Recent Results from CLEO and Plans for CLEO-c

Transcription

1 Recent Results from CLEO and Plans for CLEO-c David G. Cassel Cornell University and DESY Hamburg Outline ntroduction CESR, CLEO, and Data Samples b sγ Branching Fraction and Eγ Spectrum Vcb from Moments of B Xcl ν and b sγ Decays Vub from nclusive Leptons and the b sγ Spectrum Preliminary Vcb from B D l ν Decay Preliminary B Kπ and B ππ from CLEO Preliminary Other Recent CLEO Results CLEO-c and CESR-c Summary and Conclusions David G. Cassel NKHEF Nov 2,

2 ntroduction Quark Decay in the Standard Model Leptons ν e e ν µ µ ν τ τ Q/e 0 1 W Quarks u d c s t b +2/3 1/3 W For Q = 1/3 quarks, the unitary CKM matrix relates q weak eigenstates to q strong eigenstates d s b = Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb Leptons and quarks decay via W emission Relative couplings for quark decay are elements of the CKM matrix d s b l νlw l qd quw qd qu qdw + qu W 1 W Vquq d W V quq d νl qu qd David G. Cassel NKHEF Nov 2,

3 Wolfenstein approximation, CP Violation, and the Unitarity Triangle Vud Vus Vub Vcd Vcs Vcb Vtd Vts Vtb = λ2 λ λ 3 A(ρ iη) λ λ2 λ 2 A λ 3 A(1 ρ iη) λ 2 A 1 λ = 0.22 A = 1 η 0 SM C P Apply unitarity to columns 1 and 3: VudV ub + V cdv cb + V tdv tb = 0 defines a triangle in the complex plane: CP is conserved in the SM if the area of the triangle is zero The triangle apex is at (ρ, η) in the ρ η plane in the Wolfenstein approximation VudV ub γ α VtdV tb VcdV cb β V ub /(λv cb ) (ρ, η) γ α Vtd/(λV cb ) β 0 1 Conventional B decay measurements determine the lengths of the nontrivial sides Some CP violation asymmetries in B decay determine angles of the triangle nconsistency between sides and angles would imply CP Violation beyond the SM David G. Cassel NKHEF Nov 2,

4 * David G. Cassel NKHEF Nov 2, B S K S B c B K B + 0 D cp K + B K S V cd V cb V ud V ub * V td V tb * B B B 0 B 0 mixing B b u B Understand B decays Measure B branching fractions accurately B Physics Program Goals Study Standard Model CP violation in B decay Search for CP violation beyond the Standard Model Search for New Phenomena beyond the Standard Model Measure the sides and angles of the CKM unitarity triangle Goals of B Physics Programs

5 David G. Cassel NKHEF Nov 2, Theoretical Uncertainties dominate the widths of all bands except ACP (ψks). 0.1 m V V 0.2 K K d 0.7 A CP ψ S ) s A ( ) CP ψ K S 0.8 Regions in the ρ-η plane allowed by current measurements Allowed Regions in the ρ-η Plane

6 David G. Cassel NKHEF Nov 2, CHESS CHESS CLEO RF RF e + Linac Converter e P Gun Electrons Positrons Horizontal Separators Electron njection Point Positron njection Point e + Transfer Line e Transfer Line Synchrotron CESR Storage Ring Schematic CESR Layout Bunch Trains in CESR CESR

7 David G. Cassel NKHEF Nov 2, CLEO Microbeta 7 Bunches b c 10 5 CLEO.5 CESR Upgrades New Tracking 1 R 10 6 BB Mixing b u CLEO Crossing Angle 9X3 Bunches BB / Year CLEO b X s 3.5cm BP s K, K / Cs SC R Quads SC RF He-propane 2cm BP Silicon CLEO 10 8 CLEO Physics CLEO Upgrades Particle D New Tracking CLEO ntegrated Luminosities Brief History of CESR and CLEO

8 The CLEO.V Detector and CLEO Collaboration 25 CLEO nstitutions Helium Reservoir Muon Chambers Superconducting Coil Barrel Shower Detector Drift Chamber SVX Detector Micro-Beta Quadrupole Vertex Detector End Cap Time of Flight Pole Tip Shower Detector Time of Flight Scintillators Magnet Yoke CalTech, UC San Diego, UC Santa Barbara, Carnegie Mellon, Cornell, Florida, Harvard, llinois U-C, Carleton, thaca College, Kansas, Minnesota, SUNY Albany, Ohio State, Oklahoma, Pittsburgh, Purdue, Rochester, Southern Methodist, Syracuse, UT Austin, UT Pan American, Vanderbilt, Virginia Polytechnic, Wayne State 160 Physicists raf Meters David G. Cassel NKHEF Nov 2,

