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D 0 Mixing @ SuperBelle

D 0 Mixing @ SuperBelle. B. Golob University of Ljubljana , Jožef Stefan Institute & Belle Collaboration. “Jožef Stefan” Institute. University of Ljubljana. Outline CP states Wrong sign (non-CP) t-dependent Dalitz Average Constraints on NP Prospects & Summary.

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D 0 Mixing @ SuperBelle

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  1. D0 Mixing@ SuperBelle B. Golob University of Ljubljana, Jožef Stefan Institute & Belle Collaboration “Jožef Stefan” Institute University of Ljubljana • Outline • CP states • Wrong sign (non-CP) • t-dependent Dalitz • Average • Constraints on NP • Prospects & Summary

  2. S. Bergman et al., PLB486, 418 (2000) 1. D0→KK/pp Decays to CP eigenstates D0→ K+K- / p+p-, CP even no CPV: CP|D1> = |D1> t=1/G1; K-p+: mixture of CP states t=f(1/G1,1/G2) + = K+K-/p+p- and K-p+ratio Belle, PRL 98, 211803 (2007), 540fb-1 1stevidence for D0 mixing BaBar, arXiv:0712.2249, 384fb-1

  3. 1. D0→KK/pp Decays to CP eigenstates Belle, PRL 98, 211803 (2007), 540fb-1 t-dependent BaBar, arXiv:0712.2249, 384fb-1 ACPpp ACPKK t-integrated ACPmeas =Aep + AFB + ACPf Aep: comparison of tagged/untagged (D*+→D0p+),D0→K-p+ AFB: asymmetric f(cosqCMS) BaBar, PRL 100, 061803 (2007), 386fb-1 |cosqCMS| |cosqCMS| AFBpp AFBKK Belle, arXiv:0807.0148, 540fb-1 |cosqCMS| |cosqCMS|

  4. D0→KK/pp Belle, PRL 98, 211803 (2007), 540fb-1 Systematics breakdown largest contributions (yCP): acceptance: 0.12% scaling equal t0 assumption: 0.14% scaling bkg signal/sideband diff.: 0.09% non-scaling variation of select.: 0.11% scaling total: 0.25% non-scaling: 0.10% largest contrib. s(ACPKK): scaling non-scaling 0.09% 0.05% 0.33% Aep stat. Aep binning total: non-scaling: 0.06% L0=540 fb-1

  5. D0→KK/pp Projected sensitivity sstat=ssyst x ab-1 s(yCP) [%] 8 ab-1 s(AG) [%] L0=540 fb-1 16 ab-1 L [ab-1]

  6. D*+→ D0pslow+D0 → D0 → K+p- 2. D0→Kp WS decays (non-CP) DCS decays  interference; t-dependence to separate DCS/mixed likelihood contours d: unknown strong phase DCS/CF 1s 3.9s 1stevidence for D0 mixing 3s CDF, PRL 100, 121802 (2008), 1.5fb-1 BaBar, PRL 98, 211802 (2007), 384fb-1 Belle, PRL 96, 151801 (2006), 400fb-1 5s likelihood contours 95% FC confidence region 1s 3.8s 3s

  7. Belle, PRL 96, 151801 (2006), 400fb-1 L0=400 fb-1 D0→Kp Systematics breakdown ssyst≈ 0.5 sstat largest contrib.: Dx’2,Dy’ [sstat] +0.3 -0.2         p* variation ±0.2 ±0.2 fixed decay-t parameters +0.2 -0.2 st effect on fractions ±0.3 ±0.3 total scaling ±0.5 ±0.5 total ±0.4 ±0.4 non-scaling scales with data/MC scales with data scales with data assumed same fraction of scaling/non-scaling systematics as for x’2

  8. D0→Kp sstat=ssyst x ab-1 Projected sensitivity s(y’) [%] s(x’2) [10-3] L [ab-1] L0=400 fb-1

  9. D0→KSp+p- 3. D0→KSpp t-dependent Dalitz analyses different types of interm. states; CF: D0→ K*-p+ DCS: D0→ K*+p- CP: D0→r0 KS if f = f  populate same Dalitz plot; relative phases determined (unlike D0→ K+p-); t-dependence: regions of Dalitz plane→ specific t dependence f(x, y); D0→f access directly x, y l1,2=f(x,y); Belle, PRL 99, 131803 (2007), 540fb-1 D0→f D0→KSp+p- most accurate x

