Recent (Charm) Electroweak Results from CLEO Content I: The CESR-c and the CLEO-c Experiment. II: Leptonic D decays. III: Semileptonic D decays: Exclusive IV: Semileptonic D decays: Inclusive V: Inclusive BF of D Xln and ln VI: CPV from CLEO II.V VII: Summary & Future. Moriond EW session March 5-12, 2005 La Thuile, Italy Doris Y. Kim University of Illinois Urbana-Champaign 3/11/2005 CLEO / Doris Kim

I. The Cornell Electron Storage Ring (CESR) The size of CESR 768m long. Wigglers increase the synchrotron radiation -> damping the beam -> increase luminosity, Added 12 superconducting wigglers to CESR for low energy running. Ebeam = 1.5 – 5.6 GeV 3/11/2005 CLEO / Doris Kim

The CLEO-c Detector Run plan: ´, (3770) and Ds, J/  thresholds. CLEO-c  CLEO III det. New inner drift chamber replaced old silicon vertex 1T B field (old 1.5 T) Track (93% of 4p): s = 0.6% @ 1 GeV PID: Rich (80% of 4p), dE/dx, EM calorimeter, muon (> 1GeV) E: s = 2.2% @ 1 GeV, 5% @ 100 MeV. Don’t stay too long here. Just mention the new inner draft chamber. 1) inner drift = six-layer stereo wire 2) Drift = 47 layers 3) 7800 CsI Cal. 95% of 4pi 3/11/2005 CLEO / Doris Kim

Impact of CLEO-c Measurements  W+ Electroweak Physics: Vcq An example of semileptonic decay QCD: form factors D Leptonic decays give fD and fDs validate Lattice QCD and improve fB Semileptonic decays give Vcs, Vcd and form factors test theoretical form factor models enhance LQCD calculations, which will improve B decay form factors. test CKM unitarity. Improved (already) BF measurements of many important normalization modes and more coming. Hadronic decays measure strong phases, needed for CPV. Initial state is coherent: Ideal for charm mixing and CPV. 3/11/2005 CLEO / Doris Kim

The Future of Precision Flavor Physics The Goal: Measure all CKM matrix elements and associated phases in order to over-constrain the unitary triangles. CLEO-c + Lattice QCD +B factories Vub/Vub 5% l n B p D Vcb/Vcb 3% Vud/Vud 0.1% Vus/Vus 1% Vub/Vub 15% n  K l e n p l n B p CLEO-c Vcd/Vcd 1.7% Vcs/Vcs 1.6% l n D p K Vcd/Vcd 7% Vcs/Vcs 16% Vcb/Vcb 5% l n D p l n D K l B n D CLEO-c + Lattice QCD +B factories + ppbar Bd Vtd/Vtd 5% Bs Vts/Vts 5% Vtd/Vtd 36% Vts/Vts 39% Vtb/Vtb 29% t b W Bd Bs 3/11/2005 CLEO / Doris Kim

(3770) Analysis Techniques  K- Fully reconstruct 1st D “the tag”, then analyze decay of 2nd D to extract exclusive or inclusive properties. K+ - e+ (3770) ~ DDbar threshold No extra fragmentation = simpler geometry / combination Clean neutrino reconstruction High tagging efficiency at 25% of all D’s produced. This method is quite effective for absolute branching fraction studies. 3/11/2005 CLEO / Doris Kim

Examples of CLEO-c Tagged D samples ~60,000 tagged D0 decays From Dec 03 to Mar 04, we collected the first 60pb-1 @ 3770 MeV with 6 wigglers, corresponding to 360,000 DDbar pairs. Basic selection / fit variables are … If there are multiple candidates, choose the smallest delta E one. Delta E cut between 25 ~ 30 MeV. Ddbar pairs: Neutral 200,000 charged 160,000 Selected 32,000 charged D tags Signal: Gaussian + bifurcated Gaussian Background: ARGUS function Preliminary MBC plots from semileptonic BF study 3/11/2005 CLEO / Doris Kim

