Horizontal Error Bars Update

previous study: https://drupal.star.bnl.gov/STAR/system/files/horiz_pres.pdf

fms meeting 07.27.17
includes first assessment of E uncertainty (denoted C) and folds in incident angle correction impact as an uncertainty (denoted A)

fms meeting 08.03.17
ideas about how to more quantitatively assess the magnitude of C

fms meeting 08.10.17
Improved assessment of C, but used 'rough' pion cuts and mixed large and small cells

spin meeting 08.14.17
Better assessment of C as well as propagation of new pT uncertainty to A_LL vs. pT final plot

fms meeting 08.17.17

assessment of C broken down into regions of E1 vs. E2 plane (also denoted E+ vs. E- plane)