but the problem is MC doesn’t model data very well, so one have to apply reweighting to MC before calculating the efficiencies.
so the procedure is
- generate MC1, MC2
- reweight MC to match the data
- calculate efficiencies
- calculate number of events from real data
- estimate N_signal1
- estimate N_signal2
- calculate the ratio
so hypothesis is that even reweighted MC doesn’t give correct efficiencies and one should