Adi Bornheim. Charm and Beauty Spectroscopy at B-Factories and the Future at CLEO-c. For the CLEO Collaboration CALTECH

Transcription

1 Workshop on Heavy Quark Physics at the Upgrade HERA Collider Charm and Beauty Spectroscopy at B-Factories and the Future at CLEO-c CALTECH For the CLEO Collaboration Rehovot, Israel, 21 October 2003

2 Outline of the Talk Heavy Flavor Spectroscopy Experimental landscape at the - and -Resonances : The CLEO, BaBar, Belle and the BES experiments. Recent Results from charm-spectroscopy Recent Results from beauty-spectroscopy The Future at CLEO-c and elsewhere 2

3 Introduction Heavy Flavor Spectroscopy We have heard a lot about the theory - and a lot about heavy flavor dynamics here a simplistic view about heavy flavor spectroscopy : Hadronic matter are bound states made from quarks. Quarks interact and hadrons are held together - via the strong force. (Quarks also interact electromagnetically, weakly and via gravitational force ) The field theory describing the interaction is called QCD the field quants are gluons. The scale (the mass) of most hadrons is too low to employ pertubation theory thus it is hard (or for practical purposes impossible ) to calculate parameters (mass, width) of the quark bound states this way. (In fact it is hard or impossible to calculate almost anything reliably at a scale ~ QCD ) Other techniques HQET, LQCD were developed to overcome these problems. Simple potential models work to some extent too. But :Today we are still unable to calculate eg. the full bound state spectrum for all possible quark combinations. HQET and LQCD have been of crucial importance for recent advances in B-physics. In fact, they are considered the key in answering the questions to what extend out current model quark mixing is complete. 3

4 CLEO II/II.V Detector ( ) Almost hermetic detector Muon Chambers Superconducting Coil Barrel CsI Calorimeter Drift Chamber Silicone Vertex Detector Vertex Detector Endcap TOF Endcap CsI Barrel TOF Calorimeter Magnet Yoke CLEO Operates at the Symmetric e+e- Collider CESR 4

5 CLEOII/II.V ( ) and CLEOIII ( ) B-Physics experiment detector generation n n+1 CLEOII Ring Imaging Cherenkov Detector CLEOIII Low mass drift chamber (He based gas, low mass endplate) Thinner beam pipe, More compact vertex detector SC final focus magnets 5

6 The Belle Detector at KEKB SC solenoid 1.5T Aerogel Cherenkov counter n=1.015~ GeV e CsI(Tl) 16X0 8GeV e Central Drift Chamber He/C2H5 Si Vertex detector 3 lyr. DSSD / KL detection 14/15 layer RPC+Fe 6

7 The BaBar Detector at PEPII Silicon Vertex Tracker 5 layer double sided silicon strip; Lifetime ~ 4 Mrad Detector for internally reflected Cherenkov light 144 synthetic quartz bars PMT e+ (3.1 GeV) Drift Chamber 40 layers 80:20 helium:isobutan NTP e- 1.5T Solenoid (9.0 GeV) Instrumented Flux Return Electromagnetic Calorimeter CsI(Tl) crystals; X0 = Resistive plate chambers (L3 detector type) layers 7

8 Current Data Sets The detectors are very similar, the accelerators make all the difference : CLEO II/II.V : 13.4 fb-1, CLEOIII : 9.4 fb-1, both at Ecm~ 10 GeV, CLEO-Resonance : 1-2 fb-1 at the (1S), (2S) and (3S) resonances and some data around the resonances CLEO-c later BaBar : 135 fb-1, Ecm~ 10 GeV, ~10 fb-1/month now Belle : 160 fb-1, Ecm~ 10 GeV, up to 15 fb-1/month later 2003 / early 2004 both will roughly double their data sets until end 2004 both plan upgrades to Super-B-Factories with several ab-1 BESII : L ~ ~ /cm2 s at J/ peak, Ecm~ 2-5 GeV BESIII is now approved - operational after

9 The Discovery of the D*sJ(2317) BaBar discovered a new state with a mass of 2317 MeV. (April 2003) BABAR BABAR DsJ*(2317)+ Ds + 0 Ds + K+ K + M = MeV = MeV Ds+ K+ K + 0 M = MeV = MeV BABAR BABAR Resolution from MC is = MeV DS sideband 0 sideband At the time the nature of this new state was unclear! hep-ex/