II. Leptonic Decays: D+m+n A “D hadronic tag” is required. An additional charged track as m+ and no extra shower > 250 MeV as a signal. Fit “missing-mass”2 Tag D n m+ Signal D ~60 pb–1 Yellow Book Phys. Rev. D, 70, 112004 (2004) 8 signal candidates We don’t need muon ID detector. 1fb-1 3/11/2005 CLEO / Doris Kim

fD from Absolute Br(D+  m+n) |VCKM|2 Vcd (1.1%) from 3 generation unitarity tD+ (0.3%) well-measured The first CLEO-c paper published. Phys. Rev. D, 70, 112004 (2004) Based on 60 pb–1, 28651 tags and 8 signal events. Background is ~ one event. BES Lattice 2004 CLEO-c Isospin Mass Splittings Potential Model Rel. Quark Model QCD Sum Rules QCD Spectral Sum Rules MILC UKQCD LQCD error 10% / CLEO-c error 22%. BES f(D) = 371+129 –119 + 25 MeV Mark III <290 MeV BES I: 1 event (1998) BES II: 3 events (2004) fD ~ 371 MeV ICHEP 2004 3/11/2005 CLEO / Doris Kim

III. Exclusive Semileptonic BF.  W+ Vcq Analysis Techniques c MC Fit to U q D P, V Fit to MBC Reconstruct one hadronic D tag. Reconstruct a semileptonic signal candidate from the remaining tracks/showers. Fit kinematic variable U ( = Emiss – |Pmiss| ) for the missing neutrino of the signal. Decay rate for D  P Analysis going on in two steps: First, BF study. Second, FF study. EID efficiency: 50% at 200 MeV, 95% above 300 MeV. mis-ID rate of Kaons and pions into e =0.1% Kaon/Pion : efficiecy 95%, a few percent mis-ID, Since the kinematic constraint given by the threshold geometry and the detector resolution gives a good filter performance, we don’t need a tight selection cut set. Pi0 ID: +-3 sigma mass Ks ID: +-12 MeV within Ks mass Latest LQCD, PRL 94, 011601 (2005) 3/11/2005 CLEO / Doris Kim

Signal Candidates of Neutral Semileptonic Modes. Cabibbo favored modes Cabibbo suppressed modes The first 60pb-1 (~1400 events) (~110 events) (~90 events) First Observation Signal function = Gaussian + Crystal Ball function (asymmetry due to ISR/FSR). Background function = multinomial (~30 events) Preliminary U ( = Emiss – |Pmiss| ) plots 3/11/2005 CLEO / Doris Kim

Signal Candidates of Charged Semileptonic Modes. Cabibbo favored modes Cabibbo suppressed modes (~60 events) (~500 events) Events / ( 10 MeV ) Events / ( 10 MeV ) This is the brand new preliminary result. (~400 events) Events / ( 10 MeV ) Events / ( 10 MeV ) (~30 events) Preliminary U ( = Emiss – |Pmiss| ) plots The first 60pb-1 3/11/2005 CLEO / Doris Kim

The Preliminary Exclusive BF. (8 events) World First Observation Events / ( 10 MeV ) The first 60pb-1 Preliminary Preliminary U ( = Emiss – |Pmiss| ) Omega decaying into pi+ pi- pi0 Note the 30% increase of BF in the D+ -> Ks e nu channel. It is a 2-sigma effect. Ref) D+ -> K mu nu mode: FOCUS: 9.27 +- 0.69 +- 0.59 +- 0.61 vs PDG 2004: 7.0 + 3.0 – 2.0 % 3/11/2005 CLEO / Doris Kim

Or We Can Do Without D Tagging! With D Tag, we have cleaner signal sample, but we loose statistics. What if we do not use D Tagging? Let’s try for D  K/p e n decays. Require a signal: one e± and one K or p Assume the other tracks/showeres are coming from the other D, ID them using dE/dx, RICH and EM calorimeter information.  Calculate Pmiss Fit on E, MBC Check number again! Plots for D+ tagging modes needed! Signal MC Background MC 3/11/2005 CLEO / Doris Kim

Semileptonic Events without D Tagging D+D- Bkgd t MC Cont MC Fakes K  e n p e n p0 e n KS(p+p-) e n K0other e n Bkgd Data D+D- Bkgd t MC Cont MC Fakes p  e n K e n p0 e n KS(p+p-) e n K0other e n Bkgd Data Preliminary D+D- Bkgd t MC Cont MC Fakes KS(p+p-) e n p0 e n p e n K e n K0other e n Bkgd Data D+D- Bkgd t MC Cont MC Fakes p 0 e n KS(p+p-) e n p e n K± e n K0other e n Bkgd Data Left column cabibbo suppressed. Should mention why we fit all four modes together ... I.e. backgrounds. 3/11/2005 CLEO / Doris Kim

