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collaboration

The Belle Collaboration has achieved the highest possible grade for two consecutive years. They are pushing aggressively in their research, with a significant number of publications reporting important and high-impact results. Recent notable findings include the observation of rare decays and the discovery of new particles.

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collaboration

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  1. LCPAC 2006 Status Report collaboration S.L. Olsen U. of Hawai’i

  2. KEK B-factory Highest possible grade 2 consecutive years Sekkyokuteki suishin “push aggressively”

  3. Publications • 164 journal papers published or submitted • All reporting important, high impact results • ~42 papers submitted since LCPAC-2005 • ~9 currently in “authorship confirmation” • …

  4. Notable recent results • Observation of bdg • Evidence for BKK • Large direct CPV in B+K+r0 decays • Observation of a FB asymm in BK*l+l- • Observation of a cc1’ candidate in ggDD • A new charmonium-like state, X(3940) • New csu baryons, Xcx(2980) and Xcx(3077) • …

  5. Collaboration is stable Withdrawals: New members: • Institutions: • Nat’l Kaohsiung Normal U. • Utkal University • Aomori University • Tsukuba University • ~30 individuals • Institutions: • Illinois • Nova Gorica Inst, • Slovenia • ~40 individuals

  6. Spokesperson changes Old New!! Aihara Olsen Browder Yamauchi Iijima Yamauchi New spokespersons all ran on platforms promising major reorganization of Belle ふにきがいれ, ぉにがそと

  7. elle continues to perform very well

  8. SVD-2 team continue their heroics Belle’s long march SVD2

  9. SVD performance A.Kibayashi 4 layers + improved coverage  better tracking effic

  10. October Meltdown!!

  11. Quick fix Solder wires directly to the repeater board (connector established outside the detector during this past month) Beam off: 10/20 Resume Data taking 11/4 more details from Uno-san

  12. ~10% ~4% ~2% ~2% SVD Occupancy Present : layer 1 of SVD ~10%occupancy / 200 Krad.yr-1 SVD2 Need to upgrade the inner layers: SVD2.5 L~1.6x1034 → L~5x1034 cm-2s-1 ???

  13. Tracking continues to improve 3xBkg Pt resolution (s in %) (Bp+p-: s(DE)21MeV) Standard track finder 0.3% Tracking effic.improvements: +7% for J/y KS; +60% for D*+D*- New “Global” track finder

  14. …as does p0detection p0gg line shape Data vs MC M(p0) resolution (s in MeV) (Bp0p0: sM(p0)8MeV) 4.5MeV 100MeV 1 GeV p0 detection effic is sensitive to bkg conditions; ECL recon code.is being improved

  15. Particle ID performance remains high ~87% ACC dead tubes ~8% Last yr

  16. DAQ and computing are still keeping upalbeit just barely Faster signal processing with CMS chip in SVD (Silcon vertex det.) w/o Event Builder Upgrade New pipelined data Acquisition system (COPPER) Present operation Plan to implement this on the CDC this summer

  17. We have a new computing system Katayama’s talk this afternoon 1200 Dell servers

  18. The Belle Physics Program 1)Measure of Fundamental SM Params: CKM elements & phases 2)Search for New Physics: look for evidence of new particles in loops 3) Unanticipated new phenomena: large s(e+e-cccc), X(3872),X(3940),Y(3940),.. 4) + lots of “bread & butter” hc’, cc2’, D**,Sc*, Xcx,t-physics, spin frag-fcn,… I can only give a few small tastes from this rich & flavorful menu

  19. _ B0 tag B0 J/y K0 sin2f1= 0.652 ±0.039 (stat) ±0.020 (syst) A = 0.010 ±0.026 (stat) ±0.036 (syst) B0 tag Precision measurement well understood method

  20. 2005 results: Bkg subtracted B+ - projections B0 tagged B0 tagged 4s signal for Direct CPV p+p− Yield p+p− ACP & DE-Mbc 2D fits to individual time intervals Dt (ps)

