dN/dx fit (progress report).

I would like to show one slide with new dE/dx fit results.

This plot shows the standard dE/dx resolutions versus track length in active TPC
for Run XV pp200 data  with the standard I70 and Ifit estimations which we have used for last ~10 years
and new fit (Nfit) using more complicated dE/dx model.
This is first results obtained with this model. And at least it shows that the direction is worthwhile to proceed.

We can get 10% improvment in dE/dx resolution.