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Meson Lifetimes, Decays, Mixing and CPV in FOCUS

Meson Lifetimes, Decays, Mixing and CPV in FOCUS. Sandra Malvezzi I.N.F.N. Milano. A new charm-physics era The high statistics and excellent quality of data allow for unprecedented sensitivity & sophisticated studies Investigation of decay dynamics both in the hadronic

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Meson Lifetimes, Decays, Mixing and CPV in FOCUS

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  1. Meson Lifetimes, Decays, Mixing and CPV in FOCUS Sandra Malvezzi I.N.F.N. Milano Sandra Malvezzi - Charm Meson Results in Focus

  2. A new charm-physics era The high statistics and excellentquality of data allow for unprecedented sensitivity & sophisticated studies Investigation of decay dynamics both in the hadronic and semileptonic sector Phases andQuantum Mechanics interference FSI role & CP studies Lifetime measurements @ better than 1% non-spectator processes Mixing possible window on physics beyond SM Sandra Malvezzi - Charm Meson Results in Focus

  3. Outline Hadronic decays Amplitude Analysis of three pseudoscalar channels Semileptonic decays Anomaly in decay New BR of and Lifetimes Precise measurements for and preliminary for First clear evidence (DSCD) First evidence (SCSD) First Dalitz analysis New method for CPV s-wave interference Mixing and Prelimary results from Sandra Malvezzi - Charm Meson Results in Focus

  4. Over 1 million reconstructed!! FOCUS Spectrometer Successor to E687. Designed to study charm particles produced by ~200 GeV photons using a fixed target spectrometer with upgraded Vertexing, Cerenkov, E+M Calorimetry, and Muon id capabilities. Includes groups from USA, Italy, Brazil, Mexico, Korea 1 million charm particles reconstructed into DK , K2 , K3 Sandra Malvezzi - Charm Meson Results in Focus

  5. d u s W c s R d s hep-ex /0206049 First clear observation Yield = 65.515.0 Yield = 31.4 7.4 First observation Intervention of resonances coupling both to pp and KK or annihilation Sandra Malvezzi - Charm Meson Results in Focus

  6. Spin 0 Where Spin 1 Spin 2 and Dalitz plot analysis of K Sandra Malvezzi - Charm Meson Results in Focus

  7. DCS D+K+p+p- Decay fractions and phases NR = 9  5 % (-6  16) ° K*(892) = 43  7 % (208  16)° K*(1410) = 12  8 % (133  23)° K2(1430) = 6  3 % (48  27) ° K*(1680) = 22  10 % (2  20)° r (770) = 51  10 % (0 fixed) f0(980) = 9  5 % (73  31) ° r(1450) = 10  5 % (-113  15) ° Yield D+ = 190 24 S/N D+ = 1.0 Preliminary K+p - projection p+p - projection Sandra Malvezzi - Charm Meson Results in Focus

  8. SCS Decay fractions and phases NR = 18  4 % (34  7)° K*(892) = 22  3 % (163  7) ° K*(1410) = 14  5 % (-10  7) ° K*0(1430) = 14  6 % (68  7) ° r (770) = 40  4 % (0 fixed) f2(1270) = 2  1 % (33  21) ° r(1450) = 8  2 % (219  14) ° First Dalitz analysis Ds+K+p+p- Yield Ds+ = 468 29 S/N Ds+ = 2.4 Preliminary K+p - projection p+p - projection Sandra Malvezzi - Charm Meson Results in Focus

  9. Ds ,D+ KK Ds+ K+ K- p+ D+ K+ K- p+ Sandra Malvezzi - Charm Meson Results in Focus

  10. Interference term Sandra Malvezzi - Charm Meson Results in Focus

  11. Decay Fraction and phases K*(892) = 20.7  1.0 % (0 fixed) f(1020) = 27.8  0.7 % (243.1 5.2)° K*(1410) = 10.7  1.9 % (-47.4  4.9)° K*(1430) = 66.5  6.0 % (61.8  3.8)° f0(1370) = 7.0  1.1 % (60.0  5.3) ° a0(980) = 27.0  4.8 % (145.6  4.3)° f2(1270) = 0.8  0.2 % (11.6  7.0) ° f(1680) = 1.6  0.4 % (-74.3  7.5) ° K+ K- projection K-p + projection Yield D+ = 7106 92 S/N D+ = 8.62 Preliminary Sandra Malvezzi - Charm Meson Results in Focus

  12. Atot= g1M1eid1 + g2M2eid2 CP conjugate Atot= g1M1eid1 + g2M2eid2 * * 2Im(g2 g1*) sin(d1-d2)M1M2 |Atot|2- |Atot|2 aCP= = |Atot|2+ |Atot|2 |g1|2M12+|g2|2M22+2Re(g2 g1*)cos(d1-d2)M1M2 CP violation For a two amplitude decay di= strong phase CP asymmetry: strong phase-shift 2 different amplitudes Sandra Malvezzi - Charm Meson Results in Focus

  13. f =-f d = d q =d-f CP violation:Dalitz analysis Dalitz plot = FULL OBSERVATION of the decay COEFFICIENTS and PHASES for each amplitude q =d+f Measured phase: CP conserving CP violating CP conjugate aCP=0.006±0.011±0.005 Measure of direct CP violation: asymmetrys in decay rates ofDKK p E831  Sandra Malvezzi - Charm Meson Results in Focus

