 ! IGAMMD
1 ! ISCPLT
*
*-----------------------------------------------------------------------
The GDIA bank contains the steering parameters of diffVM that have character format. Currently, there are no such parameters, and consequently the bank is empty.
The GTR bank provided by diffVM contains a number of entries providing special information. Look at the first example GTR bank below: The process simulated is elastic diffractive rho photoproduction, i.e.
e+ p -> e+ gamma p -> e+ rho0 p
|-> pi+ pi-
The rho0 decays to pi+ pi-.
The incoming beam electron/positron is always found in the 1st row, the beam proton is in the 2nd row. The 3rd row contains the scattered electron/positron.
The 4th row contains the virtual photon. Note that the mass of the photon is set to -sqrt (Q^2); the 5th row indicates the virtual vector meson (before it has exchanged a pomeron with the proton). Row 6 contains the exchanged pomeron (particle code 29), with "mass" -sqrt (t). The pomeron is thought to be emitted off the proton.
Row 7 always contains the scattered proton state, which may be a proton, a N*+ resonance, or a diffractively excited proton state (denoted by p_diffr+, particle code 2210).
Row 8 always contains the vector meson state, which may be a real vector meson, or a diffractively excited vector meson state (denoted by either rho_diffr0, omega_diffr0, phi_diffr0, J/psi_diffr0, or Upsilon_dif0, particle codes 110, 220, 330, 440, and 550, respectively). If the proton does not stay intact, then the following rows contain the decay particles of the proton state. The decay particles of the vector meson follow sfter that.
Here are a few example GTR banks
(printed out with H1PRNT in H1UTIL):
Below, you find the GVX bank that belongs to this
GTR bank.
> This GVX bank belongs to the third
GTR example bank shown above
(printed out with H1PRNT in H1UTIL):
The "official" part of a GKI bank provided by diffVM looks like this
(printed out with H1PRNT in H1UTIL):
The words SIGMT, DSIGMT,
SIGMS, and DSIGMS are set to -99999.0 to indicate
that they are not valid, since diffVM calculates the cross section only
at the end of the generator run.
So are all other words not used by diffVM.
X2 has a special meaning, it contains x_pom, defined as
x_pom = (p_pom.q)/(P.q), where p_pom, P and q denote the 4-momenta of
the pomeron, the proton, and the exchanged photon, respectively.
SHAT also has a special meaning, it contains the mass squared
of the diffractive state on the vector meson-pomeron vertex
(i.e. the vector meson mass squared for elastic VM production).
To provide fuller information, diffVM produces an extended GKI bank
with 42 instead of 31 words. This is the DDL description of the extension:
A GHD bank provided by diffVM looks like this
(printed out with H1PRNT in H1UTIL):
A GEVC bank provided by diffVM (version greater than 1.05/01)
looks like this
(printed out with H1PRNT in H1UTIL):
NQUHUT indicates the quark flavor out of the vector meson.
If the meson is produced elastically, it is related to the PDG code of
the vector meson, i. e. NQUHUT is 1 for rho production,
2 for omega, 3 for phi, 4 for J/psi, and 5 for Upsilon.
If the vector meson dissociates, NQUHUT
refers to the flavor of the quark-antiquark pair at the ends of the LUND string.
For rho and omega dissociation, NQUHUT may be 1 or 2
(both vector mesons are assumed to be 50% uu~, 50% dd~),
for phi dissociation it will be 3, and so on.
To fill NPAHUT, diffVM loops over the total final state,
and sets the bits corresponding to all quarks and leptons it finds.
The gauge boson bits are always off, since no hard radiation processes
are implemented in diffVM, except for the gluon bit, which is set
if an Upsilon is decayed by JETSET via 3 gluons.
In the above sample, a J/psi dissociates, and one of the c quarks decays
to e nu.
Remark: The entry in NQUHUT refers to the quark content
of the vector meson, even if the flavor is "hidden".
In that case, the flavor named in NQUHUT does not necessarily
appear in NPAHUT, which lists only partons that have an extra
entry in the GTR bank.
GTR bank for elastic rho production in DIS
The rho decays to pi+ pi-.
