LUSIFER: a Monte Carlo generator for e+ e- -> 6 fermions ======================================================== ******************************************************************************** Lusifer version 1.0, August 2002 ******************************************************************************** Authors: ======== S. Dittmaier, DESY Hamburg, Germany, stefan.dittmaier@desy.de M. Roth, University of Karlsruhe, Germany, roth@particle.uni-karlsruhe.de ******************************************************************************** LUSIFER has been tested under Operating Systems: UNIX, LINUX Computers: ALPHA/DEC workstation (Digital Fortran 77) LINUX PC (Red Hat Linux 6.x, Suse Linux 6.x, GNU project Fortran Compiler (v0.5.25)) Language: Fortran 77 ******************************************************************************** A brief description: ==================== LUSIFER is a Monte Carlo generator for 6-fermion production at e+ e- colliders. Features: - all processes e+ e- --> 6 fermions with massless external fermions - gluonic diagrams can be included for processes with up to 4 quarks in the final state - higher-order leading-logarithmic corrections from initial-state radiation (ISR) up to O(alpha^3) can be included via the structure function approach - leading effects from \delta\rho and \delta\alpha by using the G_mu scheme. ******************************************************************************** Publications: ============= The tree-level predictions and matrix elements for e+ e- -> 6f are given in [1] LUSIFER: a LUcid approach to SIx FERmion production, hep-ph/0206070. ******************************************************************************** Input: ====== The input parameters are defined in the subroutine PARAMETER in public.f. The variables for the parameters are the following: alphas: strong coupling constant alpha0: fine-structure constant alpha(0) (used as coupling constant in the structure functions for sisr=1) alphaz: running electromagnetic coupling constant alpha(MZ) gf: Fermi constant mw: W-boson mass gw: W-boson width mz: Z-boson mass gz: Z-boson width mh: Higgs-boson mass gh: Higgs-boson width mt: top-quark mass gt: top-quark width me: electron mass (needed for structure functions) In the following the sample input file "inputfile" (included in LUSIFER) is explained: ------------------------start-of-inputfile-------------------------------------- outputfile ! name of output file 500d0 ! energy: CMF energy (in GeV) 10000000 ! nevent: number of events ******************************************************************************* * We recommend to use at least 10 Mio events. ******************************************************************************* 2 ! qalp: choice of input-parameter scheme: 0,1, or 2 ******************************************************************************** * qalp=0 : alpha(0) scheme: alpha = alpha0 * qalp=1 : alpha(MZ) scheme: alpha = alphaz * qalp=2 : G_mu scheme: alpha = dsqrt(2d0)*gf/pi*mw2*sw2 * recommended choice: qalp=2 * * NOTE: alpha is the variable for the electromagnetic coupling constant * which is used in the amplitude calculation. * The weak mixing angle is fixed by cw^2 = 1-sw^2 = mw^2/mz^2. ******************************************************************************** 1 ! qprop: choice of width scheme ******************************************************************************** * qprop=0: gauge-boson width = 0 * qprop=1: constant width is used in all propagators * qprop=2: constant width is used only in s-channel (time-like) propagators * qprop=3: running width is used only in s-channel (time-like) propagators * qprop=4: complex-mass scheme (constant width is used in all propagators and * the weak mixing angle is complex) ******************************************************************************** 1 ! qg: include gluon-exchange diagrams: 0:no 1:yes ******************************************************************************** * qg=0 : gluon-exchange diagrams are NOT included * qg=1 : gluon-exchange diagrams included * * NOTE: qg=1 is supported for up to 4 quarks in the final state. * In case of 6 quarks LUSIFER stops the program and gives a warning. ******************************************************************************** 1 ! sisr: include higher-order ISR: 0:no 1:yes ******************************************************************************** * sisr=0 : higher-order ISR is NOT included * sisr=1 : higher-order ISR (in leading-log approximation) up to order alpha^3 * is included (scale=energy). (For details, see hep-ph/0206070.) ******************************************************************************** 1 ! nfs: number of processes u ! fermion 3 d ! anti-fermion 4 mu ! fermion 5 nu_mu ! anti-fermion 6 b ! fermion 7 b ! anti-fermion 8 1d0 ! weight ******************************************************************************** * Specification of final-state fermions: * * LUSIFER allows to calculate several processes in one run, where the * differential cross section of each process is multiplied with the * corresponding weight specified in the input file. If you want to calculate * nfs processes then the block of the seven lines from "fermion 3" to "weight" * has to be included nfs times in the input file (once for each process). * * nfs: number of processes * fname(3:8): u,d,s,c,t,b,e,mu,tau,nu_e,nu_mu,nu_tau * wgt(1:nfs): weight of the process ******************************************************************************** 0d0 ! pp: degree of positron beam polarization [-1d0:1d0] 0d0 ! pm: degree