  21. 2005: Status of B+ - App Belle 275M Spp BABAR 227M ~2.3s difference between Belle and BABAR - App (Cpp ) Spp

  22. Belle’s measurement of ACP(B0 0 ) Chao, Chang et al, PRL 94 181803 275M BBbar pairs

  23. CPV in B0r+r Similar to Bp+p, but in principle more complicated … B  VV: not a single CP eigenstate r+p+p0: wide resonance, two0’sin the final state. Three miracles: fL ~ 100%  CP » +1 B()NR and int. small B(r0r0) << B(r+r), B(r+r0) < 1.1 30  6 (26  6 ) x 10-6(HFAG Winter05) 2q A+-/ 2 small Penguin pollution (q ) A00 A+0

  24. Somov, Schwartz et al hep-ex/0601024 CPV in B+- (274  106 BB pairs) q=1 q=-1 Results: Low quality tag High quality tag No CPV φ2 is near 900

  25. Belle Constraints on 2 (α) B [hep-ex/0502035] &  combined at 90% CL

  26. s u K+ W u c Vcb D0 s u u + d + d B B Vub D0 * VudVub b b 2(a) * c Vtd Vtb Vus Vcs   W K+ 3(g) 1(b) u u Vcd Vcb * f3 () measurement Simple mixing CPV f3 (withBd ) + Tree Tree fCOM _ fCOM O(l3) O(l3) Interference of bc and bu diagrams

  27. r r Belle method for f3: Dalitz Poluektov, Bondar et al hep-ex/0504013 3) fCOM= D0KSp+p- B+: obtain from tagged D0 (D*+ D0p+) sample |A2| |A1| B-: r = CPV: Asymmetry in Dalitz dist.: m+=m(Ksp+), m-=m(Ksp-)

  28. Constraints of the Unitarity Triangle World average as of summer 2005 from GLW, ADS, Dalitz and sin(2φ1+φ3): γ/φ3=70 -14° +12 Simplistic(?) summation: f1+ f2+ f3 182o  ~20o

  29. CP angles only ? f1~70o Disfavored >2s sin2f1 f1~20o f1 2-fold ambiguity 2f1 p-2f1 Ambiguity removed by Dalitz analysis of B0D0(Kspp)h0 Krokovny etal hep-ex/0507065 Simplistic(?) summation: f1+ f2+ f3 182o  ~20o

  30. * VudVub 2(a) * Vtd Vtb 3(g) 1(b) Vcd Vcb * How about the CKM triangle’s sides? Dmd & b  d g b  u ℓ-n & B- ℓ-n b  c l n

  31. Belle Inclusive |Vub| Limosani et al PLB 621, 28 Electron energy at endpoint • Pth = 1.9 GeV/c • Systematic limited • Hadronic and leptonic • invariant mass (Mx, q2) • Use full recon tag. • P+ also measured. Bizjak et al PRL 95, 141801 • Non-experimental error dominated by errors of shape function parameters. PDG 2002: (3.6  0.7) x 10-3

  32. Bℓn Decay Search Measures fB|Vub|2 Upper limits at EPS05 SM prediction Btn search close to SM expectation Results with 450 fb-1 expected next month Ikado et al, hep-ex/0507034

  33. signal qq K*g other B First Observation of bd  Mohapatra. Nakao, Nishida et al hep-ex/0506079 _ Addresses the same physics issue as Bs- Bs mixing (future Tevatron RunII goal).