+++++ GTR , 0 BANK LENGTH 112 NUMBER OF COLUMNS 11 NUMBER OF ROWS 10
0----------------------------------------------------------------------------------------------------------------------------------
PARTICLE PARTICLE PARENT MOMENTUM (GEV) ENERGY MASS CHARGE LINK TO
TYPE FLAG PARTICLE PX PY PZ (GEV) (GEV) VERTEX,GVX
----------------------------------------------------------------------------------------------------------------------------------
1 e+ beam part. 0 0 0.000 0.000 -27.550 27.550 0.0005 1.0000 1
2 p+ beam part. 0 0 0.000 0.000 820.000 820.001 0.9383 1.0000 1
3 e+ undecayed 1 0 -2.840 -1.049 -25.784 25.961 0.0005 1.0000 1
4 gamma document. 1 0 2.840 1.049 -1.766 1.589 -3.1242 0.0000 1
5 rho0 document. 4 0 2.840 1.049 -1.766 1.589 -3.1242 0.0000 1
6 pomeron document. 2 0 -0.055 0.106 1.528 1.528 -0.1198 0.0000 1
7 p+ undecayed 2 0 0.055 -0.106 818.472 818.473 0.9383 1.0000 1
8 rho0 decay/frag 5 6 2.785 1.155 -0.239 3.117 0.7550 0.0000 1
9 pi+ undecayed 8 0 0.904 0.397 0.247 1.027 0.1396 1.0000 1
10 pi- undecayed 8 0 1.881 0.758 -0.486 2.090 0.1396 -1.0000 1
0----------------------------------------------------------------------------------------------------------------------------------
GTR bank for J/psi production with proton dissociation
The proton becomes a diffractively excited state, which splits into a
quark-diquark system
(the quark is thought to be kicked out of the proton by the pomeron).
The quark-diquark system is linked by a Lund-string and fragmented by JETSET.
+++++ GTR , 0 BANK LENGTH 354 NUMBER OF COLUMNS 11 NUMBER OF ROWS 32
0----------------------------------------------------------------------------------------------------------------------------------
PARTICLE PARTICLE PARENT MOMENTUM (GEV) ENERGY MASS CHARGE LINK TO
TYPE FLAG PARTICLE PX PY PZ (GEV) (GEV) VERTEX,GVX
----------------------------------------------------------------------------------------------------------------------------------
1 e+ beam part. 0 0 0.000 0.000 -27.550 27.550 0.0005 1.0000 1
2 p+ beam part. 0 0 0.000 0.000 820.000 820.001 0.9383 1.0000 1
3 e+ undecayed 1 0 0.877 -1.509 -12.770 12.889 0.0005 1.0000 1
4 gamma document. 1 0 -0.877 1.509 -14.780 14.661 -2.5569 0.0000 1
5 J/psi0 document. 4 0 -0.877 1.509 -14.780 14.661 -2.5569 0.0000 1
6 pomeron document. 2 0 0.053 0.049 0.284 0.266 -0.1235 0.0000 1
7 p_diffr+ decay/frag 2 0 -0.053 -0.049 819.716 819.735 5.5460 1.0000 1
8 J/psi0 decay/frag 5 6 -0.824 1.558 -14.496 14.927 3.0969 0.0000 1
9 ud_1 decay/frag 7 0 0.000 0.000 819.582 819.582 0.9378 0.3300 1
10 u decay/frag 7 0 -0.053 -0.049 0.134 0.152 0.0005 0.6700 1
11 ud_1 decay/frag 9 0 0.000 0.000 819.582 819.582 0.9378 0.3300 1
12 u decay/frag 10 0 -0.053 -0.049 0.134 0.152 0.0005 0.6700 1
13 string decay/frag 11 12 -0.053 -0.049 819.716 819.734 5.5444 0.0000 1
14 Delta0 decay/frag 13 0 -0.062 0.232 326.026 326.028 1.1767 0.0000 1
15 pi0 decay/frag 13 0 0.294 -0.393 432.882 432.882 0.1350 0.0000 1
16 pi+ undecayed 13 0 -0.448 0.086 36.223 36.227 0.1396 1.0000 1
17 omega0 decay/frag 13 0 0.163 0.027 24.585 24.598 0.7859 0.0000 1
18 p+ undecayed 14 0 -0.104 0.195 310.220 310.222 0.9383 1.0000 1
