Steps of lifetime cut too small --> risk to overestimate the D0 lifetime
We experienced a problem in the second part (lifetime) related to the steps of the lifetime cut. If the cut is applied using a non 0 value on the less significant digit available (10^-2 ps) the first bin of the distribution (bins are 0.1 ps wide) is only partially filled and this produce a bias on the fitted value. So the cut should be applied at the 10^-1 ps level and giving that probably there is a pre-selection cut in the sample between 0.1 and 0.2 ps the lowest value to use is 0.2 ps. In particular if the left cut is applied using a non 0 value on the less significant digit (e.g. 0.22 ps) the D0 lifetime is always overestimated given that the first bin is only partially filled. This happens even if the cut is left at 0, given the pre-selection cut applied to the sample (probably 0.15 ps). One solution could be to increase the stepping of the D0 lifetime cut to 0.1 ps, using 0.2 ps as lowest possible value. Another possibility is to decrease the size of the bins in the histogram used for the fit from 0.1 ps to 0.01 ps.