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BaBar physics,

BaBar physics,. recent highlights and future prospects. Owen Long, BaBar physics analysis coordinator U. C. Riverside & SLAC December 5, 2008. Outline. General overview Highlights from core CKM measurements and searches for New Physics in the Y(4S) data

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BaBar physics,

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  1. BaBar physics, recent highlights and future prospects Owen Long, BaBar physics analysis coordinator U. C. Riverside & SLACDecember 5, 2008

  2. Outline • General overview • Highlights from core CKM measurements and searches for New Physics in the Y(4S) data • e+e- +-() cross section from ISR • Highlights from the 2008 data • Discovery of the b • Search for a light Higgs • Precision scan of Rb above the Y(4S) • Looking forward BaBar physics, recent highlights and future prospects Page 2

  3. g W b s t The BaBar physics program • Perform the first precision tests of CP violation within the Standard Model. • Over constrain the CKM quark mixing matrix parameters with measurements of CP asymmetries in B decays and semileptonic B decays. • Search for signs of New Physics in rare B decays. • Studies of open charm: mixing and CP violation in D decays, leptonic and semileptonic D decays. • Tau lepton physics: tests of unversality, searches for lepton flavor violation, determination of |Vus|. • Continuum studies using initial state radiation (ISR) events. • Quarkonium spectroscopy. BaBar physics, recent highlights and future prospects Page 3

  4. BaBar datasets Data taking ended on April 7, 2008 • Totals up to Sept. 07 465 M 630 M 460 M • Quick decision in Dec. 07 to run on Y(3S) and Y(2S). 120 M Y(3S) [20x Cleo] 100 M Y(2S) [12x Cleo] BaBar Average efficiency 96% Peak luminosity 12 x 1033 cm-2s-1 About 4 times design value! BaBar physics, recent highlights and future prospects Page 4

  5. BaBar publications Total published papers PRL 165 PRD 188 BaBar physics, recent highlights and future prospects Page 5

  6. Highlights of the CKM program and searches for New Physics Y(4S) analyses BaBar physics, recent highlights and future prospects Page 6

  7. sin2 from b(cc)s arXiv:0808.1903 One dominant decay amplitude Final analysis: 465 M BB (CP odd) No direct CPV expected Theoretical uncertainty in predictions ~1% (CP even) stat. syst. Still statistics limited! Consistent with Belle measurement BaBar physics, recent highlights and future prospects Page 7

  8. sin2 from loop-dominated B decays Expect S=sin2 in SM. Large deviations possible if NP in the loop. All new measurements. All use full dataset: 465 M BB All consistent with SM but statistics limited. No significant direct CPV, as expected in SM. BaBar physics, recent highlights and future prospects Page 8

  9. d s b u c t Testing the CKM model • BaBar and Belle have established the CKM matrix as the dominant source of CP violation. • Kobayashi and Maskawa awarded 2008 Nobel prize in physics. Cabibbo Kobayashi Maskawa matrix BaBar physics, recent highlights and future prospects Page 9

  10. “Radiative penguin” g W b s t Search for New Physics in bs 16 exclusive, self-flavor-tagging final states with 0.6 GeV < MXs < 2.8 GeV Standard Model: ACP < 1% New Physics: ACP up to 15% Published: PRL, 101, 171804 (2008) BaBar physics, recent highlights and future prospects Page 10

  11. e+e- +-() cross section from ISR BaBar physics, recent highlights and future prospects Page 11

  12. from  decay 15.1 ± 9.3 (1.6 ) from e+e- 27.5 ± 8.4 (3.3 ) e+e- +-() and the muon g-2 SM prediction: ( 11 658 471.9 ± 0.1 + 693.1 ± 5.6 + 15.4 ± 0.2 ) x 10-10 Uncertainty on direct measurment of a is ± 6.3 x 10-10. is the limiting factor in SM prediction. Measure dominant contribution to with  decays or [e+e-hadrons]. ~73% of ahad is +dominant uncertainty) BaBar physics, recent highlights and future prospects Page 12

  13. ISR e+e- +-(): experimental technique • Use ISR process to scan e+e- +-() cross section as a function of energy • Measure the ratio of () ISR and () ISR cross sections to cancel many systematics. BaBar physics, recent highlights and future prospects Page 13

