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Nuno questions 290715

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Dear Nuno, Many thanks for your questions and comments. Here are our answers.
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Dear Nuno, Many thanks for your questions and comments. Here are some answers (we are working in the others!).
  1) selection.would you mention the procedure and criteria utilised in selection optimisation.

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META TOPICPARENT name="AN14286Questions"

Nuno questions 290715

Dear Nuno, Many thanks for your questions and comments. Here are our answers.

1) selection.would you mention the procedure and criteria utilised in selection optimisation.

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2) physics backgrounds: partially and mis reconstructed b decays.a detailed description of these seems to be missing. please include MC plots showing the various components affecting each final state. presumably, MC-derived shapes are employed in the PDFs.

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3) cabibbo suppressed components: this seems to be missing for example for the B+ case. The JpsiPi bump should sit tothe right and under the main peak.

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4) long lived B+ background: this was discussed at the earlier stages if the review. please point to theconclusion of the studies performed. (cf fig.3, tab.2)

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5) K* swap: you make a selection. in some fraction of the times, an incorrect mass assignment is made. this results in a mass assignment that differs from (is broader than) thesignal. a term needs to be added to the likelihood to describe these candidates. The lifetime parameter would still be that of the signal. this is besides the systematic considerations in point 6 of section 6.

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6) ct efficiency: the ct distribution may be biased by online as well offline selection andreconstruction. were effects from the latter two considered?a data-based calibration would be suitable. use for example the 2011 B+ dataset(that is otherwise not utilised in the analysis). or the 2012 unbiased sample fromparked data. attempt to extract the efficiency parameters from a fit to this sample.

the linear model in eqn.26 may be appropriate; others could be also tried. then, inthe final nominal fit used to extract the lifetime, use a ct-efficiency functionwith these parameters constrained (via gaussian constraints aka penalty functions).

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7) ct resolution: please use the high-statistics trigger-unbiased parked-data 2012 sample, by fittingthe prompt components, to calibrate the ct resolution. there were other extensivestudies of ct resolution performed in the connect of the Bs lifetime difference andphi_s paper (BPH-13-012). please attempt to propagate these studies as cross checksof related effects.

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8) primary vertex selection: l.104-7 comment: this issue is being completed in the next version of the AN

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9) notation: for consistency with other related CMS publications, it would be nice to use ctinstead of lambda and of PDL. the is relevant for the PAS/paper.

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-- JhovannyMejia - 2015-07-30

 
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