Review of Bs→J/ψ Ks

Furthermore, you are making a blinded analysis, which is great! Could you please discuss or remind me of the unblinding procedure you propose? Since you are making a measurement of the effective lifetime and not of the yield/cross section, it is not clear to me how much sense it makes to blind the signal yield. Please don't unblind yet, but this is something that we might want to discuss with the group (was there a discussion on this before?). Also, is it necessary to blind the decay time distribution, rather than just the fit to it? I guess nobody will read off the value by eye But again to be discussed with the group at the meeting. I guess the answer also depends on the physics message which you aim for in the end. Do you expect to have the sensitivity to see new physics (then blinding is indeed very important), or do you "only" aim for improved precision of the measurement of the standard model value? If new physics, which would you be sensitive to? Can you give some examples?

Ans : We aim for better precision at this stage. We use two methods: 2D UML fit and sPlot method. We perform the toy study and whichever gives better sensitivity (better precision), we will use it as the primary method. However we would like to quote the second method as cross check as well. So, the unblinding will be done after toy MC study.

Coming to the AN :

As already stated above, it looks technically quite advanced, and in better shape than many others I have seen, but some essential parts like systematics and expected physics impact still seem to be missing.

Ans: In fact, in our first presentation, we had detailed cyst study but we realized there were some basic comments from the group that needed to change the analysis. For that reason, we will wait till the current sections are reviewed before going to syst error.