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B. Golob, Belle Charm physics at Belle 1Belle Rev. Comm. 2007 B. Golob University of Ljubljana Belle Collaboration Outline 1.Introduction 2.Spectroscopy.

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Presentation on theme: "B. Golob, Belle Charm physics at Belle 1Belle Rev. Comm. 2007 B. Golob University of Ljubljana Belle Collaboration Outline 1.Introduction 2.Spectroscopy."— Presentation transcript:

1 B. Golob, Belle Charm physics at Belle 1Belle Rev. Comm B. Golob University of Ljubljana Belle Collaboration Outline 1.Introduction 2.Spectroscopy 3.Semileptonic D decays 4.D 0 - D 0 Mixing 5.Summary Charm Physics at Belle

2 B-factory, c-factory Introduction B. Golob, Belle Charm physics at Belle 2Belle Rev. Comm √s = M(  (4S))c 2 = GeV  (B B)  1.1 nb (~750·10 6 BB pairs)  (c c)  1.3 nb (~850·10 6 X c Y c pairs) Physics of c-hadrons increased interest at B-factories in recent years Dual role of charm standalone field of SM tests and search for new phenomena (SM and/or NP) - measurements of known and new charmed baryons and mesons - measurements of new “exotic” states - understanding of charmonia production and decay - charm fragmentation - D 0 mixing and CPV experimental tests of theor. predictions (most notably of (L)QCD); improve precision of CKM measurements (B physics); - meson decay constants and form factors - confrontation of spectroscopic results and predictions - charm branching fractions

3  c (2880)  c (2940)  c (2765) 1 st observ. sign nce > 6  New c-baryons Spectroscopy B. Golob, Belle Charm physics at Belle 3Belle Rev. Comm  c →  c + K -  + ; neutral states also observed, iso-doublet Charm mesons and baryons laboratory to test predictions of quark model(s), HQS, Skyrme model, Regge trajectories,.... PRL97, (2006) 460 fb ± 50 evts significance 5.7  326 ± 40 evts significance 9.2  StateMass [MeV/c 2 ]Width [MeV/c 2 ]  c (2980) ±2.1± ±7.5±7.0  c (3080) ±0.9±0.56.2±1.2±0.8 confirmed by BaBar, hep-ex/ hep-ex/ , 553 fb -1, subm. to PRL  c (2880) →  c (2455)   c  +  - with M(  c  ± ) ~ M(  c (2455)) J P of  c (2880) and  c (2940) →  c (2455)  BaBar, PRL98, (2007), 287 fb -1

4 New c-baryons Spectroscopy B. Golob, Belle Charm physics at Belle 4Belle Rev. Comm  c (2880)  →  c (2455)  angular distribution J=1/2 J=3/2 J=5/2   c (2455)  c*c* J P =5/2 + strongly favored hep-ex/ , 553 fb -1, subm. to PRL prospects (1 ab -1 )  c (2880)  →  c (2455/2520)   → ± 4.5%; -  c (2940) →  c (2455)  yield ~450, ang. analysis J P ; -  c (2980) 0 →  c + K S  - sign. → ~ 3  ; confirmation in other decay modes; goal: well established ensemble of hadrons with determined quan. num., to be confronted to theory A. Selem, F. Wilczek, hep-ph/ deviations from linear Regge traj. & new states!

5 Double cc production Spectroscopy B. Golob, Belle Charm physics at Belle 5Belle Rev. Comm J/  X e-e- e+e+ PRL98, (2007) 350 fb -1 recoil method 266±63 evts M=3943±6±6 MeV/c 2  <52 C.L.  c1 ’ (2 3 P 1 ),  c ’’ (3 1 S 0 )? prospects (1 ab -1 ) recoil method: “factory” of cc with C=+1; 3  sensitivity  min (e + e - → J/  X) ~ 5-10 fb (  (J/  c ) = 25 fb)

6 Spectroscopy B. Golob, Belle Charm physics at Belle 6Belle Rev. Comm “Exotic” states no obvious predicted candidates; most prominent X(3872); DD* molecule? number of results, recently: B → (D 0 D 0  0 )K PRL97, (2006), 414 fb ± 6.1 evts 6.4  M=( ± 0.7 ± ± 0.8) MeV/c 2 confirmed by BaBar, P. Grenier, 42nd Moriond QCD (2007), 347 fb -1 PRL91, (2003) 152M BB B → X( → D 0 D 0  0 ) K if enhancement X(3872) large mixing between  c1 ’ and X(3872)? other measurements: J PC =1 ++, 2 -+ ; J=2: supressed decay to DD*, J PC =1 ++ ? hard to accommodate in molecular model (~0.08) E.S.Swanson, Phys.Rept. 429, 243 (2006) 2.5  diff. with X → J/  

