1 / 15

CPV in B → D (*) K (*) ( and B → D K  ) in BaBar and Belle

CPV in B → D (*) K (*) ( and B → D K  ) in BaBar and Belle. Outline: CPV in B → D (*) X s theoretical ideas experimental issues experimental results B ∓ → D (*) 0 K (*) ∓ B 0 → D (*) 0 K (*)0 some other approaches summary. Φ 2 ( α ). V td V * tb. V ud V * ub.

aminia
Télécharger la présentation

CPV in B → D (*) K (*) ( and B → D K  ) in BaBar and Belle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CPV in B → D(*) K(*)(and B → D K  )in BaBar and Belle • Outline: • CPV in B→D(*)Xs • theoretical ideas • experimental issues • experimental results • B∓→ D(*)0K(*)∓ • B0→ D(*)0K(*)0 • some other approaches • summary HEP2003 Europhysics Conference –Aachen, July 18th

  2. Φ2(α) VtdV*tb VudV*ub interference between B →D(*)0 K(Xs)⊕ B→D(*)0 K(Xs) f Φ3(γ) Φ1(β) VcdV*cb experimentally challenging: sensitive to CPV in B → DXs B → DXs is a good place to look Φ3(γ )≡ arg(-VudV*ub/ VcdV*cb) CPV in interference between b→c & b→u theoretically clean: only tree diagrams HEP2003 Europhysics Conference –Aachen, July 18th

  3. PROBLEMS: • r = A(B-→D0K-)/A(B-→D0K-)~ 0.1(0.2) • A(B-→D0K-)difficult to measure directly δ 2A(B-→DCPK-) A(B-→D0K-)= A(B+→D0K+) 2Φ3 A(B-→D0K-) A(B+→D0K+) 2A(B+→DCPK+) δ Ways to measure Φ3 in B→DXs D→fCP ( Gronau, London & Wylermethod) amplitude triangles extensions and modifications various f various Xs,(D) many observables ... statistics required: ∼ 0.5 ab-1 δ - relative strong phase HEP2003 Europhysics Conference –Aachen, July 18th

  4. Experimental issues Use beam constraints to reconstruct B: Mbc(GeV) ΔE (B-→D0h-) K/ separation Babar : dE/dx in SVT & DCH, DIRC Belle: dE/dx in CDC, TOF, ACC ≥2.5 (K/) separation up to 3.5 GeV Apply tight K-ID cut: E  -49 MeV for DK- HEP2003 Europhysics Conference –Aachen, July 18th

  5. Experimental issues Continuum suppression:multidimensional cuts exploiting event topology (Fox-Wolfram moments, thrust...)angle of B-flight direction... Background suppression from other Bdecays depends on specific final states: veto for some B-decays, .... Signal extraction: Maximum likelihood fits with signal shapefrom MC and data control samples, background from side bands and off-resonance data (combinatorial),MC (B-decays) HEP2003 Europhysics Conference –Aachen, July 18th

  6. (7.7 ± 0.9 ± 0.6 )% (8.31 0.35 ± 0.2)% ± (9.9 1.3 ± 0.7)% 56 fb-1 B- → D0 h-measurements Preliminary D0 →K D0 →K0 D0 →K Signal extracted witML fit to the DE,Mbc,PID(p/K) h-identified as K E(GeV) E(GeV) E(GeV) Belle,PRL 87,111801(2001) 10.4 fb-1 ± Babar, hep-ex/0207087 56 fb-1 CLEO, hep-ex/0302026 15.3 fb-1 For other B→D(*)K- modes see Belle, PRL 87,111801(2001) HEP2003 Europhysics Conference –Aachen, July 18th

  7. D1 = KK B D1K D1 =  E(GeV) = 0.17 ± 0.23(stat) ± 0.08(sys) = 1.06 ± 0.26(stat) ± 0.17(sys) B-→DCPK- 81.2 fb-1 Preliminary D1DCP=+ D2DCP=- Observables: asymmetries branching ratios 3 independent equations with 3 unknowns (Φ3,r, ) 24.27.2 HEP2003 Europhysics Conference –Aachen, July 18th