19 pi- undecayed 14 0 0.042 0.037 15.806 15.807 0.1396 -1.0000 1
20 gamma undecayed 15 0 0.208 -0.308 367.158 367.159 0.0000 0.0000 1
21 gamma undecayed 15 0 0.086 -0.085 65.723 65.723 0.0000 0.0000 1
22 pi- undecayed 17 0 -0.048 0.115 10.962 10.964 0.1396 -1.0000 1
23 pi+ undecayed 17 0 0.268 -0.016 11.869 11.873 0.1396 1.0000 1
24 pi0 decay/frag 17 0 -0.058 -0.073 1.754 1.761 0.1350 0.0000 1
25 gamma undecayed 24 0 -0.083 -0.006 0.647 0.652 0.0000 0.0000 1
26 gamma undecayed 24 0 0.025 -0.067 1.107 1.109 0.0000 0.0000 1
27 K0 decay/frag 8 0 -0.134 0.557 -4.952 5.010 0.4977 0.0000 1
28 n0# undecayed 8 0 -0.141 0.404 -3.367 3.522 0.9396 0.0000 1
29 n0 undecayed 8 0 -0.318 0.417 -3.755 3.906 0.9396 0.0000 1
30 K0# decay/frag 8 0 -0.230 0.180 -2.422 2.489 0.4977 0.0000 1
31 K_S0 undecayed 27 0 -0.134 0.557 -4.952 5.010 0.4977 0.0000 1
32 K_S0 undecayed 30 0 -0.230 0.180 -2.422 2.489 0.4977 0.0000 1
0----------------------------------------------------------------------------------------------------------------------------------
GTR bank for J/psi production with double diffractive dissociation
The proton becomes a N* state, which decays to Delta++ pi-, the Delta decays
then to p pi+
(handeled by a special subroutine in diffVM).
The J/psi splits into a quark-antiquark system
(the quark is thought to be kicked out of the J/psi by the pomeron,
the antiquark is a spectator).
The quark-antiquark system is linked by a Lund-string and fragmented by JETSET.
+++++ GTR , 0 BANK LENGTH 453 NUMBER OF COLUMNS 11 NUMBER OF ROWS 41
0----------------------------------------------------------------------------------------------------------------------------------
PARTICLE PARTICLE PARENT MOMENTUM (GEV) ENERGY MASS CHARGE LINK TO
TYPE FLAG PARTICLE PX PY PZ (GEV) (GEV) VERTEX,GVX
----------------------------------------------------------------------------------------------------------------------------------
1 e+ beam part. 0 0 0.000 0.000 -27.550 27.550 0.0005 1.0000 1
2 p+ beam part. 0 0 0.000 0.000 820.000 820.001 0.9383 1.0000 1
3 e+ undecayed 1 0 -3.357 -0.596 -27.300 27.512 0.0005 1.0000 1
4 gamma document. 1 0 3.357 0.596 -0.250 0.038 -3.4188 0.0000 1
5 J/psi0 document. 4 0 3.357 0.596 -0.250 0.038 -3.4188 0.0000 1
6 pomeron document. 2 0 0.079 -0.267 78.577 78.576 -0.4667 0.0000 1
7 N(1440)+ decay/frag 2 0 -0.079 0.267 741.423 741.425 1.4300 1.0000 1
8 J/psi_diffr0decay/frag 5 6 3.436 0.329 78.327 78.614 5.7490 0.0000 1
9 Delta++ decay/frag 7 0 -0.196 0.154 690.856 690.857 1.1345 2.0000 1
10 pi- undecayed 7 0 0.118 0.112 50.567 50.567 0.1396 -1.0000 1
11 p+ undecayed 9 0 -0.144 0.101 500.174 500.175 0.9383 1.0000 1
12 pi+ undecayed 9 0 -0.053 0.053 190.682 190.682 0.1396 1.0000 1
13 c decay/frag 8 0 0.263 -0.153 55.967 55.984 1.3500 0.6700 1
14 c# decay/frag 8 0 3.173 0.482 22.361 22.631 1.3500 -0.6700 1
15 c decay/frag 13 0 0.263 -0.153 55.967 55.984 1.3500 0.6700 1
16 c# decay/frag 14 0 3.173 0.482 22.361 22.631 1.3500 -0.6700 1
17 string decay/frag 15 16 3.436 0.329 78.328 78.615 5.7491 0.0000 1
18 D*_s+ decay/frag 17 0 0.757 -0.242 46.942 46.997 2.1100 1.0000 1
19 K- undecayed 17 0 0.298 0.351 7.260 7.291 0.4936 -1.0000 1