  10. L0=540 fb-1 D0→KSpp Systematics breakdown Belle, PRL 99, 131803 (2007), 540fb-1 largest model dependence [10-4]: Dx                 Dy -10.4           +0.1K*DCS/CF + 6.9           -2.7 -5.1 -4.3 G(q2) const. --------------------------------- +10+6        Total model dep. -14-8 experimental (major sources): Dx           Dy +7.6         -7.8               p* variation -5.6         -5.7  Dalitz pdf for bkg. from different t bins ----------------------- +9+8 Total experimental-7          -12 better underst. of DCS/CF; arbitrary ½ of uncertainty taken as scaling; all other model dependence non-scaling ±10 ± 7 model non-scaling all scaling ±10 ±7 total non-scaling

  11. L0=540 fb-1 D0→KSpp Systematics breakdown model dependence: D|q/p|Df [rad] ±0.08 ±0.06 experimental: D|q/p|Df [rad]+0.06 +0.06           p* variation +0.03 -0.05bkg. decay t parameters ±0.08 ±0.06 model non-scaling scales with data/MC scales with data/MC ±0.08 ±0.06 total non-scaling

  12. D0→KSpp Projected sensitivity sstat=ssyst x ab-1 s(x) [%] s(y) [%] s(|q/p|) s(f) [rad] 7 ab-1 7 ab-1 13 ab-1 L [ab-1] L0=540 fb-1

  13. 4. Average 1, 2, 3 s @ 50 ab-1 HFAG c2 fit 50 ab-1 only KK/pp, Kp and Kspp projected sensitivities included E. Barberio et al. (HFAG), arXiv:0808.1297 & http://www.slac.stanford.edu/xorg/hfag/

  14. Average 1, 2, 3 s @ 50 ab-1 HFAG c2 fit 50 ab-1 only KK/pp, Kp and Kspp projected sensitivities included E. Barberio et al. (HFAG), arXiv:0808.1297 & http://www.slac.stanford.edu/xorg/hfag/

  15. 5. Constraints on NP E. Golowich et al., PRD76, 095009 (2007) constraints from mixing existing constraints already now greatly improved for many NP models; example of R SUSY: D0 D0 D0 D0 R couplings R couplings 50 ab-1 |x| [GeV] 50 ab-1

  16. Constraints on NP constraints from CPV: SCS decays (probing penguins); small in SM, small DCPV; SUSY: squark-gluino loops; CF: c → sdu (K-p+) SCS: c → qqu (q=s, K+K-) DCS: c → dsu (K+p-) W± c u Y. Grossman et al., PRD75, 036008 (2007) Vcq Vuq d, s, b • contrib. to DC=1 enhanced • compared to DC=2 by m(g˜ )/mc • sensitivity of mixing to this contrib. • small compared to sensitivity of afdir q g q |M12| constraint from mixing values of ˜m and m(g˜ ) for which rf=1% m(g˜ )

  17. Constraints on NP constraints from CPV: squark-gluino loops contribution Y. Grossman et al., PRD75, 036008 (2007) Belle, PRL 98, 211803 (2007), 540fb-1 constraint from mixing BaBar, arXiv:0712.2249, 384fb-1 BaBar, PRL 100, 061803 (2007), 386fb-1 Belle, arXiv:0807.0148, 540fb-1 values of ˜m and m(g˜ ) for which rf=1% 50 ab-1: s(adirKK)=0.10% m(g˜ ) if ff, df O(1) all shown values excluded (rf=1%)

  18. Notes @50 ab-1: s(x), s(y) 0.05-0.1%, s(|q/p|), s(f)  0.05, s(AD)  0.5-1% most D0 oscillation studies systematics dominated need very detailed studies detector induced charge asymm. decay t bias (detector alignment) ... obtaining stringent constraints on NP models, useful to identify possible NP signals from LHC CPV parameters sensitivity not over full SM range more modes (KsKK, ppp0,....) common systematics (Dalitz models)

  19. Super t charm factory Summary on D0 mixing at Super t charm factory, Novosibirsk Super-B factory at initial stage s(x), s(y) ~ O( 0.1%) s(ACP) ~ O(0.1%); dKp precisely determined from combination of measurements; RM, y @ charm factory of lower accuracy than @ B factory (unless t-dependent meas. with asymmetric collider); various options for CPV; several competitive or better, and complementary to B-factory (including D0D0 with C=+1); many other possibilities (Dalitz studies, triple product correlations, T-odd moments, ...)

