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f 2 ( a ) Determinations

f 2 ( a ) Determinations. Masashi Hazumi (KEK) January 19, 2004 Super B Factory Workshop, Hawaii. Do you agree ?. My Charge. is to convince you that f 2 determinations at Super B Factories are more exciting than fishing, motor boating, or sailing in Hawaii.

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f 2 ( a ) Determinations

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  1. f2(a)Determinations Masashi Hazumi (KEK) January 19, 2004 Super B Factory Workshop, Hawaii

  2. Do you agree ? My Charge is to convince you that f2 determinations at Super B Factories are more exciting than fishing, motor boating, or sailing in Hawaii. Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  3. hep-ex/0401029 (appeared today !) New results on Time-dependent CP Asymmetries in B0gp+p from Belle Part I : Part II : f2 at Super B Factories Outline

  4. Part INew results on time-dependent CP asymmetries in B0gp+p from Belle(Belle Collaboration) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  5. App = +0.77 0.27(stat) 0.08(syst) Spp = 1.23 0.41(stat) (syst) +0.08 0.07 f2 (deg.) d (deg.) Previous results (evidence for CP violation) Belle 85  106 BB (78fb1): PRD 68, 012001 (2003) • (App, Spp) = (0,0) ruled out at 99.93% C.L. (3.4s) 78 ≤ f2≤ 152 (C.L. > 95.5% for |P/T|<0.45) (Note App = -Cpp) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  6. World average (as of August 2003) c2 = 6.1 (CL=0.047  2.0s) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  7. Improvements since the last publication • More data ! 152  106 BB (140fb-1) in total • Data Set I (200-2002 summer) : 78fb-1 • Data Set II (- 2003 summer) : 62fb-1 • Improvements in the analysis, which include • more efficient continuum suppression algorithm [used for Belle’s B0gp0p0 study (PRL 91, 261801 (2003)] • signal fraction determination with 2D fit in DE-Mbc plane reanalyzed new !  Other parts of the time-dependent CP asymmetry measurements (flavor tag, vtxing, resolution function, unbinned maximum likelihood fit etc.) same as those used in sin2f1 determination (hep-ex/0308036)  Statistical analysis method is essentially the same as before; quote RMS errors obtained from MC pseudo-experiments, significance of CP violation with the Feldman-Cousins approach Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  8. LR (Likelihood Ratio) r (flavor tag quality) B0gp+pcandidate selection high _ qq _ BB low poor good Optimized selection for each region in the LR-r plane (12 regions in total) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  9. Belle 140fb1 B0gp+p candidates 0.86 < LR 1.0 p+p- : 231.4 Kp : 83.3 qq : 168.3 total : 483 LR 0.86 1529 candidates (801 B0- and 728 B0-tags) containing (372  32)p+p-signal events Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  10. Determination of App and Spp consistent with the previous publication data set I (78fb1) Errors from -2lnL/Lmax (MINOS errors ) Where do we find the new data set? Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  11. Determination of App and Spp data set II (62fb1) data set I (78fb1) Errors from -2lnL/Lmax (MINOS errors ) Large CP asymmetries confirmed with the new data set Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  12. Belle 140fb1 Results 1529 ev. (all LR-r regions) App = +0.58 0.15(stat) 0.07(syst) Spp = 1.00 0.21(stat) 0.07(syst) 0.86 < LR 1.0 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  13. high LR low good poor r (flavor tag quality) Belle 140fb1 Dt distributions (background subtracted) App = +0.58 0.15(stat) 0.07(syst) Spp = 1.00 0.21(stat) 0.07(syst) (1) (3) (4) (2) (3) (1) (2) (4) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  14. History of App and Spp Belle This result Belle 140fb1 BaBar Difference still at ~2.0s level Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  15. Belle 140fb1 MC pseudo-experiments Input: (App, Spp) = maximum likelihood point in the physical region Belle result no problem probability ~ 27% Input: (App, Spp) = (0,0) Belle result almost impossible probability ~ 0.1 ppm 107 experiments (140fb-1 each) 107 experiments (140fb-1 each) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  16. 