10 The Discovery of the DsJ(2457) Motivated by the BaBar analysis CLEO searched for the D*sJ(2317) and DsJ(2457) 2.11 GeV 2.32 GeV Ds 0 Signals in both channels, at nearly the same value of M Ds 0 mode : signal remains robust Ds * mode : /- 9.7 events, width matches resol n (~ 6.5 MeV) BaBar also saw a peak here GeV 2.46 GeV Ds* 0 1+ partner of 0+ DsJ*(2317)? are these two separate particles? 10

11 CLEO measurement of new DsJ States Feed Up : DsJ(2463) D*sJ(2317) 0 D*s(2112) Ds(1969) If a random photon is added to the Ds(1969) it becomes a D*s(2112) and the D*sJ(2317) is reconstructed as a DsJ(2463). Feed up rate : ~50% BaBar, ~25% CLEO, ~30% Belle Random Feed Down : DsJ(2463) D*sJ(2317) 0 If the photon from the D*s(2112) decay is missed the DsJ(2463) is reconstructed as D*sJ(2317). Feed down rate : ~18% CLEO D*s(2112) Ds(1969) Missing CLEO Result : M(D*sJ) = ± 1.0 MeV M(DsJ) = ±1.3 MeV (D*sJ) = (8.0 ± 1.3) MeV (DsJ) = (6.1 ± 1.0) MeV hep-ex/

12 Belle measurement of DsJ Properties M= MeV/c2 M= MeV/c2 consistent with zero intrinsic width hep-ex/

13 Belle measurement of DsJ in B-decays Belle takes advantage of full reconstruction of B-decays and their huge data set B->D DsJ(2317) DsJ(2317)->Ds 0 B->D DsJ(2457) DsJ(2457)->D*s 0 B->D DsJ(2457) DsJ(2457)->Ds B (B D DsJ(2317)) x B (DsJ(2317) Ds* 0) = ( ) x 10-4 B (B D DsJ(2457)) x B (DsJ(2457) Ds* 0) = ( ) x 10-4 B (B D DsJ(2457)) x B (DsJ(2457) Ds = ( ) x 10-4 hep-ex/

14 Overview of DsJ Results on M All three experiments give consistent results 14

15 Belle measurement of DsJ(2457) Ds Decays Consistent with 1+ hypothesis, BF(DsJ(2457)->Ds ) = BF(DsJ(2457)->Ds* ) 0+, 2+ are excluded (continuum) = (B decays) 15

16 DsJ(2317) and DsJ(2457) Summary BaBar discovers the DsJ(2317). CLEO and Belle confirm BaBar s observation of DsJ(2317). DsJ(2457) is firmly established by CLEO. Belle observes both DsJ(2317) and DsJ(2457) in B D DsJ decays: consistent with 0+ and 1+ (both having jq=1/2). DsJ(2457)-> Ds decay is observed by Belle both in continuum and B decays, angular analysis favours the JP=1+ hypothesis of DsJ (2457) Other explanations : DK molecule (hep-ph/ , Lipkin et. al.); D atom (PLB 567 (2003) 23, Szczepaniak); four quark particle (several authors eg. PLB 566 (2003) 193; hep-ph/ ; PRD 68 (2003) ); low mass threshold (hep-ph/ ); Non-relatvistic vector and scalar exchange force (hep-ph/ ) 16

17 Measurement of the c by CLEO, BaBar and Belle All three experiments find a c candidate in various modes with consistent mass. +17 CLEO Analysis : c in collisions M=3642.6±1.2 CLEOII/III sig.: 5.0/5.7 M( c) WORLD = ±4.4 MeV (Belle) KsK+ KsK+ e e J X B K(KsK+ ) (2S) X CLEO CONF

18 Much more results 2002 results ~10 times larger than expected Belle 102 fb ± 8 MeV Updated this year ~ 1 pb e e J X ~ 0.06 pb ~ 0.06 pb =MX BELLE-CONF

19 Observation of b(2p) (1S) by CLEO So far -transitions were the only observed hadronic transitions. -transitions are the only other nonsuppressed transition. Three pion mass spectrum B ( b1(2p) (1S)) = (1.6 ± 0.3 ± 0.2) % B ( b2(2p) (1S)) = (1.1 ± 0.3 ± 0.1) % Photon energy spectrum Kinematical yforbidden region CLEO CONF

20 CLEO Search for the b(1s) The S0 states of the bb system (also referred to as the b ) have not been observed to date. Experimental signature : Photons from (3S) b(1s) via M1 transitions Tune search with E1 transitions : b(2p) (1S) Experimental challenge : 0 rejection CLEO CONF

21 CLEO Search for the b(1s) Sum of 3 E1 transitions peaks used to tune fit Search for M1 photons in the expected mass range Maximum yield : 698± 463 events (1.5 ) No Evidence for the b(1s) 90 % CL UL CLEOIII (Prel.) 21

