20% Discrapancy between effective lumi and XS
I am generating p p > t t~ with a heavy particle pT cut of 500 GeV at 14 GeV LHC energy with 100k events.
MG outputs:
Current estimate of cross-section: 1.75032 +- 0.00167384681091
Effective Luminosity 68558.8920883 pb^-1
Nb of events : 100000
I get XS * lumi = 120,000 events exactly. So there is an exactly 20% apparent discrepancy between XS and effective lumi.
What is the reason for the discrepancy, and should I use 1/(reported XS) or (reported effective lumi) as my true effective lumi?
Thanks,
Jack
Below is my run card in case it is relevant:
#******
# MadGraph5_aMC@NLO *
# *
# run_card.dat MadEvent *
# *
# This file is used to set the parameters of the run. *
# *
# Some notation/
# *
# Lines starting with a '# ' are info or comments *
# *
# mind the format: value = variable ! comment *
# *
# To display more options, you can type the command: *
# update full_run_card *
#******
#
#******
# Running parameters
#******
#
#******
# Tag name for the run (one word) *
#******
tag_1 = run_tag ! name of the run
#******
# Number of events and rnd seed *
# Warning: Do not generate more than 1M events in a single run *
#******
100000 = nevents ! Number of unweighted events requested
0 = iseed ! rnd seed (0=assigned automatically=
#******
# Collider type and energy *
# lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
# 3=photon from electron *
#******
1 = lpp1 ! beam 1 type
1 = lpp2 ! beam 2 type
7000.0 = ebeam1 ! beam 1 total energy in GeV
7000.0 = ebeam2 ! beam 2 total energy in GeV
# To see polarised beam options: type "update beam_pol"
#******
# PDF CHOICE: this automatically fixes also alpha_s and its evol. *
#******
nn23lo1 = pdlabel ! PDF set
230000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
# To see heavy ion options: type "update ion_pdf"
#******
# Renormalization and factorization scales *
#******
False = fixed_ren_scale ! if .true. use fixed ren scale
False = fixed_fac_scale ! if .true. use fixed fac scale
91.188 = scale ! fixed ren scale
91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
-1 = dynamical_
1.0 = scalefact ! scale factor for event-by-event scales
#******
# Type and output format
#******
False = gridpack !True = setting up the grid pack
-1.0 = time_of_flight ! threshold (in mm) below which the invariant livetime is not written (-1 means not written)
3.0 = lhe_version ! Change the way clustering information pass to shower.
True = clusinfo ! include clustering tag in output
average = event_norm ! average/sum. Normalization of the weight in the LHEF
#******
# Matching parameter (MLM only)
#******
0 = ickkw ! 0 no matching, 1 MLM
1.0 = alpsfact ! scale factor for QCD emission vx
False = chcluster ! cluster only according to channel diag
4 = asrwgtflavor ! highest quark flavor for a_s reweight
False = auto_ptj_mjj ! Automatic setting of ptj and mjj if xqcut >0
0.0 = xqcut ! minimum kt jet measure between partons
#******
#
#******
# handling of the helicities:
# 0: sum over all helicities
# 1: importance sampling over helicities #******
0 = nhel ! using helicities importance sampling or not.
#******
# Generation bias, check the wiki page below for more information: *
# 'cp3.irmp.
#******
None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
{} = bias_parameters ! Specifies the parameters of the module.