20 D*0# decay/frag 17 0 2.380 0.220 24.128 24.329 2.0071 0.0000 1
21 D_s+ decay/frag 18 0 0.716 -0.313 41.941 41.995 1.9688 1.0000 1
22 gamma undecayed 18 0 0.042 0.071 5.001 5.002 0.0000 0.0000 1
23 D0# decay/frag 20 0 2.233 0.248 22.521 22.710 1.8645 0.0000 1
24 pi0 decay/frag 20 0 0.147 -0.027 1.607 1.619 0.1350 0.0000 1
25 rho+ decay/frag 21 0 0.075 -0.362 10.855 10.887 0.7452 1.0000 2
26 pi0 decay/frag 21 0 0.169 -0.149 7.524 7.528 0.1350 0.0000 2
27 rho0 decay/frag 21 0 0.472 0.198 23.562 23.579 0.7357 0.0000 2
28 K+ undecayed 23 0 0.735 0.528 6.707 6.785 0.4936 1.0000 3
29 pi- undecayed 23 0 0.125 -0.314 2.537 2.563 0.1396 -1.0000 3
30 pi- undecayed 23 0 0.183 -0.123 3.375 3.385 0.1396 -1.0000 3
31 pi+ undecayed 23 0 1.189 0.157 9.902 9.976 0.1396 1.0000 3
32 gamma undecayed 24 0 0.092 0.048 1.011 1.016 0.0000 0.0000 1
33 gamma undecayed 24 0 0.055 -0.075 0.596 0.603 0.0000 0.0000 1
34 pi+ undecayed 25 0 -0.290 -0.170 3.442 3.461 0.1396 1.0000 2
35 pi0 decay/frag 25 0 0.364 -0.192 7.414 7.426 0.1350 0.0000 2
36 gamma undecayed 26 0 0.148 -0.124 4.226 4.230 0.0000 0.0000 2
37 gamma undecayed 26 0 0.021 -0.025 3.298 3.298 0.0000 0.0000 2
38 pi+ undecayed 27 0 0.299 0.163 4.297 4.313 0.1396 1.0000 2
39 pi- undecayed 27 0 0.174 0.035 19.265 19.266 0.1396 -1.0000 2
40 gamma undecayed 35 0 0.134 -0.029 1.618 1.623 0.0000 0.0000 2
41 gamma undecayed 35 0 0.230 -0.163 5.796 5.803 0.0000 0.0000 2
0----------------------------------------------------------------------------------------------------------------------------------
The GVX Bank
The GVX bank contains information on the location of
all vertices.
It always contains a primary vertex at (0, 0, 0);
! BANKname BANKtype !Comments
!
TABLE GVX ! Generator_VerteX
!
! Note: In H1 standard generation, particles with c*tau >= 1cm (life-
! time >= 0.333*E-10 sec) are not decayed by the generators, i.e.
! K0_s, Lambda, Sigma+, Sigma-, Chi0, Chi- and Omega- are stable.
! Particles with shorter life-time are decayed by the generators
! and may either all originate from the primary vertex or may
! obtain a decay vertex by GENOUT.
!
! ATTributes:
! -----------
!COL ATT-name FMT Min Max !Comments
!
1 X F ! x coordinate of vertex in cm
2 Y F ! y coordinate of vertex in cm
3 Z F ! z coordinate of vertex in cm
4 Vtype I ! type of vertex
! 1 = primary
! 2 = decay
! 3 = secondary interaction
5 T0 F ! time assigned to vertex in seconds
!
END TABLE
+++++ GVX , 0 BANK LENGTH 17 NUMBER OF COLUMNS 5 NUMBER OF ROWS 3
0----------------------------------------------------------------------------------------------------------------------------------
VERTEX COORDINATES (CM) VERTEX TIME OF
X Y Z TYPE FLIGHT (NS)
----------------------------------------------------------------------------------------------------------------------------------
1 0.000 0.000 0.000 primary 0.000
2 0.000 0.000 0.019 decay 0.001
3 0.019 0.002 0.191 decay 0.006
0----------------------------------------------------------------------------------------------------------------------------------
The GKI Bank
The GKI bank contains information on the kinematics of an event.
