1 / 26

CLEO-c and CKM Physics

CLEO-c and CKM Physics. Karl M. Ecklund Cornell University WIN 2003 October 7, 2003. CLEO-c and CESR-c. What’s with the “-c”? CLEO detector Symmetric e + e - collider  s=10.6 GeV Add wigglers to improve damping and run at  s=3-6 GeV Access to charm threshold region

ivana
Download Presentation

CLEO-c and CKM Physics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CLEO-c and CKM Physics Karl M. Ecklund Cornell University WIN 2003 October 7, 2003 CLEO-c and CKM Physics

  2. CLEO-c and CESR-c What’s with the “-c”? • CLEO detector • Symmetric e+e- collider s=10.6 GeV • Add wigglers to improve damping and run at s=3-6 GeV • Access to charm threshold region • Approved by National Science Board Feb 2003 • First Physics Run starts October 24, 2003 • 3+ year program CLEO-c and CKM Physics

  3. Context for CLEO-c Flavor physics: • Overconstrain VCKM • Inconsistency  new physics • Interpretation limited by strong interaction effects • Measurements in Charm decays can validate QCD corrections needed to extract Weak physics from observables • Sin 2b is clean • |Vub| is not • B mixing is not • Hadronic uncertainties confound the • extraction of weak physics • Non-perturbative QCD • Perturbative QCD (on better ground) CLEO-c and CKM Physics

  4. 1.2% ~15% (LQCD) UT Constraint from B mixing • Lattice QCD predicts decay constants fD(s)/fB(s) • If precise measurements of fD and fDs exist, then our confidence in non-perturbative QCD calculations needed to make constraints on the UT is increased. • Even better if Bs mixing is observed! CLEO-c and CKM Physics

  5. UT Constraint from |Vub| |Vub| from Bpln: • Absolute rate and shape is a stringent test of theory • Heavy quark symmetry relates Dpln to Bpln • A precise measurement of Dpln can calibrate LQCD and allow a precise extraction of |Vub| from Bpln • Form factor f(q2): • Not well known • Limits |Vub| precision • Predicted by LQCD CLEO-c and CKM Physics

  6. Vub/Vub 17% Vud/Vud 0.1% Vus/Vus =1% l l e B n n K n n p p  Vcs/Vcs =11% Vcb/Vcb 5% Vcd/Vcd 7% l D n l K B n l D D n p Vtb/Vtb 29% Vtd/Vtd =36% Vts/Vts 39% W Bd Bd t Bs Bs b Status of CKM Matrix Current VCKM From direct Measurements -no unitarity imposed CLEO-c will redefine 2nd generation elements And enable improvements in 3rd generation CLEO-c and CKM Physics

  7. CESR-c 6/12 Wigglers Installed Spring’03 6 more March-May’04 E=1.5-3 GeV CLEO-c and CKM Physics

  8. CESR-c One day scan of y’: CESR: L((4S)) = 1.3.1033 cm-2 s-1 yJ/y  J/y  s(nb) CESR-c Design Luminosity: L ~ 1.1030 (~BES) 1 wiggler Ebeam Machine performance:D Ebeam ~ 1.6 MeV at y’ (6 wigglers) CLEO-c and CKM Physics

  9. CLEO-c Detector State of Art Detector: • Drift Chamber Tracking (1 Tesla) • RICH Particle ID • Crystal EM Calorimetry • 93% of solid angle • Only small changes from CLEO III • B field 1.5  1 T • Silicon  ZD CLEO-c and CKM Physics

  10. CLEO-c and CKM Physics

  11. New Inner Detector • Replaced Silicon Vertex Detector May 2003 • 6 stereo layers: • r=5.3 cm – 10.5 cm • 12-15o stereo angle • |cos q| < 0.93 • 300, 10 mm cells • 1% X0 inner Al tube .8mm • Helium-Propane (60:40) • 20 mm Au-W sense wires • 110 mm Au-Al field wires • Outer Al-Mylar skin • Continuous tracking volume • Low mass (sp is MS limited) • Nothing to vertex at charm threshold! CLEO-c and CKM Physics

  12. CLEO III • Y(4S) • Typical • Hadronic • Event • Average: • 10 tracks • 10 showers CLEO-c and CKM Physics

  13. CLEO-c • y(3770) • Typical • Hadronic • Event • Average: • 5 tracks • 5 showers Event Recorded September 29, 2003 CLEO-c and CKM Physics

  14. Charm Threshold Region • D+D-, D0D0 aty(3770) • Ds+Ds- at s=4140 MeV • Potential for Lc+Lc- • Will also run on J/y and possibly y’ CESR-c Energies DD cross section at y(3770) ~5 nb (Mark III) DsDs cross section ~0.5 nb CLEO-c and CKM Physics

  15. CLEO-c Run Plan Phase I:y(3770) – 3 fb-1 (y(3770) DD) 30 million DD events, 6 million tagged D decays (310 times MARK III) Phase II:s=4140 MeV – 3 fb-1 1.5 million DsDs events, 0.3 million tagged Ds decays (480 times MARK III, 130 times BES) Phase III:y(3100) – 1 fb-1 1 Billion J/y decays (170 times MARK III, 20 times BES II) Now:Dec’02 5 pb-1 at y(3770) Oct’03-Jan’04 50 pb-1 on y(3770) CLEO-c and CKM Physics

