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Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed

Hadronic Charm Decays in CLEO Steven Blusk, Syracuse University (on behalf of the CLEO Collaboration) XXXIII International Conference on High Energy Physics July 26 – August 2, 2006, Moscow, Russia. Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed

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Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed

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  1. Hadronic Charm Decays in CLEOSteven Blusk, Syracuse University(on behalf of the CLEO Collaboration)XXXIII International Conference on High Energy PhysicsJuly 26 – August 2, 2006, Moscow, Russia • Introduction • Ds Scan • D0, D± Branching Fractions • Cabibbo favored • Cabibbo-suppressed • Ds Branching Fractions • Inclusiveh, h, and f. • Exclusive CF • Amplitude Analyses • D0p+p- p+ • D0K+K-p0 • Summary Other CLEO Charm Talks • Leptonic Charm decays • Sheldon Stone (this session) • Semileptonic Charm decays • Yongsheng Gao Session 10-3 • DCSD, DKp • S. Blusk, Session 8-2 • Y(4260)at CLEO • Ian Shipsey, Session 9-3 • Charmonium decays at CLEO • Tomasz Skwarnicki, Session 9-4 Steven Blusk, Syracuse University

  2. y(3770)DD e+ e- D D The Charm Landscape Near Threshold y(3770) y(4160) CLEO • y(3770)DD • Pure C=-1 • No addn’l particles • Low multiplicity • Clean n recon. E>3940 MeV for Ds production Ds Scan – next 2 slides Lep & SL decays isolate the strong interaction effectscritical checks on LQCD, models Hadronic BF’s needed for normalization of B BF’s, strong phases, strong int. effects+… Steven Blusk, Syracuse University

  3. Scan the region 3970-4260 MeV • Optimize Ds physics • Study D(s) XS in this region • Confirm Y(4260) Ecm=4160 MeV Simulations • No need to reconstruct D*, as Mbc differentiates event types. • For DD and DsDs cut on E and use Mbc to extract yields. • For other event types cut on Mbc and use invariant mass to extract yield. < DE > = 0 DsDs* DD DsDs DD* • Ecm=4160 MeV selected • Additional 180 pb-1collected at 4160 MeV D*D* The Ds Scan • 12 scan points • ~60 pb-1 (total) Steven Blusk, Syracuse University

  4. Three ways to determine hadronic cross-section: • Inclusive hadronic event counting • Inclusive D meson • Exclusive D(*) D(*) final states Clear that exclusive final states do not saturate the total charm XS. Exclusive DD Inclusive D Inclusive Hadrons Are there multi-body events? Look for D*+Dp with p(D*)<400 MeV (below kinematic limit for D*D* events) X p- e+ e- D*Dp D*+ p+ No DDp observed (using similar MM technique) D0 D0 Momentum (GeV/c) Total Charm & Multibody Steven Blusk, Syracuse University

  5. Expected #ST: Expected #DT: Since eij  ei ej, correlated systematics cancel in NDD To first order, Bi is independent of tag modes’ efficiencies, s,L. D Hadronic BF (Cabibbo-Favored) Double Tagged, 281 pb-1 Use 3 D0 and 6 D+ modes - Count #Single Tags (ST): Niobs(9 modes) - Count # Double tags (DT): Nijobs (45 pairs of modes) Preliminary • Update from 57 pb-1 to 281 pb-1 underway • Some systematics still being studied. • O(1%) stat & syst errors on golden modes in sight… Steven Blusk, Syracuse University

  6. p+p0 p+p+p- p+p0p0 p+p+p-p0 p+p+p+p-p- K-p+p+ p+p-p0 p+p- p0p0 p+p- p+p- p+p- p0p0 p+p- p+p-p0 D Hadronic BF (Cabibbo-Suppressed) • Isospin Analysisof pp final state • A(DI=2)/A(DI=0) = 0.420±0.014 ±0.010 • Strong phase shift: • = (86.4±2.8±3.3)0 Large FSI in D decays.. Other first/improved BF’s D0hp0, wp+p-, D+hp+ Steven Blusk, Syracuse University

