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Projektbericht BELLE Vorstandssitzung 28. November 2005 KEK, Tokyo Projektbericht BELLE Status BELLE Experiment SVD Upgrade bei BELLE Neue Resultate Y(5S)

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Presentation on theme: "Projektbericht BELLE Vorstandssitzung 28. November 2005 KEK, Tokyo Projektbericht BELLE Status BELLE Experiment SVD Upgrade bei BELLE Neue Resultate Y(5S)"— Presentation transcript:

1 Projektbericht BELLE Vorstandssitzung 28. November 2005 KEK, Tokyo Projektbericht BELLE Status BELLE Experiment SVD Upgrade bei BELLE Neue Resultate Y(5S) Collaboration HEPHY Physik-Analysen

2 Projektbericht BELLE Vorstandssitzung 28. November 2005 L peak = 1.56 × cm -2 sec -1 design = cm -2 sec KEKB Collider e-e- 8GeV e+e+ 3.5GeV = B-Factory (on the 4s resonance) B-Factory (on the 4s resonance) BB threshold

3 Projektbericht BELLE Vorstandssitzung 28. November 2005 BELLE-Detector CDC KLM ECL SVD

4 Projektbericht BELLE Vorstandssitzung 28. November 2005 TTM S0 Dock F0 sensors Power Supply F0 TTM S1 Dock F1 sensors Power Supply F1 TTM S2 Dock F2 sensors Power Supply F2 TTM S3 Dock F3 sensors Power Supply F3 TTM S4 Dock F4 sensors Power Supply F4 TTM S5 Dock B0 sensors Power Supply B0 TTM S6 Dock B1 sensors Power Supply B1 TTM S7 Dock B2 sensors Power Supply B2 TTM S8 Dock B3 sensors Power Supply B3 TTM S9 Dock B4 sensors Power Supply B4 SVD front-end E-Hut Rad-Ctrl area Inside End-cap Inside CDC 1. S4 problem 2. S1 problem

5 Projektbericht BELLE Vorstandssitzung 28. November 2005 Prologue Oct hybrids (S1) stopped working Oct.16 After a big earthquake, another 12 hybrids (S4) stopped working and recovered by itself by the next morning

6 Projektbericht BELLE Vorstandssitzung 28. November 2005 Burned connectors S1 S4 All the others in FWD also browned One in BWD (B4) slightly

7 Projektbericht BELLE Vorstandssitzung 28. November 2005 What should we do for BWD? We must replace the connector before being burned. Nobody knows when it will be. We dont like to have fearful days so long. During the coming winter shutdown would be the best e.g. Dec.26~28open end-yoke/end-cap Dec.26~28cosmic ray runs Dec.29,30take boards out Jan.04~09repair boards and install, test Jan.09~12cosmic ray runs Jan.10~12close end-cap/end-yoke

8 Projektbericht BELLE Vorstandssitzung 28. November 2005 Number of B s in dataset Y(5S) hadronic events bb events B s events bb continuum included N ev = 560,872 ± 3,018 ± 28,630 f s = (16.4 ± 1.4 ± 4.1 )% N ev = 91,983 ± 7,868 ± 23,470 f(B s *B s *) = (93 ± 10)% N ev = 85,544 ± 11,754 ± 21,827 B s * B s * channel Bf(B s ->D s + - ) = (9 ± 3) / / 2/ ( ± ) = (0.65 ± 0.22 ± 0.21)% CDF : Bf(B s ->D s + - ) = (0.40 ± 0.06 ± 0.06 ± 0.11 ± 0.06 )% Lumi = fb -1 Y(5S)

9 Projektbericht BELLE Vorstandssitzung 28. November 2005 Number of bb events. 2 ~ 1/E cm R = (hadrons) / ( ) N cont (5S) = N cont (E=10.519)* L (5S) / L (cont) * (E cont /E 5S ) 2 Y(5S) : exp 43 runs (5S scan excluded) N(hadron)= 6, 223, 974 events Cont : exp 43 runs N(hadron)= 11, 876,173 events Lumi = ± (stat) fb -1 (1.8574/ )*( /10.869) 2 = ± Corrections for HadronB cuts: 1. N ch >3 => ( 0.5 ± 0.3)% 2. E/E cm > 0.18 => ( 0.2 ± 0.1)% N bb (5S) = ( – * *1.007 ) / 0.99 = CLEO : 0.42 fb -1 N bb (5S) = ± 1000 ± (events / lumi : ~2.5% larger) Status of Y(5S) analysis, BGM, Nov 15, A. Drutskoy Lumi = ± (stat) fb ,872 ± 3,018 ± 28,630 Y(5S)

