Following with the discussion about the efficiency. in the last ARC-Authors meeting we showed some results about (see "Ivanquestions_02102016_talk.pdf"). So, we got a suggestion by Kevin, it is to make the efficiency without cuts and then add "cut by cut". We made it and you can see the results in "Effycutbycut_24102016_talk.pdf".
we did not only do that, we also did the same exercise for the Dimuon system, ie, for muons (no using the kaon) using the Jpsi vertex.

In all cases the efficiency behavior was the same. Therefore we thought it might be some effect in the "track reconstruction". Because of it we contact the tracker experts, Matthew Walker, Gabriele Benelli and Giovanni Petrucciani. They say that this is expected due to some steps in the track reconstruction. We can see similar results in the tracker performace paper (see section 5.1.2, figure 12).

http://cds.cern.ch/record/1704291/files/1405.6569.pdf

They also told me they could give an explanation in our hypernews forum if necessary.

Please let us know your comments.

with my best regards,

Jhovanny

-- JhovannyMejia - 2016-10-27