Prelude for practice talk: I have outdated numbers for the D Hadronic BR analysis

1. Prelude for practice talk: • I have outdated numbers for the D Hadronic BR analysis • I have the papers and a week so will fix soon. • Tables grabbed from recent talks but they will be replaced. • Figures will be as they are presented today. • Need to add “preliminary” in some places (WA). • Some “fluff” at beginning will be removed as I think of more important things to say. • Talk is 40 minutes.

2. D Hadronic Branching Fractions And Vub Dan Cronin-Hennessy University of Minnesota CLEO Collaboration May 27, 2005

3. Outline • CLEO-c Program • First Results on D Hadronic Branching Fractions • Weak Annihilation Limits from CLEOII/IIV

4. CESR CESR @ Cornell Cornell Electron-positron Storage Ring e+ e- collisions: sqrt(s): 1.8 – 5.6 GeV Low energy running: Natural damping of beam lost (1/20). CESR-c: First demonstration of wiggler dominant ring.

5. CLEO

6. RICH Kaon eff = 0.8 Kaon eff = 0.85 Kaon eff = 0.9 • Ring Imaging Cherenkov Detector • Designed for B decays. • Clean separation in charm region. K-p separation shown. B physics CLEO-c

7. CLEO-c (3770) – 3 fb-1 ((3770) DD ~ s=6 nb) Hadronic D decays Semileptonic D decay (D decay constant, form factors, Vcs,Vcd, Mixing, CPV, rare/nonSM) Accumulated Luminosity: ~ 280/pb Results Today: 60/pb (pilot sample)

8. Hadronic D Branching Fractions Motivation: Provide most precise measurement of D hadronic BRs. Many current measurements determined with respect to normalizing modes (e.g. D  K p , D  K p p). CLEO-c will provide absolute measurements. Counting D mesons provides DD production cross sections. First step toward improved constraints on D mixing parameters.

9. Hadronic D Branching Fractions Basic Strategy: (for most CLEO-c analyses) D Tagging Full reconstruction of one D meson (Tag D). Search remainder of event for signal D decay. Continuum, t pair, radiative return events suppressed significantly. Efficiency is analysis dependent -15% to 20%. (Large BR of D mesons and low multiplicity) Single tags are clean

10. Double Tags S = 2*(e*BR)*NDD D = (e*BR)2*NDD NDD = S2/4D sDD = NDD/L (do not need e, BR) Simple description Doubly Tagged D+K-p+p+, D-K+p-p- Prelim. DATA ~60 pb-1

11. Analysis 9 Decay modes measured Single tags: Double tags: Syst unc cancels. To first order Bi independent of tag modes and efficiencies. • Simultaneous fit for all BR and cross sections. • All correlations taken into account.

12. Fits D0 D+ Line shapes include ISR, FSR, resolution, beam energy spread. Efficiencies include FSR correction.

13. Tracking systematic determined using recoil mass: Reconstruct y p from y’y p+p-. Peak at p mass2. Systematics Pion found Pion not found MC Data

14. Results D0 Modes D+ Modes

15. Results *Results from CLEO-c pilot data sample. *Luminosity ~60/pb *Statistical and Systematic unc comparable for some modes. *Expect systematics to scale with luminosity since many of these are determined from data. Agreement with PDG. PDG numbers are correlated among modes. CLEO-c numbers correlated (from simultaneous fit). CLEO-c include FSR correction.

16. Cross Sections Branching fraction analysis fringe benfit: Precision measurement of DD production cross sections. Interesting to note: PDG: Gee and G s(y(3770)  hadrons) ~ 10 nb But only a 2 sigma effect at this time. CLEO-c will provide a significantly improved cross section measurement that will allow measurement of non-DDbar y(3770) decays at or below a nb.

17. Charge to Neutral Ratio Prediction: M. Voloshin (hep-ph/0402170) These (and other) data-theory discrepancies have prompted speculation of 4-quark component of y(3770). See hep-ph/0504197 Measured Rc/n Predicted sqrt(s) MeV

18. Unitarity Constraints Transition Slide Today CLEO-c will allow B factory measurements to reach full potential by calibrating lattice QCD.  form factor measurements (see Feng Liu’s talk)  D meson decay constant (fD) (Zhongchao Li’s talk) With 1000/pb from B factories and CLEO-c lattice calibration CLEO II/IIV analyses at Y(4S) energies continue to improve our knowledge of CKM constraints…