Here is its DDL description:
! BANKname BANKtype !Comments
!
BANK GKI ! Generaor Kinematics
!
! The GKI bank contains important kinematical variables of the event
! and some additional information to allow weighting and reweighting
! of the event in the analysis.
! All generators should give/calculate the variables 1 to 25 if
! possible. Generators for specific processes may define additional
! variables which follow word 29.
! Variables which are not computed or do not make any sense for a
! specific generator should contain the value -99999 for integers and
! -99999. for reals with the exception of the event weights in words
! words 20, 21, and 26 which have to be 1.0. The total event weight is
! WTX1*WTX2*WTX3 and should multiply the bin entry.
!
!COL ATT-name FMT Min Max !Comments
!
1 IRAD I ! 0/1: event without/with initial and/or
! final radiative photon from incident
! or scattered lepton
2 UNDEF1 F ! undefined
3 GENPL F ! incident lepton momentum in [GeV/c]
! (negative, -z)
4 GENPP F ! incident proton momentum in [GeV/c]
! (positive, +z)
5 GENX F ! Bjoerken x = Q**2/(2*P.q)
! for word 5 to 9 q should be calculated
! from the lepton side, q = (k-l)
! k = incident lepton 4-vector,
! l = outgoing lepton 4-vector,
! P = proton 4-vector;
! if the generator chooses x, then use
! this value.
6 GENY F ! Bjoerken y = (P.q)/(P.k)
! if the generator chooses y, then use
! this value.
7 GENQ2 F ! Q**2 = -q.q [(GeV/c)**2]
! if the generator chooses Q**2,then use
! this value.
8 GENNU F ! nu = P.q/m_p, m_p = proton mass [GeV]
9 GENW F ! W=sqrt((q+P-p_photon)**2) [(GeV/c)**2]
! p_photon = 4-vector sum over all
! radiative photons from the incident
! and scattered lepton.
10 X1 F ! the momentum fraction of the parton
! on the lepton side as used in the
! photon parton density function (pdf)
11 X2 F ! the momentum fraction of the parton
! on the proton side as used in the
! proton parton density function (pdf)
12 SCALE1 F ! the scale on the lepton side as used
! in the photon pdf [(GeV/c)**2]
13 SCALE2 F ! the scale on the proton side as used
! in the proton pdf [(GeV/c)**2]
14 PDFID1 I ! the identification number of the pdf
! on the lepton side
15 PDFID2 I ! the identification number of the pdf
! on the proton side
! pdf identification number is positive
! for numbering from PDFLIB and negative
! for PAKPDF, PHOPDF, and internal ones
16 XPDF1 F ! the value on the lepton side of
! x_1*pdf_1(flavor_1,x_1,scale_1),
! flavor_1 is to be found in bank GEVC
17 XPDF2 F ! the value on the proton side of
! x_2*pdf_2(flavor_2,x_2,scale_2),
! flavor_2 is to be found in bank GEVC
18 KTI1 F ! the intrinsic transverse momentum of
! the beam remnant on the lepton side
19 KTI2 F ! the intrinsic transverse momentum of
! the beam remnant on the proton side
! kti_1 and kti_2 in [GeV/c]
20 WTX1 F ! event weight from generating events
! by weighting a kinematical variable
21 WTX2 F ! event weight from generating events
! by weighting a second kin. variable
!
! The following information may only be available at the end of the
! event generation and will require a second pass through the file.
! (set -99999. if information not known at the beginning)
!
22 SIGMT F ! total x-section in [pb] on the file
23 DSIGMT F ! error on total x-section in [pb]
24 SIGMS F ! subprocess x-section in [pb] for
! this event on the file
25 DSIGMS F ! error on subprocess x-section in [pb]
! !
! The following information may come from a job mixing event files
! with changed subprocess x-sections. It may also have to update
! words 22 to 25.
! !
26 WTX3 F ! event weight sigma_i/sigma_i^mix after
! mixing different event files
27 UNDEF2 F ! undefined
28 UNDEF3 F ! undefined
29 UNDEF4 F ! undefined
!
! Additional Information for Photoproduction
! (set -99999. if information not computed or request nonsensical)
!
30 PT2HAT F ! transverse momentum squared of the
! final hard parton(s) in the cms of
! the hard subprocess [(GeV/c)**2]
31 SHAT F ! cms energy of the hard subprocesse
! squared [GeV**2]
END BANK
+++++ GKI , 0 NO MINIHEADER.
