Precision Leptonic, Semileptonic and Hadronic Decays of the D at CLEO-c Dan Cronin-Hennessy University of Minnesota Nov 27, 2007 BBCB WS D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Talk Overview Overview CLEO-c Results: D(s) Leptonic D(s) Semileptonic D(s) Hadronic D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Impact of Physics Vub l n B p D Vcd K Vcs Vcb Bd Vtd Bs Vts Vtb Vus  Vud e t b W CLEO-c + Lattice QCD +B factories CLEO-c CLEO-c + Lattice QCD +B factories + ppbar D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D-Tagging D-Tagging e+ e- Signal D m+ n Tag D Event Shape discrimination no longer a powerful tool in the charm region. Backgrounds at y(3770): continuum (18 nb), t pair (3 nb), radiative return (~1.5 nb) D meson has large branchings to low multiplicity modes. Requiring a reconstructed D provides background suppression. D-Tagging removes half the event (only a single D remains). Simultaneously provides 4-vector of other D meson. D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D-Tagging D. Cronin-Hennessy, U of M

Weak Annihilation: D+ l+ nm |fD|2 n l |VCKM|2 Improvement in mixing constraints with better fB Ideally one would measure B+ l+ n (rate low). Realistic alternative: Measure fD,fDs. fD CLEO-c and (fB/fD)lattice  fB (And fD/fDs checks fB/fBs) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D+ m+ nm e+ e- Signal D m+ n Tag D One D fully reconstructed: Require single track on other side: m - PID suppresses K - Calorimeter suppresses p+ - Require low energy in CC Use D 4-vector to calculate missing mass (~0 for n). D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D+ m+ nm Data (281 pb-1) Monte Carlo (1 fb-1) Mode Events Data 50 D+p+ p0 1.4 D+ Klong p+ 0.33 D+t+ nt 1.08 Total Bck: 2.81 CLEO-c PRL 95 251801 (2005) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D+ t+ nt (tpn) Data (281 pb-1) If not satisfied New physics: (Exotic intermediate bosons) = Preliminary BR(D+ t+ nt)< 2.1 x 10-3 R<1.8 @90% CL Anti-cut analysis vetoes CC energy associated with track That is consistent with muon. CC=Crystal Calorimeter PRD73 112005 (2006) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Ds m(t) n (MM2 technique) Require fully reconstructed Ds (tag). Eight reconstruction modes used. Require reconstructed invariant mass within 2.5 s of Ds mass. Number of Ds tags in 314/pb: 31302+472 Calculate MM2 for Ds tag plus photon. Peaks at Ds mass. Cut at 2.5 s. N(tag+g)=18645+426 D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Ds m(t) n (MM2 technique) Constraints used in kinematic fit. Try both hypotheses: tag from Ds and tag from Ds*. Choose solution with lowest c2. MM2=(Ecm-ED-Eg-Em)2-(pcm-pD-pg-pm)2 tpn m D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Ds m(t) n (MM2 technique) Efficiency for reconstructing p or m track 80.1%. Ecc = Calorimeter energy associated with extra track. Background from Ds candidate mass sidebands. Ecc < 300 MeV: -0.05 GeV2 < MM2 < 0.05 GeV2 (m like): 92 evts, e= 99%, bkg=3.5 0.05 GeV2 < MM2 < 0.20 GeV2 (tpn like): 31 evts, e=60%, bkg=2.5 Ecc > 300 MeV: -0.05 GeV2 < MM2 < 0.20 GeV2 (tpn like): 25 evts, e=40%, bkg=3 Backgrounds from real Ds are significant only for the t-like samples. The largest is from leptonic decay Ds t n where t p p0 n. (.55 evts for Ecc < 300 MeV and .65 events for Ecc> 300 MeV). t m nn contributes .37 evts for Ecc < 300 MeV sample. B(Dsmn) = (0.594+0.066+0.031)% B(Dstn) = (8.0+1.3+0.4)% PRL 99 071802 (2007) PRD 76 072002 (2007) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Ds t nm (t enn) Missing Energy Technique Analysis based on 195/pb @4170 MeV Reconstruct Ds and use recoil mass to count tags. Require one extra track consistent with electron. Primary background semileptonic (Ds X e n). Suppress X by requiring low amount of extra energy in calorimeter. Shown on right. Signal region Ecc(extra)< .4 GeV. Backgrounds from scaled MC. B(Dstn)=(6.29+0.78+0.52)% Preliminary D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M f D(s) Summary D+  m n: fD = 222.6+16.7+2.3-3.4 MeV D+  t n: limit, SM consistency Ds  m(t) n: fDs = 274+13+7 MeV Ds  t n (tenn): fDs = 278+17+12 MeV D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Motivation Direct access to CKM elements (Vcs,Vcd) High resolution measurement of q2 spectrum. Confronts form factor predictions.  Better extraction of Vxb from exclusive semileptonic B decays. Opportunity for first observations. D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Technique D-Tag event Identify electron Reconstruct the hadronic component Check for consistency with neutrino U=Emiss-|Pmiss| Signal component from fit to variable U From fit of Mbc and DE for number of tags CLEO III CLEO-c From Monte Carlo/Data D. Cronin-Hennessy, U of M Dp l n