  20. Phenomenology bckup DCPV in SCS decays to CP states: O(10-2) contrib. of adirf M12 for D0: G. Raz, PRD66, 057502 (2002)

  21. Mass insertions bckup mass insertion approxim. (MIA): replace sum over all possible internal propagators and mixing at the vertices, with a single off-diagonal mass insertion in basis where all gauge couplings are diagonal; MIA: Taylor expanssion in mass-squared differences between intermediate particles w.r.t. chosen mass m; example: SUSY contrib. to K0 mixing mixing angles

  22. D0→KK/pp bckup Belle, PRL 98, 211803 (2007), 540fb-1 Systematics breakdown scales with MC better detect. (MC) desc. scales with data/MC scales with data/MC scales with data/MC total non-scaling 0.10% 0.06% L0=540 fb-1

  23. D0→KK/pp bckup Systematics breakdown source s(ACPKK) Belle, arXiv:0807.0148, 540fb-1 q shape difference D0/D0 bkg. side/signal window rnd ps bkg. Aep stat. Aep binning fit binning 3/4 layer SVD 0.02% 0.01% 0.03% 0.09% 0.05% 0.03% 0.01% scales with data L0=540 fb-1

  24. D0→KK/pp bckup Belle, PRL 98, 211803 (2007), 540fb-1 Systematics breakdown acceptance: fit generated t for selected evts.; constant within MC stat. equal t0: t0 diff KK/Kp/pp from MC, including missaligned SVD; equal within MC stat. diff. bkg. signal/sideband: diff. for various sidebands → syst.

  25. L0=540 fb-1 D0→KSpp bckup Systematics breakdown Belle, PRL 99, 131803 (2007), 540fb-1 model dependence [10-4]: Dx                 Dy -10.3           +0.1K*0(1430) DCS/CF -15% + 6.9           -2.5K*2(1430) DCS/CF -30% -1.6 -0.9 K*(1410) DCS & CF -20% --------------------------------- +10+6        Total model dep. -14-8 experimental (major sources): Dx           Dy +7.6         -7.8               p* variation -5.6         -5.7  Dalitz pdf for bkg. from different t bins ----------------------- +9+8 Total experimental-7          -12 better underst. of DCS/CF; arbitrary ½ of uncertainty taken as scaling; all other model dependence non-scaling ±10 ± 7 model non-scaling scales with data/MC all scaling ±10 ±7 total non-scaling

  26. L0=540 fb-1 D0→KSpp bckup Systematics breakdown Belle, PRL 99, 131803 (2007), 540fb-1 model error better underst. of DCS/CF; arbitrary ½ of uncertainty taken as scaling; rest non-scaling

  27. L0=540 fb-1 D0→KSpp bckup Systematics breakdown Belle, PRL 99, 131803 (2007), 540fb-1 exp. error all major sources scaling

  28. Systematics bckup

  29. 1. Phenomenology x and y d, s, b d, s, b K+ difficult to estimate DCS SU(3) breaking D0 D0 W+ D0 D0 K- W- I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001); A.F. Falk et al., PRD69, 114021 (2004) unique for D0’s: down q’s loop; mixing: 30 years after discovery The duration of passion is proportionate with the original resistance of the woman. H. de Balzac (1799 -1850)

  30. Vus* 1. Phenomenology K+ CP violation Vcs D0 D0: first two quark generations; CKM elements ≈ real; using CKM unitarity: bellow current exp. sensitivity; signals New Physics K- parameterization: RD ≠1: Cabbibo suppression AD ≠0: CPV in decay AM ≠0: CPV in mixing f ≠0 : CPV in interference

  31. Cleo-c, PRD78, 012001 (2008), 281pb-1 2. Measurements E) y(3770) →D0D0 uncorrelated production at threshold D0D0 in C=-1 state  effective Br’s depending on mixing param.: y, RM=(x2+y2)/2, RDcosd S±: CP eigenstates e-: Xen fit to set of single and double Br’s single D0 reconstr. both D0 reconstr. measured from ST rates Br(D0D0→fi/fj) Br(D0→fi)Br(D0→fj) Br(D0D0→fiX) Br(D0→fi) uncorrelated production (RWS=G(K+p-)/G(K-p+))

  32. 3. Prospects and summary s(√RDcosd) [10-2] charm A) Mixing parameters Cleo-c results improved signif. with higher stat.; (all estimates based on ) x, y related measurements of similar or better accuracy at Super-B with modest lumin.; d already constrained with reasonable accuracy from combination of x’2, y’, x, y meas.; Cleo-c, PRD78, 012001 (2008), 281pb-1 L [fb-1] 0.5 5.0 0.5 5.0 s(RM) [10-3] charm s(x’2) [10-3] B s(y) [%] charm s(yCP) [%] B Prediction is very difficult, especially of the future. s(x) [%] B s(y) [%] B N. Bohr (1885 - 1962) L [fb-1] L [fb-1] L [ab-1] L [ab-1]

  33. 3. Prospects and summary A) Mixing parameters asymmetric factory at y(3770): for same <Dz> as at U(4S) gb~2 (0.42 at Belle), E(e-/e+)=8 GeV/0.45 GeV (8 GeV/3.5 GeV at Belle); resolution: sresD ~ sresB (bgB/bgD) ~0.3 ps ~tD0 N(S+K-p+, S+e-)~1300 @ 281 pb-1 sy~0.1% with 2 ab-1 (stat. only)

