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Run-11 Transverse Jets: VPDMB Embedding Including 5 - 6 GeV/c Bin

Updated on Tue, 2013-09-10 13:47. Originally created by drach09 on 2013-09-09 23:32.

Unmatched Fractions

One relevant question before adding in the 5-6 GeV/c bin is what fraction of reconstructed jets do not match to parton jets? In Run-9 ~20% of jets in the 6-7.1 GeV/c bin did not match to a parton jet. Here, in principle, the fraction should be lower. However, for VPDMB, I take all jets below 16.3 GeV/c. Thus, there is no trigger-filtering in my calculation. This fact coupled with the growing soft cross section seems to conspire to raise the unmatched fraction in 2011. It seems that the trigger-bias from Run-9 actually helps in this arena over Run-11 min-bias! Reducing the cone radius to 0.5 does appear to help to some degree. I have not run over the data trees with R = 0.5 so I cannot yet say how much is the cost in statistics.

Table 1

Bin [GeV/c] R = 0.6 R = 0.5
  Unmatched (to parton jet) Fraction Unmatched (to particle jet) Fraction Unmatched (to parton jet) Fraction
5-6 0.445149 0.105468 0.369943
6-7.1 0.343303 0.102521 0.288886
7.1-8.4 0.300243 0.102494 0.256054
8.4-9.9 0.224948 0.10803 0.137968
9.9-11.7 0.178408 0.0882758 0.152845
11.7-13.8 0.159218 0.103019 0.158194
13.8-16.3 0.000924567 2.02448e-05 0.000333341

Jet Histograms

The following histograms represent jets from anti-kT with R = 0.6.

Figure 1

Figure 2

Figure 3

Figure 4

Parton Jets Particle Jets

Table 2: Parton Jets

Bin mean (calc) mean err (calc) sigma (calc) mean (fit) mean err (fit) sigma (fit)
0 4.376700 0.050112 1.782332 4.298699 0.099149 1.995898
1 5.255551 0.070918 2.032022 5.048214 0.167162 2.171887
2 6.119759 0.114194 2.387166 5.832943 0.186998 2.531867
3 7.114054 0.177052 2.742883 6.901127 0.464553 2.823919
4 8.850526 0.242213 3.054184 8.986211 0.331816 2.786197
5 11.426827 0.275702 2.838530 11.541767 0.500606 2.639954
6 14.243042 0.174677 3.040576 14.394541 1.286680 2.772319

Table 3: Particle Jets

Bin mean (calc) mean err (calc) sigma (calc) mean (fit) mean err (fit) sigma (fit)
0 4.841764 0.036212 1.567174 4.870950 0.058215 1.754405
1 5.916643 0.053980 1.722295 5.891218 0.164114 1.726686
2 7.008965 0.096950 2.126271 6.959531 0.155951 2.333823
3 8.161178 0.153885 2.437989 8.686677 0.207796 1.989351
4 10.104818 0.188913 2.194968 9.990243 0.248133 2.203013
5 11.791698 0.368663 2.554170 12.303599 0.276353 1.898854
6 14.837272 0.146978 2.562654 15.116610 0.152352 2.163757

By rights I should calculate the pT-shifts for the two η windows as well. However, in checking the values, they are consistent with those of the combined window within statistical uncertainties.

Figure 5

Parton Jets Particle Jets

Figure 6

Parton Jets Particle Jets

Track Histograms

Figure 7

The issue from last week involving stray tracks above the pion band appears to be resolved by enforcing a cut on the number of hits used in the dE/dx calculation. Here, I require more than 5. The cut appears to resolve the issue entirely.

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

The current cut is ΔR > 0.1. This means the resolution is ~0.36 or lower. A resolution of 0.4 corresponds to a damping of ~7.7%, while a resolution of 0.36 corresponds to a damping of ~6.3%.

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