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D-meson results from CLEO “Rumors of my death are exaggerated”. –2003: CLEO re-incarnated (phoenix-like) into 3-4 GeV electron- positron collider. –First “CLEO-class” detector at charmonium energies –Continuing nearly 30 year physics program Longevity>U2 (but <Rolling Stones) –Scheduled to take data into 2008; expect active physics analysis program for additional five yrs. Focus here on updated D + (2005 pub.) plus recent results on semileptonic+hadronic D modes. THANKS TO DAVID ASNER, WERNER SUN AND ALEX SMITH, FROM WHOM I SHAMELESSLY LIFTED SLIDES WHOLESALE!
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CLEO-c Detector/CESR-c Accelerator SVX CLEO III Ability to run at cms energies from J/ up to (5S) Beam Energy (GeV) CLEO-III SVX Mini Drift Chamber CLEO-c (3770) ’’ Simple conversion of detector from (4S) to (3770) running; CESR reconfiguration now prohibits return to Upsilon system. Si low-mass tracking
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Running at the (3770) No extra energy for fragmentation particles –Known/coherent initial state –Clean neutrino reconstruction –Simple combinatorics Large cross section Good kinematic particle ID E cm ~ (3770)E cm ~ (4S) CLEO IIICLEO-c
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Overview of D-tagging techniques e e (3770) DD Kinematics analogous to (4S) BB: (M BC ) ~ 1.3 MeV, x2 with 0 ( E) ~ 7—10 MeV, x2 with 0 Single tag (ST): n i = N DD B i i Double tag (DT) : n ij = N DD B i B j ij –Ratio + algebra allows extraction of BR; eff cancels to 1 st order. Take advantage of low multiplicity, low backgrounds. Example: MC tracking, K 0 S, and 0 efficiency systematics: –Missing mass (MM) technique to compare data and MC. –Fully reconstruct entire event, but deliberately leave out one particle. –Fraction of MM peak where the last particle is found = efficiency.
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K not found (MC) K found (MC) Example: K eff from D 0 K + ≈ 91% in fiducial volume DKDK D D KXX Same tracking eff technique in earlier CLEO-II D Kpi analysis
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Leptonic Decays: D + →μ + ν Compare with lattice QCD predictions!
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f D+ from Absolute Br(D + ) 1 additional track ( ) Compute missing mass 2 : peaks at 0 for signal Tag D fully reconstructed Mark III PRL 60, 1375 (1988 ) ~9 pb -1 2390 tags ~33pb -1 5321 tags S=3 B=0.33 BESII Phys.Lett.B610:183-191, (2005)
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D Leptonic Decays: D + + Many large BR tag modes –~25% efficiency for reconstructing a tag Signal is very pure after tagging Roughly 30x BES sample Getting the ABSOLUTE branching fractions... “Other side D” tag e+e+ e-e- Signal D ++ Tag D Tag D decay modes: – Fit for (“missing mass”) 2 :
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Compare with previous results & Lattice Calcs Since f D measures w.f. overlap at origin, expect comparable (slightly smaller than) f Ds
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Semileptonic Decays c e+e+ e W+W+ |V cs |, |V cd | Test LQCD on shape of f + (q 2 ) Use tested Lattice for norm. Extract |V cd | Extract B(D Xe ) D FF related to B FF by HQS Precise D FF’s can lead to reduced theory in |V ub | at B factories Same holds for D Vln, except 3 FF’s enter
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Exclusive Semileptonic D Meson Decays Reconstruct one D meson in hadronic tagging channel – Reconstruct the remaining observable tracks Use the missing energy (E miss ) and missing momentum (|P miss |) in the event to form kinematic fit variable for the neutrino Technique: From fit of M bc and E for number of tags Signal component from fit to variable U From Monte Carlo/Data Both flavors combined:
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K-K- -- e+e+ K+K+ Semileptonic Decays Tagging creates a single D beam of known 4-momentum Semileptonic decays are reconstructed with no kinematic ambiguity Hadronic Tags: 32K D + 60K D 0 Events / ( 10 MeV ) (~1300 events) U = E miss – |P miss | (GeV)