  34. Current status CPV angles only: η=0.321±0.027 =0.193±0.57 sides only: η=0.342±0.022 =0.216±0.036

  35. SM with KM ansatz works remarkably well for tree-level processes Next step: Look for new physics in penguin loops

  36. _ Example: bsss Example: no KM phase f1 * Vtd (or h’, K+K-) , (h’, K+K- + B B 0 0 * Vtd f1 _ SM: sin2f1 =sin2f1 from BJ/y KS (bc c s) unless there are other, non-SM particles in the loop eff

  37. hep-ex/0507037 (180±16) (78±13)

  38. Significant CP Violation in a bs penguin mode!! Chen et al PRD 72012

  39. >>all systematically below sin(2b) >>QCD corrections : sin2b(penguin)>sin2b(tree) Many bs modes were studied: recent QCD factorization estimates : [Beneke, hep-ph/0505075] [Cheng,Chua,Soni, hep-ph/0506268] sin2φ1(penguin)-sin2φ1(tree)

  40. sin2f1(penguin) = 0.50  0.06 (HFAG’s “naïve average”) 0.4-

  41. new physics in EW penguins? • AFB for B K*ℓ+ℓ- Interference btw  and Z (loops with virtual t’s, W’s, & Z’s) AFB (Kℓ+ℓ -) = 0.09  0.14 (stat) AFB(K*ℓ+ℓ -) = 0.56  0.13 (stat) 3.4 s from 0 Ishikawa et al hep-ex/0603018

  42. Not just beauty • Charm physics • Tau physics • Hadron spectroscopy • Charmed mesons & baryons • Charmonium states hc’ , cc1’ • Mystery states X(3872), X(3940), Y(3940) • Fragmentation functions • Bs • Dark matter search

  43. D0-D0 mixing Zhang, Li et al hep-ex/0601029 Belle 2006 Shipsey @ DIF06

  44. High precisiont-p-p0 nt Fujikawa, Hayashii et al hep-ex/0502171

  45. bonuses: new mesons, many puzzles! Choi et al, PRL 89 112001 Choi et al , PRL 91 262001 Z(3931) cc2’? hc’ X(3872) Uehara et al , PRL 96 082003 Y(3940)wJ/y e+e-cccc Choi et al , PRL 94 182002 ?? Pakhlov et al , hep-ex/0507019 M(wJ/y) MeV

  46. more bonuses: charmed baryons c+- c+0 c++ c0(2800) c++(2800) c+(2800) Mizuk et al PRL 94 122002 & mesons D0’0(2427) D0*(2308) Kuzmin et al PR D69 112002

  47. CLEO PRL 54, 381 (5S) (5S) “engineering” rundetails from Alan Schwartz this PM (4S) 3-day, 1.86 fb-1 test run Bs*Bs* Mbc BsBs* BsBs 100% BqBq DE Bs(*)Bs(*) Bq(*)Bq(*) BqBq(*)π BqBqππ Bf(Bsgg)< 0.56 x 10-4 (90%CL) ~factor 3 improvement on on world best limit

  48. DAMA NaI 3s Region CDMS 04 CDMS 05 Dark matter search McElrath, PRD 72, 103508: Br((1S)cc)~0.4% Mc < 4.7 GeV Experimental signature: (3S)pp(1s)  pp nothing Belle (with optimized trigger): Direct dark-matter searches cannot see M<10 GeV region McElrath prediction 3fb-1 engineering run data @ the (3S) under analysis

  49. Summary f3 error ~100 ?? B+t+n ?? cc2’ X(3940), Y(3940) bd penguins (bdg BKK) DD-mixing (world’s best limit) f2 error~100 |Vub| error <10% Sc* baryon triplet Direct CPV in BK+p- X(3872) BK*ℓ+ℓ- EW penguin D0*0 & D1*0 mesons CPV in B decays hc’ & e+e-cccc

  50. Conclusion • The Belle collaboration remains strong • Our publishing is nearing 1 paper/week • We have two new & energetic spokespersons • Our detector continues to perform well • Continuously improvements to handle increased luminosity (&bkg) • We have shown that the CKM ansatz works well for tree processes • Verified with high precision • Provides “anchor point” for new physics searches • CPV in penguins provide us with sensitive probe for new physics • Theoretically and experimentally clean • We are measuring Bf~10-6 penguin processes with high precision • We have made a number of “unexpected discoveries” • And expect many more in the future

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