Dear Ray and Group,
I have house guests this week and may not be able to call in for our usual
meeting since our time falls directly on the French dinner hour.
In case I'm not able to call my comments/questions on BAD 2060 V.9 are
below:
1. Line 180-183 states that charge conjugation is assumed. A question of
physics - is it proper to assume CCI when there could be direct CP
violation? In any case it's practical to do so but could the BR of B+ be
different from the BR of B-, at least in principle?
2. The discussion of paragraph 211-236 is about the signal reconstruction
cuts but leaves the reader hanging. I would like to see mention of
efficiency and cleanness of the cuts to extract the signal. One must read
further to get to Table I where the NN efficiencies and S/B are discussed.
Some bridge sentence saying that there is more to come in the analysis
would be helpful on line 236.
3. In the determination of the missing neutrino 4-momentum I am worried
about the asymmetry of the BaBar detector stemming from the asymmetric
collider. Are the segments of calorimetry and resolution of tracking
completely symmetric in the COM? There seem to be an asymmetry in the cuts
- line 263, for example or line 281. Perhaps a word about this would be
reassuring ... Calorimetry resolution scales are 1/sqrt(E) so the high
energy side has a different resolution from the low energy side of the
detector, etc.
4. Line 281 - Is not a cosine bounded by {-1 to +1}? An 'unbounded' cosine
is a ratio parameter and has nothing to do with an angle.
5. What are the errors of the parameters of Table I? Don't they contribute
to the overall error?
6. The various numbers quoted in the text around lines 377-397 are hard to
follow. It would be more clear is these were tabulated.
7. After line 480 - Mention is made at the beginning of the paper that
these BRs could be used to better determine |Vub| but the paper concludes
without any further enlightening of the |Vub| goal. Further in the
next-to-last paragraph it says '.. decays are important ingredients in the
understanding of the composition of the inclusive charmless semilelptonic
decay rate'. Is this an obvious statement - or is there some deeper
physics. To my reading it seems obvious as stated so perhaps some
elaboration could be given ... or the sentence eliminated.
Have a good meeting ...
--
Best regards,
Frank
Frank E. Taylor
CERN MIT
ATLAS Collaboration Bldg. 26 - Rm 569
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Switzerland USA
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On Sat, 12 Jul 2008, Ray F. Cowan wrote:
> Hi Everyone,
>
> Our next LQS group meeting will be Wednesday, July 16, at 2 PM Eastern.
> Those of us at MIT can meet in the LNS conference room.
>
> Dial-in info: 510-665-5437, passcode 7336.
>
> Yet another BaBar paper review for ICHEP 2008 has arrived; we will review
> it at this meeting. The url is below; I've also attached a pdf copy to
> this email.
>
> - BAD 2060 v9 from the Semileptonic AWG:
> - "Measurement of the B -> omega l nu and B -> eta l nu branching fractions
> using neutrino reconstruction."
> - http://www.slac.stanford.edu/BFROOT/www/Physics/BAD/vol17/02060.009.pdf
> - This is a journal article aimed at Physical Review D - Rapid Communications
> - Supporting Documents: BAD 2007
> - Previous related publication: None
> - Changes since preliminary result: None
> - Collaboration-wide talk: 9 July 2008
> - https://www.slac.stanford.edu/BFROOT/www/doc/BbrMeetingOrganizer/vol02/pro/mtg001201/itm0003933/
>
> Our review of BAD 2059 v4 from last week was posted in Hypernews at
> http://babar-hn.slac.stanford.edu:5090/HyperNews/get/rev-Charmon-07-01/19/3.html
> The authors have not yet responded.
>
> Hope you can join in.
>
> Thanks,
> --Ray
>