of electron beam polarization [-1d0:1d0] ******************************************************************************** 10 ! scuts: separation cuts ******************************************************************************** * scuts=0 : NO separation cuts are applied * scuts=1 : ADLO cuts are applied as defined in montecarlo.f * scuts=2 : LC cuts are applied as defined in montecarlo.f * scuts=3 : standard cuts are applied as defined in montecarlo.f * scuts=10 : a minimal set of cuts must be specified in the input file * scuts=11 : most general set of cuts must be specified in the input file * * Standard cuts for scuts=1,2,3: * * ecutl = charged-lepton energy cut in GeV * ecutq = quark energy cut in GeV * scutqq = quark-quark invariant-mass cut in GeV * ccutll = angular cut between charged leptons in degrees * ccutqq = angular cut between quarks in degrees * ccutlq = angular cut between charged lepton and quark in degrees * ccutlb = angular cut between charged lepton and beam in degrees * ccutqb = angular cut between quark and beam in degrees * * scuts | 1 | 2 | 3 | * ------------------|------|------|------| * ecutl in GeV | 1 | 1 | 10 | * ecutq in GeV | 3 | 3 | 10 | * scutqq in GeV | 5 | 10 | 10 | * ccutll in degrees | 5 | 5 | 5 | * ccutqq in degrees | 0 | 0 | 0 | * ccutlq in degrees | 5 | 5 | 5 | * ccutlb in degrees | 10 | 10 | 5 | * ccutqb in degrees | 0 | 5 | 5 | * * NOTE: If the cuts are not uniquely defined for the different processes * LUCIFER will stop the program. For instance, if scut=10 and * fermion 3 is a muon for process 1 and a d quark for process 2 and * ecutl differs from ecutq, LUCIFER stops with a warning. ******************************************************************************** 10d0 ! charged-lepton energy cut 10d0 ! quark energy cut 10d0 ! quark-quark invariant-mass cut 0d0 ! angular cut between charged leptons 0d0 ! angular cut between quarks 5d0 ! angular cut between charged lepton and quark 5d0 ! angular cut between charged lepton and beam 5d0 ! angular cut between quark and beam ******************************************************************************** * scuts=11 : cuts on the energies of all final-state particles, on all angles * and invariant masses must be specified in the input file * (e+ e- -> f3 anti-f4 f5 anti-f6 f7 anti-f8): ******************************************************************************** *0d0 ! energy cut on particle 3 *0d0 ! energy cut on particle 4 *0d0 ! energy cut on particle 5 *0d0 ! energy cut on particle 6 *0d0 ! energy cut on particle 7 *0d0 ! energy cut on particle 8 *0d0 ! angular cut between beam1 and particle 3 *0d0 ! angular cut between beam1 and particle 4 *0d0 ! angular cut between beam1 and particle 5 *0d0 ! angular cut between beam1 and particle 6 *0d0 ! angular cut between beam1 and particle 7 *0d0 ! angular cut between beam1 and particle 8 *0d0 ! angular cut between beam2 and particle 3 *0d0 ! angular cut between beam2 and particle 4 *0d0 ! angular cut between beam2 and particle 5 *0d0 ! angular cut between beam2 and particle 6 *0d0 ! angular cut between beam2 and photon *0d0 ! angular cut between particle 3 and 4 *0d0 ! angular cut between particle 3 and 5 *0d0 ! angular cut between particle 3 and 6 *0d0 ! angular cut between particle 3 and 7 *0d0 ! angular cut between particle 3 and 8 *0d0 ! angular cut between particle 4 and 5 *0d0 ! angular cut between particle 4 and 6 *0d0 ! angular cut between particle 4 and 7 *0d0 ! angular cut between particle 4 and 8 *0d0 ! angular cut between particle 5 and 6 *0d0 ! angular cut between particle 5 and 7 *0d0 ! angular cut between particle 5 and 8 *0d0 ! angular cut between particle 6 and 7 *0d0 ! angular cut between particle 6 and 8 *0d0 ! angular cut between particle 7 and 8 *0d0 ! particle 3-particle 4 invariant-mass cut *0d0 ! particle 3-particle 5 invariant-mass cut *0d0 ! particle 3-particle 6 invariant-mass cut *0d0 ! particle 3-particle 7 invariant-mass cut *0d0 ! particle 3-particle 8 invariant-mass cut *0d0 ! particle 4-particle 5 invariant-mass cut *0d0 ! particle 4-particle 6 invariant-mass cut *0d0 ! particle 4-particle 7 invariant-mass cut *0d0 ! particle 4-particle 8 invariant-mass cut *0d0 ! particle 5-particle 6 invariant-mass cut *0d0 ! particle 5-particle 7 invariant-mass cut *0d0 ! particle 5-particle 8 invariant-mass cut *0d0 ! particle 6-particle 7 invariant-mass cut *0d0 ! particle 6-particle 8 invariant-mass cut *0d0 ! particle 7-particle 8 invariant-mass cut ******************************************************************************** * NOTE: Non-standard cuts, i.e. cuts that are not covered by the choices of * scuts, can be included in subroutine CUT in 'public.f'. ******************************************************************************** 0 ! shisto: include histograms ******************************************************************************** * shisto=0 : NO histgrams are included * shisto=1 : histgrams are included. The histgrams can be switched on in the * input file as follows (0=off,1=on): *1 ! histgram 1 *1 ! histgram 2 *1 ! histgram 3 *1 ! histgram 4 *1 ! histgram 5 *1 ! histgram 6 *1 ! histgram 7 *1 ! histgram 8 *1 ! histgram 9 * Here we assumed that the number of histgrams is maxh=9. * maxh is specified in montecarlo.f and public.f. The histograms * are defined in the subroutine SETTINGS in public.f. The output of * the output files of the histograms are dat.01, dat.02, etc. ******************************************************************************** ------------------------end of inputfile----------------------------------------