22 Spectroscopy: Observation of (13D2) Preliminary results at ICHEP02 Update: More data and better background suppression M( (13D2))= ± 0.6 ± 1.6 MeV CLEO III Recoil mass e+e-, B( (3S) (1D) (1S) l+l-) = (2.6 ± 0.5 ± 0.5) 10-5 Theory = B( (3S) (1D)) ( (1D) (1S)) < B( (1D2) (1S)) B( (1D2) (1S)) -5 (Godfrey & Rosner PRD (2001)) < 0.25 (90% C.L.) CLEO CONF xb 22

23 More CLEO More hadronic transitions of resonances -e.g. two body PS-V decays. Kinematic distributions in transitions of. Properties of the resonances (width etc.). Photon transitions of and resonances. Preliminary results of all of the above have been shown this summer. Final results are expected in the next few month. 23

24 CLEO-c The Context The Past CLEO made major contributions to B/c/ physics. But, with the spectacular success of the B factories, CLEO is no longer taking data at the (4S) resonance. Last run was June 25th, The Present Flavor Physics is in the B Factory era akin to precision Z. Over-constrain CKM matrix with precision measurements. Limiting factor is non-pertubative QCD. LHC may uncover strongly coupled sectors in the physics that lie beyond the Standard Model. The LC may then study them. The Future Strongly-coupled field theories are an outstanding challenge to theoretical physics. Critical need for reliable theoretical techniques & detailed data to calibrate them. Example: Complete definition of pertubative & non-pertubative QCD. Lattice QCD Matured over last decade and can calculate to 1-5% B, D,, Charm at threshold can provide the data to calibrate QCD techniques Convert CESR/CLEO to a charm/qcd factory CESR-c/CLEO-c 24

25 CLEO-c Physics Program Charm measurements Precise charm absolute branching ratio measurements Leptonic decays: decay constants fd and fds Semileptonic decays: form factors, Vcs, Vcd, test unitarity Hadronic decays: normalize B physics QCD studies Precise measurements of quarkonia spectroscopy Searches for glue-rich exotic states: Glueballs and hybrids Probes for Physics beyond the Standard Model D-mixing, CP Violation, rare D decays Possible additions to Run Plan spectroscopy, threshold, c threshold, R scan 25

26 The Cornell Electron Storage Ring 12 additional wigglers to improve transverse cooling EBEAM= GeV 26

27 CESR-c CESR: L( (4S)) = cm -2 s-1 J/ J/ One day scan of : (nb) CESR-c: s 3.1 GeV L(1032 cm-2 s-1 ) GeV GeV 3.6 L ~ (~BES) Ebeam Expected machine performance: Ebeam ~ 1.2 MeV at J/ 27

28 The CLEO-c Detector Superconducting Solenoid coil Barrel calorimeter Ring Imaging Cherenkov detector Drift chamber Inner tracker / Beampipe Endcap calorimeter Drift chamber/ Inner tracker 93% of 4 p/p = 1 GeV de/dx: 5.7% min-ionizing Ring Imaging Cherenkov 83% of 4 87% Kaon ID with 0.2% 0.9GeV Iron polepiece Cesium Iodide Calorimeter 93% of 4 E/E = 1GeV = 100MeV Muon chambers SC quad pylon SC quads Data Acquisition Event size = 25kB Thruput < 6MB/s Rare earth quad Muon system 85% of 4 for p >1 GeV Magnet iron Trigger - Tracks & Showers Pipelined Latency = 2.5ms 28

29 NEW - Inner Drift Chamber Replace Silicon Vertex Detector with Inner Drift Chamber 6 layers 2cm < R < 12cm All stereo 300 channels 29

30 Run Plan CESR/CLEO Prologue : Year 1 : Upsilon ~1-2 fb-1 each at (1S), (2S), (3S), and (5S) Spectroscopy, matrix elements, ee, b, hc Last run of CLEO (5S) on March 3rd 2003 (3770) ~3 fb-1 ( (3770) DD) 30 million DD events, 6 million tagged D decays 310 times MARK III data s ~ 4140 MeV Year 2 : Year 3 : ~3 fb million DsDs events, 0.3 million tagged Ds decays 480 times MARK III data, 130 times of BES data (3100) CLEO-c ~1 fb-1 1 billion J/ decays 170 times MARK III data, 20 times BES II data 30