10 Projektbericht BELLE Vorstandssitzung 28. November 2005 Inclusive analysis : Y(5S) -> D s X Y(5S) D s ± 100 ev P/P max < 1 Theory : hep- ex/ CLEO Bf (B s D s X) = (92 ± 11) % PDG : Bf (D s + )=(3.6 ± 0.9)% Sum: Bf(D s + ) = (4.4 ± 0.5)% Bf(D s + )=(4.8 ± 0.6)% Babar : CLEO : Bf (B D s X) = ( 9.0 ± 0.3 ±1.4 )% Bf (B D s X) = ( 8.94 ± 0.16 ± 1.12 )% After continuum subtraction and efficiency correction: Bf (Y(5S) D s X) 2 = (22.6 ± 1.2 ± 2.8) % CLEO measured: Bf (Y(5S) D s X) / 2 = (22.35 ± 2.1 ± 4.95)% f s = (16.4 ± 1.4 ± 4.1 )% => Using D s mesons CLEO measured f s = (16.0 ± 2.6 ± 5.8 )% Syst. err. dominated by Bf(D s + ) Y(5S)

11 Projektbericht BELLE Vorstandssitzung 28. November 2005 Exclusive B s D s ( * )+ - decays B s B s, B s *B s, B s *B s * D s + +, D s + K* 0 K +, D s + K s K + Cut on angle between B s and beam direction was recently removed ( ) (few more events). Clear signal at B s * B s * channel ; signals in B s * B s and B s B s channels are not seen. MC B s D s events in B s * B s * B s D s * events in B s * B s * Y(5S)

12 Projektbericht BELLE Vorstandssitzung 28. November 2005 E distribution, sum of all B s decay modes Decay (5S) -> B s * B s *, with B s * -> B s E peak = E cm (accel.)/2 – E cm (real)/2 – E( ) E peak = – 47.6 ± 2.6 MeV Small signal, N ev = 1.5 ± 2.0 (7±10%) Potential models predict B s * B s * dominance over B s *B s and B s B s channels, but not so strong < M BC <5.429 GeV/c 2 B s * N ev =20.0 ± < M BC <5.405GeV/c 2 B s * B s Y(5S)

13 Projektbericht BELLE Vorstandssitzung 28. November 2005 M BC distribution, sum of all B s decay modes M bc = E* B 2 – P* B 2 M bc = (E* B + E peak ) 2 – P* B 2 E cm = MeV ; E* B = E cm /2 M (B s *) = 5418 ± 1 ± (acc. err) MeV/c 2 Photon momentum is neglected => does not change B s * mass position, only smearing. M (B s ) = 5370 ± 1 ± 3 MeV/c 2 Photon energy smearing does not change B s mass position CDF: M (B s ) = ± 0.8 MeV/c 2 B s * < E< MeV B s * < E< MeV Y(5S)

14 Projektbericht BELLE Vorstandssitzung 28. November 2005 HEPHY Physik-Analysen Christoph Schwanda: Momente der E l und M X 2 in B X c l Laurenz Widhalm: Formfaktoren semileptonischer D° Zerfälle Heinz Dibon: Parallelanalyse als Cross-Check Franz Mandl: BRs der inklusive Zerfälle D° X/ K*X / X Gerhard Leder: BRs der inklusive Zerfälle D s Gerald Richter: Dekohärenz Modelle verschränkter B-Paare

15 Projektbericht BELLE Vorstandssitzung 28. November 2005 Christoph Schwanda

16 Projektbericht BELLE Vorstandssitzung 28. November 2005 Christoph Schwanda

17 Projektbericht BELLE Vorstandssitzung 28. November 2005 Christoph Schwanda

18 Projektbericht BELLE Vorstandssitzung 28. November 2005 tag side: reconstruction & fit of D 0,± K, K2, K3 reconstruction & fit of D* 0,± D, D use either D or D* as primary meson signal side: reconstruction & fit of inclusive D* 0,± via recoil from e+e- D (*) D*n /K reconstruction & fit of inclusive D 0 via recoil from D* D reconstruction & fit of neutrino via recoil from D m D D* e+e- D e/µ D* tagsignal K ( ) K K additional primary mesons Method of Reconstruction Laurenz Widhalm

19 Projektbericht BELLE Vorstandssitzung 28. November 2005 Summary of Signal / Background Decomposition Ke Ke signal events statistical error systematics non-D bkg semileptonic bkg hadronic bkg signal non-D bkg Kl bkg D 0 e D 0 l bkg m ² / GeV² D 0 e D 0 hadronic bkg Laurenz Widhalm

20 Projektbericht BELLE Vorstandssitzung 28. November 2005 Absolute Branching Ratios BRs (%) this analysisPDGCLEO (hep-ex/ ) theory K - e ± 0.10 stat ± 0.15 syst 3.58 ± ± 0.10 stat ± 0.10 syst 3.76 ± 0.30 K ± 0.10 stat ± 0.15 syst 3.19 ± ± e ± stat ± syst 0.36 ± ± stat ± syst 0.31 ± ± stat ± syst no entry yet 0.32 ± 0.03 K ± ± ± 0.56 K ± ± ± ± 0.4 measured event numbers normalized to number of inclusive D 0 efficiency corrected using the generic MC sample corrected for bias from differences in the multiplicity distribution MC/data reference hadronic channels as a cross-check Laurenz Widhalm