19. BXu l n • Vub Inclusive: • Isolating bu component requires • measurement in restricted kinematic regions. • Must know fraction of b u events in acceptance • region. • Progress has been made in last five years by • using b to s g to understand b quark fermi motion • and b quark mass. This essentially trades modeling • uncertainties for experimental uncertainties and • has resulted in precision Vub extraction. • Does not remove all sources of theoretical uncertainties. Must find other ways to limit these uncertainties using additional measurements. Lepton energy spectrum PRL 88 231803 2002

20. Weak Annihilation *Annihilation of valence quarks (leptonic). *Hadronization of residual “brown muck”. *Estimates of rate suggest small contribution from these processes. (Order ~ 1/mH3) *However, if rate is distributed differently than the more dominant bu production processes then the impact on Vub can be significant. *Extreme example: Leptonic decay, B l n, places rate at the kinematic endpoint.

21. Weak Annihilation Are there methods of quantifying WA experimentally? *High statistics of B-factories will allow comparison of charge and neutral measurements. *D meson analyses at CLEO-c provide additional opportunities (m3 dependence suggests effects may be larger in charm sector (D0/D+ width difference) *Or… we can just look directly for WA kinematic signature in available B samples: We have looked. Using CLEOII/IIV data (~10/fb). Approach: Traditional inclusive B semileptonic analysis. Lepton identification plus neutrino recontruction. Observable of interest is lepton-neutrino mass (q2 spectrum). Look for anomalous rate in high q2 region. Bump hunting yes but with a model as a guide.

22. WA Search Expected Contributions: *B Xc l n Kinematically limited well below B Xu l n but still contributes due to experimental resolution. *Continuum *B Xu l n (b  u l n) *Weak annihilation?

23. WA Search DeFazio-Neubert: JHEP 99, 017 bu model: “Hybrid” model which includes resonant and non-resonant modes. Known branching ratios and form factors for resonances. Combined resonant and non-resonant modes follow HQET expectations (with constraints on HQET parameters imposed by b s g measurements).

24. Weak annihilation model: *Invented for this analysis. *Leptons carry most momentum. *Soft hadronic component, X Ex, Mx, px ~ LQCD q2 ~ MB2 - LMB WA Search q2 for various PDF parameters Distribution function for Mx and px. Flat distribution of width x. Exponential drop dictated by L

25. WA Search 30 models used. q2 for various PDF parameters

26. WA fits Strategy: Binned c2 fit. 30 bins in q2. 3 bins in pl.. Fakes and continuum normalization known/fixed. Normalizations for bc, bu, and WA float. Results in N bc, N bu & NWA.

27. WA fits Sample fit projections.

28. WA fits Sample fit projections. All but bu and WA subtracted

29. Key points: 1)This is a lousy method for measuring the WA rate. The WA model has too much freedom in the kinematics. 2)This a good method for quantifying the impact of WA on Vub. *This analysis is sensitive to WA when these processes contribute significantly in the endpoint region. When such is the case the impact on Vub is large. *If WA processes are spread over a large region of phase space we are not sensitive (and neither is the extraction of Vub). We quote our results in terms of the “impact” on a “typical” endpoint analysis rather than in terms of WA rates. Ra = “Impact Ratio” Results

30. Results q2 and Mx q2>8.0 GeV2 Mx<1.7 GeV Pl>1.0 GeV/c Mx Mx<1.55 GeV Pl>1.0 GeV/c Endpoint El>2.2 GeV Shape function regime

31. Summary • D Hadronic Branching Fractions: • I have presented first results from CLEO-c on D hadronic BR fractions. • With the pilot data sample (60/pb) we have agreement with PDG and comparable superior uncertainties. • Expect significant improvement with new data samples already accumulated (and future data). • We have measured 9 D decay modes with double tagging method which provides absolute BRs. We have provided new/improved measurements for critical normalizing modes. • We are at the level where careful treatment of radiative corrections is required. • DD cross sections and the charge to neutral ratios measured. • Future extensions of this analysis will provide new D mixing constraints.

32. Summary • Vub: • I have presented a preliminary measurement from CLEOII/IIV (10/fb) that allow us to set experimental limits on WA contamination of analyses that extract Vub. • The measurement is statistics limited and we are adding data from CLEOIII. • We find that the impact on Vub is well below current uncertainties. • This approach could be improved with better WA modeling (need help from theory). • We have invented our own model which use LQCD as the relevant energy scale for the hadronic component.