1. Update on Measurement of the angles and sides of the Unitarity Triangle at BaBar Martin Simard Université de Montréal For the B A B AR Collaboration 12/20/2008 MIAMI 2008 3/1/20161

2. Introduction - Unitarity Triangle 3/1/20162 Wolfenstein parameterization Unitarity condition This defines the Unitarity Triangle Each term is O(λ 3 ) The main goal of the B-factory is to over-constrain the unitarity triangle by measuring angles and sides in as many ways as possible. (ρ, η) = ( ρ, η). (1-λ 2 /2) Quark flavor changes can only occur through weak interactions, via the coupling of a W gauge boson. Such couplings are proportional to the relevant CKM matrix elements. In particular, the probability of a b quark to decay into a u quark is proportional to |V ub | 2.

3. B A B AR Data 3/1/20163 End of Υ(4S) data Taking (2007) The entire Υ(4S) dataset has a integreted luminosity of about 426 fb -1 (467M BB)

4. Constraining the Unitarity Triangle - Sides Sides of the Triangle: We measure decay rates. ~ |V ij | 2 From exclusive sl decays: |V cb |: B  D*l, B  Dl ; |V cb |: B  D*l, B  Dl ; |V ub |: B  l, B  l, B  (‘)l, B  l. |V ub |: B  l, B  l, B  (‘)l, B  l. From inclusive B  X c l : |V cb | and B  X u l decays : |V ub | From radiative decays: (b  d  /b  s  )  |V td |/ |V ts | (b  d  /b  s  )  |V td |/ |V ts | inclusive and exclusive decays inclusive and exclusive decays 3/1/20164

5. |V ub | from B  πlv decays untagged PRL 98, 091801(2007) Untagged (high stat., most precise)  Untagged (high stat., most precise)  Tagged (hadron or semileptonic) Untagged Analysis loose reconstruction: use the events' missing  loose reconstruction: use the events' missing momentum as an approximation to the signal momentum as an approximation to the signal neutrino. (p = p beams -  p i ) neutrino. (p = p beams -  p i ) Two-Dimensinal Fit  E = E B – s/2 and  Two-Dimensinal Fit  E = E B – s/2 and m ES = s/4-|p* B | 2 m ES = s/4-|p* B | 2 q 2 = (p B - p  ) 2 in 12 q 2 bins  Form factor fit  q 2 = (p B - p  ) 2 in 12 q 2 bins  Form factor fit 3/1/20165 untagged

6. |V ub | from B  πlv decays tagged Tagged Analysis with B → D(*)lν PRL101, 081801 (2008) Untagged (high stat., most precise)  Untagged (high stat., most precise) Tagged (hadron or semileptonic)  Tagged (hadron or semileptonic) 3/1/20166 Statistical error on the BF is 3 times larger than the untagged analysis. Compatible result with the untagged analysis. 348 fb -1

7. |V ub | from inclusive semileptonic decays PRL100, 171802 (2008) 3/1/20167 Integrated over optimized region in the phase space Tagged analysis, use B → D(*)lν as tags. |V ub | values are higher than from exclusive semileptonic B  πlv decays: -> More Data is needed and improvement from theory is also needed. theoretical error is the largest error on |V ub |. theoretical error is the largest error on |V ub |. 347 fb -1

8. |V cb | with B → Dlν decays 3/1/20168 Many methods also for |V cb |: here is a tag exclusive analysis From PANIC08 417 fb -1

9. BABAR has used three different ways to obtain |V cb | from B → D*lν: 1) Fully reconstructed B 0  D* + lv (exclusive) 1) Fully reconstructed B 0  D* + lv (exclusive) 2) Fully reconstructed B +  D* 0 lv 2) Fully reconstructed B +  D* 0 lv 3) Combined fit to partially reconstructed Dlv and D*lv in D(n)lv events. 3) Combined fit to partially reconstructed Dlv and D*lv in D(n)lv events. 3/1/20169 Very consistent result |V cb | with B → D*lν decays

10. |V tb /V ts | from radiative decays |V td | is accessible through loops: radiative penguin B → XsB → Xs B → XdB → Xd PRL 101 111801,2008 Exclusive Inclusive 3/1/201610 arXiv: 0808.1379, accepted by PRD veto to photons  veto to photons from  0 and  from  0 and  Select high energy  Select high energy photons photons Yield from  E and m ES  Yield from  E and m ES See Bruce Schumm talk

11. Constraining the Unitarity Triangle - Angles Angles of the Triangle: Interference appears ~ |V ij | 2 3/1/201611 Interference between B mixing and decay Interference between two decays

12. Angle α Interference between B mixing and b  u Four solutions ambiguity Isospin analysis to resolve Δα 3/1/201612 α eff = α + Δα We have to measure A +-, A +0 and A 00

13. Angle α - Time-dependent CPV in B → π + π - Evidence of direct CP violation arXiv: 0807.4226 [hep-ex] 3/1/201613 (3.0σ) (6.3σ) N ππ : 1394±54 B 0 tagged

14. Angle α - B → π o π o Contrains A 00 arXiv: 0807.4226 [hep-ex] 3/1/201614

15. Angle α - B →ρρ Complication due to vector-vector is saved by f L (ρ + ρ - )~1. PRD78, 071104(R) (2008) 3/1/201615 Smaller A 00 /A +0 means smaller error on Δα B(ρ 0 ρ 0 ) = (0.92 ± 0.32 ± 0.14) × 10 −6 Combined results ρ0ρ0ρ0ρ0 Measured range is compatible with the CKM fit

16. Angle β – Angle β – Benchmark sin2β arXiv: 0808.1903 [hep-ex] = sin2β (SM) C = 0.026 ± 0.020 ± 0.016 S = 0.691 ± 0.029 ± 0.014 β = (21.8 ± 1.3) o HFAG average Decays: BaBar Results: sin2β 3/1/201616 CP odd J/Ψ K L

17. Angle β – B → η’K 0 and B → ωK 0 S Penguin diagram can change the CPV phase with new physics: This method gives larger errors on β. This method gives larger errors on β. η’K S ωK S (large error) η’K L 3/1/201617 arXiv: 0809.1174 [hep-ex] No evidence of New Physics

18. Angle γ – B ± → DK (*)± Interference between Cabibbo-suppressed b → c and color-suppressed b → u tree decays D 0 and D 0 decays into the same final state 3/1/201618 Small CP asymmetry.

19. Angle γ – B ± → DK (*)± PRD 78 034023 (2008) D→KSπ+π-D→KSπ+π- D 0 (D 0 ) → K S π + π -, K S Κ + Κ - : Dalitz method (Giri, Grossman, Soffer, Zupan) Interference comes from overlap region on the Dalitz plot This method gives the smaller error 3/1/201619 DALITZ METHOD

20. Angle γ – B ± → DK (*)± PRD 78 034023 (2008) D 0 (D 0 ) → Kπ, Kππ 0, Kπππ : ADS method (Atwood, Dunietz, Soni) 3/1/201620 Interference between D 0 → Cabibbo-favored K - and D 0 → Doubly-Cabibbo-suppressed K - This method gives larger error (Only additional information to constrain γ) ADS METHOD Ratio Combined mode favored suppressed Kππ 0

21. Summary 3/1/201621 All these observations are in agreement with each other. The combined fit to all observations leads to these sides and angles of the unitarity triangle. No evidence of new physics: The SM describe what we observe. Kobayashi and Maskawa: 2008 Nobel Prize in Physics for introducing the third quark generation into the SM which explains CP violation by quark mixing with the matrix V CKM.