7 Spectroscopy B. Golob, Belle Charm physics at Belle 7Belle Rev. Comm “Exotic” states e + e - → Y( → J/   )  ISR BaBar, PRL95, (2005), 233 fb -1 hep-ex/ , 553 fb evts sign.: 11  M=(4295 ± 10 ± 10 3 ) MeV/c 2  =(133 ± 26 ± 13 6 ) MeV 2.5  difference with M from BaBar Y(4260) D* + D* - D* + D -  s = Exclusive  ( e + e - → D*D ( * ) ) using ISR; partial recon.,  (  M rec )=1 MeV  M rec = M rec (D ( * )+  ISR ) - M rec (D ( * )+  -  ISR ); data to help understand Y(4260) nature; coupled channels effects (D s *D s *, DD 1 thresholds), hybrid state (decays to DD 1, M?) M.B. Voloshin, hep-ph/ S.L. Zhu, PLB625, 212 (2005) PRL98, (2007), 550 fb -1 in agreement with Cleo-c scan  s < 4.25 GeV

8 Spectroscopy B. Golob, Belle Charm physics at Belle 8Belle Rev. Comm  c (2800)  c (2980)  c (3077)  c (2880) hep-ex/ PRL97, PRL94, D sJ (2715) hep-ex/ List X(3872) X(3940) Y(3940) Z(3930) Y(4260) hep-ex/ hep-ex/ PRL91, PRL97, PRL98, PRL94, PRL96, hep-ex/ prospects (1 ab -1 ) X(3872): new results B → XK to test models Br(B 0 → K S X)/Br(B + → K + X) ~ ± 15% molecular model: 6-29% M(X h )-M(X l ) ~ ± 1 MeV tetra-q model: 8 ± 3 MeV Y(4260): data to help interpretation combining e + e - → Y( → J/   )  ISR and  (e + e - → D ( * ) D ( * ) ); M ~ ± 10 MeV/c 2 ; enough to distinguish from thresholds?  min ~ ± 15% in each mode e.g. F.E. Close, P.R. Page, PLB578, 119 (2004) L. Maiani et al., PRD71, (2005)

9 Semileptonic D decays B. Golob, Belle Charm physics at Belle 9Belle Rev. Comm D 0 semileptonic decays determination of form factor; test of LQCD to  ± 5%; e + e - → D tag ( * ) D sig *; inverse reconstruction; start from D tag ( * ) and CMS momentum  recoil momentum; method enables: - good q 2 resolution (  (q 2 )~ GeV 2 /c 2 ) - absolute normalization (inclusive D 0 signal) signal: p 2 ( )=0; PRL97, (2006), 282 fb -1 |V ub | from B 0 →  l : ± 14% from f.f., ± 3% from Br D 0 →   N=106 ±12 D 0 →  e  N=126 ±12 m 2 [GeV 2 ] fake-D 0 bkg data hadronic bkg data Kl bkg data  l bkg MC

10 current lumin. expected accuracy D 0 → K l D 0 →  l Semileptonic D decays B. Golob, Belle Charm physics at Belle 10Belle Rev. Comm D 0 semileptonic decays competitive  (K) l Br measurement; PRL97, (2006), 282 fb -1 Y. Gao (Cleo-c), ICHEP06, 281 pb -1 first direct Br(D 0 →  ) determination; comparison to LQCD; f + D (0) = ± ± unquenched: C. Aubin et al., PRL94, (2005) f + D (0) = 0.64 ± 0.03 ± 0.05

11 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 11Belle Rev. Comm Mixing phenomena well known in K 0, B d 0 and B s 0 system (last year); eluded observation so far in the D 0 system; c u u c d, s, b W+W+ W-W- D0D0 D0D0 V ci * V cj V uj * V ui d-like quarks exchanged; effective GIM suppression; D 0 decays: CF; mixing: DCS; x, y ~ sin 2  C  (SU(3) breaking) difficult to calculate; x, y affect the t distribution of D 0, observables; largest predictions in SM: |x|, |y|  I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001); A.F. Falk et al., PRD69, (2004) CPV in D 0 system: first two generations involved; Wolfenstein param.,  (V cs )=  A 2 4 ~ O (10 -3 )

