User may change, with precautions, the starred items, while the doubly starred ones should never be changed.
General and related to QED radiation input parameters.
| Parameter | Position and Meaning |
|---|---|
CMSene |
xpar(1) (=100): \(\sqrt{s}\), centre-of-mass (CMS) energy [GeV] |
DelEne |
xpar(2) (=0d0): Beam energy spread [GeV] |
Ninp |
xpar(3) (=5): Input unit number (unused) |
Nout |
xpar(4) (=16): Output unit number |
LevPri |
xpar(5) (=0): PrintOut Level 0,1,2 |
Ie1Pri |
xpar(6) (=1): PrintOut Start point |
Ie2Pri |
xpar(7) (=1): PrintOut End point |
WtMax* |
xpar(9) (=1): Maximum weight for rejection |
KeyWgt |
xpar(10) (=0): Switch between constant =0 and variable =1 weight events |
IdeWgt* |
xpar(11) (=74): Ident of the EEX principal weight |
KeyELW |
xpar(12) (=1): Type of electroweak corrections, =0 only for tests, =1 default for DIZET |
vvmin* |
xpar(16) (=1D-5): Minimum real photon energy in units of beam energy |
vvmax |
xpar(17) (=1d0): Maximum value of \(v=1-s'/s\)-variable, where \(s'\) is mass squared of \(f\bar{f}\) system including FSR photons! See more comments in the text. |
DelFac* |
xpar(18) (=1d-3): FSR cut eps=vvmin*DelFac |
KeyISR |
xpar(20) (=1): Test switch, KeyISR=0 switches off the ISR |
KeyFSR |
xpar(21) (=1): Test switch, KeyFSR=0 switches off the FSR |
KeyPia** |
xpar(22) (=1): Removal of FSR photons below Emin=Ene*Delta in CMS, for KeyPia=0,1 removal is OFF,ON |
mltISR** |
xpar(23) (=0): Special tests: fixed ISR multiplicity for mltISR>0 |
mltFSR** |
xpar(24) (=0): Special tests: fixed FSR multiplicity for mltFSR>0 |
KeyFix |
xpar(25) (=0): Type of ISR, for KeyFix=0,1 QED without beamstrahlung, for KeyFix=2 beamstrahlung is ON, see also KeyGrid |
KeyWtm** |
xpar(26) (=0): Special tests only: mass terms in “crude” MC photon distrib. |
KeyINT |
xpar(27) (=2): Switch of ISR-FSR Interference (IFI), for KeyINT=0 it is OFF, for KeyINT=2 it is ON, KeyINT=1 is only for special tests |
KeyGPS |
xpar(28) (=1): Level of new exponentiation CEEX, note vmaxGPS overrules KeyGPS for each type of final fermion |
KeyQSR |
xpar(29) (=1): Photon emission from the final quarks is ON,OFF for KeyQSR=0,1 |
Technical cuts for non-IR real photon corrections etc.
| Parameter | Position and Meaning |
|---|---|
AlfInv* |
xpar(30) (=137.0359895D0): Inverse of \(\alpha_{\rm QED}\) |
GNanoB* |
xpar(31) (=389.37966D3): GeV\(^{-2} \to\) [nb] conversion factor |
Gfermi* |
xpar(32) (=1.16639d-5): Fermi coupling [GeV\(^{-2}]\) |
Technical cuts for non-IR real photon corrections etc.
| Parameter | Position and Meaning |
|---|---|
Xenph** |
xpar(40) (=1.25d0): Enhancement factor for “crude” photon multiplicity |
vcut1* |
xpar(41) (=1.d-9): Technical cut for single non-IR bremsstrahlung correction |
vcut2* |
xpar(42) (=5.d-2): Technical cut for double non-IR bremsstrahlung correction |
vcut3* |
xpar(43) (=0.1d0): Technical cut for triple non-IR bremsstrahlung correction |
QCD flags/data
| Parameter | Position and Meaning |
|---|---|
KeyHad |
xpar(50) (=1): Hadronization/showering flag, for KeyHad=0,1 hadronization is OFF,ON |
HadMin* |
xpar(51) (=0.200d0): Minimum mass [GeV] for hadronization/showering |
alfQCD* |
xpar(52) (=0.118d0): \(\alpha_{\rm QCD}\) |
Non-zero beam polarization may require adjustment of WtMax
| Parameter | Position and Meaning |
|---|---|
spin1x |
xpar(61) (=0d0): Polarization vector beam 1, \(x\)-component |
spin1y |
xpar(62) (=0d0): Polarization vector beam 1, \(y\)-component |
spin1z |
xpar(63) (=0d0): Polarization vector beam 1, \(z\)-component |
spin2x |
xpar(64) (=0d0): Polarization vector beam 2, \(x\)-component |
spin2y |
xpar(65) (=0d0): Polarization vector beam 2, \(y\)-component |
spin2z |
xpar(66) (=0d0): Polarization vector beam 2, \(z\)-component |
Beamstrahlung parameters for Thorsten Ohl’s package CIRCE
| Parameter | Position and Meaning |
|---|---|
IRCroots |
xpar(71) (=350d0): \(\sqrt{s}\) [GeV] discrete values 350,500,800 GeV |
IRCacc |
xpar(72) (=3d0): Accelerator type |
IRCver |
xpar(73) (=5d0): Version number |
IRCdat |
xpar(74) (=19980505d0): Date |
IRCxchat |
xpar(75) (=1): Printout level |
KeyGrid* |
xpar(76) (=2): Activated by setting KeyFix=2. KeyGrid=2 invokes Foam, KeyGrid=0,-1,+1 invokes Vegas: KeyGrid=0 creates and writes Vegas grid on the disk, KeyGrid=-1 creates and dumps grid on the disk, +1 reads only |