D. Cronin-Hennessy, U of M D+ and D0 Tag Modes 281/pb (1.8M DDbar) D-Tagging Eff: ~10% for D+ ~15% for D0 Tagging provides absolute BR measurements with low backgrounds D. Cronin-Hennessy, U of M

First Observations of Cabibbo Suppressed Modes Preliminary (281/pb) D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Preliminary (281/pb) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Untagged D0 K(p) e n Uses neutrino reconstruction: Identify semileptonic decay. Reconstruct neutrino 4-momentum from all measured energy in the event. Use K(p), e, and missing 4-momentum and require consistency in energy and beam-energy constrained mass. Higher efficiency but larger backgrounds and larger systematics. Mbc distributions fitted simultaneously in 5 q2 bins to obtain d(BF)/dq2. Integrate to get branching fractions and fit to obtain form-factor parameters. D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M D0K(p) e n Summary Precision measurements from Belle, Babar, CLEO-c. Experimental uncertainties smaller than theory. D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Form Factors and Vcx From 281/pb, Preliminary Modified pole model used as example: Normalization uncertainty is 2%. Consistent with LQCD. CLEO-c prefers smaller value for shape parameter, a. D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Form Factors and Vcx From 281/pb, Preliminary Modified pole model used as example: Normalization uncertainty is 4%. Consistent with LQCD. D. Cronin-Hennessy, U of M

Exclusive Semileptonic Decays Form Factors and Vcx From 281/pb, Preliminary We measure |Vcx| f+(0) and use f+(0) From Becher-Hill Parameterization with FNAL/MILC/HPQCD D. Cronin-Hennessy, U of M

Inclusive Semileptonic Decays Motivation: BR(DXln) Precision measurement of lepton momentum spectrum. Compare Gsl(D0)/Gsl(D+) Test HQT with Gsl(D0)/Gsl(Ds) Technique: D-Tag Electron ID Gold DTags only K-p+ and K- p+p+ Charge correlation D. Cronin-Hennessy, U of M

Inclusive Semileptonic Decays From 281/pb B (D+Xe+n) = (16.13+0.20+0.34)% (S D+ exclusive =15.1 %) B(D0Xe+n) = (6.46+0.17+0.12)% (S D0 exclusive =6.1%) Gsl(D+)/Gsl(D0) = 0.985+0.028+0.015 PRL 97 251801 (2006) D. Cronin-Hennessy, U of M

Absolute Hadronic BR for D0, D+ and Ds We use the double-tag method for measuring BRs. Determines absolute BR scale for normalizing modes such as Kp, Kpp, KKp. Refinement of D meson simulation in B factory MC. Normalizes exclusive modes used in exclusive Vcb analyses. Provides a count of the DD-bar pairs produced. Results from Ecm=3770 MeV based on 281/pb Results from Ecm=4170 MeV based on 298/pb D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Double Tags Single Tag D+K-p+p+, 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. Doubly Tag D+K-p+p+ D-K+p-p- D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Results for D0 and D+ Accepted by PRD: hep-ex/0709.3783 DFSR shows the impact of ignoring final state radiation in the simulation. D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Data collected at Ecm=4170 MeV. 298/pb collected. Optimal energy for DsDs* production. Analysis same as for DDbar. Eight decay modes used in analysis. Single tag Ds mass plots shown left. Or order 1000 double tags (~3.5% statistical uncertainty). Ds Hadronic BRs D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Results for Ds Results based on 298/pb. Ds  f p in progress. Preliminary (298/pb) D. Cronin-Hennessy, U of M

D. Cronin-Hennessy, U of M Summary Leptonic: Presented results and updates on BR’s for D m(t) n, Dsm(t) n and associated decay constants. Semileptonic: Presented Exclusive and Inclusive semileptonic D decays, CKM elements and FF extractions. Hadronic: Presented significant improvements in the Ds and D hadronic BR. Opportunities for the future: Decay constants with uncertainties at the % level, rare semileptonic decays, improved FF measurements (p l n) D. Cronin-Hennessy, U of M