#
#******
# Parton level cuts definition *
#******
#
#
#******
# BW cutoff (M+/-bwcutoff*
#******
15.0 = bwcutoff ! (M+/-bwcutoff*
#******
# Apply pt/E/eta/
# (note that etmiss/
#******
False = cut_decays ! Cut decay products
#******
# Standard Cuts *
#******
# Minimum and maximum pt's (for max, -1 means no cut) *
#******
20.0 = ptj ! minimum pt for the jets
0.0 = ptb ! minimum pt for the b
10.0 = pta ! minimum pt for the photons
10.0 = ptl ! minimum pt for the charged leptons
0.0 = misset ! minimum missing Et (sum of neutrino's momenta)
-1.0 = ptjmax ! maximum pt for the jets
-1.0 = ptbmax ! maximum pt for the b
-1.0 = ptamax ! maximum pt for the photons
-1.0 = ptlmax ! maximum pt for the charged leptons
-1.0 = missetmax ! maximum missing Et (sum of neutrino's momenta)
{} = pt_min_pdg ! pt cut for other particles (use pdg code). Applied on particle and anti-particle
{} = pt_max_pdg ! pt cut for other particles (syntax e.g. {6: 100, 25: 50})
#
# For display option for energy cut in the partonic center of mass frame type 'update ecut'
#
#******
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#******
5.0 = etaj ! max rap for the jets
-1.0 = etab ! max rap for the b
2.5 = etaa ! max rap for the photons
2.5 = etal ! max rap for the charged leptons
0.0 = etajmin ! min rap for the jets
0.0 = etabmin ! min rap for the b
0.0 = etaamin ! min rap for the photons
0.0 = etalmin ! main rap for the charged leptons
{} = eta_min_pdg ! rap cut for other particles (use pdg code). Applied on particle and anti-particle
{} = eta_max_pdg ! rap cut for other particles (syntax e.g. {6: 2.5, 23: 5})
#******
# Minimum and maximum DeltaR distance *
#******
0.4 = drjj ! min distance between jets
0.0 = drbb ! min distance between b's
0.4 = drll ! min distance between leptons
0.4 = draa ! min distance between gammas
0.0 = drbj ! min distance between b and jet
0.4 = draj ! min distance between gamma and jet
0.4 = drjl ! min distance between jet and lepton
0.0 = drab ! min distance between gamma and b
0.0 = drbl ! min distance between b and lepton
0.4 = dral ! min distance between gamma and lepton
-1.0 = drjjmax ! max distance between jets
-1.0 = drbbmax ! max distance between b's
-1.0 = drllmax ! max distance between leptons
-1.0 = draamax ! max distance between gammas
-1.0 = drbjmax ! max distance between b and jet
-1.0 = drajmax ! max distance between gamma and jet
-1.0 = drjlmax ! max distance between jet and lepton
-1.0 = drabmax ! max distance between gamma and b
-1.0 = drblmax ! max distance between b and lepton
-1.0 = dralmax ! maxdistance between gamma and lepton
#******
# Minimum and maximum invariant mass for pairs *
# WARNING: for four lepton final state mmll cut require to have *
# different lepton masses for each flavor! *
#******
0.0 = mmjj ! min invariant mass of a jet pair
0.0 = mmbb ! min invariant mass of a b pair
0.0 = mmaa ! min invariant mass of gamma gamma pair
0.0 = mmll ! min invariant mass of l+l- (same flavour) lepton pair
-1.0 = mmjjmax ! max invariant mass of a jet pair
-1.0 = mmbbmax ! max invariant mass of a b pair
-1.0 = mmaamax ! max invariant mass of gamma gamma pair
-1.0 = mmllmax ! max invariant mass of l+l- (same flavour) lepton pair
{} = mxx_min_pdg ! min invariant mass of a pair of particles X/X~ (e.g. {6:250})
{'default': False} = mxx_only_
#******
# Minimum and maximum invariant mass for all letpons *
#******
0.0 = mmnl ! min invariant mass for all letpons (l+- and vl)
-1.0 = mmnlmax ! max invariant mass for all letpons (l+- and vl)
#******