12 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 12Belle Rev. Comm D 0 → K S  +  - t-dependent Dalitz analysis different decays (CF, DCS, CP eigenstates) identified through Dalitz analysis; their relative phases determined; arXiv: no CPV 1,2 = f (x,y); analogous for M = fit M (m - 2,m + 2,t) to data distribution  x, y Two recent Belle measurements - decays to CP final state, D 0 → K + K - /  +  - - decays to hadronic multi-body final state, D 0 → K S  +  - common: D* + →D 0  s + p*(D*) > 2.5 GeV/c

13 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 13Belle Rev. Comm D 0 → K S  +  - arXiv: signal in M(K S  +  - ) and Q= M(K S  +  -  s )- M(K S  +  - )- M(  ) M Q signal rnd slow  combin. (534.4 ± 0.8)x10 3 evts Dalitz model: 13 BW resonances, non-resonant contr.; test of S-wave  contr.: K-matrix formalism K*(892) -  K*(892) + K* X (1400) + Results (fit fractions, phases) in agreement with (measurement of  3 ) PRD73, (2006)

14 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 14Belle Rev. Comm D 0 → K S  +  - arXiv: t [fs] x = 0.80±0.29±0.17 % y = 0.33±0.24±0.15 %  = 409.9±0.9 fs most sensitive meas. of x; Cleo, PRD72, (2005) x = 1.8 ± 3.4 ± 0.6% y = -1.4 ± 2.5 ± 0.9 %  PDG =410.1 ± 1.5 fs t-projection

15 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 15Belle Rev. Comm D 0 → K + K - /  +  - hep-ex/ v2 CP even final state; t distribution not pure exponential (D 1 and D 2 contr.); treated as exponential  changed effective  S. Bergman et al., PLB486, 418 (2000) A M,  : CPV in mixing and interference; CPV: D 0 → f and D 0 → f decay rates different; effective  different side band K+K-K+K- K-+K-+ +-+- N sig 111x x x10 3 P98%99%92% M, Q,  t selection optimized in MC

16 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 16Belle Rev. Comm D 0 → K + K - /  +  - hep-ex/ v2 simultaneous binned likelihood fit to K + K - /K -  + /  +  - decay-t R : ideally each  i Gaussian resol. term with fraction f i ; pulls: described by 3 Gaussians   2 /ndf=1.084 (ndf=289)  = 408.7± 0.6 fs

17 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 17Belle Rev. Comm D 0 → K + K - /  +  - hep-ex/ v2 results y CP = (1.31 ± 0.32 ± 0.25) % evidence for D 0 mixing (regardless of possible CPV) 3.2  from zero (4.1  stat. only) K + K - /  +  - and K -  + ratio search for CPV: A  = (0.01 ± 0.30 ± 0.15) % difference of lifetimes visually observable K S  +  - : (x,y)=(0,0) has C.L. 2.6% K + K - /  +  - : y=0 has C.L. 6x10 -4

18 D 0 - D 0 Mixing B. Golob, Belle Charm physics at Belle 18Belle Rev. Comm perspective (1 ab -1 ) 1  3  x, y at upper limit of SM expectation  search for CPV; at current level of sensitivity positive signal clear indication of NP; preliminary study in K S  +  - :  (|q/p|  1 + A M /2) ~ 0.30,  (  ) ~ 17 o K + K - /  +  - :  (A  /y CP  A M /2 - x/y tan  ) ~ 0.25 combination at 1 ab -1 :  (x) ~ ± 0.21%  (y) ~ ± 0.17%  (  ) ~ 9 o,  (|q/p|) ~ 0.15

19 Summary B. Golob, Belle Charm physics at Belle 19Belle Rev. Comm  Belle great exp. environment for charm studies; complementary to c-factories;  In several areas exp. results ahead of theor. predictions in accuracy  Spectroscopic results: conventional states - confrontation with predictions; “exotic” states - new challenge; all - quantum number determ.  (Semi)leptonic D meson decays: tests of non-pert. QCD  First evidence for D 0 mixing: more precise determ. of parameters and search for CPV

