1. Heavy Flavor Results from CMS
Sridhara Dasu, University of Wisconsin For CMS Collaboration
Key to CMS Heavy Flavor Physics capability is its dimuon trigger
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

2. Sridhara Dasu (Wisconsin) - SUSY2015
Menu
Rare decays and angular distributions of B meson decay products are particularly sensitive probes of physics beyond the Standard Model.
Branching ratios for Bsmm and Bdmm
Forward-backward asymmetry of muons, longitudinal polarization of K* and differential branching fraction with Q2 in BK*mm
CP violating phase fs and decay width difference DGs from BJ/yf
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

3. Sridhara Dasu (Wisconsin) - SUSY2015
Candidate Bmm Event
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

4. Bsmm Rare Decay SM has no FCNC SM Loops leading to Bsmm Decay
BSM Contributions could enhance Bsmm Rate
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

5. Long Quest with BSM Hopes
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

6. Boosted Decision Tree Analysis
Discriminating variables
3D flight length significance
Distance of closest approach between muons
B vertex c2/dof
Pointing angle
B candidate isolation and muon isolation
Distance of closest track to B vertex
Number of close tracks
Impact parameter (significance) w.r.t. primary vertex
Categorized (2+2 in 2011, 4+4 in 2012)
12 fits based on signal to background & barrel / endcap
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

7. Sridhara Dasu (Wisconsin) - SUSY2015
2011 Fits in 2+2 Categories
PRL 111 (2013)
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

8. Sridhara Dasu (Wisconsin) - SUSY2015
2012 Fits in 4+4 Categories
PRL 111 (2013)
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

9. Weighted Distribution of all Data
PRL 111 (2013)
Evidence for Bsmm signal @ 4.3s
Extracted Branching Ratios:
Bs: 3.0±1.0 x 10–9
Bd: <1.0 x
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

10. Standard Model Compatibility
PRL 111 (2013)
Alas, no new physics
Compatible with SM
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

11. Combination with LHC-B : Mmm
Nature 522 (2015) 68
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

12. Combination with LHC-B : Results
Nature 522 (2015) 68
BR(Bsmm) = (2.8 ± 0.7) x 6.2s
BR(Bdmm) = (3.9 ± 1.6) x 3.2s
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

13. Angular Analysis of B0K*0mm
arXiv:
Angular distribution can provide insight on new physics
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

14. Fit of B0K*0mm Data
arXiv:
Un-binned ML fit to invariant mass, and two angles
Side bands, MC and signal region used to extract FL, AFB & BR in multiple Q2 bins
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

15. Sridhara Dasu (Wisconsin) - SUSY2015
Sample Fits for Q2 Bin 2
arXiv:
The q2 bins are defined as follows:
bin 0: (GeV2)
bin 1: (GeV2)
bin 2: (GeV2)
bin 3: (GeV2) bin 4: J/ψ region
bin 5: (GeV2) bin 6: ψ(2S)
bin 7: (GeV2)
bin 8: (GeV2)
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

16. K* Longitudinal Polarization (FL)
arXiv:
Measurements are in good agreement with the Standard Model
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

17. K* Longitudinal Polarization (FL)
arXiv:
Measurements of all experiments are compatible with each other
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

18. Forward-Backward Asymmetry of m
arXiv:
Measurements are in good agreement with the Standard Model
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

19. Forward-Backward Asymmetry of m
arXiv:
Measurements of all experiments are compatible with each other
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

20. Differential Branching Fraction
arXiv:
Measurements are in good agreement with the Standard Model
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

21. Differential Branching Fraction
arXiv:
Measurements of all experiments are compatible with each other
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

22. Angular Analysis of B  J/y(m+m–) f(K+K–)
arXiv:
Bs meson CP violating phase (fs) and decay width difference (DGs) between heavy and light Bs states could be sensitive to new physics effects
SM predictions are precise
Time dependent analysis
Flavor tagged Bs sample
Transversity Basis
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

23. Invariant Mass of J/y(m+m–) f(K+K–)
arXiv:
Invariant mass peaks on a smoothly falling small background
With 4 well- reconstructed tracks lifetime measurement is quite accurate
Flavor tagging is done with semi-leptonic decay of the other B-hadron in the event
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

24. Decay Length and its Uncertainty
arXiv:
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

25. Fitted Angular Distributions
arXiv:
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

26. Results of CP violating phase & decay width difference
arXiv:
Strong Phases
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015

27. Sridhara Dasu (Wisconsin) - SUSY2015
Summary
Rare decays Bsmm & Bdmm measured to be at SM level
Long quest finally ended with 6.2s LHC
In BK*mm decays: forward-backward asymmetry of muons, longitudinal polarization of K*, and differential branching ratio are also consistent with SM
CMS measurements are amongst the most precise
Decay B  J/y f used to measure CP violating phase fs and decay width difference of heavy and light Bs-meson
Results are consistent with SM expectation
What next?
The LHC Run 13 TeV  100 fb–1 is underway
Stay tuned !!
24 Aug 2015
Sridhara Dasu (Wisconsin) - SUSY2015