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BaBar Winter Highlights

BaBar Winter Highlights. SLAC Experimental Seminar April 3, 2007 For the BaBar Collaboration. Jim Olsen Princeton University BaBar Physics Analysis Coordinator. Data input and physics output. Publication “Luminosity”. Run 6. BaBar Publications. Journal Publications

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BaBar Winter Highlights

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  1. BaBar Winter Highlights SLAC Experimental Seminar April 3, 2007 For the BaBar Collaboration Jim Olsen Princeton University BaBar Physics Analysis Coordinator

  2. Data input and physics output Publication “Luminosity” Run 6

  3. BaBar Publications • Journal Publications • Submitted: 270 (15 in 2007) • Published: 248 • About half PRL, half PRD • Ongoing Analyses • New results for winter: > 30 • Targeted for summer: > 100

  4. Electron-Positron Annihilation @ s = 10.58 GeV Non-B physics accounts for ~25% of all BaBar publications • Bulk of BaBar effort is in B physics: • CKM elements: Vub, Vcb, Vtd, Vts • searches for CP, T, and CPT violation • searches for rare and forbidden decays • hadronic B decays, HQET,…

  5. Publications by topic* *some papers cover multiple areas

  6. BaBar Winter Results at a Glance • Beta • sin2b from (c cbar) K0 • sin2b with D*D and DD • sin2b with D0(CP) h0 decays • sin2b in B0→ KSKSK0 • sin2b in B → p0 p0KS • Radiative Penguins • Evidence for B → rg • Search for B → pl+l- • Charmless Hadronic B Decays • Observation of B → rKS • Angular analysis in B → fK* • Search for B → K*K • Search for a0h and hr/f0 • Alpha • observation of CP violation in B0→ h+h- • BF and Acp in B → rp0 • Time-dep CP asymmetry in B → r+r- • Time-dep Dalitz in B → r+p- • Evidence for B0→ r0r0 • Time-dep CP asymmetry in B0 → a1p • BF(B → K1p) • Hadronic B Decays • Angular analysis of Charmonium K* • Measurements of B → J/ypp • B → Lpp • Non-B Physics • Evidence for D0 mixing • Search for D0 mixing in semileptonic decays • Measurement of Wc branching fractions • Form factors in D → Ken • Observation of e+e- → r+r- • Observation of e+e- → r+r- • t → l(p, h, h’) • Gamma • Measurement of g in B → D0(ppp0)K • Semileptonic B Decays • Decay rates for B → (D, D*, D**)ln • Vcb and form factors in B → D*ln

  7. Outline • D mixing • New results on CP violation • New results on spectroscopy and QCD

  8. DOW plummets 200 points press release on D mixing Evidence for D0 Mixing See SLAC seminar by Brian Petersen for details: https://www.slac.stanford.edu/exp/seminar/talks/2007/20070314_BrianPetersen_BaBar_Dmixing.pdf

  9. Charm-Meson Mixing (SM) short distance ~ x ~ Dm long distance ~y ~ DG O(10-5) O(10-3 - 10-2) Most calculations give: x,y < 1% 1% “D0-D0 mixing is expected to be too small to measure with BaBar if the Standard Model is a complete description of physics.” - BaBar Physics Book (1998) cf. A. Petrov, hep-ph/0611361, and references therein

  10. Charm-Meson Mixing (NP) New particles enter primarily in the short distance contribution (x): Signs of New Physics: |x| >> |y| CP violation 1% Suppression of new FCNCs via quark-squark alignment predicts “large” effects in D-D mixing: Y. Nir and N. Seiberg, hep-ph/9304307 (1993)Y. Nir, hep-ph/0206064 (2002) cf. A. Petrov, hep-ph/0611361, and references therein

  11. B Factory, Tevatron LHC Observation of D-D mixing opens a new window on the off-diagonal elements of the squark matrix in the up-quark sector Constraining the Squark Mass Matrix Squark mass matrix (d sector)

  12. Analysis of D0→ Kp Two paths to the “wrong-sign” state: (DCS decays) (Mixing) Mixing modifies the exponential decay-time distribution: DCS interference mixing Strong phase d→ 0 in SU(3) limit