0----------------------------------------------------------------------------------------------------------------------------------
IRAD = 0 initial/final radiation
GENPL = -0.275500E+02 incident lepton momentum
GENPP = 0.820000E+03 incident proton momentum
GENX = 0.288826E-03 Bjorken X value
GENY = 0.254592E+00 Bjorken Y value
GENQ2 = 0.664471E+01 Q**2 value
GENNU = 0.122598E+05 nu = P.q/m_proton
GENW = 0.151658E+03 W value
X1 = -0.999990E+05 x in PDF lepton side
X2 = 0.791366E-02 x in PDF proton side
SCALE1 = -0.999990E+05 Q2 in PDF lepton side
SCALE2 = -0.999990E+05 Q2 in PDF proton side
PDFID1 = -99999 PDF id. lepton side
PDFID2 = -99999 PDF id. proton side
XPDF1 = -0.999990E+05 value of PDF lepton side
XPDF2 = -0.999990E+05 value of PDF proton side
KTI1 = -0.999990E+05 intr. k_t lepton side
KTI2 = -0.999990E+05 intr. k_t proton side
WTX1 = 0.100000E+01 event weight 1. variable
WTX2 = 0.100000E+01 event weight 2. variable
SIGMT = -0.999990E+05 total cross section
DSIGMT = -0.999990E+05 error of cross section
SIGMS = -0.999990E+05 subpr. cross section
DSIGMS = -0.999990E+05 error of cross section
WTX3 = 0.100000E+01 event weight mixing
PT2HAT = -0.999990E+05 only photoprod.
SHAT = 0.175069E+03 only photoprod.
0----------------------------------------------------------------------------------------------------------------------------------
diffVM fills the words IRAD (always 0), GENPL,
GENPP, GENX, GENY, GENQ2,
GENNU, GENW, WTX1 (always 1.0),
WTX2 (always 1.0), and WTX3 (always 1.0)
in the usual way.
32 AMX F 0.268 INF ! Mass of the diffractive
! photon-pomeron system
! M_X = Sqrt (q + p_pom)**2
33 AMPD F 0.938 INF ! Mass of the scattered proton-state
! M_Pd = Sqrt (p_p - p_pom)**2
34 XPOM F 0.0 1.0 ! Momentum fraction of the pomeron
! x_pom = (q.p_pom)/(q.p_p)
35 T F -INF 0.0 ! Momentum transfer of the pomeron
! t = (p_pom)**2
36 Z F 0.0 1.0 ! Momentum fraction of the struck
! quark from the pomeron
! z = (q.p_q)/(q.p_pom)
37 B F 0.0 INF ! Actual slope parameter used for the
! generation of the t-distribution
! according to exp (b*t)
38 ZVM F 0.0 1.0 ! momentum fraction of the produced
! vector meson (if it is produced)
! w.r.t. the photon
! z_VM = (p_VM.p_p) / (q.p_p)
39 IHELI I -1 1 ! Helicity of the virtual photon
! +1, -1: transverse photon,
! 0: longitudinal photon
40 FTRANS F 0.0 1.0 ! Transverse photon flux
! at this y and Q**2
41 EPSIL F 0.0 1.0 ! Ratio of longitudinal to transverse
! photon flux at this y and Q**2
42 RLT F 0.0 INF ! Ratio of longitudinal to transverse
! gamma-p cross section at this Q**2
This extended version has been provided since version 1.01/02,
but then contained a bug so that the words IHELI, FTRANS,
and EPSIL were not filled.
This bug was removed in version1.04/01.
The GHD Bank
The GHD bank contains information on the generator module versions
that actually ran. This is the DDL description:
! BANKname BANKtype !Comments
!
BANK GHD ! Generaor HeaD bank
! a maximum of six different generator
! modules are allowed.
! e.g. LEPTO consists of two modules,
! LEPTO and JETSET,
! which amounts to 12 words
!
!COL ATT-name FMT Min Max !Comments
!
1 PRGNAM A ! program module name (1:4)
2 PRGNAM A ! program module name (5:8)
3 PRGVRS A ! program module version number (1:4)
4 PRGVRS A ! program module version number (5:8)
5 CMZVRS A ! program module cmz version numb. (1:4)
6 CMZVRS A ! program module cmz version numb. (5:8)
! ........ Word 1..6 are repeated for each generator module
END BANK
+++++ GHD , 0 NO MINIHEADER.