20 Spectroscopy,  c, bck up  c →  c + K -  + ; no reflections in  c + K +  - Wrong sign charge comb.:  c + K +  - ; possible reflections from  c * + →  c +  +  - with  misidentified as K would appear here PRL97, (2006) 460 fb -1 s s c+c+ u c d d c u u ++ K-K- u c+c+ K-K- p ++ 67 ± 20 evts significance 4.4  neutral states also observed, iso-doublet StateMass [MeV/c 2 ]Width [MeV/c 2 ]  c (2980) ±2.1± ±7.5±7.0  c (3080) ±0.9±0.56.2±1.2±0.8  c (3080) ±1.8±1.55.2±3.1±1.8 B. Golob, Belle Charm physics at Belle 20Belle Rev. Comm. 2007

21 Spectroscopy,  c, bck up  c →  c + K -  + ; BaBar: 2-D fits in M(  c K  ) and M(  c  ) hep-ex/ B. Golob, Belle Charm physics at Belle 21Belle Rev. Comm cKcK non-res.

22 Spectroscopy,  c, bck up  c →  c + K -  + ; new states; Belle discoveries and measurem. J.L. Rosner, hep-ph/ B. Golob, Belle Charm physics at Belle 22Belle Rev. Comm  c high mass  L=2? S l = 0 (lightest orbital excit.) J P = 5/2 +, 3/2 + 5/2 + →  c  F-wave 3/2 + →  c  P-wave

23 Spectroscopy,  c, bck up Belle, hep-ex/ , 553 fb -1, subm. to PRL   c (2455)  c*c* J=1/2 J=3/2 J=5/2  2 /ndf = 49.9/9 (J=1/2) 36.0/8 (J=3/2) 10.8/7 (J=5/2) angular analysis repeat fit in bins of  J=5/2 strongly favored  c (2880) J P B. Golob, Belle Charm physics at Belle 23Belle Rev. Comm. 2007

24 Spectroscopy,  c, bck up Belle, hep-ex/ , 553 fb -1, subm. to PRL  c (2880) →  c (2455)   c (2880) →  c (2520)   c (2880) →  c   c (2880) J P repeat fit in bins of M(  c  ± )   c (2880)) vs M(  c  ± )  c (2880) P interpretation HQS: 5/2 + s l  l  c */  c /2 - s l  l  c */  c M(2880)= ± 0.2 ± 0.4 MeV B. Golob, Belle Charm physics at Belle 24Belle Rev. Comm N. Isgur, M.B. Wise, PRL66, 1130 (1991) S. Capstick, N.Isgur, PRD34, 2809 (1986)

25 Spectroscopy,  c, bck up Belle, hep-ex/ , 553 fb -1, subm. to PRL comparison of two charged states; reflections from  c (2980, 3077) →  c + K -  + with K - misid. appear in  c ++  - but not in  c 0  +  c (2880) J P B. Golob, Belle Charm physics at Belle 25Belle Rev. Comm  c ++  - c0 +c0 +

26 Spectroscopy, 2cc, bck up B. Golob, Belle Charm physics at Belle 26Belle Rev. Comm Double cc production  (e + e - → J/  X)(fb) exp. LO NLO  c 25.6±2.8± ±  c0 6.4±1.7± ±1.02  c (2S) 16.5±3.0± ±0.52 22S22S 24S24S Belle, PRD70, (2004) E. Braaten, J. Lee, PRD67, (2003) Y. Zhang et al., PRL96, (2006) PRL98, (2007) 350 fb -1

27 Spectroscopy, 2cc, bck up B. Golob, Belle Charm physics at Belle 27Belle Rev. Comm Double cc production C(  ) = -1 C(J  ) = -1 C(X) = +1 C(  ) = -1 C(X) = -1 X(3940)→D ( * ) D ? reconstruct J/  + one D M rec ( J/  D) ~ M(D ( * ) ) constrain M rec ( J/  D)=M(D ( * ) )  (M rec ( J/  ))~10 MeV/c 2 M rec ( J/  D)=M(D) M rec ( J/  D)=M(D*) 24.5±6.9 evts 5  no evidence for X(3940)→J/  X(3940)≠Y(3940) inclusive/D*D tagged sample, common evts removed B >2 (X→D*D) > C.L. B(X→D D) < C.L. B(X→J/  ) < C.L. PRL98, (2007) 350 fb -1

28 Spectroscopy, 2cc, bck up B. Golob, Belle Charm physics at Belle 28Belle Rev. Comm Double cc production X(3940)=  c1 ’? DD* mode dominant no  c1 in M rec,  X(3940)=  c ’’? expected mass MeV/c 2 PRL98, (2007) 350 fb -1

29 Spectroscopy, D sJ, bck up B. Golob, Belle Charm physics at Belle 29Belle Rev. Comm B + → D 0 D 0 K + hep-ex/ fb -1 fit to  E, M bc in bins of M(D 0 K) J=-1?