  13. Evidence for Mixing Wrong-sign decay-time distribution First assume no mixing: Mixing gives a better description of the data c2/ndof = 50/28 c2/ndof = 31/28 3.9s hep-ex/0703020 Submitted to PRL on March 9 No evidence for CP violation

  14. Comparison of BaBar and Belle Assuming d → 0 and no CP violation Belle KK,pp BaBarpreliminary 3.9s 1s 2s 3s 4s Belle Kspp 5s Full interpretation depends critically on the strong phase: “My call: SU(3) violation” – J. Rosner (Moriond QCD)

  15. CP Violation

  16.  Goal of the B Factories is to overconstrain the apex (r,h) and look for inconsistencies → New Physics! CP Violation and the Unitarity Triangle Sidesare determined from the rates for various processes “The” Unitarity Triangle Anglesare determined from CP-violating asymmetries Area is proportional to the amount of CP violation Length of each side ~ O(l3)

  17. Observing CP violation at the (4S) Three possible interference effects: CP if q ≠ p CP violation in mixing (|q/p| ≠ 1) (indirect) CP violation in the interference between mixing and decay: Im(q/p) ≠ 0 (direct) CP violation in decay: Indirect CPV Direct CPV

  18. a b g Indirect CP Violation: experimental method Lepton Tags: mistag rate ≈ 8% e+ t = 0 Kaon Tags:mistag rate ≈ 18% (4S)  hfS = sin2b Asymmetry

  19. New results on sin2b in b → ccs BaBar Preliminary (hep-ex/0703021; submitted to PRL) hf = -1 NBB = 383 million pairs Golden modes (J/yK0): hf = +1

  20. B Factory Average Disfavored by J/yK*, D*D*KS, D0h0

  21. Latest on sin2b in Penguins

  22. sin2b in b → cud: B0 → D(*)0(CP)h0 Interference between mixing and the b → cud decay tree amplitude when the D0 decays to a CP eigenstate No penguin amplitude, NP must enter at tree level: Ex. R-parity-violating SUSY with baryon number violation Y. Grossman, Y. Worah, Phys. Lett. B 395 (1997) 241-249 Longterm goal: compare sin2b in charmonium, b → s penguin, and b →c tree

  23. sin2b in b → cud: B0 → D(*)0(CP)h0 • Decay modes: • D*0→ D0p0 • D0 → KK, KSw • h0 → p0, w, h BaBar Preliminary CP even BaBar Preliminary CP odd

  24. sin2b in b → cud: B0 → D(*)0(CP)h0 SM expects S = -sin2b, C ~ 0 First measurement of sin2b in these modes Fully consistent with the world average for sin2b in charmonium, another victory for the standard model! hep-ex/0703019, submitted to Phys. Rev. Lett.

  25. D(*)+ D(*)+ B0 D(*)- B0 D(*)- sin2b in b → ccd: B0 → D(*)+D(*)- • Two decay amplitudes interfere • b → c tree diagram with S = -sin2b • b → d penguin diagram with S ~ 0 • Penguin is expected to be small • ~2-10% (PRD 61, 014010, 2001) Standard Model predicts:

  26. Belle sin2b in b → ccd: B0 → D+D- Belle @ CKM 2006 (NBB = 535 million pairs) B0 B0

  27. BaBar sin2b in b → ccd: B0 → D+D- BaBar @ Moriond EW (NBB = 383 million pairs) BaBar Preliminary S consistent with sin2b in charmonium, no evidence for direct CP violation! Note the sign flip: C = -A, C(BaBar) – C(Belle) = 1.02 ± 0.33!

  28. CP Violation in B0→ h+h- BaBar: 347 MBB @ICHEP06 Belle: 535 MBB

  29. How to add data over a shutdown DCH DRC Use dE/dx for tracks with no qc +12% from forward coverage +9% from f cracks in barrel +16% overall in B+→ h+X0 +35% overall in B0 → h+h- dE/dx p/K separation competitive in the forward region  high momentum

  30. Belle Observation of CPV in B0→ h+h- BaBar: 383 MBB Now more events/fb-1 than Belle! BaBar Preliminary (hep-ex/0703016; submitted to PRL)