0----------------------------------------------------------------------------------------------------------------------------------
GENERATOR NAME diffVM VERSION NUMBER 1.05/01 CMZ Version 1.05/01
GENERATOR NAME JETSET VERSION NUMBER 7.404 CMZ Version 7.40/41
0----------------------------------------------------------------------------------------------------------------------------------
The GEVC Bank
! BANKname BANKtype !Comments
!
BANK GEVC ! Generator_EVent_Classification
! for Monte Carlo events
!
! Every generator has to fill the interface common
! COMMON /CGEVC/ NEVTYP,NINTYP,NSPPRC,NELRAD,NPARSH,
! > INBEAM,INTARG,NQUHUT,NLEHUT,NGAHUT,NPAHUT,MSUBPR
! before the statement CALL GENFIL in the main subroutine of the
! MC generator.
!
! Since a simultaneous generation of different processes is possible
! in most of the generators and in addition it is forseen to mix
! different event types in one file, a user should be able to
! recognize easily the events of interest in an event sample.
!
! We see three concerns for the user:
!
! a) While the generators are based on (Feynman-) diagrams and the
! number of diagrams is enormous, the 'average user' probably
! needs more general categories telling the sort of physics:
! type of event (standard/exotics...), interaction and a list of
! important processes.
! b) General features of the generation like parton showers on or off
! etc. should be reported.
! c) An overview of flavours in the event should be easily accessable.
! Here partons from the hard subprocess are of interest as well as
! all outgoing partons and leptons.
!
! Note: If a word is not applicable then its value is zero.
! For partons and leptons and information related to them the
! numbering scheme as given by the particle data group is used
! as closely as possible.
!
!COL ATT-name FMT Min Max !Comments
!
! The sort of physics:
! --------------------
1 NEVTYP I ! type of event:
! 1 = standard physics
! 2 = exotic (non-standard) physics
! 3 = standard and exotic
! (with interference)
! 4 = background (e.g. word 3, 400+i)
! 5 = real gamma-p physics
!
2 NINTYP I ! type of interaction viewed from the
! incident electron vertex (disregarding
! any QED radiative effects):
! 22= photon : electro-magnetic
! 23= Z : neutral current
! 24= W : charged current
! 45= phot./Z: em + nc + interference
!
3 NSPPRC I ! special processes (standard/exotic/
! background):
! 1 = deep-inelastic-scattering
! 2 = massive boson-boson fusion
! (at least 1 massive boson)
! 3 = direct photon (photo-production)
! 4 = resolved photon (photo-production)
! 5 = radiative Z,W
! 6 = elastic
! 7 = diffractive
! 8 = vector dominance
! 9 = higher twist
!10 = lepton pair production (QED)
! ...
! 201=leptoquarks
! ...
! 401=beam gas
! 402=beam wall
! ...
! 501=non-fragmented event
! ...
! 999=others
!
!
! General features of the generation:
! -----------------------------------
4 NELRAD I ! radiation by the electron:
! bit pattern: 2**(i-1), where
! i= 1 = initial state photon radiation
! i= 2 = final state photon radiation
! (if initial and final can not be
! distinguished, i+f are set)
!
5 NPARSH I ! parton shower:
! bit pattern: 2**(i-1), where
! i = 1 = initial state parton shower
! i = 2 = final state parton shower
! for colour dipole model NPARSH = 4
!
! Information on partons/bosons and leptons
! -----------------------------------------
! - INPUT to the hard subprocess:
!
6 INBEAM I ! incoming parton/boson of the hard
! subprocess, electron side:
! 1 = d, 2 = u, 3 = s,
! 4 = c, 5 = b, 6 = t,
! 11 = e, 13 = mu, 15 = tau,
! 12 = nue, 14 = numu, 16 = nutau,
! 21 = gluon, 22 = photon, 24 = W,
! 23 = Z, 25 = higgs
! 45 = phot./Z (photon+Z+interference)
!
