VERY preliminary and incomplete!!!
Data/MC comparison (standard analysis): standard shape ( plots )
For low mass:
Data: 13 evts instead of 5 (7 at low mass, 1 very high mass - plots )
Background: 12.0 versus 9.2
Mass distribution of the additional background: mostly at low mass, but also an increase (~10%) at high mass ( plots ).
CONCLUSIONS: more work required - probably worthwhile
Waiting feedback and suggestions!