Fit Type B:  Fit the mass peak for the signal region definition
Obtain the error on the signal region definition from that fit:
Mean: 3.09327
Sigma:0.0158659
Norm: 48278.6
Signal fraction: 0.910045+/-0.000378823
The fitted value of tau:     0.0443759+/-0.000739287
The fitted value of Lambda+: 0.0686481+/-0.00241886
The fitted value of Lambda-: 0.0723578+/-0.00227116
The fitted value of F+:      0.120462+/-0.00355316
The fitted value of F-:      0.0869345+/-0.00274662
The fitted value of Scale:   1.04586+/-0.00417098
The fitted value of alpha:   0.909631+/-0.000377368
The fitted value of Bfrac:   0.165941+/-0.00221576