1. Charm results overview1 Charm...the issues Lifetime Rare decays Mixing Semileptonic sector Hadronic decays (Dalitz plot) Leptonic decays Multi-body channels (4,5,6 bodies!) Charm Baryons D* spectroscopy

2. Charm results overview2 A brief review of the measurements for each topic: summary of the present experimental situation a comment about the next future reach to be done a more precise picture of the experimental status within 5 and 10 years –BaBar, Belle, Cleo-c, CDF, BEPC, LHC-b, BTeV

3. Charm results overview3 Charm lifetimes Motivation: investigation of non-spectator processes FOCUS ( * ) produced new lifetimes results with precision better than the previous world average (○), PDG 2002. Already at the level of comparison with theory. Systematics will dominate

4. Charm results overview4 Rare decays FOCUS improved results by a factor of 1.7 –14: approaching theoretical predictions for some of the modes but still far for the majority CDF and D0 can trigger on dimuons  promising Motivation: lepton number violation study investigation of long range effects and SM extention CDF Br(D 0  +  - )<2.4 x10-6 @ 90% C.L. is the best limit for this mode (65 pb -1 data)

5. Charm results overview5 Mixing Motivation: suppressed in the charm sector in the SM. If “measured”, would suggest SM extention Future is @ Babar & Belle

6. Charm results overview6 Summary of reach Where we are and where we go

7. Charm results overview7 The semileptonic sector FOCUS 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% Motivation: semileptonic decays are the easiest way to determine CKM elements Branching ratio

8. Charm results overview8... and form factors The vector and axial form factors are generally parametrized by a pole dominance form Nominal spectroscopic pole masses D+D+ d d uuuu s

9. Charm results overview9 form factors FOCUS analysis is the first to include the effects on the acceptance due to changes in the angular distribution brought about the s-wave interference Form Factor lattice calculations available!

10. Charm results overview10 Groupelectronmuon FOCUS 0.54  0.033  0.048 CLEO2 0.54  0.05  0.04 E687 0.58  0.17  0.07 ARGUS 0.57  0.15  0.15 CLEO 0.49  0.10  0.12 Br(D s  / D s 

11. Charm results overview11 form factors 1.Most precise measurement to date 2.very consistent with D +  K 0    3.very consistent with th. expectation Cleo-c expects experimental error in most of the measurements in the sl sector in the range 1 to a few %

12. Charm results overview12 Hadronic decay investigation A few slides follow about Dalitz plot analysis

13. Charm results overview13 “Future” of hadronic decays Full observation of the decay (for three-body channels) Learn about strong effects (but also a complication for the analysis!) CP investigation (see example of D ±  K K ±  ± ) Interplay between charm (and beauty) decays and light meson spectroscopy (very clean samples!) Motivation: Investigation of decay dynamics via Dalitz plot analysis The analysis is difficult, need an analysis strategy to keep under control the strong effects accompanying the weak decays of Heavy Flavours!

14. Charm results overview14 An instructive example from FOCUS Milano group analogy with operatively : complete Dalitz plot analysis (time-dependent) to deal with all interference with other (  )  intermediate channels crucial for determination of the angle  of the SM unitarity triangle

15. Charm results overview15 FOCUS D s +   +  +  - analysis Observe: f 0 (980) f 2 (1270) f 0 (1500) Sideband Signal Yield D s + = 1475  50 S/N D s + = 3.41 f 0 (980) signal is clean!

16. Charm results overview16 First fits to charm Dalitz plots in the K-matrix approach! C.L fit 3 % Low mass projection High mass projection decay channel phase (deg) fit fractions (%) Projections of the f 0 (980) signal

17. Charm results overview17    No significant direct three-body- decay component No significant  (770)  contribution     Marginal role of annihilation in charm hadronic decays A reliable measurements of the annihilation processes in the hadronic sector is still missing.... need more data!

18. Charm results overview18 Yield D + = 1527  51 S/N D + = 3.64 FOCUS D +   +  +  - analysis Sideband Signal

19. Charm results overview19 C.L fit 7.7 % K-matrix fit results Low mass projection High mass projection decay channel phase (deg) fit fractions (%) Good channel to investigate the nature of the  meson (aka the  puzzle) . No new ingredient (resonance) required not present in the scattering!