  16. Tagging Technique – Tag Purity • y(3770)  D D s ~4140  Ds Ds • Charm mesons have many large branching ratios (~1 - 15%) • High reconstruction efficiency •  High net tagging efficiency ~20% • Anticipate 6M D tags and 0.3M Ds tags D  Kp tag: S/B ~ 5000/1 Ds fp (f  KK) tag:S/B ~ 100/1 Log Scale! Monte Carlo Monte Carlo Log Scale! CLEO-c and CKM Physics

  17. Absolute Charm Branching Ratios Double tag technique: Almost zero background in hadronic tag modes Measure absolute B(D  X) with double tags B = D- tag D+  K-p+p+ Monte Carlo # of X # of D tags CLEO-c: potential to set absolute scale for heavy quark measurements 50 pb-1 ~1,000 events  x2 improvement (stat) on D+ K-p+ p+ PDG dB/B CLEO-c and CKM Physics

  18. |fD|2 |VCKM|2 l n fDs from Absolute B(Ds m+n) • Measure absolute • B(Ds mn) • Fully reconstruct • one D (tag) • Require one • additional charged • track and no • additional photons Monte Carlo • Compute MM2 • Peaks at zero for • Ds+ m+ n decay • Expect resolution • of ~O(Mpo) DS tag DS mn Vcs (Vcd) known from unitarity to 0.1% (1.1%) CLEO-c and CKM Physics

  19. Semileptonic Decays: |VCKM|2 |f(q2)|2 CLEO-c Monte Carlo D0pln Tagged Events & Low Bkg D0 pln dG/dpp Monte Carlo D0 Kln pp Lattice QCD Emiss - Pmiss D0 pln • Measurement of complete set of charm P  P ln & P  V ln absolute form factor magnitudes and slopes to a few %: • almost no background • one experiment dG/dpp Stringent test of theory! pp CLEO-c and CKM Physics

  20. CLEO-c Impact on Semileptonic dB/B 1: D0 K- e+n 2: D0 K*- e+n 3: D0 p- e+n 4: D0 r- e+n 5: D+ K0 e+n 6: D+ K*0 e+n 7: D+ p0 e+n 8: D+ r0 e+n 9: Ds K0 e+n 10: Ds K*0 e+n 11: Ds f e+n PDG CLEO-c CLEO-c will make significant improvements in precision for each absolute charm semileptonic branching ratio. CLEO-c and CKM Physics

  21. Determining |Vcs| and |Vcd| Combine semileptonic and leptonic decays – eliminating VCKM G(D+ p ln)/G(D+ ln) independent of |Vcd| Test rate predictions at ~4% level G(Ds f ln) /G(Ds ln) independent of |Vcs| Test rate predictions at ~4.5% level Test amplitudes at 2% level Stringent test of theory - If theory passes test … D0  K- e+ndVcs/Vcs = 1.6% (now: 11%) D0  p-e+ndVcd/Vcd = 1.7% (now: 7%) Use CLEO-c validated lattice to calculate B semileptonic form factor  B factories can use B r/p/h/ln for precise |Vub| determination. CLEO-c and CKM Physics

  22. Inclusive Semileptonic Decays • Significantly improved D X e spectrum possible using tagged D’s • Backgrounds in B X lnanalyses (bcl) • Test of HQET: D0, D+, Ds+ same to few % • Ds and D+ weak annihilation contribution – a concern for |Vub| from El endpoint • Inclusive spectra + HQET used for |Vcb| from bc ln DELCO y(3770)  DD  eX Also can measure BSL to get GSL - currently no measurement for Ds CLEO-c and CKM Physics

  23. Strong Phases in Hadronic D • Methods to measure g in B± D0K±; D0 f • Aided by measurements of strong phases in hadronic D decays: • Dmany Atwood & Soni PRD 68, 033003 • D0K*±K Rosner & Suprun PRD 68, 054010 • CLEO-c: advantage of quantum coherence: y(3770)  DD ; JP=1- ( ) ( ) Interference of K*+ & K*- bands CLEO-c and CKM Physics

  24. CLEO-c & Unitarity Triangle • Potential Impact • Top: current experimental and theoretical uncertainties • Bottom: current experiment with 2% theory uncertainties – perhaps possible with LQCD calibrated with CLEO-c data CLEO-c and CKM Physics

  25. Vub/Vub 17% Vud/Vud 0.1% Vus/Vus 1% 5% l l e B n n K n n p p  3% 2% 2% Vcd/Vcd 7% Vcs/Vcs 11% Vcb/Vcb 5% l D n l B n K l D Future VCKM D n p Vtd/Vtd 36% 5% 5% Vtb/Vtb 29% Vts/Vts 39% W Bd Bd t Bs Bs b Potential Impact on VCKM Current VCKM From direct Measurements -no unitarity imposed CLEO-c will redefine 2nd generation elements And enable improvements in 3rd generation CLEO-c and CKM Physics

  26. Summary • The CLEO detector is state of the art, understood at a precision level, and collecting data in the cc resonance region. • CLEO has a long history of weak decay and CKM physics interests that will carry over to the CLEO-c program • CKM physics • semileptonic D decays: spectra, form factors, |Vcs| & |Vcd| • Leptonic decays: fD fDs informing B mixing interpretation • Enabling measurements of Hadronic D decays • Strong Phases to inform g determinations in BDK • Measurement of absolute branching fractions CLEO-c and CKM Physics

More Related