7 INTARG I ! incoming parton/boson of the hard
! subprocess, proton side:
! 1 = d, 2 = u, 3 = s,
! 4 = c, 5 = b, 6 = t,
! 11 = e, 13 = mu, 15 = tau,
! 12 = nue, 14 = numu, 16 = nutau,
! 21 = gluon, 22 = photon, 24 = W,
! 23 = Z, 25 = higgs
!
! distinguish between particle and anti-
! particle, i.e. report sign in INBEAM
! and INTARG.
!
! - OUTPUT from the hard subprocess:
8 NQUHUT I ! QUARK output from the hard subprocess,
! report only the "heaviest" parton:
! 1 = d, 2 = u, 3 = s,
! 4 = c, 5 = b, 6 = t
!
9 NLEHUT I ! LEPTON output from the hard subprocess
! report only the "heaviest" lepton:
! 12 = nue, 14 = numu, 16 = nutau,
! 11 = e, 13 = mu, 15 = tau
!
10 NGAHUT I ! GAUGE boson or HIGGS output from the
! the hard subprocess,
! report only the "heaviest" boson:
! 21 = gluon, 22 = photon, 24 = W,
! 23 = Z, 25 = higgs
!
! distinguish between particle and anti-
! particle, i.e. report sign in NQUHUT,
! NLEHUT, and NGAHUT. in case of
! ambiguity (i.e. pair production),
! report a positive sign.
!
11 NPAHUT I ! bit pattern with all final state
! partons, leptons, and gauge bosons,
! i.e. primary and secondary from parton
! shower, fragmentation and decays.
! It is written by 2**i, where
! i= 1 1 1 1 1 1 2 2 2 2 2
! 1 2 3 4 5 6 1 2 3 4 5 6 1 2 3 4 5
! quarks leptons gauge&higgs
! d u s c b t e n m n t n g p Z W h
! e m t
! Note:
! - particles and antiparticles are not
! distinguished, i.e. always report
! a positive sign.
! - the initial state particles are not
! reported.
! - the scattered lepton is not reported
! since this information is contained
! in word 2.
! - photons are reported if they come
! from the hard subprocess or from
! radiation, but not from the initial
! state or particle decays (pi-zero,
! etc).
!
! Generator dependent information
! -------------------------------
12 MSUBPR I ! generator dependent subprocess
! identification number to which
! corresponds an x-section in GEND.
!
!..
!.. background, exotic needs ?
!..
END BANK
+++++ GEVC, 0 NO MINIHEADER.
*** GEVC: mc generator event classification ***
1) NEVTYP= 1 : standard ep physics
2) NINTYP= 22 : photon : electro-magnetic
3) NSPPRC= 7 : diffractive
4) NELRAD= 0 : no radiation by the electron
5) NPARSH= 0 : no parton showers
6) INBEAM= 22 : photon : hard subprocess: input, electron side
7) UNDEFINED PARTICLE: INTARG= 29
8) NQUHUT= 4 : c : hard subprocess:"heaviest" quark out
9) NLEHUT= 0 : hard subprocess: no outgoing lepton
10)NGAHUT= 0 : hard subprocess: no outgoing gauge/higgs
11)NPAHUT= bits : all final partons, leptons, and gauge bosons, i.e.
primary and secondary from P.S. and fragm.process
quarks leptons gauge&higgs
d u s c b t e n m n t n g p Z W h
0 0 0 1 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0
12)MSUBPR= 0 : no subprocess number of generator
The words 1-7, 9, and 11 are always set the same way;
the "29" in word INTARG stands for "pomeron".
The GEND Bank
The GEND bank contains information on the number of generated events
and the cross section of the generated process:
! BANKname BANKtype !Comments
!
BANK GEND ! Generaor END bank
! Every file should at least provide
! the first three words.
! Then up to 50 different subprocess ID's
! the corresponding total subprocess
! x-sections and their errors may follow
! ATTributes:
! -----------
!COL ATT-name FMT Min Max !Comments
!
1 NEVT I ! total number of events generated
2 SIGMT F ! total x-section in pb
3 DSIGMT F ! error on total x-section in pb
! 1. subprocess
4 MSUBPR I ! subprocess identification number
! which is generator dependent
5 SIGMS F ! total subprocess x-section in pb
6 DSIGMS F ! error on total subprocess x-section
! ..............
END BANK
diffVM fills the words NEVT, SIGMT, and DSIGMT,
the other words are not used, since diffVM generates only one subprocess
at a time.