9 CLEO Data Samples Detector Υ(4S) Continuum B B Events fb 1 fb 1 (10 6 ) CLEO CLEO.V Subtotal CLEO Total CLEO data are used in the B 0 D + l νl analysis CLEO and.v data are used in most other analyses CLEO data are used in the new B Kπ(ππ) analyses David G. Cassel NKHEF Nov 2,

10 b sγ Decays γ b B q t W s Xs q Radiative penguin diagram nclusive B(b sγ) is sensitive to charged Higgs, anomalous W W γ couplings, and other New Physics (NP) beyond the Standard Model (SM) NP can appear as additional contributions to the loop B(b sγ) calculated to next-to-leading-log order With confidence B(b sγ) and the Eγ spectrum of b sγ can be related to observed B Xsγ decays Exclusive B(B K ( ) γ) are sensitive to hadronization effects and therefore insensitive to NP David G. Cassel NKHEF Nov 2,

11 b sγ Decays CLEO published the first measurement of B(b sγ) in 1995 This update uses the full CLEO and.v data sample. Factor of 3 more data than the previous CLEO analysis Signal is an isolated γ with 2.0 < Eγ < 2.7 GeV ncludes essentially all of the Eγ spectrum Previously used 2.2 < Eγ < 2.7 GeV Much less model dependence now David G. Cassel NKHEF Nov 2,

12 b sγ Decays Search for an isolated γ with 2.0 < Eγ < 2.7 GeV Above about 2.3 GeV most backgrounds are γs from nitial State Radiation or π 0 s from continuum events Reduce huge background with event shapes and energies in cones relative to pγ Xs pseudoreconstruction presence of a l in the event Combine all information into a single weight between 0.0 (continuum) and 1.0 (B Xsγ) David G. Cassel NKHEF Nov 2,

13 David G. Cassel NKHEF Nov 2, E (GeV) 0 Large continuum data sample is essential for this analysis Then subtract B B background Weights / 100 MeV 200 On - Scaled Off Data BB Prediction ( b ) On Resonance Scaled Off Resonance ( a ) Utilizing weights: Subtract Off-Υ(4S) (continuum) data from On-Υ(4S) data Note that subtracted data agree: with B B background below 2 GeV and with 0 above 3 GeV b sγ Decays

14 David G. Cassel NKHEF Nov 2, Weight distribution after subtracting continuum and B B backgrounds E (GeV) Conclusions: CLEO errors close to theoretical uncertainty. There is not much room for New Physics. Weights / 100 MeV 0 B(b sγ) = (3.73 ± 0.30) 10 4 (Gambino-Misiak) 40 Theory: B(b sγ) = (3.29 ± 0.33) 10 4 (Chetyrkin-Misiak-Munz) Spectator Model Data CLEO and.v Result: B(b sγ) = (3.21 ± 0.43 ± ) 10 4 (stat) (sys)(thry) b sγ Decays

15 Summary of B(b sγ) Measurements and Theory B(b sγ) [10 4 ] ALEPH 3.11 ± 0.80 ± 0.72 Belle 3.36 ± 0.53 ± 0.68 CLEO &.V 3.19 ± 0.43 ± 0.32 SM Theory 3.29 ± 0.33 SM Theory 3.73 ± B [10 4 ] David G. Cassel NKHEF Nov 2,

16 Measuring Vcb and Vub W B b q νe e c q νµ µ (u) X c(xu) Vcb and Vub can be determined from semileptonic decays Γ c SL Γ( B Xcl ν) = B( B Xcl ν) τb = γc Vcb 2 (for Γ u SL Measure B( B Xcl ν) Determine from fits to the inclusive pl spectrum: The theoretical parameters γc and γu are a serious problem Previously they were obtained from theoretical models b sγ decays can substantially reduce model dependence replace c with u) David G. Cassel NKHEF Nov 2,

17 Vcb from Hadronic Mass Moments and b sγ Γ( B Xcl ν) can be written in the form: Γ c SL = G2 F V cb 2 M B 5 192π 3 G G1( Λ) + 1 G2( Λ, λ1, λ2) MB M B M 3 B G3( Λ, λ1, λ2 ρ1, ρ2, T1, T2, T3, T4) + O 1 M 4 B Λ, λ1, λ2, ρ1, ρ2, T1, T2, T3, T4 are nonperturbative parameters, Gn are polynomials of order n in Λ, λ1, λ2, and αs G3 is linear in ρ1, ρ2, T1, T2, T3, T4, and We use theoretical estimates of bounds for ρ1, ρ2, T1, T2, T3, T4. There are similar expressions for the moments (M X 2 M D 2 ) of the B Xcl ν hadronic mass (MX) spectrum (polynomials Mn) MX is the mass of the hadronic system in B Xcl ν decay MD (MD + 3MD )/4) spin averaged D( ) mass Eγ of the b sγ photon energy (Eγ) spectrum (polynomials En). David G. Cassel NKHEF Nov 2,

