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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