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Measurements of Hadronic, Semileptonic and Leptonic Decays of D Mesons at E cm =3.77 GeV in CLEO

Measurements of Hadronic, Semileptonic and Leptonic Decays of D Mesons at E cm =3.77 GeV in CLEO. Steven Blusk Syracuse University. CLEO- c. Outline Introduction Hadronic Branching Fractions Semileptonic Decays D +  m + n m Conclusion. CESR-c/CLEO-c.

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Measurements of Hadronic, Semileptonic and Leptonic Decays of D Mesons at E cm =3.77 GeV in CLEO

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  1. Measurements of Hadronic, Semileptonic and Leptonic Decays of D Mesons at Ecm=3.77 GeV in CLEO Steven Blusk Syracuse University CLEO-c Outline • Introduction • Hadronic Branching Fractions • Semileptonic Decays • D+m +nm • Conclusion Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  2. CESR-c/CLEO-c • The CLEO program has migrated from running on the  resonances to the region around the y(3770) Charm factory to study D, Ds mesons -- Broad program of charm physics (3 fb-1 goal) • Additional running at J/y (search for exotics in radiative decay) in year 3 CLEO-c • Tracking (93% of 4p): • 16 axial, 31 stereo layers • sp/p ~ 0.6 % • CsI (93% of 4p): • 6144 crystals (barrel only): • sE/E ~ 5% at 100 MeV ~2.2% at 1 GeV • Particle ID • RICH (80% of 4p) + dE/dx • eK>90% for pfake<5% Inner DriftChamber Accelerator changes - installation of SC wigglersto improve damping  higher L CLEO-c detector largely same as CLEO-III, • Silicon replaced with drift inner chamber • B field reduced from 1.5T1.0T Log y’ y(3770) Ebeam Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  3. Some highlights of the CLEO-c Charm Program • Precision measurements of D branching fractions • Precise measurements of fD and fDs, the D decay constants. • When combined with LQCD will enable ~5% determinations of Vtd and Vts • Pave the road for a more accurate extraction of Vub • Measurements of Dpln and Drln form factors will provide “tested”lattice QCD predictions on heavy-to-light FFs. • Extraction of |Vcd|, |Vcs| • Unitarity Triangle • Once Vub& Vtd are measured to O(5%)  Allows for a stringent test of CKM angles (ie., sin2b) vs sides Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  4. e+e-y(3770)DD CLEO & D Tagging • Pure DD final state, no additional particles (ED = Ebeam). • Low particle multiplicity ~ 5-6 charged particles/event • Good coverage to reconstruct n in semileptonic decays • Pure JPC = 1- - initial state • Tag one D meson in a selected tag mode. • Dictates whether final state is D+D- or D0D0 • Study decays of other D, (signal D) K Dsig e+ e- Dtag p p ED Ebeamimproves mass resolution by ~10X Analysis Preview • Hadronic BF: Use double-tagged and single-tagged yields • Semileptonic decays: Dtag + (DsigXene), reconstruct ne using Pmiss • Leptonic Decays: Dtag + (Dsigmnm) Analyses shown today based on 57 pb-1 Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  5. D e+ e- D Since eij  ei ej, correlated systematics cancel in NDD D0 K+p- D0 K+p-p0 D0 K+p-p-p+ To first order, Bi is independent of tag modes’ efficiencies, s, L. • NDD and Bi’s extracted using a c2 minimizationtechnique • Validated on toy MC and 50X simulated data. Absolute D Hadronic Branching Fractions Single Tags: Reconstructed one D meson Double Tags: Reconstruct both D mesons D0 K-p+ D0 K-p+p0 D0 K-p+p+p- D+ K-p+p+ D+ K-p+ p+p0 D+ Ksp+ D+ Ksp+p0 D+ Ksp+p+p- D+ K-K+p+ D- K+p-p- D- K+p- p-p0 D- Ksp- D- Ksp-p0 D- Ksp-p-p+ D- K-K+p- Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  6. D+ Modes D0 Modes Fits to Data Signal shape includes: • y(3770) line shape, ISR, beam energy spread & momentum resolution Kp Kspp0 Kpp Ksppp Kpp0 Kppp0 Ksp * Efficiency includes FSR losses KKp Kppp Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  7. Systematic Uncertainties Tracking, p0 and Ks all use similar “missing