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Recent Results from Belle

Recent Results from Belle. Shiro Suzuki (Saga University) PASCOS04 / Pran Nath Fest, Aug 20, 2004 Northeastern University, Boston, MA. Outline. Belle / KEKB CPV “Standard” sin2 f 1 as the SM reference TCPV in b  s penguin dominated decays Direct CPV Rare processes

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Recent Results from Belle

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  1. Recent Results from Belle Shiro Suzuki(Saga University) PASCOS04 / Pran Nath Fest, Aug 20, 2004Northeastern University, Boston, MA Recent results from Belle

  2. Outline Belle / KEKB CPV • “Standard” sin2f1 as the SM reference • TCPV in b  s penguin dominated decays • Direct CPV Rare processes • FCNC ( b  sg, sll) via EW penguin Recent results from Belle

  3. KEKB Collider 8 GeV e- x 3.5 GeV e+ Mt. Tsukuba 11mrad crossing KEKB Belle ~1 km in diameter Lpeak = 1.39 x 1034 sec-1cm-2 @ 1.2A x 1.6A 274M BB 253 fb-1 on Y(4S) 28 fb-1 below Y(4S) 281 fb-1 Recent results from Belle

  4. The Belle Collaboration Seoul National U. Shinshu U. Sungkyunkwan U. U. of Sydney Tata Institute Toho U. Tohoku U. Tohuku Gakuin U. U. of Tokyo Tokyo Inst. of Tech. Tokyo Metropolitan U. Tokyo U. of A and T. Toyama Nat’l College U. of Tsukuba Utkal U. VPI Yonsei U. IHEP, Moscow IHEP, Vienna ITEP Kanagawa U. KEK Korea U. Krakow Inst. of Nucl. Phys. Kyoto U. Kyungpook Nat’l U. U. of Lausanne U. of Ljubljana Jozef Stefan Inst. U. of Maribor Aomori U. BINP Chiba U. Chonnam Nat’l U. Chuo U. U. of Cincinnati Ewha Womans U. Frankfurt U. Gyeongsang Nat’l U. U. of Hawaii Hiroshima Tech. IHEP, Beijing U. of Melbourne Nagoya U. Nara Women’s U. National Central U. Nat’l Kaoshiung Normal U. Nat’l Lien-Ho Inst. of Tech. Nat’l Taiwan U. Nihon Dental College Niigata U. Osaka U. Osaka City U. Panjab U. Peking U. Princeton U. Riken Saga U. USTC 13 countries, 59 institutes, 400 members Recent results from Belle

  5. Belle Detector Aerogel Cherenkov cnt. n=1.015~1.030 SC solenoid 1.5T 3.5 GeVe+ CsI(Tl) 16X0 TOF conter 8 GeVe- Central Drift Chamber small cell +He/C2H5 Si vtx. det. 3(4) lyr. DSSD m / KL detection 14/15 lyr. RPC+Fe Recent results from Belle

  6. Kobayashi-Maskawa Scheme CPV: due to a complex phase in the quark mixing matrix Unitarity triangle Weak eigenstate Mass eigenstate h (r,h) CKM matrix observables * VudVub * 2 (a) Vtd Vtb Wolfenstein representation 3 (g) 1(b) r * Vcd Vcb Recent results from Belle

  7. Direct CPV where Mixing induced CPV Time dependent CP Violation (TCPV) General description For single decay diagram as above,  |l|=1 (i.e. A=0, no DCPV), S = Iml Recent results from Belle

  8. sin2f1=0.728±0.056±0.023 |l ccs|=1.007 ±0.041 ±0.033 consistent with no direct CPV Good agreement with SM SM Reference sin2f1by b →ccs processes 5417 events @ 140 fb-1 Poor Tag WA = 0.736±0.049 Good Tag • now issue is to measure “sin2f1” with different decay processes such as ccd, sqq . Recent results from Belle

  9. + CP Violation in penguin dominated decays b→sqq: Possible contribution of new physics → new phase f SM Penguin : same CPV phase as ccs + New Physics with different phase CPV may be different : Sbs≠Sbc, A≠0 ⇒hint of new physics Ex) B0fKs 7.8  1.1 (×10-6)*theoretically clean but Br small B0h’Ks 65.2  6.0 B0 K+K-Ks 25.2  2.7 Recent results from Belle

  10. b→s modes in 2003 140fb-1 Fit sin2f1 [PRL 91, 261602 (2003)] B0 fKS B0h’KS B0K+K-KS 3.5saway from SM ! “sin2f1” = Recent results from Belle ⇒ Needs measurements w/ larger data sample & additionalmodes

