Ha Rob, Tjeerd, Attached are my comments. Cheers, Niels
On Fri, 7 Sep 2012, Marcel Merk wrote:
Dear all, I can unfortunately not be present at the meeting. I give my (general) comments below.
Here are my comments/questions:
What does the measured number *mean*? A) The CP asymmetries vary strongly over the Dalitz plot phase space. Does the integrated number give the CP asymmetries over the integral of the Dalitz plot after kinematical cuts corresponding to the LHCb acceptance and reconstruction, or is there some (MC-) extrapolation involved?
B) The more I thought of it, the less I understand. How can we ever interpret these large asymmetries in areas of the Dalitz plot in terms of physics parameters? Perhaps I just confused myself...
On line 113 I read that the background is calculated on the total event sample and then divided equally to the two CP samples. Why is it not determined independently for the two CP samples? At least one could do this and assign a systematic to the assumption that it is equal.
3. On line 131 it is stated that the K+K- asymmetry dependence on momentum is weak. Do we have an experimental prove of that?
4. Systematics: I presume there is a magnet-up vs magnet down cross check done that at least shows there is no statistical significant difference for the asymmetries. It is not mentioned.
I like the cross check of lines 160 - 166.
6. As far as I saw the vertical "empty bands" (or "white bands") in the Dalitz plots in fig 3 are not explained in the text. Did I miss it?
cheers and have a fruitfull discussion,
- Marcel
On 5 September 2012 23:03, Tjeerd Ketel tjeerd@nikhef.nl wrote: Bfys Meeting at Friday 7 September at 14:00 h on EVO
14:00 Discussion of conference note LHCb-conf-2012-028 Title: Evidence for CP violation in B+- -> pi+- pi+ pi- and B+- -> K+ K- pi+- decays. The summary will be given by Rob Lambert. 15:00 End Analysis note: ANA-2012-077 Deadline: 11-Sep-2012 Link: https://cdsweb.cern.ch/record/1475804 [cdsweb.cern.ch] Twiki:https://twiki.cern.ch/twiki/bin/view/LHCbPhysics/Bu2KKpiAndBu2pipipiSumme> 012 [twiki.cern.ch] The unusual time is chosen because of Piet Mulders' Lectures at 10:30. I am at CERN for the VELO this week and did not reserve a room at Nikhef. At CERN the EVO meeting will be broadcasted from Rob's room. =================================================================== EVO: Title: Nikhef Description: Bfys Meeting 14:00-15:00 h Community: LHCb Password: N328 Meeting Access Information: - Meeting URL http://evo.caltech.edu/evoNext/koala.jnlp?meeting=MeMMMu2e28D8DB9v9nDv9e - Password: N328 - Phone Bridge ID: 578 2011 Password: 4119 EVO Phone Bridge Telephone Numbers: --------------- - Switzerland (CERN, Geneva) +41 22 76 71400 - Netherlands (Nikhef, Amsterdam) +31 20 7165293 Dial '2' at the prompt - Skype (tm) (World-wide) evo.phone See: http://evo.caltech.edu/evoGate/Documentation/extclient/skype/skype.html =================================================================== _______________________________________________ Bfys-physics mailing list Bfys-physics@nikhef.nl https://mailman.nikhef.nl/mailman/listinfo/bfys-physics