mass” technique. • For pion: • Look at mass recoiling against J/yp in y’J/yp+p- events  Peak at Mp2 for J/yp+p-. • Count the number of times the track is found versus not found. p track not found p track found MC DATA Uncertainty  0.7% / (p/K) Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  8. to be submitted to PRL Preliminary Results D+ Modes D0 Modes Normalized to PDG As many of the systematics are evaluated using data, they will shrink as L Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  9. Semileptonic Decays e |Vcs| , |Vcd| e+ W+ c • Test LQCD on shape of f+(q2)Use tested Lattice for norm. From B(DXen) extract |Vcd| • Dp FF related to Bp FF by HQS  Precise Dp FF’s can lead to reducedstheory in |Vub| at B factories • Similar for DVln, except 3 FF’s enter • Can also form ratios, where theory should be more precise LQCD, PRL 94, 011601 (2005) Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  10. K- p+p0p0 K-p+p0 K-p+ Dtag K- p+p+p- KSp+ p- p0 KSp+p- y(3770) e+ e- K-K+ p-p+p0 KSp0 ( ) ( ) X = K, K*, p, h, r, w • Require no extra tracks in event • Average X and X modes • Reconstruct n from pmiss Fit to U distribution Efficiencyfrom MC Fit to MBCdistributions D0 Tag Modes Basic Technique MBC Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  11. Pseudoscalar Modes: D  Pene cdCabibbo Suppressed csCabibbo Favored (~110 events) (~1400 events) Events / ( 10 MeV ) Events / ( 10 MeV ) U = Emiss– |Pmiss| (GeV) U = Emiss– |Pmiss| (GeV) (~60 events) (~500 events) Events / ( 10 MeV ) Events / ( 10 MeV ) U = Emiss– |Pmiss| (GeV) U = Emiss– |Pmiss| (GeV) Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  12. 57 pb-1 Data Vector Modes: D  Vene csCabibbo Favored First Observations First Observation cdCabibbo Suppressed (~30 events) (~90 events) U = Emiss– |Pmiss| (GeV) (~8 events) (5s) (~30 events) (~400 events) U = Emiss– |Pmiss| (GeV) Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  13. Ratio CLEO-c PDG - - - CLEO-c goal (3 fb-1): - Assuming sFF’s to ~3% from LQCD, 3 fb-1 • dVcd/Vcd~1.7% from Dpen • dVcs/Vcs~1.6% from DKen Preliminary Results to be submitted to PRL Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  14. Inclusive SemileptonicElectron Spectra CLEO-c Preliminary D0& D+ Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  15. Leptonic Decay G(Btn) ~ 10-4 – 10-5 difficult Goal: Extract fD, and eventually fDs (with precision)  Test LQCD, if it passes then trust it in predicting fB, fBs  Critical to measuring |Vtd|/|Vts|, one of the sides of the UT Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  16. Tag D e+ e- Form a “missing mass” (= 0 for n) m+ Signal D n • Require 1 additional track from IP (cosq < 0.8) • Momentum too low for m system, require Ecal<300 MeV • No additional showers with E>250 MeV Test on Ksp, by ignoring the Ks Data “Extra” shower energy-studied with double-tagged events Data MC MC Energy deposition of muons MM2(Ksp) The Technique Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  17. BES • CLEO-c • Lattice 2004 • Isospin Mass Splittings • Potential Model • Rel. Quark Model • QCD Sum Rules • QCD Spectral Sum Rules • MILC • UKQCD CLEO-c Yellow Book: 1 fb-1 MostlyKLp±background Results 8 events DATA Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  18. Summary • CLEO-c is off to a great start. • With only 57 pb-1 on y(3770) (3 fb-1 proposed), measurements are already comparable or better than world average. • Many more analyses are in the pipeline which I haven’t had timeto discuss. • Many more exclusive BR’s being investigated • Several variants of inclusive and exclusive SL analyses • Techniques for estimating systematics established using data. • With more data, they will be reduced. • Look forward to many precision results in charm physics comingfrom CLEO. Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  19. Backup Slides Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  20. Particle ID • Use modes where the particle content is unambiguous. • For p: D+K-p+p+, D0Kspp, D0Kpp0 • For K: D+K-p+p+, D0Kpp0 • Then apply tagging requirements • If both p & K hypotheses analyzed, • 3s dE/dx consistency, and • D = ( s(dE/dx)p2 -s(dE/dx)K2 + LogLik(p)- LogLik(K)< 0 (Ng>2) • Drop RICH if: • RICHDONE is false, or, p(p)<0.55 GeV/c, or |cosq|>0.8 Correction applied: (0.3±0.3)% for p and (1.3±1.3)% for K Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  21. D Hadronic Systematics • DE requirement: compare yields with & without DE cut (1.5%) • FSR: Validated using J/ymm, conservatively 0.5% for ST, 1% for DT • G3770: Lowe from 30.6 MeV 23 MeV and take shift in data as systematic (0.6%) • Resonant substructure: affects efficiencies, depending on mode: 0.4 – 1.5% • Trigger efficiency: trigger simulation  0.1%(Ksp) & 0.2% (K-p+p0) • Multiple candidates: • Multiple candidates can result in choosing the wrong combination resultingin a loss in efficiency. • MC does not model the number of multiple candidates/event well. • Affects modes with p0’s: • 1.30% for Ksp+p0, 0.44% for K-p+ p+p0, 0.32 for K-p+p0 • Double DCSD: Unknown relative phase between DCSD & CAD amplitudes (0.8%) • Fit functions: 0.5% • Data processing 0.3% • Quantum (CP) correlations: Negligible Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  22. Candidate withbest (MD+MD)/2 CBX 05-06, A. Ryd. Yield Extraction in D Hadronic • Signals are fit using: • y(3770) line shape, ISR, beam energy spread, momentum resolution(G3770 set to 30.6 MeV, as determined from data; reduced to WA for systematics) • Fit double tags first, using DX / DX, then fit single tags with sig pars fixed • Disentangle momentum resolution from beam energy spread • Signal Resolution (Signal MC) (5 parameters per D) • 3 Gaussian widths (s1,s2,s3) 1.5s1< s2< 4s1 1.5s2< s3< 4s2 • Two fractions: f2, f3, (1-f2-f3) • Fixes resolution for double &single tag fits in MC & data Beam Energy, inc. ISR Signalregion All candidates • Background • 1 correct D +1 incorrect D (fsig * ARGUS) • Mispartitioning of daughters ARGUS(<M>)*GAUSS(DM) • Both D’s are background ARGUS(MD1)*ARGUS(MD2) Kpp0 Kpp0 Double TagFit to Signal MC Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  23. Branching Fraction Fitting CBX 04-36 (W. Sun) Corrected yields are given by: • n = Raw yields of single & double tags • b = estimated backgrounds from “other” D modes • N = Fitted yields of single & double tags ~ NDD*Bi • E = Efficiency matrix • diagonal elements are efficiencies • off-diagonal are cross-feed probabilities • F = background probability matrix Test using Toy MC- 3 neutral + 2 charged modes - no biases- proper error estimation V is the variance matrix, and contains both statistical & systematic uncertainties Since eij  ei ej, correlated systematics cancel in NDD To first order, Bi is independent of tag modes’ efficiencies. Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  24. Backgrounds Single Tags “External” – Not simulated in MC Cross-feed Double Tags: assumeonly 1 fake contributes, since P(2 fakes) very small Backgrounds that are dependent on fit parameters, ie., NDD, are updated after each iteration.. Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  25. Backgrounds - II MBC distributions for generic MC after signal modes and backgrounds considered are removed MBC distributions for non-DD MC Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  26. Fit to Generic MC(50X Data!) Worst difference is 2.1s, for Kpp But this is for 50X data  Scale by 50 for data  0.3sstat. Deemed acceptable by committee, and noted in PRL. Steven Blusk, Syracuse University Recontres de Moriond, March 2005

  27. D0→K-e+ν D0→π-e+ν D0→K*-e+ν Form Factor Shapes No efficiency corrections, resolution ~ 0.025 GeV2 Future goal: slopes ~ 4%, form factors over all q2 Steven Blusk, Syracuse University Recontres de Moriond, March 2005

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