IV. Inclusive Semileptonic BF. Preliminary P(e+) spectra PDG(2004) B(D0  X e+ n) = 6.87 ± 0.28 % PDG(2004) B(D+  X e+ n) = 17.2 ± 1.9 % Analysis Techniques Reconstruct one hadronic D tag. Signal e+ : ID’d by dE/dx, RICH and E/p calorimeter Right/Wrong sign defined by K charge for D0, signal side charge for D+  background subtraction by wrong sign events. Both charm and beauty physics needs precise decay spectrum of charm particles in their MC. Inclusive BF is an excellent channel to test MC. HQET predicts slightly different endpoint behavior between D0 and D+. Cut off at 200 MeV: low efficiency, high background due to gamma conversion, pi0 Dalitz decay, etc. These plots have all the background subtractions and efficiency correction except the final state radiation correction. CLEO-c (in D rest frame) Cut-off 3/11/2005 CLEO / Doris Kim

Expected Uncertainty from the First 60 pb-1 tag mode tag mode Preliminary No BR yet 3/11/2005 CLEO / Doris Kim

V: Inclusive BF of D Xln, ln Electron and Neutrino Spectra are Different! Conservation of angular momentum  n get boost from W+ in the lab frame. s e+ W+* Low Q2 Analysis Techniques Reconstruct one hadronic D tag. Signal side: ID’d by dE/dx, RICH and E/p calorimeter, than add all. Get Pmiss and Mmiss^2. KL suppression is important. This analysis is lepton flavor blind. We study spin correlations to determine favorable and suppressed directions for neutrino. The top diagram is favored, the neutrino will get a boost from the W+* compared to the electron in the lab frame. 3/11/2005 CLEO / Doris Kim

MC Example of Emiss Spectra Red = signal Blue = background Black = Red + Blue D0 MC D± MC D±  ln Zero supressed due to minP cut, and V cut Point out D -> munu Emiss(GeV) Emiss(GeV) 3/11/2005 CLEO / Doris Kim

The Inclusive D  Xln, ln Candidates MC Data 60 pb-1 Missing Energy (GeV) KL Background KL Background Signal This is the N-1 cut plot, to show you the reliability of our selection. Missing energy = neutrino energy. Missing mass^2 = cut variable. 0.25 (GeV)^2 means Klong Signal 3/11/2005 CLEO / Doris Kim

VI. CPV search in D0  Ks p+ p- from CLEO II.V D0 + D0bar D0 - D0bar PRL 92, 142001 (2004) D0 / D0bar tagged by D*  D0 p+(slow). Standard Model prediction at 10–6 for this channel from K mixing.  sensitive to new physics Dalitz technique studies decay amplitude, not decay rate.  sensitivity increase. M(Ks p-) M((p+ p-) Get mixing numbers from David Asner. The plots are not fits, but the projections of the actual fits. M(Ks p+) 3/11/2005 CLEO / Doris Kim

VII: Summary and Future New results on BF D+  mn and fD (2) Exclusive BF of semileptonic decays coming (pretty) soon. With just 60 pb-1, stastistical power of many decay modes already at the world best. The world first events of and We have two analysis options available: With and wo DTag (3) Inclusive BF of D Xen and D Xln, ln coming. (4) Currently we are running at (3770) with 12 “8-pole” wigglers. More data is coming on (3770), Ds threshold, etc. Vub : Currently, both exclusive and inclusive analyses are going on based on CLEO II, II.V, III data (9 + 6 fb-1). fDs 3/11/2005 CLEO / Doris Kim

Question slides 3/11/2005 CLEO / Doris Kim

CLEO-c Impacts on the Unitarity Triangle Now: Theory Uncertainties Dominate Future: With CLEO-c, improved LQCD and 500 fb-1 each from the B factories 3/11/2005 CLEO / Doris Kim

Electron Spectrum of Inclusive Events time Very Preliminary CLEO-c (in D rest frame) 3/11/2005 CLEO / Doris Kim

Charged D Meson Tags – Distributions of Mbc ~30,000 tagged D± decays Examples only .... Other modes similar Preliminary MBC plots from semileptonic BF study 3/11/2005 CLEO / Doris Kim