18 Vcb from Hadronic Mass Moments and b sγ Moments of the B Xl ν hadronic mass spectrum and b sγ energy spectrum as functions of Λ, λ1, λ2, ρ1, ρ2, T1, T2, T3, T4: (M 2 X M 2 D ) M 2 B = M0 + 1 M1( Λ) + 1 M2( Λ, λ1, λ2) MB M B M 3 B M3( Λ, λ1, λ2 ρ1, ρ2, T1, T2, T3, T4) + O 1 M B 4 Eγ MB = E0 + 1 E1( Λ) MB + 1 E2(ρ1, ρ2, T1, T2, T3, T4; C2/(M 2 M B 2 D C 1 7)) + O M B 3 David G. Cassel NKHEF Nov 2,

19 Vcb from Hadronic Mass Moments and b sγ To extract Vcb we determine λ2 from MB M B, and determine Λ and λ1 from (M X 2 M D 2 ) and E γ. Other experimental parameters: B( B Xcl ν) = (10.39 ± 0.46)% from CLEO, τ B and τ B 0 from PDG 2000, and (f+ τ B )/(f00τ B 0) = 1.11 ± 0.08 from CLEO. f+ B(Υ(4S) B + B ) f00 B(Υ(4S) B 0 B 0 ) Theoretical functions: (M X 2 M D 2 ) are measured for E l > 1.5 GeV, Eγ are measured for Eγ > 2.0 GeV, and Gn, Mn, and En calculated with same cuts using Falk-Luke, Phys. Rev. D 57, 1 (1998) David G. Cassel NKHEF Nov 2,

20 David G. Cassel NKHEF Nov 2, ) M 2 (GeV 2 X The dispersion included in the systematic error Events / 0.5 GeV For a wide variety of XH models, the XHlν fraction is sensitive to the models and the M X 2 moments are insensitive to the models. X H 1500 D* Fit D Calculate M X 2 moments by fitting the M X 2 distribution to contributions from: B Dlν B D lν B XHlν Vcb from Hadronic Mass Moments and b sγ

21 David G. Cassel NKHEF Nov 2, E (GeV) Weights / 100 MeV 0 Results of the four estimates agree and dispersion is included in the systematic error. 40 Spectator Model Data Calculate Eγ moments using fits of the b sγ spectrum to the Ali-Greub and Kagen-Neubert models, and hadronization from Monte Carlos with JETSET and multiple K ( ). Vcb from Hadronic Mass Moments and b sγ

22 Vcb from Hadronic Mass Moments and b sγ Measured M 2 X moments: (M 2 X M 2 D ) = ± ± GeV2 (M 2 X M 2 X )2 = ± ± GeV 4 Measured Eγ moments: Eγ = ± ± GeV (Eγ Eγ ) 2 = ± ± GeV 2 Use only (M X 2 M D 2 ) and E γ to determine Λ and λ1 since theoretical expressions for the next moments are much less reliable. David G. Cassel NKHEF Nov 2,

23 David G. Cassel NKHEF Nov 2, Γ Γ c SL uncertainties, and T αs scale and O(1/M B 3 ) term M moment uncertainties, < M M > X D Errors are due to 0.3 (M) (Γ) (T) Vcb = (40.4 ± 0.9 ± 0.5 ± 0.8) Then the expression for Γ c SL yields (M) (T) < E > 0 Λ = 0.35 ± 0.07 ± 0.10 GeV λ1 = ± ± GeV Experimental Total ntersection of moments yields Vcb from Hadronic Mass Moments and b sγ

24 Summary of nclusive Measurements of Vcb Experiment Vcb [10 3 ] LEP HFWG Average 40.7 ± 2.5 CLEO &.V 40.4 ± 0.9 ± Vcb [10 3 ] Note: LEP measurements are made with model values of γc David G. Cassel NKHEF Nov 2,

25 David G. Cassel NKHEF Nov 2, p l (GeV / c) f (p )(Arbitrary Units) l 2 3 Either way need theory for fraction fu(p) of events in the momentum interval (p) above a pl cut leads to severe model dependence eliminate most of this uncertainty for inclusive B Xul ν decays using the b sγ spectrum 4 ACCMM b c b u (x10) lν l ν Determine Vub from: inclusive pl spectrum above or near the B Xcl ν endpoint or exclusive B π(ρ)l ν decays. Vub from nclusive Leptons and the b sγ Spectrum

