W AL extraction --- RooStats::ProfilelikelihoodCalculator

About likelihood method, Justin has given a nice summary talk:
https://drupal.star.bnl.gov/STAR/system/files/spinPWG8.8.13_v2.pdf

RooStats package should be used in ROOT 5.28.00 of higher version, 
              > setup root 5.30.00

here is the code used to extract W AL and the confidence interval by using RooStats::ProfilelikelihoodCalculator

some results have been put in  Attachment A  .