  11. Validity checks of 250fb-1 sample Data set I • SM control sample : J/yK0 • Data set I (140fb-1) • S = 0.696±0.061 • A = 0.011±0.043 • Data set II (110fb-1) • S = 0.630±0.069 • A = 0.035±0.044 • Life time in J/yK0, fK+, fK0 • Null asymmetry in D*ln , fK+ ⇒ overall check of resol. func. & flavor tagging Good tags Data set II Good tags Recent results from Belle

  12. 274M BB pB* B → fK0 fKS fKL Nsig=139 14 purity 0.63 Nsig= 36 15 purity 0.17 includes Ks p0po (Nsig=13 5) Recent results from Belle

  13. 274M BB S = 0.736 fit B → fK0CPV result preliminary Poor tags Good tags fKS+fKL:S(fK0) = +0.06 ±0.33 ±0.09 A(fK0) = +0.08 ±0.22 ±0.09 “sin2f1”~2.2s away from SM Recent results from Belle

  14. S = 0.736 fit B0 → h’KS & K+K-KS high statistics modes h’KS K+K-KS h’rg, hp+p- (hgg, p+p-p0) Nsig=399 28 Nsig=512 27 purity 0.56 purity 0.61 CP=+1: 1.03 0.15 0.05 Raw Asymmetry Good tags Good tags (~1.0s @SM) (~0.5s @SM) “sin2f1” S = +0.65 0.18 0.04 -S = +0.49 0.18 0.04 ( ) A = -0.19 0.11 0.05 A = -0.08 0.12 0.07 0.17 0.00 Recent results from Belle

  15. S = 0.736 fit B0 → wKS & f0(980)KS New modes ! wKS f0(980)KS Nsig=31 7 purity 0.56 Nsig=102 18 purity 0.58 Raw Asymmetry Good tags Good tags “sin2f1” (~0s @SM) (~2.9s @SM) S = +0.75 0.64 -S = -0.47 0.41 0.08 A = +0.26 0.48 0.15 A = -0.39 0.27 0.08 0.13 0.16 Recent results from Belle

  16. Summary of b→sqq TCPV “sin2f1” 2.4s A : consistent with 0 Recent results from Belle

  17. W s K+ Vtb W u s K+ g u t u Vub B 0 d B 0 d b b u p- p- d d d d Penguin Tree   Vts Vus Direct CPV in B →Kp • Another essence of KM scheme – existence of direct CPV • More than two diagrams should contribute -- With different CP and strong phase • CPV in decay – partial rate asymmetry Recent results from Belle

  18. 274M BB Evidence for direct CPV in B0→K+p- _ B0 K-p+ B0 K+p- • Continuum BG elimi-nated by modified F-W • K/p ID efficiency and fake rates determined by D*+→D0p+,D0→K-p+ sample • Signal yield: 2139±53 • ACP (K+p-) = -0.101±0.025±0.005 ( 3.9s significance ) 2nd evidence ofDCPV at Belle Submitted to PRL Recent results from Belle

  19. 274M BB, New ACPfor B+→K+p0 K+p0 • Signal yield : 728±34 • ACP(K+p0) = 0.04±0.05±0.02 Hint of ACP(K+p-)≠ACP(K+p0) 2.4saway Large EW penguin contribution ? New physics ? p0 K- B- Recent results from Belle

  20. 274M BB, New Observation of B0p0p0 Key mode for f2 in B→pp CPV isospin analysis Signal: 82  16 (6.0s) B= (2.32  ) x 10-6 0.41 0.48 0.22 0.18 Mbc uses same Flavor-tagging as TCPV analysis ACP = 0.43  0.51  0.17 0.16 1st measurement ! Recent results from Belle

  21. Radiative and EW Penguins b→sg, sl+l- decays proceed via FCNCBox and penguin diagrams • Br(b→sg) ≈ 3.5×10-4 • Br(b→sl+l-) ≈ aem×Br(b→sg) ≈ 10-6 • New particle (via loops) may make appreciable contribution to decay rates and/or asymmetries. • Good testing ground of SM and beyond SM. b→sg b→sl+l- Recent results from Belle

  22. 274M BB B→ K(*)l+l-results 82 11 signals 79 10 signals Updated with 274M BB Preliminary Recent results from Belle

  23. K* B→ K(*)l+l-FB Asymmetry AFB in K*ll provides information on sign of Wilson coef. ⇒ sensitive to NP that may not be seen in bsg First look ! Preliminary Recent results from Belle

  24. Summary Based on 253 fb-1 data sample • TCPV of b → s penguin processes are measured in various processes. • Updated “sin2f1” in fK0 is+0.06 ±0.33 ±0.09 ~2.2saway from SM • b→s average ： +0.43±~2.4s away from SM. • Evidence of DCPV in B0→K+p- is observed. • Hint of ACP(K+p-) ≠ACP(K+p0) • First look at B  K*ll AFB is made. 0.13 0.11 Recent results from Belle

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