  7. Inclusive D(s) Hadronic Decays • Inclusive ss rates expected to be higher for Ds+ than D0/D+. • Ds(h,h,f)+X ingredient in one method of measuring Bs fraction in Y(5S) decays. • CLEO-c measurements with 281 pb-1D0/D+ (3770 MeV) and 71 pb-1Ds+ (4170 MeV). • Fully reconstruct one D(s), search for h, h, f on other side, subtract sideband. D+ hX Ds+ hX D0hX 228K tags 152K tags 3K tags h includes feed-down fromh´. Much larger rates for Ds as anticipated. Steven Blusk, Syracuse University

  8. Ds hadronic BF’s, particular fp+, critical. sBF(fp)~20% • Follows very similar procedure as for y(3770)DD • Minv vs Mbc driven by DsDs* kinematics. • Look at 6 modes: KsK+, K+K-p+, K+K-p+p0, p+p-p+,hp+,hp+ Sideband regions Double Tag yieldsdetermined via sidebandsubtraction Signal region Double Tag Yields Exclusive Ds Hadronic Decays Steven Blusk, Syracuse University

  9. Dsfp+ is a critical measurement, but must be careful • Interference & cross-feed with nearby f0(980) is an issue • Define a partial BF within some window around the f. • This is actually what experimentalists need DsK+K-p+ partial BF: CLEO-c (±10 MeV around f) 1.98±0.12±0.09 (~x2+O(10%)) (Preliminary !!) DsK+Kpyield vsK+K- mass For reference: Dsfp+ PDG06: 4.4±0.6 BaBar: 4.8±0.5±0.4 (1.008<M(K+K-)<1.035 GeV) Ds Hadronic BF’s Preliminary Likelihood fit used to extract BF’s Errors already << PDG Steven Blusk, Syracuse University

  10. D+ p+p-p+ Dalitz Analysis - Motivation E791 FOCUS: K-matrix approach - No need for as, employed a (pp) S-wave to describe data Although not entirely clear this is correct:“… the K-matix approach employed in Ref [5] does not meet the chiral requirementsof a soft expansion for low energies…” [J. Oller, PRD71 054030] Projections/Fits Isobar Model No s BESII- J/ywp+p- Described viaa complex pole With s σ required, implemented as a BW resonance Can CLEO-c confirm, refute, add more confusion to the s saga? But BW does not account for phase variation across the Dalitz plot [D. Bugg hep-ph/0510021] Steven Blusk, Syracuse University

  11. D+ p+p-p+ Dalitz Analysis • L=281 pb-1 @ y(3770) • Untagged analysis • Signal box for DP • |ΔE|<2s • |mBC-mD|< 2s • Backgd boxes for DP • |ΔE|<2s • 5s<|mbc-mD|<9s • DP Statistics: • N(π−π+π+) ~2600 ev. • N(Ksπ+) ~2240 ev. • Nback ~ 2150 ev. D+→π−π+π+ Signal~2600 ev. 6991 on DP D+→K0Sπ+ Steven Blusk, Syracuse University

  12. D+ p+p-p+ Dalitz Results (Preliminary) Likelihood Fit including: Amplitude, phase, spin-dependent PW (ie. BW), angular distribution, Blatt Weiskopf angular momentum penetration factor. • Consistency with E791 - E791 BW s Fit Fraction = (46.3±9.0±2.1)% • s pole provides a good description of the DP Steven Blusk, Syracuse University

  13. D0K+K-p0 Dalitz Analysis (1) • Motivation: • CKM angle g can be measured using interference betweenB+D0K+ and B+D0K+ and the CC modes. [GLS, PRD 67 071301 (2003)] • Two of the key inputs are rD and dD, defined through: • rD and dD can be independently determined by analyzing the D0K+K-p0 DP. • Analysis Overview • Uses ~9 fb-1 of data collected on/just below U(4S) • Reconstruct D*+D0p+, D*-D0p- • Charge of bachelor p tags the D0 flavor at production • Signal/sideband regions as shown • 735 Signal candidates Steven Blusk, Syracuse University