1) Observation of CP violation (5.2s) 2) Evidence for direct CP violation 3.2s for App=0 and any Spp App 3.3s for “superweak” case Spp Belle 140fb1 Significance Feldman-Cousins Analysis Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  17. Constraints on f2 convention taken from M.Gronau and J.L.Rosner PRD65, 093012 (2002) 4 parameters e.g. |P/T| = 0.276  0.064 (Gronau-Rosner PRD65, 013004 (2002) |P/T| 0.15-0.45 (representative) sin2f1 0.736  0.049 (HFAG Summer 03) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  18. Belle 140fb1 Model-independent constraint on f2, d, |P/T| 95.5% C.L. volume f2 (deg.) d (deg.) |P|/(|T|+|P|) sin2f1 = 0.736 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  19. Belle 140fb1 Constraint on f2 and |P/T| 3s 2s 1s |P/T| > 0.17 [95.5% C.L. ( 2s)] for -180  d  180 (i.e. any d) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  20. CL=0.683 (1s) CL=0.955 (2s) f2 (deg.) CL=0.9973 (3s) f2 (deg.) d (deg.) d (deg.) Belle 140fb1 Constraint on f2 and d 78fb1 140fb1 90 ≤ f2≤ 146 (95.5% CL) |P/T| = 0.45 (more stringent bound for |P/T|<0.45) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  21. Belle 140fb1 Paper just submitted ! hep-ex/0401029, submitted to PRL on Jan. 18, 2004 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  22. Belle 140fb1 Conclusion App = +0.58 0.15(stat) 0.07(syst) Spp = 1.00 0.21(stat) 0.07(syst) • We observe CP violation (5.2s) in B0 p+p–. • We find evidence for direct CP violation (3.2s for any Spp) in B0 p+p–. Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  23. Part II: f2 at Super B Factories -- compilation of Super BaBar and Super KEKB studies -- • Isospin Analysis with Bgpp • B0gp+pp0 • B0grr • CKM fit • Summary I thank many people who provide me various information and slides; in particular I thank H. Sagawa, K. Sumisawa and A. Roodman. Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  24. Overview • Time-dependent CP asymmetries in b g uud tree transition (assuming no penguin)  sin2f2 • Penguin is not negligible in general, need to trap it out • Methods that have been studied so far • B0gpp Isospin analysis • B0grp quasi 2-body method • B0grp “full” Dalitz analysis • B0grr Isospin analysis for a given polarization, which can be determined experimentally. Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  25. Remark • What methods can we try to extract maximal information with available data ? • What (luminosity, p0 reconstruction performance, clean methods etc.) is needed for precision measurements of f2 ? • What precision is needed for what purpose ? my apology for ignoring some of interesting methods that can be applied at Super B factories or even at present B factories Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  26. Assumptions in the studies • Integrated luminosity • Super BaBar 10 ab-1 (Lpeak = 1 x 1036) • Super KEKB 5 ab-1 (Lpeak = 5 x 1035) • Cf: 2~3 x 1035 “equivalalent” to LHCb taking dsin2f1 as a benchmark • Detector performance • Same as present B factories • Maximal use of Monte-Carlo (MC) pseudo-experiments Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  27. CP violation inB0 π+π– mixing b d B0 t t B0 d b decay Penguin(P) Tree(T) u B0 p+ d b p+ d W+ t u g b B0 u p- B0 u p- d d d d b