  14. e+e- +-(): results and interpetation Preliminary result shown by Michel Davier at tau’08 0.6% measurement in rho region (0.6-0.9 GeV)! Measurement agrees better with results. (g-2) discrepancy significantly reduced. BaBar physics, recent highlights and future prospects Page 14

  15. Highlights from data taken in 2008 Discovery of the b Search for a light Higgs Precision scan of Rb above the Y(4S) BaBar physics, recent highlights and future prospects Page 15

  16. The bottomonium spectrum Bottomonium (bb) first discovered ~30 years ago. Many states below the open beauty (BB) threshold yet to be discovered. Measurement of b mass useful for testing lattice QCD and potential models. JPC BaBar physics, recent highlights and future prospects Page 16

  17. Y(nS)b : analysis technique • Inclusive search for • Signal is a mono-chromatic photon peak. • Two peaking backgrounds close to expected signal ~770 MeV ~855 MeV For M(b) = 9.4 GeV, E = ~911 MeV BaBar physics, recent highlights and future prospects Page 17

  18. Y(3S)b : discovery PRL 101, 071801 (2008) BaBar physics, recent highlights and future prospects Page 18

  19. Y(2S)b : confirmation U(2S) spectrum U(3S) spectrum Shown at QWG by Peter Kim ISR b(1P) ISR b b(2P) b U(2S) analysis: U(3S) analysis: BaBar physics, recent highlights and future prospects Page 19

  20. Search for a light Higgs: Y(3S) A0 • Next-to-minimal SUSY adds a singlet Higgs field. • Extra CP-odd Higgs state (A0) can be light (mA < 2mb) and dominantly decay into a pair of LSPs (invisible). • Search for Y(3S)   A0 : 2-body decay with a mono-chromatic photon recoiling against something undetected. • Special single photon triggers added (E* > 1 GeV and E* > 2 GeV). BaBar physics, recent highlights and future prospects Page 20

  21. Light Higgs search: analysis results Low energy sample High energy sample Sample fits showing a particular assumed A0 mass. Fitted signal yield as a function of A0 mass. BaBar physics, recent highlights and future prospects Page 21

  22. Non-singlet fraction of the A0 Light Higgs search : analysis results Scan of NMSSM parameters upper limit vs Higgs mass arXiv:0808.0017 Higgs mass ranges for colored points in NMSSM parameter scan. PRD 76, 051105 (2007) BaBar physics, recent highlights and future prospects Page 22

  23. Precision scan of Rb above the Y(4S) • Motivated by recently observed exotic cc states • Tetraquarks, molecular states, hybrid qqbar+gluon states, …? • The bb JPC = 1-- states should be above the Y(4S), below 11.2 GeV. • Collected 10 days of data in Ecm from 10.54 GeV to 11.2 GeV. • 5 MeV steps (x4 finer than previous scans) • Integrated luminosity of 25 pb-1 / step (>x30 higher than previous scans) • Energy of positron beam fixed at 3.12 GeV, electron beam energy varied. • Previous scan was ~25 years ago. BaBar physics, recent highlights and future prospects Page 23

  24. Precision scan of Rb above the Y(4S) arXiv:0809.4120, submitted to PRL • Structures above 4S in region of threshold openings qualitatively match predictions of coupled channel model. • Simple fit above 10.8 GeV gives substantial differences w.r.t. the PDG for the Y(10860) and Y(11020) (or “Y(5S)” and “Y(6S)”). PRL 53, 878 (1984) Prediction of coupled channel model (circa 1984). BaBar physics, recent highlights and future prospects Page 24

  25. BaBar looking forward BaBar physics, recent highlights and future prospects Page 25

  26. BaBar plans TaskForce BaBar Beyond 2010 Archival 10 5 Final Editing Pier-review BaBel Writing Launch Build up Steady 20 15 Intense 55 40 30 IFC 150 New publications BaBar physics, recent highlights and future prospects Page 26

  27. Taskforce BaBar beyond 2010 70 35 2009-2010 2011-2012 2013 - BaBar physics, recent highlights and future prospects Page 27

  28. 2008 Nobel Prize in physics “Please accept our deepest respect and gratitude for the B factory achievements. In particular, the high-precision measurement of CP violation and the determination of the mixing parameters are great accomplishments, without which we would not have been able to earn the prize.” - Makoto Kobayashi and Toshihide Maskawa BaBar physics, recent highlights and future prospects Page 28

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