26 Vub from nclusive Leptons and the b sγ Spectrum Measure B Xul ν in a lepton momentum interval (p) at the B Xl ν endpoint Bub(p) is the branching fraction for B Xul ν in (p), fu(p) is the fraction of the B Xul ν spectrum in (p), and Bub B( B Xul ν) is the B Xcl ν branching fraction. New measurement of fu(p) fit b sγ data to a shape function (Kagan-Neubert) use shape parameters to determine fu(p) (De Fazio-Neubert) Then get Bub from Bub(p) = fu(p) Bub and obtain Vub from Vub = [ (3.06 ± 0.08 ± 0.08) 10 3] (Hoang-Ligeti-Manohar) Bub 1.6 ps τb 1 2 David G. Cassel NKHEF Nov 2,

27 David G. Cassel NKHEF Nov 2, Momentum (GeV/c) 3.00 Leptons / (50 MeV/c) ( b ) Figure (b) filled circles are the total of e and µ data after subtraction of scaled Off-Υ(4S) and B Xcl ν backgrounds and correction for efficiencies histogram is B Xul ν prediction from the b sγ spectrum 2500 ( a ) Figure (a) filled circles are data shaded histogram is scaled Off-Υ(4S) histogram is sum of scaled Off and B Xcl ν Vub from nclusive Leptons and the b sγ Spectrum

28 Vub from nclusive Leptons and the b sγ Spectrum For the momentum interval (2.2 < pl < 2.6) GeV Nub = 1, 874 ± 123 ± 326 (without efficiency correction) B Xul ν events Bub = (2.35 ± 0.15 ± 0.45) 10 4 fu = ± from the b sγ spectrum 1/(0.95 ± 0.02) factor for QED radiative correction Vub = (4.09 ± 0.14 ± 0.66) 10 3 David G. Cassel NKHEF Nov 2,

29 Vcb from B D l ν Decay W B b q νe e c q νµ µ D From Heavy Quark Effective Theory (sgur-wise symmetry) the differential decay width for B D l ν decay is dγ(w) dw = G2 F 48π 3 G(w) V cb 2 F 2 D (w) with w vb vd = E D MD = M 2 B + M 2 D q 2 2MBMD vb and vd are the 4-velocities of the B and D, ED is the energy of the D in the B rest frame. The w range is (1.00 < w < 1.51) for B D l ν decay. G(w) is a known function of w. David G. Cassel NKHEF Nov 2,

30 Vcb from B D l ν Decay The form factor FD (w) parameterizes the w dependence of the hadronic current and is constrained by Heavy Quark Effective Theory (HQET) FD (1) η A[1 + O(1/m 2 Q )] for large heavy quark masses However G(1) = 0 (phase space) so measure dγ(w)/dw over the full w range, extract Vcb FD (w) and fit it over the full w range, extrapolate Vcb FD (w) to w = 1 to get V cb FD (1). Reduce w dependence of FD (w) in the fit to a slope parameter ρ2 using theory from Caprini-Lellouch-Neubert and the form factor ratios R1(1) and R2(1), previously measured by CLEO We now have results for B 0 D + l ν and B D 0 l ν previously (e.g., CHEP 2000 Osaka) only B 0 D + l ν David G. Cassel NKHEF Nov 2,

31 David G. Cassel NKHEF Nov 2, cos B D* 20 Fake Leptons cos θb D l = 2E BED l M 2 B M 2 D l 2 PB PD l Correlated Uncorrelated 40 Continuum Combinatoric find a D using D D 0 π and D 0 K π +, find a lepton l (e or µ) with the same sign as the K, and separate the B D l ν signal from background using the angle θb D l between the momenta of the B and the D l combination Candidates / Data D* D** D* The strategy for reconstructing B D l ν is to: D* Vcb from B D l ν Decay

32 David G. Cassel NKHEF Nov 2, W F V W cb (f+ τ B )/(f00τ B 0) 0.03 CLEO measurement of Γ(D + l ν) = Γ(D 0 l ν) 0.04 FD +(w) = F D 0(w) Fit D* FD (w) from Caprini-Lellouch-Neubert D* The fit uses: Vcb from B D l ν Decay

33 Vcb from B D l ν Decay From the B D l ν fit and systematic error estimates: Vcb FD (1) = (42.2 ± 1.3 ± 1.8) 10 3 ρ 2 = 1.61 ± 0.09 ± 0.21 Γ( B D l ν) = ( ± ± ) ps 1 Using PDG 2000 lifetimes and branching fractions B(B D 0 l ν) = (6.21 ± 0.20 ± 0.040)% B( B 0 D + l ν) = (5.82 ± 0.19 ± 0.037)% Using FD (1) = ± (BaBar Physics Book) Vcb = (46.2 ± 1.4 ± 2.0 ± 2.1) 10 3 (stat) (sys)(thry) David G. Cassel NKHEF Nov 2,

34 David G. Cassel NKHEF Nov 2, ρ ALEPH DELPH OPAL exc ρ 2 FD V cb correlation Large correlation at LEP Smaller CLEO correlation due to use of form factor ratios R1(1) and R2(1) OPAL inc F(1) V cb CLEO Possible sources of apparent discrepancy between CLEO and the LEP experiments D Xl ν component CLEO fits LEP uses model Vcb from B D l ν Decay