  8. =0.06 ± 0.19(stat) ± 0.04(sys) = 1.21 ± 0.25(stat) ± 0.14(sys) = -0.19 ± 0.17(stat) ± 0.05(sys) = 1.41 ± 0.27(stat) ± 0.15(sys) sin2(Φ3)≤ r 1/4 || 78 fb-1 B-→DCPK- hep-ex/0304032 Signal yields extracted with a likelihood fit to the DE 179.615 165.414.5 D1=KK, pp 25.06.5 22.16.1 D2=Ksp0, Ksf, Ksh, Ksw, Ksh’ 29.96.5 20.55.6 HEP2003 Europhysics Conference –Aachen, July 18th

  9. D1=K+K-, p+p- 13.14.34.4.3 D2=Ksp0, Ksf, Ksw 7.23.6 2.4 = -0.02 ± 0.33(stat) ± 0.07(sys) = 0.19 ± 0.50(stat) ± 0.04(sys) Similar analysis can be performed with K*- replacing K- 88 fb-1 B-→DCPK*- Preliminary D0 → K, K,K 0 MK*- coshel from P→PV No indication for non-resonant DK (6.1 ± 1.6(stat) ± 1.7(sys)) x 10-4CLEO HEP2003 Europhysics Conference –Aachen, July 18th

  10. 81.2 fb-1 B→V V can be also used, angular analysis required, B- → D*0 K*- Preliminary B → D*0 K*-ALL D*0 → D00 D*0 → D0 (8.0 ± 1.0(stat) ± 1.2(sys)) x 10-4 (7.7 ± 2.2(stat) ± 2.6(sys)) x 10-4CLEO HEP2003 Europhysics Conference –Aachen, July 18th

  11. B0→ D0 K(*)0 both amplitudes are color suppressed r ~ 0.4 isospin relations ⇒ extract Φ3 and  B0→ D0 K*0 , K*0 → K+- (kaon tags B0 flavour) rates and asymmetriesB0→ D1,2K*0⇒Φ3 B0→ D0 K0s , B0 – B0 mixing time dependent asymmetries (B0-decay vertex needed) HEP2003 Europhysics Conference –Aachen, July 18th

  12. 27.07.3 41.08.4 E M(D0) sidebands 78 fb-1 B0→ D0 K(*)0 PRL 90, 141802 (2003) 90% CL Vub. HEP2003 Europhysics Conference –Aachen, July 18th

  13. | | | | | | Summary of Br’s, event yields, ..... 347±20 @ 78 fb-1 D  K 360±20 @ 56 fb-1 D  K 70±10 @ 88 fb-1 D  K 10±4 @ 78 fb-1 D  K 15±5 @ 78 fb-1 D  K PDG HEP2003 Europhysics Conference –Aachen, July 18th

  14. uu us cu us b c b u u u u u Some other approaches • Atwood,Dunietz, Soni (ADS): use doubly Cabibbo-suppressed D decays • Dalitz plot analysis of BDK • BDK, Dalitz plot analysis of multibody D decays ( e.g. DKs+-) • ................ r ~ 1, Br~ 10-7 Both amplitudes are color allowed HEP2003 Europhysics Conference –Aachen, July 18th

  15. Summary and outlook No direct CPV observed in B→DXs, no direct constraints on Φ3 yet, but there is a steady progress: • new relevant decay modes observed: • B-→ DK(*)- D→fCP, CP=+,- • B0→ DK(*)0 • other analyses in progress • accelerator performance • KEKB: Lpeak>1034cm-2 s-1 PEP-II: Lpeak>61033cm-2 s-1 • Belle and BaBar aiming for ≈ 0.5 ab-1 in 2005 • some meaningful constraints on Φ3 possible by that time • new theoretical ideas • precise measurements in D sector ........ HEP2003 Europhysics Conference –Aachen, July 18th

More Related