VUB-RECOIL Archives

Vub measurement using recoil of fully reconstructed Bs

VUB-RECOIL@LISTSERV.SLAC.STANFORD.EDU

Options: Use Forum View

Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Daniele del Re <[log in to unmask]>
Date:
07 Jul 2002 13:23:13 -0700 (PDT)Sun, 07 Jul 2002 13:23:13 -0700 (PDT)
Content-Type:
TEXT/PLAIN
Parts/Attachments:
TEXT/PLAIN (125 lines)


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








ATOM RSS1 RSS2