35 The CLEO Detector Superconducting Solenoid Silicon Strip Tracker Wire Drift Chamber Ring maging Cherenkov CLEO Upgrades New Silicon Vertex Detector New Drift Chamber RCH Detector Cesium odide Calorimeter Muon ron Pole Tip Muon Chambers Return Yoke David G. Cassel NKHEF Nov 2,

36 CLEO Detector Performance Component Performance Tracking 93% of 4π; σp/p = 0.35% at p = 1 GeV/c 5.7% de/dx resolution for minimum-ionizing π RCH 80% of 4π; 87% kaon efficiency with 0.2% pion fake rate at p = 0.9 GeV/c Calorimeter 93% of 4π; σe/e = 2.2% at E = 1 GeV and σe/e = 4.0% at E = 100 MeV Muons 85% of 4π for p > 1 GeV/c Trigger Fully pipelined, latency 2.5 µs Based on track and shower counts, topology DAQ Event Size: 25 kbyte, Throughput 6 MB/s David G. Cassel NKHEF Nov 2,

37 David G. Cassel NKHEF Nov 2, M (B) (GeV/c 2 ) (2.9 ± 0.8) 10 4 CLEO Rest of Kπ, ππ, and K K reconstruction techniques similar to previous CLEO analyses Events / 2.5 (GeV/c 2 ) 40 (3.8 ± 1.3) 10 4 CLEO With RCH Cut With RCH Cut B(B D 0 K ) = 0 80 Very clean preliminary signal for Cabibbo suppressed B D 0 K decays with vastly simpler analysis Without RCH Cut Without RCH Cut Clean K/π separation at p 2.5 GeV using RCH K efficiency 85% π fake rate 5% in fiducial volume (80% of 4π) CLEO PRELM B D 0 B D 0 K Preliminary results using 1 2 CLEO data of the B Kπ and B ππ from CLEO

38 David G. Cassel NKHEF Nov 2, M (B) (GeV/c 2 ) M (B) (GeV/c 2 ) 5 10 Events / 2.5 (MeV/c 2 ) With RCH Cut Events / 2.5 (MeV/c 2 ) B K Without RCH Cut CLEO PRELM B 0 + K B K S + CLEO PRELM B Kπ and B ππ from CLEO

39 B Kπ and B ππ from CLEO CLEO 2001 Preliminary (CLEO 1999 published results) Mode Eff (%) Yield Signif B (10 6 ) UL (10 6 ) K ± π σ σ ± 1.3 K ± π σ σ K 0 π ± σ σ ± 1.6 K 0 π σ σ David G. Cassel NKHEF Nov 2,

40 B Kπ and B ππ from CLEO CLEO 2001 Preliminary (CLEO 1999 published results) Mode Eff (%) Yield Signif B (10 6 ) UL (10 6 ) π ± π σ π ± π σ ± σ σ π 0 π σ σ 5.7 David G. Cassel NKHEF Nov 2,

41 B Kπ and B ππ from CLEO CLEO 2001 Preliminary (CLEO 1999 published results) Mode Eff (%) Yield Signif B (10 6 ) UL (10 6 ) K ± K σ σ 2 K 0 K ± σ σ 5.1 K 0 K David G. Cassel NKHEF Nov 2,

42 B Kπ and B ππ from CLEO CLEO CLEO &.V CLEO Exclude Mode B [10 6 ] B 0 K + π 18.6 ± 4.3 ± ± 2.7 ± 1.3 B + K + π ± 5.4 ± ± 2.9 ± 1.8 B + K 0 π ± 11.0 ± ± 4.3 ± 1.6 B 0 K 0 π ± 9.2 ± ± 5.5 ± B David G. Cassel NKHEF Nov 2,

43 B Kπ and B ππ from CLEO Mode B [10 6 ] B 0 π + π 3.2 ± 2.9 ± ± 1.7 ± 0.6 B + π + π ± 5.2 ± ± 2.5 ± 1.7 B + π 0 π 0 < 11 < 5.7 B 0 K + K < 4.5 < 2 B + K + K 0 < 18 < 5.1 B 0 K 0 K 0 < 13 < B David G. Cassel NKHEF Nov 2,

44 Other Recent CLEO Results First significant measurement of B φk ( ) B(B φk ) = ( B(B 0 φk 0 ) = ( ± 0.6) ) 10 6 First clear signal of a gluonic penguin diagram Upper limits on FCNC decays B Kl + l and B K l + l B(B K l + l ) < (90% CL) B(B K l + l ) < (90% CL) (mll > 0.5 GeV) Another window on b sγ processes and NP Combined upper limit is only a factor of 1.5 above theoretical predictions Search for B + D + K S 0 B(B + D + K S 0 ) < (90% CL) Should only occur via an annihilation diagram Observation of B 0 D 0 π 0 and B 0 D 0 π 0 B( B 0 D 0 π 0 ) = ( ± 0.55) 10 4 (12σ significance) B( B 0 D 0 π 0 ) = ( ± 0.79) 10 4 (5.9σ significance) First color-mixed internal-spectator B decay without charmonium David G. Cassel NKHEF Nov 2,