31 CLEO-c Signature (3770) events are simpler than (4S) events! (4S) event (3770) event D0 K- + D0 K+e- Charm events produced at threshold are extremely clean The demands of doing physics in the 3-5 GeV range are easily met by the existing detector BUT B factories: 400 fb-1 ~500M cc by 2005 What is the advantage of running at threshold? Large cross section, low multiplicity Double tag events are pristine These events are the key to make absolute BR measurements Pure initial state: no fragmentation Neutrino reconstruction is clean Signal/Background is optimum at threshold Quantum coherence aids D mixing & CP violation studies 31

32 Precision Flavor Physics Goal for the decade: High precision measurements of all CKM matrix elements & associated phases over-constrain the Unitary Triangles Inconsistencies New Physics! V us / Vus = 1% V ud / Vud = 0.1% n CKM Matrix Current Status: e p l - - K V cd / Vcd = 7% 1.7% Vcs /Vcs =11% 1.6% ll- D V td / Vtd = 36% 5% Bd D K Vub / V ub= 17% 5% l B V cb / Vcb = 5% 3% l B D V ts / Vts = 39% 5% Bd Bs Bs V tb / Vtb = 29% t W b Many experiments will contribute: CLEO-c will enable precise 1st column unitarity test & new measurements at BFactories/Tevatron to be translated into greatly improved CKM precision 32

33 Absolute Charm Branching Ratios Double tag technique: Monte Carlo D- tag Almost zero background in hadronic tag modes D+ K- + + Measure absolute B(D X) with double tags # of X B = # of D tags Decay s L (fb-1) D0 K D+ K Ds 4140 Double tags B / B (%) PDG CLEO-c 53, , , CLEO-c: potential to set absolute scale for all heavy quark measurements 50 pb-1 ~1,000 events x2 improvement (stat) on D+ K- + + PDG B/B 33

34 Comparison: B Factories & CLEO-c CLEO: fds: Ds* Ds with Ds CLEO-c 3 fb-1 bkgd Statistics limited 30 M = M( ) M( ) / GeV Error (%) 25 Ds Monte Carlo 20 fd Systematics & Background limited B(Ds ) fds 15 Error (%) CLEO-c B Factory PDG 400 fb-1 10 B(D+ K ) B(D0 K )

35 Semileptonic Decays VCKM 2 f(q2) 2 CLEO-c Monte Carlo D l 0 Tagged Events & Low Bkg D0 l d /dp Monte Carlo D0 Kl p Lattice Emiss - Pmiss First time measurement of complete set d /dp of charm PS PS & PS V absolute form factor magnitudes and slopes to a few % with almost no background in one experiment p Stringent test of theory! D0 l 35

36 CLEO-c Impact on Semileptonic B/B 1: D0 K- e : D0 K*- e : D0 - e+ 60 5: D K e : D+ K*0 e+ Error (%) 3: D0 - e+ 50 7: D e 8: D+ 0 e : Ds K e 0 + CLEO-c PDG : Ds K*0 e Decay modes 11: Ds e+ CLEO-c will make significant improvements in the precision with which each absolute charm semileptonic branching ratio is known! 36

37 Determining Vcs and Vcd Combine semileptonic and leptonic decays eliminating VCKM (D + l ) / (D+ l ) independent of Vcd Test rate predictions at ~4% level (D s l ) / (D s l ) independent of Vcs Test rate predictions at ~4.5% level Test amplitudes at 2% level Stringent test of theory - If theory passes test D 0 K - e+ Vcs/Vcs = 1.6% (now: 11%) D 0 - e+ Vcd/Vcd = 1.7% (now: 7%) Use CLEO-c validated lattice to calculate B semileptonic form factor Then B factories can use B / / /l for precise Vub 37

38 CLEO-c Physics Impact Crucial Validation of Lattice QCD: Lattice QCD will be able to calculate with accuracies of 1-2%. The CLEO-c decay constant and semileptonic data will provide a golden & timely test. QCD & charmonium data provide additional benchmarks. World Average ~2005 Assumes theory errors reduced by x2 (excluding CLEO-c) World Average with CLEO-c Theory errors = 2% 38

39 CLEO-c Physics Impact Knowledge of absolute charm branching fractions is now contributing significant errors to measurements involving b s. CLEO-c can also resolve this problem in a timely fashion. Measuring the relative strong phase between D0 K*+K- and D0 K*-K+ is crucial to determining angle with B K D0, D0 K*K Vcd Vcsof CKM Vcb elements, V ub V tdwhich Vts is now not very good PDG Improved knowledge 7% 11% 5% 17% 36% 39% 1.7% 1.6% 3% 5% 5% 5% CLEO-c Data and LQCD B Factory/Tevatron Data & CLEO-c Lattice Validation The potential to observe new forms of matter glueballs & hybrids and new physics D mixing / CP Violation / rare decays provides a discovery component to the CLEO-c research program. 39

