Cuts for Figures 1-4:
dca < 3
# fit points > 5
nSigmaPion < 5
0.48 < p < 0.56

Figure 1:  nSigmaPion distribution shows a shift due to the loose cuts and noticable contamination on the rightside tail.

Figure 2:  nSigmaPion distribution with nSigmaKaon and nSigmaElectron cuts, which cleans up much of the contamination and shifts the distribution mean much closer to zero.

Figure 3:  dE/dx distribution associated with nSigmaPion plot in Figure 1.

Figure 4: dE/dx distribution associated with nSigmaPion plot in Figure 2.

Figure 5:  dE/dx vs. p from the calibration, where the curves are the Bichsel values.