45 CLEO-c and CESR-c CLEO-c is a focused program of measurements and searches in e + e collisions in the the s = 3 5 GeV energy region, including: charm measurements absolute charm branching fractions the decay constants fd and fds semileptonic decay form factors Vcd and Vcs searches for new physics including CP violation in D decay D D mixing without DCSD rare D decays QCD studies c c spectroscopy searches for glue-rich exotic states: glueballs and hybrids measurements of R between 3 and 5 GeV direct between 1 and 3 GeV indirect (nitial State Radiation) τ studies A major emphasis is challenging Lattice QCD (LQCD) with precision measurements. David G. Cassel NKHEF Nov 2,

46 Lattice QCD Theoretical analysis of strongly-coupled, nonperturbative quantum field theories remains one of the foremost challenges in modern physics. Experimental progress in flavor physics (e.g., the CKM matrix elements Vcb, Vub, and Vtd ) is generally limited by knowledge of QCD parameters (e.g., decay constants and semileptonic form factors). n the last decade technical problems in LQCD have been identified and overcome and substantially improved algorithms have been developed. LQCD is now poised to move from O(15%) precision to O(1%) precision in calculating many important parameters that can be measured experimentally or are needed to interpret experimental measurements, including masses, leptonic widths, EM transition form factors, and mixing amplitudes for bound states in the J/ψ and Υ families; masses and semileptonic form factors of low-lying baryons containing b and c quarks; and masses, decay constants, and semileptonic decay form factors of D and B mesons. CLEO-c will provide data to motivate and validate many of these calculations. This will help to establish a comprehensive mastery of nonperturbative QCD. David G. Cassel NKHEF Nov 2,

47 CLEO-c Run Plan 2002 Prologue Υ s > 1 fb 1 each Υ(1S), Υ(2S), Υ(3S),..., Υ(6S)(?) Matrix elements, Γ, Γee, spectroscopy (ηb, hb, D states,...) the existing world s data 2003 Act ψ(3770) 3 fb 1 30 M D D events, 6 M tagged D 310 MARK 2004 Act s 4.1 GeV 3 fb M Ds Ds events, 0.3 M tagged Ds 480 MARK and 130 BES 2005 Act J/ψ 1 fb 1 1 G J/ψ decays 170 MARK and 20 BES The CESR-c Accelerator At low energies loss of synchrotron radiation damping would reduce luminosity Compensate with wiggler magnets Designed and constructed a superferric prototype (Fe poles & SC coils) Excellent prototypes for Linear Collider damping ring wigglers. The only substantial hardware upgrade in the program Expected luminosity performance s (GeV) L (10 33 cm 2 s 1 ) David G. Cassel NKHEF Nov 2,

48 CLEO-c Detector Capability and CLEO-c Physics Reach We will use the CLEO detector in CLEO-c. We will replace the silicon vertex detector (SVX) with a thin gaseous drift chamber. The SVX is abnormally sensitive to radiation damage. A thinner detector is better in this energy region anyway (The maximum momentum of a secondary from D decay is 1 GeV/c.) The CLEO-c physics reach has been studied using a parameterized Monte Carlo simulation The resolutions, acceptances, detection efficiencies, and particle identification efficiencies were carefully tuned to match achieved CLEO performance. D D events near charm threshold are substantially simpler than B B events at the Υ(4S) due to significantly lower multiplicities. The capability and performance of the CLEO detector are substantially beyond those of others that have operated in this energy region. David G. Cassel NKHEF Nov 2,

49 Absolute Measurements of D Reference Branching Fractions Measure absolute D branching fractions by comparing double tag (D D) rates to single tag (D or D) rates Double tag events are very clean with little background Most systematic errors cancel Do not need to know production rates Tracking uncertainties dominate systematic errors Background not negligible in Ds Measure tracking eff. with data to 0.2% per track using missing mass reconstruction David G. Cassel NKHEF Nov 2,

50 Absolute Measurements of D Reference Branching Fractions D 0 K π + B (%) PDG 3.83 ± 0.09 CLEO-c 3.83 ± 0.02 ± B(D 0 K π + ) (%) D + K π + π + B (%) PDG 9.1 ± 0.7 CLEO-c 9.10 ± 0.04 ± B(D + K π + π + ) (%) D + s φπ+ B (%) PDG 3.60 ± 0.90 CLEO-c 3.60 ± 0.05 ± B(D s + φπ+ ) (%) David G. Cassel NKHEF Nov 2,