21 Projektbericht BELLE Vorstandssitzung 28. November 2005 Form Factors – Fit to Pole Model D 0 l q² / GeV² arbitrary normalization f + (q²) = 1-q²/m² m Ke =1.86 ± 0.06 GeV m K =1.78 ± 0.05 GeV m e =2.01 ± 0.12 GeV m =1.91 ± 0.08 GeV χ²/ndf=31/28 χ²/ndf=6/10 simple pole f + (q²) = (1-q²/m²) (1- q²/m²) modified pole m Ke =2.15 ± 0.08 GeV m K =2.04 ± 0.06 GeV m e =2.21 ± 0.17 GeV m =2.07 ± 0.13 GeV = 0.50 (Kl ) = 0.44 ( l ) theor. f + (0)=0.704 ± ± f + (0)=0.628 ± ± Laurenz Widhalm

22 Projektbericht BELLE Vorstandssitzung 28. November 2005 Current Status summer conference paper CONF-519 ready archived as hep-ex/ gives relative BFs and form factors next step: journal publication will give absolute BFs and form factors second draft for PRL submitted to internal referees, waiting for response first reaction from theory side (A. Kronfeld, preliminary) Laurenz Widhalm

23 Projektbericht BELLE Vorstandssitzung 28. November 2005 Heinz Dibon

24 Projektbericht BELLE Vorstandssitzung 28. November 2005 Franz Mandl D 0 X (1.7 ±0.8%) K + K - (49.1±0.6%) D 0 K + K - (0.389±0.015%) BR(D 0 X)= = ±0.14%

25 Projektbericht BELLE Vorstandssitzung 28. November 2005 Gerhard Leder T. Uglov at BGM D s inklusiv

26 Projektbericht BELLE Vorstandssitzung 28. November 2005 Thedecay βγcτ B0 = 196 μm(LAB) Δm = ћs -1 = τ B0 -1 beam axis 3.5 GeV e + 8 GeV e - entanglement region l-l- l+l+ K0sK0s π-π- π+π+ μ+μ+ typical Υ (4S) resonance decay z 0, t 0 z 1, t 1 z 2, t 2 θ Gerald Richter

27 Projektbericht BELLE Vorstandssitzung 28. November 2005 Changing the parametrization new resolution function for t 1, from double gaussian fit : z abs t1t1 resolution function for Δt, single gaussian : z abs Δt that should be on the safe side... Gerald Richter

28 Projektbericht BELLE Vorstandssitzung 28. November 2005 Parameter fit results the scatter of fitted λ parameters shows a dependence on the true parameters, that can be modeled. Gerald Richter

29 Projektbericht BELLE Vorstandssitzung 28. November 2005 Electronic II From SVD 2.0 to SVD 2.5

30 Projektbericht BELLE Vorstandssitzung 28. November 2005 Electronic II From SVD 2.0 to SVD 2.5

31 Projektbericht BELLE Vorstandssitzung 28. November 2005 Electronic II

32 Projektbericht BELLE Vorstandssitzung 28. November 2005 Electronic II From SVD 2.0 to SVD 2.5

33 Projektbericht BELLE Vorstandssitzung 28. November Luminosity (10 34 ) SVD2.0 Reinforcement SVD2.0SVD2.5 Replace L1 ladders SVD2.5SVD3 Full upgrade Layer 1+2 replacement is scheduled in 2007 summer SVD3 schedule depends on approval of the project. R&D Prod. Test Prod. Test R&D Installation SVD Upgrade SVD 2.5

34 Projektbericht BELLE Vorstandssitzung 28. November 2005

35 line: e + e D* + D* MC (2 pr) red crosses: e + e D* + D* ( 0, data (2, 3, 4 pr) D 0 K* 0 X (signal) D 0 K X D 0 h 1 X h 2 X at least one particle misidentified M (K ) arbitrary normalization ok for 3, 4 pr Franz Mandl

36 Projektbericht BELLE Vorstandssitzung 28. November 2005 Franz Mandl Inclusive Decays D 0 K* 0 X and D 0 0 X Some time ago ( Fig) reported: B (D 0 K*X) B (K* K - + ) 6.67% B (D 0 K*X) 10% Method: Full reconstruction of events: + 0, 1, 2 primary mesons tag side signal side right sign e + e - preliminary studies on efficiences etc have been reported (also for D 0 0 X) all particles left over in reconstruction should come from D 0 (signal side) ideal method for the determination of inclusive branching ratios for D 0 hX, h = K* 0, 0,,, ……. (not yet known)

37 Projektbericht BELLE Vorstandssitzung 28. November 2005 some time ago B(D 0 K*X) * B(K* K - + ) = * 3.8% = 6.67% K - + effective masses of combinations of charged particles from kinematically selected D 0 via recoil, tagging D *+ D *-, D *+ D *- 0 and D *+ D *- + -, …. events not in PDG list OLD Franz Mandl


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