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D + semileptonic results (including omega!) D 0 semileptonic results – note wrt PDG
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M BC (log scale) for ST modes: D+D Double Tag Analysis gives Had BR’s ModeN D (10 3 ) D (%) KK 5.11±0.075.15±0.0765.1±0.2 K 9.51±0.119.47±0.1131.6±0.1 K 7.44±0.097.43±0.0943.8±0.1 K 7.56±0.09 51.0±0.1 K 2.45±0.072.39±0.0725.7±0.1 K0sK0s 1.10±0.041.13±0.0445.7±0.3 K 0 s 2.59±0.072.50±0.0722.4±0.1 K 0 s 1.63±0.061.58±0.0631.2±0.1 KK 0.64±0.030.61±0.0341.1±0.4 All D 0 DT 2484 ± 51 All D + DT 1650 ± 42
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Double Tag Analysis: Fit Results Fit includes both statistical and systematic errors (with correlations) [arXiv:physics/0503050]. Precision comparable to PDG WA. (systematic) ~ (statistical). –Many systematics measured in data, will improve w/time. Simulation includes FSR, so we measure B (final state + n ). –Using efficiencies without FSR correction would lower B. N DD includes continuum and resonant production. ParameterValue no FSR NDDNDD (2.01±0.04±0.02)x10 5 -0.2% B(K+)B(K+) (3.91±0.08±0.09)%-2.0% B(K+)B(K+) (14.9±0.3±0.5)%-0.8% B(K++)B(K++) (8.3±0.2±0.3)%-1.7% ND+D-ND+D- (1.56±0.04±0.01)x10 5 -0.2% B(K++)B(K++) (9.5±0.2±0.3)%-2.2% B(K++0)B(K++0) (6.0±0.2±0.2)%-0.6% B(KS+)B(KS+) (1.55±0.05±0.06)%-1.8% B(K0S+0)B(K0S+0) (7.2±0.2±0.4)%-0.8% B(K0S+-+)B(K0S+-+) (3.2±0.1±0.2)%-1.4% B(K+K+)B(K+K+) (0.97±0.04±0.04)%-0.9% (D0D0)(D0D0) (3.60±0.07 +0.07 -0.05 ) nb-0.2% (D+D-)(D+D-) (2.79±0.07 +0.10 -0.04 ) nb-0.2% (+-)/ (00) 0.776±0.024 +0.014 -0.008 +0.0%
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Comparison with PDG 2004 Measurements and errors normalized to PDG. PDG global fit includes ratios to K - + or K - + +. No FSR corrections in PDG measurements. Our measurements also correlated (statistics and efficiency systematics). B(D0 K-+)B(D0 K-+) B (D + K - + + ) Other direct meas. Overall C.L 25.9%
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M BC distributions in E signal region and E sidebands D → n( + ) m( 0 ) Study Cabibbo-suppressed D decays with single tags only. –Double tag technique not as profitable—statistics too low. –Normalize B s to ref. modes. MC tuned to match mass spectra in data. Bkgnd from Cabibbo-favored decays with K 0 S → + -, 0 0. –Veto M( ) near K 0 S mass. D0D0 D+D+ M(+-)M(+-) M(00)M(00) Reference modes
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X-checked with search including
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What’s coming? Results on CP-modes, Dalitz analyses & rare decay modes, Via scan, have found “optimal” run energy for production of D s mesons…beginning to accumulate tag sample; apply D-reconstruction machinery to D s, Immediate D s goals: high-precision msrmnt of normalizing mode ( semileptonic modes (CF and CS), rare modes “tailored” for threshold msmrnts (p-nbar, e.g.)
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Tags Invariant Masses from the 4160 & the 4180 MeV DATA 233 16 150 1897 19 304 22 227 5370 1082 1556 15 Total # of Tags = 1219 ± 67(stat) ss K * K -
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Impact of CLEO-c Measurements Calibration and validation of Lattice QCD Test theoretical form factor calcs. and models –Impacts prediction of form factors for B meson decays Measurements of |V cs | and |V cd | Improved decay constants f B possible from CLEO-c f D measurement + LQCD Improved measurement of many important normalization modes e+e+ W+W+ Electroweak Physics Strong Physics
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CLEO-c Impact on Unitarity Triangle Now: Theory uncertainties dominate With few % theory errors made possible by CLEO-c and 500 fb -1 each from the B factories:
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CLEO-c + Lattice QCD +B factories + ppbar CLEO-c + Lattice QCD +B factories CLEO-c Future of Precision Flavor Physics Vub/Vub~15 5% l B l D Vcd/Vcd~7 1.1% l D Vcs/Vcs~16 1.4% l B D Vcb/Vcb~5 3% BdBd BdBd Vtd/Vtd~36 5% BsBs BsBs Vts/Vts~39 5% Vtb/Vtb~29% Vus/Vus~1% l Vud/Vud~0.1% e p n t b W Goal: Measure all CKM matrix elements and associated phases in order to over-constrain the unitary triangles
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