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D 0 D 0 Mixing and CP Violation Results from the B Factories

D 0 D 0 Mixing and CP Violation Results from the B Factories. Brian Meadows, Bostjan Golob, Ikaros Bigi. Outline from 1 st Meeting. i. Theory 1. Brief history 2. Mixing 3. CPV 4. NP ii. General Exp. Remarks 1. D* tagging 2. Decay-t resolution iii. Decays to CP eigenstates

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D 0 D 0 Mixing and CP Violation Results from the B Factories

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  1. D0D0 Mixing and CP Violation Results from the B Factories Brian Meadows, Bostjan Golob, Ikaros Bigi

  2. Outline from 1st Meeting • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  3. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  4. Theory (and Formalism) • i. Theory • 1. Brief history • Invention of charm (GIM mechanism) • Pais and Treiman, 1975 • Short range -> x is small • Long range (Wolfenstein) • Compare w/other neutral systems • Uniqueness of charm • 2. Mixing • Definitions (x, y, q/p, phi,  and all that) • Decays to state accessible to D0 or D0 • dN/dt ~ e- t x [r2 + r(y cos+x sin)t + (x2+y2)t2] - (1) Point out that this is how most mixing measurements are made • 3. CPV • Mixing, Decay and Interference • Define f • 4. NP • Best outlined by theorist !

  5. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  6. General Exp. Remarks • ii. General Experimental Remarks • 1. D* Tagging • Usual “cartoon” showing vertices and vertex resolution • Figures illustrating M, M for varous channels • 2. Decay Time Resolution • Resolution for • K • Ks+- and variation over Dalitz plot + Belle equivalent?

  7. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  8. Decays to CP eigenstates • iii. Decays to CP eigenstates • 1. Method • Decay not truly exponential but nearly so - relate to (1) • 2. Results KK/pipi • Definitions of A and Y and what they measure • Compare D*-tagged with untagged results • 3. Results Ksphi + others • Outline method and results • Comment on D0 +-0 (dominated by I=0  CP=+1)

  9. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  10. Hadronic WS decays • iv. Hadronic WS decays • Formalism • IMHO, this should be covered in i. theory – refer to Eq. (1) • Eq. (1) applies to decays to CP eigenstates and to time-dependent Dalitz plots too. • 2. Results Kpi • Describe results obtained • Include some discussion on the confidence level contour plots • [Project the 68.3% contour onto (x,y) plane ?]

  11. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  12. t-dependent Dalitz • t-dependent Dalitz • Point out that each “bin” (coordinates (s1,s2)in Dalitz plot is analogous to WS K decay – refer to Eq. (1) • t-dependence for each bin determined by local “r(s1,s2)” and “(s1,s2)” values • An amplitude model can provide both, but not the overall phase difference 0 between D0 and D0 decays to that point. • Kpipi0 • 0 is “unknown” (though recently measured by CLEO) • Outline results (only Babar so far). • 2. Ks h h • Method pioneered by CLEO (9 fb-1 ) • 0=0 since self-conjugate final state is sum of CP=+/-1 eigenstates • Outline results • Discuss Belle extraction of CPV parameters • 3. Other multibody • Describe Babar phase-space averaged preliminary results • No amplitude models so far.

  13. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  14. Mixing from WS Semileptonic Decays • vi. Semileptonic • General remarks • Time-dependence is ~ (x2+y2) t2 e- t – refer to Eq. (1) • RM=(x2+y2)/2~ 5 x 10-5 [x very small, y ~ 0.01] • Too small to have been observed so far. Backgrounds need to be kept under control Missing neutrinos make life difficult D* tagging essential • 2. comparison of results tagged/un-tagged • Belle chose a D*-tagged sample  Large RS signal and background of ~5000 events Babar chose a double tagged sample • Small RS signal but low background ~ 3 events Results are relatively comparable

  15. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  16. t-integrated CPV measurements • vii. t-integrated CPV measurements • Using data to measure eff. Asymmetry • Describe - D*/D ratio same for both charges of s • Point out that this means results should improve with higher luminosity. • Results KK/pipi • Add new D(s)+ Ks+(K+) results from Belle • Multi-body (KKpi0, pipipi0, KKpipi) • Point out that CPV probably occurs in some channels but not others • Model-dependent vs Model-independent approaches • Normalization to total in phase space (Dalitz) plot. • T-odd correlations • Describe • New results from Babar on K+K-+-

  17. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  18. t-dependent CPV measurements • viii. t-dependent CPV measurements • Belle time-dependent analysis of Ks+- Dalitz plot • Any other ??

  19. Next Level • i. Theory • 1. Brief history • 2. Mixing • 3. CPV • 4. NP • ii. General Exp. Remarks • 1. D* tagging • 2. Decay-t resolution • iii. Decays to CP eigenstates • 1. Method • 2. Results KK/pipi • 3. Results Ksphi + others • iv. Hadronic WS decays • 1. Formalism • 2. Results Kpi • v. t-dependent Dalitz • 1. Kpipi0 • 2. Ks h h • 3. Other multibody • vi. Semileptonic • 1. General remarks • 2. comparison of results tagged/un-tagged • vii. t-integrated CPV measurements • 1. Using data to measure eff. asymmetry • 2. Results KK/pipi • 3. Multi-body (KKpi0, pipipi0, KKpipi) • 4. T-odd correlations • viii. t-dependent CPV measurements • ix. Summary

  20. Summary • Summary • Make average(s) for Babar and Belle • Either as a group or individually ? • Compare one with the other ? • Given that a principal group of readers is to consist of new students and postdocs working on future flavour experiments, make a projection of our results to these experiments.

  21. Summary of Measurements - Babar

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