  14. D0K+K-p0 Dalitz Analysis (2) Similar fitting technique to Dp+p-p+ analysis K*- f K*+ K*+ Read off the values from the DP fit rD= 0.52±0.05±0.04 dD = (332±8±11)o • First measurement of dD. • Significant improvement on rD over previous value using K*K BF’s Steven Blusk, Syracuse University

  15. Next-to final remarks Many thanks to my CLEO collaborators, especially:P. Onyisi, A. Ryd, B. Lang, M. Dubrovin, H. Mahlke-Krueger Some more details, recent talks, pubs on these topics • Ds Scan: • R. Poling, CHARM2006, “New results of the CLEO-c scan from 3970-4260” • S. Blusk, CIPANP2006, “Ds Scan and Confirmation of the Y(4260)” • D Hadronic Analysis: • Q. He et al., Phys. Rev. Lett, 95, 121801 (2005) (57 pb-1) • P. Onyisi, CHARM2006, “Hadronic Charm decay at CLEO-c” (281 pb-1) • Cabibbo-suppressed Decays: P. Rubin et al., Phys. Rev. Lett.96, 081802 (2005). • Ds Inclusive & Exclusive: S. Stone, FPCP06, “Hadronic Charm Decays and D Mixing “ • Dp+p-p+ Dalitz Analysis: • D. Cinabro, FPCP06 “Interference Effects in D Meson Decays” • M. Dubrovin, CHARM2006, “Charm Dalitz Analyses from CLEO-c” • DK+K-p0 Dalitz: • C. Cawfield, et al, hep-ex/0606045, submitted to Phys. Rev. D • D. Cinabro, FPCP06 “Interference Effects in D Meson Decays” Steven Blusk, Syracuse University

  16. Summary • CLEO-c is hitting it stride  already many measurements have surpassed world averages • Ds scan  Ecm = 4160 MeV optimal for Ds physics • Expect ~4-5X more DD and Ds+Ds- data by mid-2008. • Significant improvements on knowledge of D hadronic BF’s and many new modes being uncovered. • Critical improvements on golden modes • Should have error on Beff(Dsfp) ~ 5% • Hadronic analyses have just begun… many more to come. • More (open charm) hadronic, semileptonic and leptonic results in this session and CKM/Rare decays session Steven Blusk, Syracuse University

  17. BACKUPS Steven Blusk, Syracuse University

  18. e+ e- D D D Hadronic Overview • D Reconstruction Techniques in CLEO-c • Untagged analysis – reconstruct only one D meson in signal mode, use Bref • Tagged analysis • Reconstruct 1 D meson in “clean” hadronic modes with “large” e*B • Use remaining charged particles & showers to reconstruct second D meson. • Hadronic (this talk) • Semileptonic (see talk by Yongshen Gao in Session 10) • Leptonic (see talk by Sheldon Stone in Session 10) Use kinematic variables:DE=Ebeam-ED Steven Blusk, Syracuse University

  19. Substructure in CS modes Mbc-MD3s DE Signal Region DE Sideband Region D+p+p+p-p0 Signal D+p+p+p-p0 Sideband h w D+p+p+p0p0 Signal D+p+p+p0p0 Sideband D+p+p+p-p-p0 Signal D+p+p+p-p-p0 Sideband p+p- p0p0 Steven Blusk, Syracuse University

  20. Dalitz Fit Details • Minimize Log likelihood • PDF • Matrix element • Partial waves (PWR): • Spin-dependent BW for conventional resonances • I=2 π+π+ S-wave • π+π−S-waves: • Oller • Flatte aR= amplitude, fR = relative phase PWR = Mass & spin dependent partial wave function WR = Angular distribution FR = Blatt-Weiskopf angular momentum penetration factor For pp S-wave (s=mpp2) gab== coupling of f0 to ab rab=2pa/m (phase space factor) Steven Blusk, Syracuse University

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