Here I test several jet pt correction schemes ...

 

Below are the results of three jet pt correction schemes I have implemented. The simulation used was the full run 9 RFF sample generated by Pibero.

 

The first correction method uses the plots of detector jet pt / particle jet pt vs det Eta shown in figure 1. The mean values of this quantity for 6 different pt ranges are fit with a function of the form A+(1-A)*(1/(Exp[(x-B)/C]+1)). The fits in figure 1 give 6 values for each parameter, one for each pt bin. I plot the 6 values of each parameter as a function of pt and fit them with a smooth curve, see figure 2. Thus, the three parameters in the fit function shown above can be found for any pt. So for a given jet pt and detector eta, a correction factor can be generated by plugging the pt into the parameter fits shown in figure 2 and then plugging those parameters and the jet eta into the fit function shown above. The original jet pt is then corrected by the correction factor to get the corrected jet pt. I only apply this correction to jets with pt <= 35GeV and det Eta >= 0.5.

 

The second correction method uses the plots of particle jet pt vs detector jet pt shown in figure 4. This correction method works in much the same way as method 1 does. The particle vs detector plots are divided into 6 det Eta bins and the mean of the distribution in each is fitted with a second order polynomial. I then plot each parameter as a function of det Eta and fit those points with first order polynomials as shown in figure 5. As in method 1, I can then take the pt and det Eta of a given jet, plug them into the functions and find the corrected jet pt. I only apply this correction on jets with pt <= 25GeV and det Eta >= 0.5.

 

The third correction method was a test to see how well one could recover the true endcap jet pt by replacing it with the detector jet pt measured in the barrel. As you will see below, this dosen't work too well but I think the method can be greatly improved by utilizing a fit to the plot of endcap particle jet pt vs barrel detector jet pt to find the correction.

 

Figure 1: The ratio of detector jet pt over particle jet pt vs detector eta for 6 different pt bins. The points are the means of the distribution in that bin. The fit is of the form: A+(1-A)*(1/(Exp[(x-B)/C]+1)).

 

Figure 2: This plot shows the values of the three fit parameters in the 6 different eta bins for the curves shown in figure 1. The points are fit with a Log (upper left) and pol2 (other two pannels).

 

Figure 3: This figure shows a summary of the first correction method. The top two pannels show the size of the correction factor as would be calculated for a given jet pt and det Eta (the right plot is just a 3-D plot of the left). The bottom two plots show the difference in the pt between the corrected jet and the original jet pt for a given original jet pt and det Eta. As mentioned above, I stop using the correction at 35GeV which is where the correction starts leading to jets with lower pt than the original.

 

Figure 4: This figure shows the particle jet pt vs the detector jet pt for 6 different detector eta bins. The points are again the mean in each bin and the fits are 2nd order polynomials.

 

Figure 5: This figure shows the fit parameters from figure 4. Note that I have made these fits while ignoring the error bars on the points. Also note that I have omitted one outlier point from the eta [1.3,1.5) bin, the plot with this point included can be seen here.

 

Figure 6: This figure shows a summary of the second correction method. The top two pannels show the value of the corrected jet pt for a given original jet pt and det Eta. The bottom two pannels show the difference between the original jet pt and the corrected jet pt for a given value of original jet pt and det Eta. As noted above, I only apply the correction up to a pt of 25GeV.

 

The plots below show the results from the three correction methods described above. The first 7 figures show the correction in terms of the detector / particle jet pt vs det Eta quantity and the 7 plots following those show the correction in terms of the particle vs detector jet pt scatter plots. For all the plots below, the error bars now show the RMS in each bin instead of the error on the mean in each bin.

 

Figure 7: This figure shows the detector jet over particle jet pt ratio vs det eta for all pt values. The upper left pannel shows the ratio using uncorrected pt. The upper right pannel shows the ratio when the detector pt is corrected using method 1. The lower left pannel shows the ratio when the detector pt is corrected using method 2. And the lower right pannel shows the ratio when the detector pt is corrected using method 3.

 

Figure 8: Same as figure 7 but now for pt [5,10).

 

Figure 9: Same as figure 7 but now for pt [10,15).

 

Figure 10: Same as figure 7 but now for pt [15,20).

 

Figure 11: Same as figure 7 but now for pt [20,25).

 

Figure 12: Same as figure 7 but now for pt [25,30).

 

Figure 13: Same as figure 7 but now for pt [30+].

 

Figure 14: This figure shows the particle jet pt vs the detector jet pt for all eta bins. As in the figures above, the upper left pannel shows the uncorrected detector pt and the remaining three pannels show the corrected detector jet pt for the three correction methods.

 

Figure 15: Same as figure 14 but now for eta [0.5,0.7).

 

Figure 16: Same as figure 14 but now for eta [0.7,0.9).

 

Figure 17: Same as figure 14 but now for eta [0.9,1.1).

 

Figure 18: Same as figure 14 but now for eta [1.1,1.3).

 

Figure 19: Same as figure 14 but now for eta [1.3,1.5).

 

Figure 20: Same as figure 14 but now for eta [1.5,1.7].