  34. 3. Prospects and summary s(AG) [%] B s(|q/p|) B s(f) [rad] B B) CPV parameters various options at y(3770); decays to same sign CP eigenstates: (assuming no direct CPV) suppressed by RM; not feasible; L [ab-1] >>

  35. 3. Prospects and summary B) CPV parameters various options at y(3770); untagged asymmetry: ACP linear in CPV and mixing param., feasible (stat. only); systematics from charge dependent e asymm.? also possible at B-factories L[fb-1] 1400 1000 600 200 current d >> RD, y uncertainty 300 fb-1 0.2 0.5 0.9 sind

  36. 3. Prospects and summary B) CPV parameters D0D0 in C=+1 state (D0D0 g); tagged asymmetry:

  37. 3. Prospects and summary s(AG) [%] B s(|q/p|) B s(f) [rad] B B) CPV parameters various options at y(3770); CPV in mixing: ACP linear in CPV param., feasible (stat. only); systematics from e- spectrum extrapolation (cancels in ACP)? s(AM)~1% with 300 fb-1 sensitivity better than at Super-B; L [ab-1]

  38. 3. Prospects and summary B) CPV parameters s(AD) [%] charm s(AD) [%] B various options at y(3770); direct CPV: ACP linear in CPV param., feasible (stat. only); systematics from e- spectrum extrapolation (cancels in ACP)? sensitivity better than at Super-B; a complete overview of physics cases (for BES-III) can be found in L [fb-1] 0.5 5.0 L [ab-1] K.T. Chao, Y. Wang, editors, arXiv:0809.1869

  39. L0=281 pb-1 Systematics bckup y(3770) →D0D0 Cleo-c, PRD78, 012001 (2008), 281pb-1 assume sensitivity on y is mainly due to S±e- RDcosd is mainly due to S±K-p+ RM is mainly due to K-p+K-p+ calculate fraction of non-scaling syst. on DT yields in total relative error: S±e- (y) s(non-scaling)/s(total)=15% extrap. of e- momentum S±K-p+ (RDcosd) s(non-scaling)/s(total)=15% FSR, sideband subtr. K-p+K-p+ (RM) s(non-scaling)/s(total)=2.4% FSR

  40. d bckup y(3770) →D0D0 • constraints • average • direct meas. • (fit w/o external input) cosd 1.0 0.5 0 -0.5 -1.0 1 0 -1 y’ measured y’=ycosd-xsind [%] d measured 0 1 2 3 4 5 d [rad] 0 1 2 3 4 5 d [rad]

  41. Vuj* Vci* Vcj Vui u c W+ D0 D0 d, s, b d, s, b W- u c K+ D0 D0 K- Phenomenology bckup x and y in SM 2nd order perturb.: short distance: |x| ~ O(10-5) G. Burdman, I. Shipsey, Ann.Rev.Nucl.Sci. 53, 431 (2003) DCS SU(3) breaking absorptive part (real interm. states)  y dispersive part (off-shell interm. states)  x long distance: |x|, |y| ~ O(10-2) I.I. Bigi, N. Uraltsev, Nucl. Phys. B592, 92 (2001); A.F. Falk et al., PRD69, 114021 (2004) D0 mixing: rare process in SM; possible contrib. from NP

  42. K+p-p0 bckup BaBar, arXiv:0807.4567, 384fb-1 D0→K+p-p0 separate WS/RS Dalitz distributions; t-distrib. analogous to D0 →K+ p-; RS t-integrated Dalitz analysis; WS Dalitz analysis; no mixing point 0.8% C.L. BaBar, Lepton Photon 07, 384fb-1 dKpp: unknown strong phase shift DCS/CF

  43. K-p+ K+K-/ p+p- bckup Belle, PRL 98, 211803 (2007), 540fb-1 Fit simultaneous binned likelihood fit to K+K-/K-p+/p+p- decay-t, common free yCP R : ideally each si Gaussian resol. term with fraction fi; : described by 3 Gaussians  event-by-event st trec-tgen/st parameters of R depend slightly on data taking conditions t = 408.7±0.6 fs

  44. K+K-/ p+p- bckup Belle, PRL 98, 211803 (2007), 540fb-1 equal t0 assumption DyCP=t0CP - t0Kp / tKp from MC cocktail, including running periods with slight misalign. of SVD

  45. y(3770) →D0D0 bckup D0, D0 in anti-symmetric state

  46. Triple product correl. bckup D →K*(p1,e1)K*(p2,e2) T(pi,ei) = -pi,ei; but AT ~ sin(f+d) f: weak phase d: strong phase;  asymmetry of conjugated process ATCP ~ sinfcosd n.b.: ACPdir ~ sinfsind

  47. T-odd moments bckup D →KKpp a: angle between KK and ppplanes; direct CPV; CPV;

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