The problem of a 'bad converging' fit shows up for the BS mode (and with some minor differences in the BD mode) AFTER the change from v4r6 and v4r7. Those two fit versions do differ (mainly) JUST for the threatment of the time distribution: in v4r6 we use the time distributions in v4r7 we use the time/mass distributions instead (in order to move 1 setp forward in the direction of a simultaneous fit). This change introduces some correlations among DeltaGamma and tau (BD fit) or ReEta, ImEta, and w (BS fit) that results in an unstable fit result: this means that the time needed to converge is much larger in both cases and that in the BS case the error matrix is not accurate!
As material I link here the full log files for the various fits:
Full details on the problem can be found below. Since, as shown below, the PDF have not changed, the problem is coming from elsewhere...
V4R6 version V4R7 version
Floating Parameter InitialValue FinalValue +/- Error GblCorr. InitialValue FinalValue +/- Error GblCorr.
-------------------- ------------ -------------------------- -------- ------------ -------------------------- --------
B02Kpi_A -1.2250e-01 -1.2257e-01 +/- 3.52e-03 0.020008 -1.2250e-01 -1.2020e-01 +/- 3.53e-03 0.017990
DeltaGammaB0 0.0000e+00 1.2290e-02 +/- 1.06e-02 0.350707 0.0000e+00 9.9940e-03 +/- 1.98e-02 0.002730
DeltaMassB0 5.0000e-01 5.0342e-01 +/- 4.27e-03 0.204821 2.6395e+03 2.6342e+03 +/- 2.34e+01 0.204087
ImEtaB0 -5.6340e-01 -5.3480e-01 +/- 6.00e-02 0.376153 -5.6340e-01 -6.1761e-01 +/- 7.27e-02 0.307252
N_B02KpiSig 8.8221e+04 8.8389e+04 +/- 2.44e+02 0.180780 8.8221e+04 8.7963e+04 +/- 2.44e+02 0.184133
N_B02pipiSig 2.2889e+04 2.2878e+04 +/- 1.63e+02 0.148446 2.2889e+04 2.2750e+04 +/- 1.62e+02 0.126644
ReEtaB0 1.0041e+00 9.9321e-01 +/- 3.63e-02 0.341890 1.0041e+00 1.0402e+00 +/- 4.08e-02 0.295791
deltaB02Kpi 1.3100e+00 1.3094e+00 +/- 4.82e-03 0.589309 6.9155e+03 6.7120e+03 +/- 2.61e+01 0.623539
deltaB02pipi 1.3100e+00 1.3017e+00 +/- 5.11e-03 0.588326 6.9155e+03 6.8476e+03 +/- 2.94e+01 0.625607
etaB02Kpi 9.9000e-01 9.9391e-01 +/- 3.97e-03 0.591412 5.2262e+03 5.2668e+03 +/- 2.16e+01 0.625057
etaB02pipi 9.9000e-01 9.9146e-01 +/- 4.25e-03 0.592951 5.2262e+03 5.2341e+03 +/- 2.31e+01 0.626484
mB0_mean 5.2790e+03 5.2790e+03 +/- 5.60e-02 0.025570 5.2790e+03 5.2789e+03 +/- 5.65e-02 0.019278
mB0_width 1.6000e+01 1.5944e+01 +/- 4.63e-02 0.206823 1.6000e+01 1.6035e+01 +/- 4.68e-02 0.209635
muB02Kpi 1.3400e-03 1.3520e-03 +/- 1.41e-05 0.044000 1.3400e-03 1.3389e-03 +/- 1.41e-05 0.045450
muB02pipi 1.3400e-03 1.3226e-03 +/- 1.53e-05 0.038988 1.3400e-03 1.3245e-03 +/- 1.52e-05 0.039125
tauB0 1.5400e+00 1.5340e+00 +/- 4.73e-03 0.307629 2.9200e-04 2.9226e-04 +/- 8.59e-07 0.101264
wB0 3.5000e-01 3.4586e-01 +/- 2.63e-03 0.273367 3.5000e-01 3.5416e-01 +/- 2.63e-03 0.272174
V4R6 version V4R7 version
Floating Parameter InitialValue FinalValue +/- Error GblCorr. InitialValue FinalValue +/- Error GblCorr.