51 Absolute Measurements of D Reference Branching Fractions D 0 K π + σb/b (%) PDG ±2.3 CLEO-c ±0.4 ± 0.4 D + K π + π + PDG ±7.7 CLEO-c ±0.4 ± 0.6 D + s φπ+ PDG ±25 CLEO-c ±1.3 ± σb/b (%) These three B s determine the scale for all heavy quark B s. David G. Cassel NKHEF Nov 2,

52 Measuring D Meson Decay Constants l + Dq c q νl The factor fdq V cq occurs in the decay amplitude for the c qw vertex The decay widths for leptonic D + and D s + decays are: Γ(D + q l+ νl) = 1 8π G2 F M Dq m2 l 1 m2 l M 2 Dq f 2 Dq V cq 2 Measurements of B(D + l + νl) and B(D s + l+ νl) Determine f D + Vcd and fds V cs Conventionally expect measure fdq V cq and use unitarity for Vcq to get fdq We will also measure Vcd and Vcs accurately with semileptonic D decays Challenge LQCD theorists with values of f D + and fds with errors O(1%) Lead to understanding of the level of reliability of f B 0 and fbs calculations f B 0 uncertainty dominates error in Vtd from value of md in B 0 B 0 mixing David G. Cassel NKHEF Nov 2,

53 Measuring D Meson Decay Constants D + µ + νµ Decays D + s µ+ νl Decays Decay Mode Signal Bkg 1 2 (δb/b) 1 2 (δτ /τ ) δ V cq / Vcq δfdq /f Dq PDG D + µ + ν % 0.6% 1.1% 2.3% f D + D + s µ+ ν 1, % 1.0% 0.1% 1.7% fds 35% D + s τ + ν 1, % 1.0% 0.1% 1.6% fds 60% David G. Cassel NKHEF Nov 2,

54 Measuring Vcs and Vcd in Semileptonic D Decays e + µ + Dq W c q νe νµ s (d) q Xqs(Xqd) Semileptonic decay rates of Dq are proportional to Vcd 2 or Vcs 2 Γ(Dq Xqd l + νl) = B(D q Xqdl + νl) τdq = γ(xqd) Vcd 2 (same for s d) γ(xqd) and γ(xqs) must come from theory (soon LQCD) Decays depend on the mass-squared (q 2 ) of the virtual W through form factors f(q 2 ) which are related to γ(x) Decay to a pseudoscalar meson (P ) involves one form factor Γ(Dq Pd l + νl) = V cd 2 p3 dq 2 24π f +(q 2 ) 2 (same for s d) 3 Decay to a vector meson (V ) involves 3 form factors and a much more complicated expression involving 3 decay angles (or 3 other variables) in addition to q 2 David G. Cassel NKHEF Nov 2,

55 Measuring Vcs and Vcd in Semileptonic D Decays Measure semileptonic branching fractions and form factors Branching fraction measurements and γ(xqs) and γ(xqd) from LQCD determine Vcs and Vcd Form factor measurements will challenge LQCD f LQCD meets the challenges: Reinforces confidence in γ(xqs) and γ(xqd) Compare these values of Vcs and Vcd with those from unitarity Reinforces confidence in LQCD calculations of quantities needed for determining Vcb and Vub. Detect semileptonic decays in events with a single hadronic tag and an e ± High rates due to high single tag rates Excellent background rejection from kinematics and particle identification Use U Emiss pmiss to separate signal from background efficiently David G. Cassel NKHEF Nov 2,

56 Studying Exclusive Semileptonic D Decays to Pseudoscalars These plots correspond to 1 fb 1 of D 0 D 0 data David G. Cassel NKHEF Nov 2,

57 Studying Exclusive Semileptonic D Decays to Pseudoscalars Results of Monte Carlo simulations: Excellent separation of D 0 π e + νe from D 0 K e + νe even though B(D 0 K e + νe) 10B(D 0 π e + νe) Semileptonic branching fractions can be measured with errors δb/b 1%. The exponential slopes (α) of the form factors can be measured with a errors δα/α 4% Again these measurements will challenge LQCD theorists to calculate form factors and γ(x) with precisions of O(1%). David G. Cassel NKHEF Nov 2,

58 David G. Cassel NKHEF Nov 2, m K V V K m d V ub V d 0.7 A CP ψ ) S s A CP ( ψ K S ) (95% CL) Allowed regions of the ρ-η plane determined by: current experimental results and current theoretical uncertainties Allowed regions of the ρ-η plane determined by: current experimental results and theoretical uncertainties of O(1%) after CLEO-c has verified LQCD Contributions of CLEO-c to CKM Measurements

