Dear Tjeerd,

Replace "signal events" by "signal decays".
(Patrick, I like to remove this comment, because we do select events, not decays.
I do not understand the  assumption about the branching fraction here.
Therefore, I may misunderstand the whole meaning of this optimization.)

I try to get rid of the word "event" as much as possible as it's lazy jargon that prevents us from thinking about what we really mean. I keep "event" for the whole data corresponding to one bunch crossing, as in "the typical event has 50 tracks and 90 kB", or "global event variable". The SPD multiplicity is a property of an event. It got selected because it contains *candidate* (which are mostly background). In the end we measure a certain number of decays. It may or may not be equal to events due to multiple candidates. I think here we have decays. But I agree that event is understandable too.

> All our "events" are "downstream". Patrick, what do you mean here?).

well, all tracks are downstream of the PV ;-) (If nobody gets the joke, remove it).

BTW

Line 33:
Write "\B=\bd,\Bs decay vertex" here.

you mean \B=\Bd,\Bs

Thanks for having taken care of that one.

Patrick

On 13/09/15 21:43, Tjeerd Ketel wrote:mu

-- 
========================================================================
 Patrick Koppenburg                           LHCb Physics Coordinator
 Nikhef, Amsterdam & CERN
 http://www.koppenburg.org/address.html