  14. D+/D- split sample analysis Preliminary! Coefficients: D±,D+,D- No evidence of CPV Phases:D±,D+,D- K-matrix approach to improve the quality ofthe analysis Sandra Malvezzi - Charm Meson Results in Focus

  15. New results on Our Kp spectrum looks like 100% K*(892) This has been known for about 20 years ...but a funny thing happened when we tried to measure the form factor ratios by fitting the angular distributions Sandra Malvezzi - Charm Meson Results in Focus

  16. forward-backward asymmetry in cos below the K* pole but almost none above the pole An unexpected asymmetry in the K* decay A 4-body decays requires 5 kinematics variables: 3 angles and 2 masses Sounds like QM interference Sandra Malvezzi - Charm Meson Results in Focus

  17. We simply add a constant amplitude in the place where the K* couples to an m=0 W+ with amplitude Try an interfering spin-0 amplitude Phys.Lett.B535,43,2002 (plus mass terms) will produce 3 interference terms Sandra Malvezzi - Charm Meson Results in Focus

  18. Studies of the acoplanarity-averaged interference Extract this interference term by weighting data by Since all other c-averaged terms in the decay intensity are constant or We begin with the mass dependence: A constant 45º phase works great.... ...but the solution is not unique . Sandra Malvezzi - Charm Meson Results in Focus

  19. Sandra Malvezzi - Charm Meson Results in Focus

  20. New FOCUS semileptonic BRs & Form Factors Our number is 1.59 standard deviation below CLEO and 2.1 standard deviation above E691 All values consistent with their average value with a CL of 19% Sandra Malvezzi - Charm Meson Results in Focus

  21. Form Factors hep-ex /0207049 The vector and axial form factors are generally parametrized by a pole dominance form Nominal spectroscopic pole masses Decay intensity (including s-wave amplitude) parametrized by New FOCUS results Sandra Malvezzi - Charm Meson Results in Focus

  22. Form Factor Ratios Our analysis is the first to include the effects on the acceptance due to changes in the angular distribution brought about the s-wave interference rad Sandra Malvezzi - Charm Meson Results in Focus

  23. hep-ex /0206056 Baseline cuts a) 2682 evts b) 4695 evts Baseline, out-of-material. isolation cuts c) 793 evts d) 2192 evts Sandra Malvezzi - Charm Meson Results in Focus

  24. Signal Lifetime fits Charm Meson Lifetimes 139433520 evts 68274360 evts 109877385 evts Sandra Malvezzi - Charm Meson Results in Focus

  25. fs fs Phys.Lett.B537,192 ,2002 FOCUS ........difference in the hadronic sector PDG2002 Sandra Malvezzi - Charm Meson Results in Focus

  26. signal PDG 2002 4909 fs Lifetime 506 8 fs 5668  95 events (50% FOCUS data) Preliminary Theoretical prediction (Bigi Uraltsev) 1.00-1.07 (no WA/WX) 0.8-1.27 (different process interference) 4 x statistics including Sandra Malvezzi - Charm Meson Results in Focus

  27. Mixing Direct comparison of CP final state lifetime Phys.Lett.B485,62,2000 Sandra Malvezzi - Charm Meson Results in Focus

  28. New Mixing Results Preliminary • is the relative strong phase @ 95% C.L. FOCUS K+ m-n only statistical error ! ....towards CLEO & a big relative phase Sandra Malvezzi - Charm Meson Results in Focus

  29. Conclusion Charm physics is revealing itself a rich source of new results FOCUS is playing a crucial role in understanding the charm phenomenology new suppressed decay modes decay dynamics of three-body hadronic channels via quasi two-body decays semileptonic sector very precise lifetime measurements (will dominate PDG) mixing Sandra Malvezzi - Charm Meson Results in Focus

  30. d u s W c s R d s QUESTION SLIDES Not obvious evidence of Intervention of resonances coupling both to ppand KK Sandra Malvezzi - Charm Meson Results in Focus

  31. Left-handed m+ Right-handed m+ Two amplitude sums over W polarization Wigner D-matrices (“mass terms”) A 4-body decays requires 5 kinematics variables: 3 angles and 2 masses Five observables are studied are helicity-basis form factors Sandra Malvezzi - Charm Meson Results in Focus

  32. Since A<<B, interference will dominate..... There will be only three terms as If we average over acoplanarity we only get the first term This is the term creating forward-backward asymmetry! • If our model is right: • The asymmetry will have a particular mass dependence • The asymmetry should be proportional to • The asymmetry should have a dependence from q given by Sandra Malvezzi - Charm Meson Results in Focus

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  35. Sandra Malvezzi - Charm Meson Results in Focus

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  38. All values consistent with an average of 0.54  0.04 Sandra Malvezzi - Charm Meson Results in Focus

  39. 2000 picture E791: CLEO: The comparison with CLEO is valid only if there is a small strong phase difference d BELLE: (preliminary) 2002 new measurements: BELLE BaBar preliminary Very preliminry FOCUSresult on from semileptonic 3 times better than E791 Sandra Malvezzi - Charm Meson Results in Focus

  40. Sandra Malvezzi - Charm Meson Results in Focus

  41. Inner muon preliminary Sandra Malvezzi - Charm Meson Results in Focus

  42. outer muon preliminary Sandra Malvezzi - Charm Meson Results in Focus

  43. Sandra Malvezzi - Charm Meson Results in Focus

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