Hi all,
finally something that has a large difference between Q0 and Q1.
I did again the test using the generic MC and generic+crossfeed as a
model.
I discovered that the difference we observed between generic MC and
cocktail 0.0169 -> 0.0140 was DUE TO THE RATIO eps(u)sl/eps(c)sl
calcualted in the fit that was affected by a fit on a very dirt
sample (generic MC with no cut applied).
This introduces a large bias in this factor when we fitted the
generic MC (~20% up since the signal before the lepton cut is
overestimated for b->clnu)
Then these are the results (correcting this effect):
generic MC:
==========
Q0
--
B0 BRBR = 0.00383 +- 0.00703(stat)
Bch BRBR = 0.02544 +- 0.00541(stat)
All BRBR = 0.01649 +- 0.00428(stat)
Q1
--
B0 BRBR = 0.01244 +- 0.00773(stat)
Bch BRBR = 0.03057 +- 0.00635(stat)
All BRBR = 0.02277 +- 0.00487(stat)
generic + crossfeed MC
======================
Q0
--
B0 BRBR = 0.00290 +- 0.00705(stat)
Bch BRBR = 0.02644 +- 0.00539(stat)
All BRBR = 0.01700 +- 0.00429(stat)
Q1
--
B0 BRBR = 0.00655 +- 0.00789(stat)
Bch BRBR = 0.03102 +- 0.00635(stat)
All BRBR = 0.02054 +- 0.00492(stat)
The usage of generic + crossfeed MC as a very large impact on Q1!!!
especially on B0s.
I summarize
Q0 default gene + crossfeed
--
B0
BRBR 0.0029+-0.0071 0.0024+-0.0071
chi2 0.90232 1.24949
Bch
BRBR 0.0264+-0.0054 0.0264+-0.0054
chi2 1.37897 1.72423
All
BRBR 0.0170+-0.0043 0.0170+-0.0043
chi2 1.03306 1.56583
Q1 default gene + crossfeed
--
B0
BRBR 0.00142+-0.0076 0.0066+-0.0079
chi2 1.04791 1.56062
Bch
BRBR 0.0336+-0.0063 0.0310+-0.0064
chi2 2.58364 1.9846
All
BRBR 0.0253+-0.0048 0.02054+-0.0049
chi2 1.56594 0.866931
The disagreement Q0 - Q1 now becomes (using the difference in
quadrature):
B0 -1.2 sigmas
Bch -1.3 sigmas
I don't quote the difference in the total (B0+Bch) since it could be
wrong due to a not correct ratio B0/Bch (BTW is -1.5 sigmas)
Let's think about this very carefully.
Daniele
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