20. Charm results overview20 With  Without  C.L. ~ 7.5% Isobar analysis of D +   +  +  would instead require a new scalar meson:  C.L. ~ 10 -6 m = 442.6± 27.0 MeV/c  = 340.4 ± 65.5 MeV/c preliminary

21. Charm results overview21 Another interesting example from FOCUS D +, D s  KK  D s +  K + K   + D +  K + K   +

22. Charm results overview22 K + K   projectionK    projection Yield D + = 7106  92 S/N D + = 8.62 Decay Fraction and phases K*(892) = 20.7  1.0 % (0 fixed)  (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)° f 0 (1370) = 7.0  1.1 % (60.0  5.3) ° a 0 (980) = 27.0  4.8 % (145.6  4.3)° f 2 (1270) = 0.8  0.2 % (11.6  7.0) °  (1680) = 1.6  0.4 % (-74.3  7.5) ° Preliminary Possible investigation of a 0 (980) & the f 0 series

23. Charm results overview23 CP violation For a two amplitude decay  i  i = strong phase CP asymmetry: 2 different amplitudes strong phase-shift A tot A tot = g 1 M 1 e i  1 + g 2 M 2 e i  2 CP conjugate A tot A tot = g 1 M 1 e i  1 + g 2 M 2 e i  2 ** a CP = 2Im(g 2 g 1 *) sin(  1 -  2 )M 1 M 2 |g 1 | 2 M 1 2 +|g 2 | 2 M 2 2 +2Re(g 2 g 1 *)cos(  1 -  2 )M 1 M 2 |A tot | 2 - |A tot | 2 |A tot | 2 + |A tot | 2 =

24. Charm results overview24 FULL OBSERVATION Dalitz plot = FULL OBSERVATION of the decay COEFFICIENTS and PHASES for each amplitude Measured phase :  =  +  CP conserving CP violating CP conjugate  =   =  -   =  -  E831 a CP =0.006±0.011±0.005 Measure of direct CP violation: D   K  K   asymmetrys in decay rates of D   K  K    CP violation via D +  K - K +  +  Dalitz analysis

25. Charm results overview25 phi(1020) K*(1430) a0(980)K1(1410) f2(1270) f0(1370)phi(1680)         K*(1430) phi(1020) a0(980) K1(1410) f2(1270) f0(1370) phi(1680)       , D +, D - Coefficients: D ±, D +, D - D ±, D +, D - Phases: D ±, D +, D - Preliminary! No evidence of CPV

26. Charm results overview26 Other Dalitz plot analyses The K s 0  +  - channel could contribute to mixing studies –D 0 is tagged from D * so CF decay makes K 0. DCS or mixing make K 0. –These interfere and it may be possible to determine  +  from Dalitz plot. In any case, it contains much physics - a real challenge to fit well. 15,753 events 23 fb -1 Scale to the full sample! BaBar & Belle have the statistics to make it! The problem is the formalism! In Cleo-c there is a dedicated working group consisting of experimentalists and theoreticians BaBar

27. Charm results overview27 Leptonic decays Motivations: decay constants present future

28. Charm results overview28 for the future... Multi-body charm decays Charmed baryon spectroscopy D* spectroscopy –Statistics is still limited: some results from BaBar, Belle, FOCUS –More data necessary: CDF, Cleo-c, B-factory, LHC-B, BTeV

29. Charm results overview29 Some slides of general interest Why charm at a B factory How is Tevatron working Cleo-c run plan Comparison among experiments BEPC future

30. Charm results overview30 Charm at B Factory? Cross section is large Present BaBar sample of 91 fb -1 contains Compare with earlier charm experiments: –E791 - 35,400 1 –FOCUS - 120,000 2 –CDF - 56,320 (new number available soon)

31. Charm results overview31 Temperature of Tevatron

32. Charm results overview32 Cleo-c

33. Charm results overview33 comparison

34. Charm results overview34 BEPC future Program and schedule