# Minimum and maximum pt for 4-momenta sum of leptons *
#******
0.0 = ptllmin ! Minimum pt for 4-momenta sum of leptons(l and vl)
-1.0 = ptllmax ! Maximum pt for 4-momenta sum of leptons(l and vl)
#******
# Inclusive cuts *
#******
500.0 = ptheavy ! minimum pt for at least one heavy final state
0.0 = xptj ! minimum pt for at least one jet
0.0 = xptb ! minimum pt for at least one b
0.0 = xpta ! minimum pt for at least one photon
0.0 = xptl ! minimum pt for at least one charged lepton
#******
# Control the pt's of the jets sorted by pt *
#******
0.0 = ptj1min ! minimum pt for the leading jet in pt
0.0 = ptj2min ! minimum pt for the second jet in pt
0.0 = ptj3min ! minimum pt for the third jet in pt
0.0 = ptj4min ! minimum pt for the fourth jet in pt
-1.0 = ptj1max ! maximum pt for the leading jet in pt
-1.0 = ptj2max ! maximum pt for the second jet in pt
-1.0 = ptj3max ! maximum pt for the third jet in pt
-1.0 = ptj4max ! maximum pt for the fourth jet in pt
0 = cutuse ! reject event if fails any (0) / all (1) jet pt cuts
#******
# Control the pt's of leptons sorted by pt *
#******
0.0 = ptl1min ! minimum pt for the leading lepton in pt
0.0 = ptl2min ! minimum pt for the second lepton in pt
0.0 = ptl3min ! minimum pt for the third lepton in pt
0.0 = ptl4min ! minimum pt for the fourth lepton in pt
-1.0 = ptl1max ! maximum pt for the leading lepton in pt
-1.0 = ptl2max ! maximum pt for the second lepton in pt
-1.0 = ptl3max ! maximum pt for the third lepton in pt
-1.0 = ptl4max ! maximum pt for the fourth lepton in pt
#******
# Control the Ht(k)=Sum of k leading jets *
#******
0.0 = htjmin ! minimum jet HT=Sum(jet pt)
-1.0 = htjmax ! maximum jet HT=Sum(jet pt)
0.0 = ihtmin !inclusive Ht for all partons (including b)
-1.0 = ihtmax !inclusive Ht for all partons (including b)
0.0 = ht2min ! minimum Ht for the two leading jets
0.0 = ht3min ! minimum Ht for the three leading jets
0.0 = ht4min ! minimum Ht for the four leading jets
-1.0 = ht2max ! maximum Ht for the two leading jets
-1.0 = ht3max ! maximum Ht for the three leading jets
-1.0 = ht4max ! maximum Ht for the four leading jets
#******
# Photon-isolation cuts, according to hep-ph/9801442 *
# When ptgmin=0, all the other parameters are ignored *
# When ptgmin>0, pta and draj are not going to be used * #******
0.0 = ptgmin ! Min photon transverse momentum
0.4 = R0gamma ! Radius of isolation code
1.0 = xn ! n parameter of eq.(3.4) in hep-ph/9801442
1.0 = epsgamma ! epsilon_gamma parameter of eq.(3.4) in hep-ph/9801442
True = isoEM ! isolate photons from EM energy (photons and leptons)
#******
# WBF cuts *
#******
0.0 = xetamin ! minimum rapidity for two jets in the WBF case
0.0 = deltaeta ! minimum rapidity for two jets in the WBF case
#******
# Turn on either the ktdurham or ptlund cut to activate *
# CKKW(L) merging with Pythia8 [arXiv:1410.3012, arXiv:1109.4829] *
#******
-1.0 = ktdurham
0.4 = dparameter
-1.0 = ptlund
1, 2, 3, 4, 5, 6, 21 = pdgs_for_
#******
# maximal pdg code for quark to be considered as a light jet *
# (otherwise b cuts are applied) *
#******
4 = maxjetflavor ! Maximum jet pdg code
#******
#
#******
# Store info for systematics studies *
# WARNING: Do not use for interference type of computation *
#******
True = use_syst ! Enable systematics studies
#
systematics = systematics_program ! none, systematics [python], SysCalc [depreceted, C++]
['--mur=0.5,1,2', '--muf=0.5,1,2', '--pdf=errorset'] = systematics_
le
# Syscalc is deprecated but to see the associate options type'update syscalc'
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