Hi Kirstof,
You mean this one?
(5) Can you demonstrate (at least in the ANA note) that the efficiency ratio between Bs->D-Ds+ and Bd->D-Ds+ is indeed exactly/mathematically equal to 1?
-> No, I will not do this. There is absolutely no physical basis for expecting the RELATIVE EFFICIENCY to have a slope with decay time. This is a VERY DIFFERENT statement than there being a difference in the absolute efficiency. Of course I would not be surprised if Bs->DsD had O(1%) higher efficiency, but there is NO WAY it depends on proper time. At most, the D's get a bit more of a boost, and the proper time takes out the boost. So, there is no conceivable way that a 3% difference in the boost is going to give any measurable difference in the efficiency vs proper time.
Tsja, I must admit I don't know either... I'm tempted to let him get away with it.
I have one more comment on 2) (why B- and not B0 as normalisation.) My point was that he could add a sentence in the paper making the motivation of his choice explicit.
Cheers, Niels
On Tue, 12 Nov 2013, Kristof De Bruyn wrote:
Dear all,
Steve has already replied to our comments. See http://cds.cern.ch/record/1627619
I am not yet happy with (at least) his answer to my first question, so I will get in touch with him. If there are other points you are not satisfied with, please let me know asap.
Could somebody with more experience also have a look at his reply to question 5? I can't judge ... The assumption is the main reason why the systematic error on Bs->D-Ds is only half that of Bs->DsDs, something that is a priori surprising.
Cheers, Kristof
Quoting Kristof De Bruyn debkr@nikhef.nl:
Dear all,
I am collecting the comments from Nikhef on LHCb-PAPER-2013-060: "Measurement of the B0s(bar) to Ds+ Ds- and B0s(bar) to D- Ds+ effective lifetimes". So far I have already received comments from Jeroen van Tilburg, and from Niels. If there are no objections, I will post the attached list to CDS tonight (Deadline is tomorrow, November 12th).
Cheers, Kristof
Quoting Tjeerd Ketel tjeerd@nikhef.nl:
Dear colleagues,
Bfys Meeting Friday 8 November in N328 and Vidyo
9:30 - 9:55 Staff meeting (only permanent staff) 10:00 - 10:50 "Introduction and discussion of LHCb-PAPER-2013-060: Measurement of the B0s(bar) to Ds+ Ds- and B0s(bar) to D- Ds+ effective lifetimes" by Kristof de Bruyn
The presentation can be found at http://agenda.nikhef.nl/conferenceDisplay.py?confId=2622 and will be protected by lhcb, etc.
Vidyo link in Nikhef Bfys Meeting (at Institutes->Nikhef of Friday 21 June 2013) https://indico.cern.ch/conferenceDisplay.py?confId=255991 protected by PIN 1328.
Best regards, Tjeerd
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