  28. Prospect for pp isospin analysis A full isospin analysis is needed.

  29. Bgpp branching fractions All are available now ! Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  30. Isospin Analysis Results Super KEKB Input values • CL vs. f2 (deg) at • 0.14 ab-1 (solid curve) • 0.5 ab-1 (dashed curve) • ab-1 (dotted curve) • 50 ab-1 (shaded area) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  31. Ap0p0 dependence of df2 Super KEKB 50ab-1 discrete ambiguities remain in general Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  32. Super BaBar (=q) ~5 at 10ab-1 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  33. Improved VTX and PID • Conditions: • present performance • vertex (Dz) resolution = present x 2/3 • vertex (Dz) resolution = present x 1/2 • PID efficiency = 0.95, fake rate = 0.05 • (present: efficiency = 0.9, fake rate = 0.1) • (2)&(4) • (3)&(4) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  34. Improved VTX and PID 20-30% improvements (corresponding to 40-60% Ldt increase) systematic errors will also be reduced (mean)(R.M.S) (at 3 ab-1) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  35. B→rp branching fractions Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  36. Quasi two-body analysisB0 →rπ Time-dependence Decay rate distribution r charge

  37. Super BaBar SU(2) Analysis Arbitrary amplitudes and phases to reproduce experimental values: Experimental values:

  38. Dalitz analysis in B0→rp→p+p-p0 Snyder-Quinn, PRD 48, 2139,1993 interference region Discrete ambiguities can be resolved ! Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  39. 2 3 4 Benchmark analysis with MC pseudo-experiments Super KEKB • Perform the 9-parameter fit w/ present detector performance • Signal fractions and shapes from Belle’s 78 fb-1 results • Background (continuum) from sideband data • Efficiency corrections taken into account Smoothed histogram for MC pseudo-experiments (no rare B background in this study) Efficiency drop arround each corner due to p0 eff. (momentum dependence) N(rp∓)=25844 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  40. Results of MC pseudo-experiments Super KEKB statistical errors • All 9 parameters obtained correctly • df2increase by 37% w/ BG added input w/o BG(3ab-1) with BG(3ab-1) f2 1.57 1.5780.043 1.5740.059 |T| 1.59 1.5950.038 1.6200.050 dT -0.65 0.6600.056 -0.6690.079 |T-+| 0.78 0.7680.023 0.7480.029 d-+ -2.91 -2.9000.041 -2.8790.051 |P0| 0.19 0.1850.015 0.1880.023 d0 -0.61 -0.6270.074 -0.5910.113 |P1| 0.19 0.1650.023 0.1650.034 d1 1.04 1.0050.192 0.9660.263 Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  41. B0grr Super BaBar Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  42. Theoretical uncertainties nice summary by H. Quinn and M. Ciuchini in WG2 of Super BaBar study • Isospin-breaking effects on pp (similar in rr) • DI=1/2 penguin can be trapped out • DI=3/2 contribution: negligible ~ 5 • genuine isospin-breaking: ~5 • Effects of other resonances on rp Dalitz • should be addressed with increased statistics • Total theoretical uncertainties • ~ 10 as a fairly conservative estimate for now • to go below 5 need more studies ( you may open the Pandora’s box) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  43. f2 “banana” in r-h plane (0.5 ab-1) Super KEKB case w/o new physics Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  44. f2 “banana” in r-h plane (5 ab-1) Super KEKB case w/o new physics Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  45. f2 “banana” in r-h plane (50 ab-1) Super KEKB case w/o new physics Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  46. Constraints on New Physics (NP) in mixing Super KEKB f2 measurements used as SM reference allowing possible DI=1/2 NP in decay amplitudes being trapped out Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  47. Discussion + Summary • Precision (~5 or better) measurements of f2 possible and only possible at Super B factories • Current B factories (w/o upgrade): not enough statistics • Isospin analysis (“p0 modes”) very challenging at hadron experiments • Theoretical uncertainties ~ statistical/systematic uncertainties • Further investigation of theoretical uncertainties will be necessary (and will flourish) in the Super B era. • New physics studies in transitions between 3rd 1st generations will remain important. • e.g. Lack of new amplitude is just interesting and important if a new elementary particle is found at LHC. • Need a new physics case study for demonstration. Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  48. Backup SlidesforPart I Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  49. Better continuum suppression Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

  50. B0gp+pcandidate selection Optimized selection for each region in the LR-r plane (12 regions in total) Masashi Hazumi (KEK) @ Super B Factory Workshop (Hawaii)

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