Measurement of the ϒ( nS )  μ + μ - Decay Angular Distribution Questions from pre-blessing

1. Measurement of the ϒ(nS)μ+μ- Decay Angular DistributionQuestions from pre-blessing http://www-cdf.fnal.gov/~mjones/internal/Upsilon.html Matthew Jones Purdue University B Production and Decay Meeting

2. B Production and Decay Meeting

3. Question #0 • Check the quality of the CMP efficiency fits. Can they be improved at low 1/pT? • Answer #0… • Yes, they have been improved significantly. • No significant change in the results • Necessary to revisit this anyway so that the statistical uncertainties in the fit could be propagated into a systematic uncertainty on the angular distribution parameters. B Production and Decay Meeting

4. Question #1 • Is there symmetry in the acceptance? What is it? Fold in phi looks good, but not theta. • Answer #1… • Yes, there is indeed 4-fold symmetry, but it isn’t exactly just folding the 2d distribution. • See the explanation in the hyperlink. • Answering this question also provided explicit validation of an important assumption that was previously not checked. B Production and Decay Meeting

5. Question #2 • Limit range of muonpTto have good matching efficiency • Answer #2… • Would prefer not to cut on pT since this would limit the high pT(ϒ) bins. • Instead, try to measure efficiency using higher pT sample of muons • Use the ϒ(nS) resonances themselves. B Production and Decay Meeting

6. Question #2 • Perform simultaneous fit to pass/fail distributions. • Reasonable agreement between upsilons and mu+SVT sample in CMX • Systematic difference between upsilons and mu+SVT in CMU • Prefer to use upsilon efficiency… B Production and Decay Meeting

7. Question #3 • Check z0 shift in data vs time. • Answer #3… • The Monte Carlo seems to model the time dependence reasonably well, but it isn’t perfect. • We re-weight the zvtx distribution in the Monte Carlo to match the data. • The change in angular distribution parameters is small. B Production and Decay Meeting

8. Question #4 • Effect of FSR on background fraction in low sideband and under signal (background scale factor) • Answer #4… • Small systematic shift in polarization • Would prefer to use 0.25 GeV/c low side-band veto for default analysis. B Production and Decay Meeting

9. Question #5 • Effect of FSR on signal: split 1S peak • Answer #5… • Major changes to fitting framework to handle split signal bins. • Need to finish documenting findings • There are observed shifts, but they may be largely statistical (ie, no obvious trends in angular distribution parameters.) B Production and Decay Meeting

10. Question #6 • Effect of B background structure moving under the upsilon peak(s)? • Answer #6… • A 4th or 5th order polynomial appears to be adequate when fitting in limited cos(θ) bins. • Need to test whether this could bias signal yields. B Production and Decay Meeting

11. Question #7 • Dissect the outlier bin(s) in the lambda fits. • Answer #7… • Some anomalies found with 9-10 GeV/c bin • Wider pT range generated than in other bins • Different luminosity file used for generation • These have been corrected • No significant change in the result • No similar anomalies found in other bins • The data looks slightly more “transverse” in this bin than in the adjacent bins and the fit reflects this. B Production and Decay Meeting

12. All the other questions… • Question #8 • Question #9 • Question #10 • Question #11 • Question #12 • Question #13 • Question #14 • Question #15 B Production and Decay Meeting

13. Summary • Many questions answered • Analysis significantly improved in doing so • Requires re-running over MC files which takes about a day • Full results still need to be pulled together • Remaining questions might be ready and documented in the note by Thursday. • Certainly by the following Thursday. B Production and Decay Meeting