W 2012 comparison of SL13b and Fall2012 productions

 2012 W-stream was re-produce with   SL13b .

Jinlong Zhang run W code over new muDst and prepare our standard movies for the barrel & endcap Ws, new and old production:
http://drupal.star.bnl.gov/STAR/blog/jlzhang/2013/apr/25/pdf-movie-new-produced-data-p13ib-and-previous-run12-w
In general new production look good, all plots are similar, we gain some Ws - measureable but not impacting error of reco AL in significant way.
However, one plot (fig 1) shows unexpected problem. For the endcap we gain extra 40 Ws (30% increase) but the charge separation (Q/PT vs. ET) degraded in a visible way. 

Fig 1.


Jinlong constructed new histogram file being the difference between SL13b and the old production.  He made the PDF movie just for the excess events in SL13b:
http://drupal.star.bnl.gov/STAR/system/files/diff_P13ib-old_EndCap.pdf

It start to be interesting, see my comments in attachement 1.