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# ALPGEN 8TeV CMS Production

## Grid Files

The grid files, produced by Alex, are in his public home in afs:

~amott/public/ALPGEN/8TeV/grids/

And in my personal afs area:

### Unweighting and Matching Efficiency of Grid files

I have to run on the grid files to discover the efficiencies of producing:

• Unweighted events, given a number of weighted events to produce;
• Showered events, after matching procedure on PYTHIA, so we can deliver the correct amount of .lhe files.

The order of the grid files to run is:

• W + jets
• Z + jets
• ttbar + jets
• QCD

### Grid Files Production

I've used Alex's script to produce all the input cards with 8TeV center of mass energy, and I am running to get the grid files according to: Number of warm-ups = 2 + number of jets Number of iteration/warm-up = 1.000.000 Number of events = 2 x (2+njets) x 1.000.000

### Efficiencies Calculation

#### List of Grid Efficiencies

For calculating the grid efficiencies, have to run in all the process (through PYTHIA and so on) to get the matching efficiency. I also have to know the cross section, so I can calculate the number of events needed for a given luminosity.

I'm running 1.000.000 .wgt events to get the .unw and matching efficiency

• First, have to run on imode=1, to get the .wgt
• Then, run on imode=2, to get the .unw

Grid .wgt eff .unw eff (from .wgt) Matching eff (from .unw) Matching eff (from submitted) Cross section (pb)
w0j.grid2 0.982703 0.723857 0.859 calculate 2.441e+4 +/- 1.044e+2
w0j.grid2 NEW seed 0.504036 0.638775 0.863 calculate 2.450e+4 +/- 7.005e+1
w1j_100ptw300.grid2 0.424175 0.099343431 0.539 calculate 1.098e+2 +/- 5.497e-1
w1j_300ptw800.grid2 0.128871 0.189328864 0.37 calculate 9.147e-1 +/- 8.160e-3
w2j_0ptw100.grid2 0.0284464 0.41629 0.18 calculate 7.952e+2 +/- 7.498e+0
w2j_100ptw300.grid2 0.0158608 0.375 0.289 calculate 8.401e+01 +/- 8.057e-01
w2j_300ptw800.grid2 0.0290226 0.09854 0.227 calculate 1.168e+00 +/- 1.849e-02
w2j_800ptw1600.grid2 0.01706 0.065283 0.18 calculate 5.196e-06 +/- 1.512e-07
w3j_0ptw100.grid2 0.008296 0.1995 0.539 calculate 1.098e+02 +/- 5.497e-01
w1j_0ptw100.grid2 0.611141 0.20049 0.336 0.041180 3.442e+3 +/- 1.469e+1
w1j_800ptw1600.grid2 0.127199 0.132736893 0.228 0.003854 2.264e-06 +/- 3.581e-08
w3j_100ptw300.grid2 0.00879273 0.120774 0.15 0.00015933 3.432e+01 +/- 6.595e-01

starting scan/unweighting of 124441.00000000000 events Crosssection(pb)= 5.5825448215862359 +- 2.30194773087273874E-002 Generated 8859 unweighted events, lum= 1586.9106801873891 pb-1

 w3j_300ptw800.grid2 0.008296 0.07119 0 0 0

 w3j_800ptw1600.grid2 0 0 0 0 0 w4j_0ptw100.grid2 0 0 0 0 0 w4j_100ptw300.grid2 0 0 0 0 0 w4j_300ptw800.grid2 0 0 0 0 0 w4j_800ptw1600.grid2 0 0 0 0 0 w5j_0ptw100.grid2 0 0 0 0 0 w5j_100ptw300.grid2 0 0 0 0 0 w5j_300ptw800.grid2 0 0 0 0 0 w5j_800ptw1600.grid2 0 0 0 0 0

### Massive Production

Initially, the aim is to produce samples equivalent to 1fb^-1 of data.

Number of matched events needed: N = sigma . L

Where sigma is the cross section for the given PROCESS, and L is the accumulated luminosity.

So, for 1fb^-1, I have to produce the number of events equal to the cross section given for the process, in fb.

### Step by step plan - Working with crab, efficiencies evaluation, etc.

I've runned the test for Alpgen on crab in my CERN afs area. Need to do the same steps in my own personal area in ACCESS from SPRACE.

• Copy the files needed (from the tarball given in this Twiki) to my local ACCESS area.

• What I need to do for running with this package:

• crab_genAlpgen_grid.cfg - From the CRAB configuration file, I have to change:
• total_number_of_events
• events_per_job
• Output files
### The output files (comma separated list)
output_file=w1j_0ptw100.wgt, w1j_0ptw100.par, w1j_0ptw100.unw, w1j_0ptw100_unw.par
• Set the storage element and copy mode:
copy_data = 1
storage_element = T2_BR_SPRACE
user_remote_dir = FlaviaAlpgenTest
• Set the input files:

• alpgen.input - Take care to change the input card.

• runAlpgen.sh - Change the name of the executable in the line: export ALPGEN_EXECUTABLE=wjetgen

#### Test

Run Alpgen with a few (60.000) events for cross-section/efficiency test. Process chosen: w0j_0ptw100

### Previous Alpgen Production Page

AlpgenProduction7TeV

-- FlaviaDias - 14 Dec 2010

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Topic revision: r9 - 2010-12-15 - FlaviaDias

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