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Exploring B Meson Decays at LHC: CKM and Beyond

Dive into B meson decays, CKM matrix, and new physics effects at LHC for a deeper understanding of flavor physics. Discover potential NP shifts and NP effects in decays. Explore possibilities beyond the Standard Model and ways to reduce theoretical constraints. Experiment results corroborate NP consistency.

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Exploring B Meson Decays at LHC: CKM and Beyond

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  1. Belle results relevant to LHC & BaBar v S.L. Olsen U of Hawai’i Pheno-07 May 8, 2007 Madison Wisc.

  2. CKM with trees CKM Global Fit (Sep.2006) SM+CKM is “correct” at tree level

  3. Next Step Check the Unitary Triangle with Penguins

  4. SM FCNC: NP: QCD-vertices EW-vertices ~ c- g ~ ~ ~ c ~ s t b x t x huge effects are possible (but not seen) This mixing matrix is 6x6 (lots of CP phases) at least V i.e. > 0.1 for MNP accessible @ LHC ~

  5. sin21from BfCP + BBfCPinterf. J/y Vcb B0 KS  V*2 no CP phase td J/y V* Vtb td B0 B0 KS Vtb V* td Sanda, Bigi & Carter:

  6. sin2f1 with bs penguins (SM) Example: no CP phase f1 * Vtd , h’, K+K- , h’, K+K- + B B * Vtd f1 SM: sin2f1 =sin2f1 from BJ/y KS (bc c s) _ eff

  7. Smaller than bgccs in all of 9 modes Theory tends to predict positive shifts (originating from phase in Vts) 2006: f1 with bgs Penguins Naïve average of all b g s modes sin2beff = 0.52 ± 0.05 2.6 s deviation between penguin and tree (b g s) (b g c)

  8. eff History of sin2f1 2.8s 2.6s 2.6s 3.1s 3.9s sin2f1 from bccs decays (2007) D  0.15 sin2f1 (bqqs decays) (Belle&BaBar average) 2002 2003 2004 2005 2006

  9. How to make D small?

  10. How to make D small? ~ g ~ ~ s b x • Tune the squark mixing terms • is there enough freedom to do this? • Make the squark masses degenerate • invoke a GIM-like mechanism • Make the SUSY mass scale very high (~few TeV) • not much fun for LHC experimenters

  11. Parameters are already constrained by KK & DD mixing Same diagrams contribute NP: SM: ~ ~ c s d u c d,s u x X X X X ~ ~ W W g,c- g,c- K & D mixing are consistent with 2nd order SM EW

  12. B  Decays w/ “Missing E(>1n)” SM : B decay constant Lattice QCD BSM : sensitive to New Physics from H

  13. 449M BB B tn(nearly invisible decays) tn signal B e- (8GeV) e+(3.5GeV) Υ(4S) p B Tag-side: Full reconstruction N= 680k eff.= 0.29% purity = 57% 4-momentum determined  B meson beam ! Charged B

  14. B  candidate event Missing momentum

  15. B gtn results Belle BaBar PRL97, 251802 (2006). hep-ex/0608019 Belle Hadronic tag D l n tag e+nn (3.6%) m+nn (2.4%) p+n (4.9%)p+p0n(2.0%) pppn (0.8%) t+  e+nn (eff: 4.1%), m+nn (2.4%), p+n (4.9%), p+p0n (1.2%) No clear signal First evidence, 3.5 s

  16. We measure Branching fraction Babar preliminary Product of B meson decay constant ƒB and CKM element |Vub | Compare with

  17. Constraints on H mass Use known fB and |Vub |Ratio to the SM BF. excluded rH=1.130.51 excluded

  18. BXsg W+, H+

  19. Nakao

  20. NNLO theory Theory News M. Misiak et al, hep-ph/0609232, PRL 98,022002(2007) NNLO calculation (29826) x 10-6

  21. 95% CL lower limit on H+ mass from exp and NNLO 300 GeV Error on BF BaBar/Belle/CLEO avg M(H+)>295 GeV Central value of BF M. Misiak et al, hep-ph/0609232, PRL 98,022002 (2007)

  22. LHC People: or here 350- look here BXsg Btn

  23. Summary Any “new physics” that is seen at the LHC is very carefully hidden from the Flavor Sector

  24. Backup Slides

  25. Validate the EECL simulation using double-tagged events (with on the signal side) Extra Calorimeter Energy Signal reconstruction (purity ~ 90%) MC: B+B–: 494 ± 18 B0B0: 8 ± 2 Combined: 502 ±18 Data: 458 _

  26. SM NP? ~ g ~ ~ s b t x i.e. > 0.1 for MNP accessible @ LHC ~

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