59 David G. Cassel NKHEF Nov 2, PC The hermetic CLEO-c detector with its excellent γ, π ±, and K ± detection and resolution is nearly ideal Observe glueballs in many different modes (signature) Facilitates angular analysis to establish J P r 0 m G * + + m G (GeV) Since gluons carry color charge, they self-interact and should bind A rich spectrum of glueballs or glue-rich states is expected in the few-gev region J/ψ γx decays are an ideal hunting ground Caveat glueballs may mix with nearby conventional q q mesons 8 0* * Glueball Spectrum (Morningstar and Peardon) Searching for Gluonic Matter

60 Search for the fj(2220) The fj(2220) candidate for a glue-rich meson has been rather elusive: Observed by MARK Most robust signals come from BES Not observed by Crystal Barrel Most other sightings have disappeared BES branching fractions imply enormous CLEO-c rates BES fj(2220) Data fj(2220) CLEO-c Decay Mode Yield π + π 23,000 π 0 π 0 13,000 K + K 15,600 K 0 S K0 S 4,500 p p 8,500 David G. Cassel NKHEF Nov 2,

61 Search for the fj(2220) n the CLEO-c detector fj(2220) signals would stand out clearly above backgrounds in many modes Monte Carlo simulations with only 150 M J/ψ decays ( <1/6 of the projected CLEO-c data sample) show clear signals above the estimated backgrounds David G. Cassel NKHEF Nov 2,

62 nclusive J/ψ γx Measurements The inclusive J/ψ γx spectrum is also a hunting ground for new gluonic states Monte Carlo studies with only 60 M J/ψ decays show a clear fj(2220) signal if B(J/ψ γfj) = With the full 1 G J/ψ CLEO-c data sample, B(J/ψ γx) > 10 4 should be observable David G. Cassel NKHEF Nov 2,

63 Searching for the Missing Υ States So far the only bound Υ states that have been observed are: Υ(1S), Υ(2S), Υ(3S) 1 3 PJ and 2 3 PJ Many states are missing n 1 S0 (ηb,...) n 1 P1 (hb,...) D states Spectroscopy of the Υ System n the next year CLEO will run on the Υ resonances to Search for the missing states and measure their masses Measure Γee, transition rates, and hyperfine splittings This program will also challenge LQCD theorists with precise measurements David G. Cassel NKHEF Nov 2,

64 Summary and Conclusions New measurements using all CLEO and.v data B(b sγ) = (3.21 ± 0.43 ± ) 10 4 SM Theory (3.28 ± 0.33) 10 4 SM Theory (3.73 ± 0.30) 10 4 Vcb using hadronic mass and b sγ energy moments Vcb = (40.4 ± 0.9mom ± 0.5Γ ± 0.8thry) 10 3 Vub using the b sγ spectrum to determine fu(p) Vub = (4.09 ± 0.14stat ± 0.66sys) 10 3 Measurement of Vcb from B D l ν decays Vcb = (46.2 ± 1.4stat ± 2.0syst ± 2.1thry) 10 3 First results from CLEO data B(B Kπ), B(B ππ), and B(B K K) Mentioned searches for and measurements of B(B φk ( ) ), B(B K ( ) l + l ), B(B D + K S 0 ), and B(B D( )0 π 0 ) Motivations and plans for the CESR-c/CLEO-c program David G. Cassel NKHEF Nov 2,

65 Summary and Conclusions Highlights of the CLEO-c program include: Precision O(1%) measurements in the charm threshold region of absolute reference hadronic branching fractions for D decay, Vcd f D + and Vcs f D + s from leptonic D + and D s + decays, and Vcd and Vcs from semileptonic D 0 and D + decays, with very small and well-controlled backgrounds and systematic errors. These measurements will challenge the ability of LQCD to calculate decay constants and form factors for D decay, which will determine the utility of LQCD for these calculations in B decay High-statistics, high-resolution, and low-background searches for gluonic states in the 1 2 GeV mass region in J/ψ γx decays. For example, we should be able to definitely establish or rule out the fj(2220). The hermetic CLEO detector will facilitate angular analysis to establish J P for any states observed. David G. Cassel NKHEF Nov 2,

66 Summary and Conclusions Things to remember: No detector with the acceptance, resolution, and particle identification capability of the CLEO detector has ever operated in the charm threshold region No other detector with these capabilities is likely to operate in the charm threshold region in the foreseeable future. CESR-c will provide much more luminosity than has been devoted to measurements in this region. High event rates, very small well-controlled backgrounds, and very small and well-understood systematic errors are unique features of the CLEO-c and CESR-c program in the charm threshold region! More information is available in the CLEO-c/CESR-c project description: CLEO-c and CESR-c: A New Frontier of Weak and Strong nteractions Cornell Report No. CLNS 01/1742, Revised October 2001 Links to WWW versions at: For a hard copy send a request to: preprint@lns.cornell.edu New collaborators are welcome! David G. Cassel NKHEF Nov 2,