40 fds from Absolute B(Ds + ) Measure absolute B(DS ) Monte Carlo Fully reconstruct one D (tag) DS tag VCKM 2 Compute MM 2 Peaks at zero for Require one DS+ + decay additional charged Expect resolution track and no of ~O(M ) additional Vcs (Vcd) known from unitarity to 0.1% (1.1%) photons DS fd 2 Decay Constant Reaction Energy (MeV) L (fb-1) f Ds Ds f Ds Ds + f D+ D+ f / f (%) PDG CLEO-c UL

41 Open Charm Production The (3770) is by far the best place to determine absolute charm branching ratios. MARKIII L CLEO-c 100 Number of Event (Million) Experiments at (3770) BESI/II Mark III 9.6 pb BES II 8 pb -1 CLEO III 5 pb -1 CLEO-c 3 fb-1 BES III (approved) 30 fb -1 BESIII J/psi psi(2s) psi(3770) Ds Pairs(4100) Family CLEO-c Physics Run MARKIII BESII BESIII Construction BESIII Engineer & Physics Run 2010 Year 41

42 CLEO-c Probes of QCD Verify tools for strongly coupled theories Quantify accuracy for application to flavor physics and spectroscopy Confinement, Relativistic corrections Masses, spin fine structure Leptonic widths of S-states Wave function Tech: fb,k BK fds Form factors Rich calibration and testing ground for theoretical techniques apply to flavor physics EM transition matrix elements resonances done in fall fall 2002 ~4 fb-1 DD / DsDs running in anticipate each ~3 fb-1 J/ running in 2005 anticipate 1 billion J/ Uncover new forms of matter gauge particles as constituents Glueballs G = gg Hybrids H = gqq Study fundamental states of the theory The current lack of strong evidence for these states is a fundamental issue in QCD Requires detailed understanding of ordinary hadron spectrum in theheavy 1.5Flavor 2.5 GeV and mass Spectroscopy CLEO-c range the 42

43 Gluonic Matter Many Glueball sightings without confirmation CLEO-c 1st high statistics experiment with modern 4 detector covering the GeV mass range c X J/ c Radiative J/ decays are ideal glue factory anticipate 60 million J/ radiative decays f 0 (1370) f 0 (1370) KK f 0 (1370) (D. f 0 (1370) KK Branching ratios of f0 triplet from WA102 Barberis et al., Phys. Lett.B (2000)) f 0 (1500) f 0 (1500) Input for glueball - scalar mixing models f 0 (1500) KK f 0 (1500) (F. Close et al., Eur.Mode Phys. J. C (2001)) CLEO-c J/ f0(1500): f0(1500) ,000 J/ f0(1710): f0(1710) ,000 J/ f0(1710): f0(1710) 93,000 J/ f0(1710): f0(1710) KK 250,000 f 0 (1500) ' f 0 (1500) f 0 (1710) f 0 (1710) KK f 0 (1710) f 0 (1710) KK f 0 (1710) ' 0.05(90%cl ) f 0 (1710) 43

44 CLEO III Running at (3770) Calibration M odes = 26% B = 1.5T (2S) (1S) + - CLEO III 9.1M (2S) (3770) + - J/ Data sample: 5.2 ± 0.2 pb pb-1 (4.5 ± 0.4) 104 (3770) decays 21,300 events Efficiency: 37.1% = 37% B = 1.0T (2S) + - J/ < 4.75 events at 90% C.L. Upper limit branching ratio: 1.5M (2S) 2.7 pb-1 B ( (3770) + - J/ ) < 0.26% at 90% C.L. 21,000 events = 37% B = 1.0T e+e- (2S) (2S) + - J/ 4.5k (3770) BES II: B = (0.59 ± 0.26 ± 0.16)% (hep-ex/ ) 5.2 pb events? (3770) + - J/ Ecm Mass(recoiling + -) + -l+l- events After cuts on M(l+l-) to make it close to M(J/ ) or M( (2S)) 44

45 Summary There are many new results on Heavy Flavor Spectroscopy - some come as a surprise and challenge theory - some were expected but are only now in reach of the experiment Many more results are to be expected because of rapidly growing data sets, new experimental efforts are starting or are being planed. HQET and LQCD are expected to catch up with the precision and breadth of new results. The Heavy Flavor Community expects major progress in the forthcoming years. 45

46 BACKUP SLIDES 46

47 Spin Parity of DsJ Mesons 47