  31. Time Evolution of Spp 2000 2001 2002 2003 2004 2005 2006 2007

  32. hep-ex/0607106 hep-ex/0612021; accepted by PRL B → pp|Da| < 41o B → rr|Da| < 18o The problem with a… S  sin2aeff = sin2(a+ d) All modes suffer from “penguin pollution” due to b → d transition Use isospin to relate the decay amplitudes for the various modes and set a bound on the shift in a Optimal Case:

  33. A New Direction: B → a1p First time-dep CP asymmetry in B → a1+p- Similar to rp, but no overlapping regions in phase space where a1+, a1-, and a10 can interfere directly BaBar Possible solution: Use SU(3) to relate a1p, a1K, and K1p First observation of B → a1+p- BaBar hep-ex/0612050; accepted by PRL Phys. Rev. Lett. 97, 051802 (2006)

  34. First Step: B → K1p SU(3) relates p K and a1 K1A: Gronau & Zupan, Phys. Rev. D73, 057502 (2006) related to K1p related to a1K • Experimental problem: • K1A is an admixture (q ~ 33o) Wide overlapping resonances First pass: quasi-two-body approach

  35. Results for B → K1p BaBar preliminary Evidence for K1(1400), but large correlation with K1(1270) complicates the interpretation • Full analysis, including interference term, is underway • next step: a1K • sPlot constructed from a fit using mES, DE, and event-shape info: • data points do not use MKpp • curves are the result of the full fit

  36. Spectroscopy and QCD

  37. Spectroscopic Mysteries Open Charm Charmonium-like DsJ(2700) New BaBar results using B → D(*)D(*)K

  38. DsJ(2700) @ Belle First observed by Belle (hep-ex/0608031) Potential model: cs(23S1)(expected mass @ 2720) S. Godfrey and N. Isgur, Phys. Rev. D 32, 189 (1985) Chiral symmetry: 1+ - 1- doubletpaired with DsJ(2536) M. A. Nowak, M. Rho, I. Zahed, Acta Phys.Polon. B 35, 2377 (2004)

  39. DsJ(2700) @ BaBar BaBar confirms a broad enhancement near 2.7 GeV, but is it one resonance or two? Possible low-mass structure in DK. Next step: full Dalitz analysis

  40. X(3872) X(3872) first observed by Belle Observation of J/yg mode → C = +1 Belle angular analysis → JPC = 1++ Inconsistent with expected charmonium states

  41. Search for X(3872) in D*D Belle: BaBar: PRL 97, 162002(2006) X(3875)?

  42. Observation of e+e-→ r+r- Exclusive reactions allow fundamental tests of QCD Single photon (JPC = 1--) In the CM frame: r+ r+ For vector gluons: ds/dcosq* ~ sin2q* e- q* e+ r- r- Two-Virtual Photon Annihilation (C = +1) followed by FSI → unlikely? u u r+ r0 u d r0 u d r- u u BaBar observation of TVPA process in r0r0, r0f→ good agreement with theory: B. Aubert et al., Phys. Rev. Lett. 97, 112002 (2006); G. Bodwin et al., Phys. Rev. D74, 074014 (2006)

  43. Observation of e+e-→ r+r- • Fit in (m-, m+) plane: • signal = p-wave relativistic BW • rpp = threshold function • comb = linear N = 308 ± 25 signal events (> 5s)s(e+e-→ r+r-) = (20.0 ± 1.6± 3.6 ± 1.7)fb (stat) (syst) (ampl)

  44. Angular Distributions Use mass fit to produce sPlots for various angular distributions, then perform c2 fit over the sPlot bins Prediction (single g*): q± = r± helicity angle f± = azimuthal angle of p in r frame q* = scattering angle in the CM frame Brodsky and Lepage, PRD 24, 2848 (1981)

  45. Angular Distributions: Results BaBar Preliminary Fit normalization constraint: Results: |F00|2≠ 1 s(e+e-→ r0r0) > s(e+e- → r+r-) No evidence for Y(4S) → rr Are we seeing TVPA + FSI?

  46. Summary and Outlook • BaBar did not hibernate this winter • >30 fresh results for the winter workshops/confs • Highlights • First evidence for D0 mixing • Many new results on CP violation, including first observation in pp from BaBar • New results in spectroscopy and QCD • We are approaching 300 papers submitted! • Wide range of physics topics, no signs of slowdown • Looking forward to ~500fb-1 and >100 new results for the summer season!

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