30 Spectroscopy, X, bck up Possible J PC C parity B ±,0 → K ±,0 X ( →  J/  ) 13.6 ± 4.4 evts. (4  ) mode with substantial Br B ±,0 → K ±,0  c1 ( →  J/  ) serves for calibration of width hep-ex/ , 275M BB C(X(3872))=C(  )·C(J/  )=+1 confirmed by BaBar, PRD74, (2006), 260 fb -1 B. Golob, Belle Charm physics at Belle 30Belle Rev. Comm. 2007

31 Spectroscopy, X, bck up 0 -+, 1 --, 1 +-, 0 ++, 1 ++, 2 ++, 2 -+, 2 --, 3 -- Angular distributions B ±,0 → K ±,0 X ( →  +  - J/  ) (only examples shown)  -- l+l+ l-l- X(J/  ) ++ |cos(  )|  2 /ndf=31/9 J PC =0 ++ J PC =1 ++ |cos(  )|  -- ++ K B X(J/  )  2 /ndf=5/9 in the limit where X, J/  rest frames coincide dN/d(cos(  ))  sin 2 (  ) relative motion of frames included in MC cc J PC hep-ex/ , 275M BB B. Golob, Belle Charm physics at Belle 31Belle Rev. Comm. 2007

32 Spectroscopy, X, bck up B. Golob, Belle Charm physics at Belle 32Belle Rev. Comm B → (D 0 D* 0 )K BaBar: D* 0 → D 0  0 / D 0  BaBar, P. Grenier, 42nd Moriond QCD (2007), 347 fb -1

33 Spectroscopy, Y, bck up Coupled channels threshold DD 1, 4285 MeV/c 2 M(Y)=4295 MeV/c 2 parameterization acc. to Y(4260) M(D)+M(D 1 )  E [GeV]  (e + e - → D*D*) arb. units 4265 GeV M.B. Voloshin, hep-ph/ B. Golob, Belle Charm physics at Belle 33Belle Rev. Comm hep-ex/ Exclusive  ( e + e - → DD) BaBar

34 Semileptonic D decays, bck up D 0 semileptonic decays determination of form factor, test of LQCD; e + e - → D tag ( * ) D sig *; inverse reconstruction: D tag ( * ) fully reconst. K n , n=1,2,3; p(D tag ), p(e + e - ), p(primary , K)  p(D sig *);  + slow from D sig * + → D 0  + slow  p(D 0 sig );  and l  p( ); PRL97, (2006), 282 fb -1  D   e+ e- D  e/µ  D* tag signal  K   K K primary mesons D 0 → K e  D 0 → K  N=1318 ±37 N=1249 ±37 K l signal m 2 [GeV 2 ] B. Golob, Belle Charm physics at Belle 34Belle Rev. Comm. 2007

35 Semileptonic D decays, bck up D 0 semileptonic decays determination of form factor, test of LQCD; PRL97, (2006), 282 fb -1 D 0 →  e Y. Gao (Cleo-c), ICHEP06, 281 pb -1 f + D (0) = ± ± f + D (0) = ± ± ± Br results: B. Golob, Belle Charm physics at Belle 35Belle Rev. Comm. 2007

36 Semileptonic D decays, bck up D 0 semileptonic decays background fake D 0 : from WS sample (D tag, D sig same flavor); K l (in  l ): from measured K l with independently measured fake rate; hadronic (misid as l ): sample with charge of l opposite to the  s from D* sig (OS sample); contains no signal and no semil. background; use K and  intentionally misid-ed as l ; fit the OS sample  amount of  and K misid-ed background PRL97, (2006), 282 fb -1 B. Golob, Belle Charm physics at Belle 36Belle Rev. Comm. 2007

37 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 37Belle Rev. Comm D 0 → K S  +  - Dalitz results arXiv:

38 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 38Belle Rev. Comm D 0 → K S  +  - systematics arXiv:

39 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 39Belle Rev. Comm D 0 → K S  +  - systematics arXiv: Systematics (largest) model dependence [10 -4 ]:  x  y variation of DCS/CF ratios for K*'s ± 7.3 ± 5.8 K-matrix Total model dep t fit:  x  y p* variation Dalitz pdf for bkg. from different t bins Total t fit Total [10 -4 ]:  x  y

40 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 40Belle Rev. Comm D 0 → K S  +  - scalar  arXiv: BW formalism: M(  1 ) = 527 ± 6 MeV/c 2  (  1 ) = 442 ± 10 MeV M(  2 ) = 1031 ± 11 MeV/c 2  (  2 ) = 94 ± 6 MeV K-matrix formalism: unit. relat. for 2-body scatt. trans. operator: T: N ch xN ch matrix for N ch coupled chann.;  : density of final states product. process (init. state non-interacting with channel j); trans. ampl. unitarity: satisf. by defining unitarity satisf. if product. ampl.: V.V. Anisovich, A.V. Sarantev, Eur.Phys.J. A16, 229 (2003) BaBar, hep-ex/ parameters taken from:

41 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 41Belle Rev. Comm D 0 → K S  +  - efficiency and resol. in M(  arXiv: rnd  s P rnd  [(1-f w ) M (m - 2,m + 2,t) +f w M (m + 2,m - 2,t)]  R (t) f w from fit to Q side band: f w = ± diff. w.r.t. f w =0.5 in systematic error

42 D 0 - D 0 Mixing, K S  +  -, bck up B. Golob, Belle Charm physics at Belle 42Belle Rev. Comm D 0 → K S  +  - arXiv: MC tests, correct reconstruction of input; t-projection; P sig  M (m - 2,m + 2,t)  R (t) P rnd  [(1-f w ) M (m - 2,m + 2,t) +f w M (m + 2,m - 2,t)]  R (t) P cmb  [  (t) + Exp(t) ]  R ’(t)

43 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 43Belle Rev. Comm M [GeV/c 2 ] D 0 → K + K - /  +  - hep-ex/ v2

44 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 44Belle Rev. Comm D 0 → K + K - /  +  - systematics hep-ex/ v2

45 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 45Belle Rev. Comm D 0 → K + K - /  +  - running periods w/ diff. conditions fitted t 0 of R for K  robust to resol. f. shape; R(t): single Gauss →  =3.5%,  y CP =0.01%; no bias, reweigted MC: y CP (out) - y CP (in) < 0.04%; background P=98% (KK), 99% (K  ), 92% (  ); changing data side band/MC signal,  y CP = -0.04%; bkg. subtracted / no bkg. subtraction,  y CP = -0.07%; bkg. subtracted / MC signal subtr.,  y CP = -0.03%; systematic checks hep-ex/ v2

46 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 46Belle Rev. Comm D 0 → K + K - /  +  - fitted t 0 of R in diff. run periods and diff. decay modes hep-ex/ v2

47 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 47Belle Rev. Comm D 0 → K + K - /  +  - equal t 0 assumption  y CP =t 0 CP - t 0 K  /  K  from MC cocktail, including running periods with slight misalign. of SVD hep-ex/ v2

48 D 0 - D 0 Mixing, K + K - /  +  -, bck up B. Golob, Belle Charm physics at Belle 48Belle Rev. Comm D 0 → K + K - /  +  - background comparison small tail of signal present in side band, only visible in K  sample; fraction of rnd  s negligible: 0.3%, 0.3%, 0.2% KK K   hep-ex/ v2

49 D 0 - D 0 Mixing, prosp., bck up B. Golob, Belle Charm physics at Belle 49Belle Rev. Comm Combination numbers very preliminary  (y CP ) ~ 0.15%,  (A  /y CP ) ~ 0.10  (x) ~  (y) ~ 0.15%,  (|q/p|) ~  (  ) ~ 0.10  (x’ 2 ) ~ 0.12x10 -3,  (y’) ~ 0.20%  (x) ~  (y) ~ 0.10%  (cos  ) ~ 0.07  (|q/p|) ~ 0.09,  (  ) ~0.05 rad D 0 → K + K - /  +  - D 0 → K S  +  - D 0 → K +  - combined approximate projections to 5 ab -1


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