-------------------- ------------ -------------------------- -------- ------------ -------------------------- --------
BS2Kpi_A 1.4002e-01 1.7413e-01 +/- 1.85e-02 0.081627 1.4002e-01 1.2480e-01 +/- 1.89e-02 0.062194
DeltaGammaBS 6.8500e-02 6.9737e-02 +/- 8.96e-03 0.374322 3.6800e+02 3.3117e+02 +/- 5.05e+01 0.378807
DeltaMassBS 2.0000e+01 1.9980e+01 +/- 1.10e-02 0.339786 1.0738e+05 1.0739e+05 +/- 5.46e+01 0.344549
ImEtaBS 3.0950e-01 3.6401e-01 +/- 4.32e-02 0.692582 3.0950e-01 5.6220e-01 +/- 2.65e-02 0.315765
N_BS2KKSig 2.1578e+04 2.1431e+04 +/- 1.13e+02 0.185425 2.1578e+04 2.1607e+04 +/- 1.13e+02 0.178883
N_BS2piKSig 5.8900e+03 6.0394e+03 +/- 1.15e+02 0.221637 5.8900e+03 5.8592e+03 +/- 1.13e+02 0.192940
ReEtaBS 8.2820e-01 7.7806e-01 +/- 4.15e-02 0.673356 8.2820e-01 7.9403e-01 +/- 2.54e-02 0.352285
deltaBS2KK 1.3100e+00 1.2993e+00 +/- 1.06e-02 0.585474 7.0334e+03 7.0171e+03 +/- 6.57e+01 0.627462
deltaBS2piK 1.3100e+00 1.3137e+00 +/- 4.61e-03 0.584016 7.0334e+03 6.9401e+03 +/- 2.71e+01 0.631198
etaBS2KK 9.9000e-01 9.9599e-01 +/- 8.83e-03 0.586562 5.3153e+03 5.2246e+03 +/- 4.86e+01 0.628514
etaBS2piK 9.9000e-01 9.9108e-01 +/- 3.76e-03 0.585658 5.3153e+03 5.3193e+03 +/- 2.11e+01 0.632590
mBS_mean 5.3690e+03 5.3690e+03 +/- 1.16e-01 0.018359 5.3690e+03 5.3690e+03 +/- 1.16e-01 0.016543
mBS_width 1.6000e+01 1.6088e+01 +/- 9.53e-02 0.215808 1.6000e+01 1.6079e+01 +/- 9.43e-02 0.209741
muBS2KK 1.3400e-03 1.3484e-03 +/- 3.23e-05 0.115346 1.3400e-03 1.3125e-03 +/- 3.24e-05 0.110522
muBS2piK 1.3400e-03 1.3326e-03 +/- 1.40e-05 0.124330 1.3400e-03 1.3577e-03 +/- 1.40e-05 0.123159
tauBS 1.4600e+00 1.4668e+00 +/- 6.30e-03 0.385894 2.7200e-04 2.7166e-04 +/- 1.17e-06 0.381958
wBS 2.9000e-01 3.1191e-01 +/- 1.72e-02 0.769416 2.9000e-01 2.2588e-01 +/- 2.93e-06 0.000279
The PDFs are identical. We use everywhere the variablew time/mass instead of time. The only other change is in the parameters.
Fixed parameters have been changed in this way:
| BD fit | BS fit | ||
| Time Fit | Time over Mass Fit | Time Fit | Time over Mass Fit |
|---|---|---|---|
Constant Parameter Value
-------------------- ------------
DeltaMassMeanRdn 4.9052e-01
DeltaMassSigmaB0 7.0000e-03
N_B02KpiTot 1.8870e+05
N_B02pipiTot 1.0854e+05
alphaB02Kpi 1.3000e+00
alphaB02pipi 1.3000e+00
massMax 5.7000e+03
massMin 4.9000e+03
offset -6.8281e+05
tauMeanRdn 1.5547e+00
tauSigmaB0 1.4000e-02
timeMeanB0 0.0000e+00
timeSigmaB0 3.9100e-02
|
Value
------------
2.5894e+03
3.6953e+01
1.8870e+05
1.0854e+05
6.8627e+03
6.8627e+03
5.7000e+03
4.9000e+03
-3.2263e+06
2.9477e-04
2.6500e-06
0.0000e+00
7.4100e-06
|
Parameter Value
-------------------- ------------
DeltaGammaMeanRdn 6.3063e-02
DeltaGammaSigmaBS 1.2100e-02
DeltaMassMeanRdn 1.9984e+01
DeltaMassSigmaBS 1.2000e-02
N_BS2KKTot 4.1383e+04
N_BS2piKTot 1.0969e+05
alphaBS2KK 1.3000e+00
alphaBS2piK 1.3000e+00
massMax 5.7000e+03
massMin 4.9000e+03
offset -2.1917e+05
tauMeanRdn 1.4676e+00
tauSigmaBS 7.3000e-03
timeMeanBS 0.0000e+00
timeSigmaBS 3.9100e-02
|
Value
------------
3.3881e+02
6.4960e+01
1.0729e+05
6.4428e+01
4.1383e+04
1.0969e+05
6.9797e+03
6.9797e+03
5.7000e+03
4.9000e+03
-1.5151e+06
2.7342e-04
1.3600e-06
0.0000e+00
7.2800e-06
|