Here I make preliminary data / simulation comparisons using Pibero's 2009 inclusive jet embedding test sample ...

I have done a data / simulation comparison using the detector jet trees created from Pibero's 2009 inclusive jet embedding test sample. I used the full 178 simu jet trees available which cover RFF and FF field configurations. The data sample I used consisted of ~90 runs from the RFF field configuration only.

I run the data and the simulation through my dijet code, so all my standard dijet cuts apply (see here). Since I am focussing on dijets, I make separate comparisons for the high and low pt jet for each quantity I look at.

I have also split up the jets by trigger type. I use five catagories: All - this contains all jets; JP2 - this contains all jets which fired the dijet condition of the L2JetHigh trigger and had jet pt > 8.4; JP1Lo - this contains all jets which fired the JP1 trigger and had jet pt < 8.4 GeV; JP1Hi - this contains all jets which fired the JP1 trigger, had jet pt > 8.4, and did not fire the L2JetHigh trigger; Untriggered - this contains all jets which fail the three above triggers but were included in an event in which the other jet fired the trigger.

For all data / simulation comparisons shown below, the simulation sample is scaled to the data by the ratio of the total number of dijets in the data to the total number of dijets in the simulation.

Figure 1: This figure shows the jet eta spectra for data (Blue) and simulation (Red). There is an obvious excess of events in simulation as compared to data in the endcap region. The top set of five plots show the spectra and the bottom set of five plots show the data/simulation ratio. The five pannels are for the five different trigger divisions described above.

I think the enhancement in simulation compared to data in the endcap region can be (at least partially) understood by looking at how the different endcap gains were used when creating the simulation mudsts and jet trees. The simulations were created using the OLD endcap gains, which we believe were too high by ~8%, this will result in more events passing the trigger filter than should have. The jet trees created from the simulation, however, used the NEW endcap gains which were lowered by ~8% relative to the old gains. I believe this will increase the energy seen in the endcap relative to what it would have been if the jet trees were created using the same gains as the simulation, most likely resulting in more jets reconstructed. We are of course comparing this to data jet trees created using the old gains.

Figure 2: This figure shows the jet pt spectra for data (Blue) and simulation (Red). The data simulation agreement is not great. The top set of five plots show the spectra and the bottom set of five plots show the data/simulation ratio. The five pannels are for the five different trigger divisions described above.

Figure 3: This figure shows the dijet invariant mass spectra for data (Blue) and simulation (Red). The data simulation agreement is again not great. The top set of five plots show the spectra and the bottom set of five plots show the data/simulation ratio. The five pannels are for the five different trigger divisions described above.

In addition to the plots shown above, I have done data / simulation comparisons between several other quantities such as jet phi, jet mass, jet neutral fraction, sum of track and tower pts, number of tracks and towers, and average track, tower, and jet pt as a function of jet detector eta. I also show the plots for the low pt jet. All these quantities can be found in this pdf.