Goal

Plot the yield of inclusive DIS events vs x, Q2, W2, and y for 100 pb-1 of luminosity at HERMES kinematics (27.6 GeV beam energy, hydrogen target). Apply these standard DIS cuts:

Also impose the standard HERMES 'box acceptance' cuts on the scattered beam lepton: and require that it exceeded the energy threshold of the DIS trigger: You can leave radiative corrections turned off for simplicity.

Generate events with gmc_disNG

Make a kumac for GMC with the requested DIS and acceptance cuts. Here, we'll just use the defaults for all that were not explicitly specified.

Download: dis-accep.kumac

Use the kumac to generate 20,000 DIS events: 

       gmc_disNG -b dis_accep
You could also have started gmc_disNG interactively, and done exec dis_accep from the command line. For the kumac given above, this procedure has the advantage that you can change the run number easily if you wish to accumulate more statistics: exec dis_accep runno.

You've now produced an events file dis_accep_1.devents.gz and a little normalization file dis_accep_1.norm.kumac.

Run makent to produce an ntuple

First you have to write an ntuple-descriptor file for makent. It'll be a simple one, as we're only interested in inclusive information in this example.

Download: inclusive.in

A couple of simple notes. The MAINTABLE in use is mcEvent, since we want one ntuple record per DIS event. Also, I included our three DIS cuts in a CONDITION line, just to show how it works. Since we already applied these cuts at the GMC-generation level, this line isn't necessary.

So let's run makent on our GMC events file: 

       makent -in inclusive -out inclusive_1 dis_accep_1.devents.gz
That'll produce a nice row-wise ntuple called inclusive_1.rz.

But here's one more trick. We want a normalized result, so we will eventually need the sumievgen and extraweight numbers for our samples. Inspect the normalization file dis_accep_1.norm.kumac to find out what they are. You should get: extraweight = 1 (always true for disNG) and ievgen = 57930. makent allows you to include the ievgen number in your ntuple (for convenience) via a command-line option, so let's do that: 

       makent -in inclusive -out inclusive_1 -ievgen 57930 dis_accep_1.devents.gz

Plots the results in PAW

Start PAW and read in your ntuple: 

       h/file 1 inclusive_1.rz
You might want to have a look at its structure with nt/print 1 to be sure everything went ok. Now let's plot the results:

Download: inclusive-plot.kumac

Please look at the weighting that's set up at the beginning, that's essential to get a result normalized to 100 pb-1! Anyway, if everything worked, you should get 5.2 million inclusive DIS events (the number will be reported to your screen).