1. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL1 Charm Studies at CDF Burkard C. Reisert for the CDF Collaboration Charm Meson Pair Production Studies of Charmonium Production - J/  and  ' polarization - Relative  c1,  c2 Production Picture of FNAL or Oxford

2. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL2 Motivation: Inclusive Charm Meson Cross Sections D0D0 Kniehl et al., hep-ph/0508129 The measurement of inclusive charm meson\cross sections (D 0, D* ±, D +, D s + ) was one of the first CDF Run II results - up to a factor 2 higher than expected - progress in theory reduced deviation - still on the high side - measurement systematically limited (L=5.8 pb-1) CDF Run II (L=5.8 pb -1 ) FONLL Cacciari et al., JHEP, 05:00, 1998 CDF Collab., PRL 241804

3. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL3 Heavy Quark Production: Leading Order Picture Second charm particle in the event gives access to the underlying production mechanism Study fully reconstructed prompt charm meson pairs allows for acceptance and efficiency correction PS = Parton Shower

4. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL4 Charm Meson Pair Reconstruction Simple experimental approach Find triggered charm meson D 0, D +, D*, D s +, Look for second charm meson probe D* + Take advantage of inclusive measurement from a short well controlled running period: Measure of pair cross section relative to inclusive cross section, systematic uncertainties largely cancel over the entire CDF Run II Primary Vertex

5. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL5 Prompt Charm Production Cross Sections Inclusive production (already measured by CDF): Pair production: Relative pair Cross section: uses N i :Number of observed charm mesons in i th P T bin N ij : Number of observed charm meson pairs with D 1 in i th P T bin and D 2 in j th P T bin f P D : fraction of prompt D mesons f P DD : fraction of prompt pairs  i : trigger and reconstruction efficiency  ij :pair trigger and reconstruction efficiency  j :probe-side reconstruction efficiency  dt : integrated luminosity B : branching fraction e.g. D 0  Kp

6. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL6 Inclusive triggered charm mesons

7. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL7 Number of D 0 Trig D* ± Probe Pairs 2dim SB-subtraction by weighting events In mass plane of Trigger D and soft  tagged Probe D 0

8. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL8 Number of D 0 Trig D* ± Probe Pairs 2dim SB-subtraction by weighting events In mass plane of Trigger D and soft  tagged Probe D 0

9. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL9 D s + D* - D* + D* - D + D* -

10. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL10 Charm Meson Pairs vs.  (Raw Yields) Uncorrected for efficiency (  ) and secondary (f b ) detector level  distributions fully reconstructed decays of both D  correct for  (simulation verified on data) D 0 D* - D+D*-D+D*-

11. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL11 Extraction of Prompt D Production ● Extract prompt/secondary fractions from Ip of probe side D 0 : f bb =34% ● Cross checks : Ip, L xy of trigger/probe D and DD*- pair Secondary D Prompt D PV = Primary Vertex Ip

12. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL12 Measurement of Charm Meson Pair Cross Section published CDF measurements of inclusive cross sections branching fraction from PDG Efficiency for fully reconstructed Probe side D* + Inclusive Charm Meson Yields and prompt Fractions DD Pair yields and Prompt fraction

13. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL13 D 0 D* - Pair Cross Section binned in P T (Trig) Error: stat  sys(f b ) Common Syst. Error:  ~15%

14. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL14 D 0 D* - Cross Section ● Normalization of D 0 D* - cross section in Pythia is about right, ● Gluon Splitting as important as Flavour Creation ● Pythia under estimates GS (over estimates FC)

15. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL15 Error: stat  sys(f b ) Common Syst. Error:  ~19% Significant shape discrepancy Consistent for D 0 D* - and D + D* - D + D* - Pair Cross Section binned in P T (Trig)

16. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL16 Charmonium Production

17. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL17 Color Singlet & Color Octet models Color Singlet Model: ● cc pair is “bleached” by radiating off a hard gluon ● Underestimates J/  (1/10) and  ’ (1/50) production ● Feed down from  cj dominates (>90%) J/  production (CDF Run I finds 30%) ● PT spectrum does not match data pp pp J/  hard g soft g c c c c Non relativistic QCD introduces Color Octet Mechanism: ● Soft gluon radiation ● Adjustable hadronization parameter allows to match the observed PT spectra and production cross sections ● Predicts transverse polarization for J/  deviates from data

18. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL18 “Pomeronic Idea” J/  p p P P P P p p Pomeron picturepQCD Recent idea by V.A. Khoze, A.D. Martin, M.G. Ryskin and W.J. Sterling hep-ph/0410020 Fusion of a symmetric colour octet state and a gluon ● Cross sections calculated in LO pQCD consistent with data ● PT spectra match data ● Predicts longitudinal polarisation of J/  increasing with p T Emission of omerons omerons have vacuum Quantum numbers J P = 0 0 P P P P

19. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL19 Polarization of J/   * angle between  + in J/  rest frame and J/  in lab frame  polarization parameter  =0 all 3 helicity states are equally populated  MC polarization templates (trigger efficiency from data)

20. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL20 J/  Yields and Separation of Prompt and Secondary J/  Use     combined impact parameter significance to separate prompt S≤8 and secondary S>16 J/  selection Central: |y|<0.6 5<P T <30GeV/c

21. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL21 Polarization of J/  Mesons Polarization of J/  from B decays ● independent of P T ●  B = -0.066±0.050 ● Consistent with BaBar (  B = -0.129±0.009) CDF result includes B s and B baryons Polarization of prompt J/  ● Corrected for residual secondary J  ●  <0: longitudinal polarization

22. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL22  ’ Polarization ● Same theoretical framework applies to prompt  ’ and J/  production ● no contribution from feed down from higher states therefore  ’ is a cleaner system to test direct charmonium production ●  ’ uses analysis approach as just described for J/ 

23. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL23  ’ Polarization Results Polarization of prompt  ’ ● Longitudinal polarization at high p T, just as for J/  Polarization in B decays ● First measurement of  B for  ’ ●  B = 0.28±0.27± 0.03 (consistent with J/  within stat.)

24. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL24  cJ Production ● Models of prompt charmonium production in hadron collisions always contain significant  cJ contributions ● The measurement of  (  c2 )/  (  c1 ) has been performed at several energies and beam types over the years.  Best measurements have ~100 events, 30% statistical uncertainty on the cross section ratio.  Results like 1.0±0.3 are consistent with most models.

25. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL25 Measurement of  (  c2 )/  (  c1 ) ● Measurement of properties of  cJ production has always been an experimental challenge ● Low energy photon from  cJ  J/  is difficult to measure (~400 MeV in  cJ rest frame) ● Calorimeter measurements have good efficiency but poor resolution and high background in a hadron collider environment ● Conversion measurement - good resolution - poor efficiency (now compensated L=1fb -1 )  cJ J/   e e 

26. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL26  cJ Data Set Here we reconstruct:  cJ  J/ , J/    +  -,   e + e - ● J/  selection as polarization analysis ● Photon conversion gives excellent energy (mass) resolution. ● Prompt and B-decays are easily separated Simultaneous fit to the mass and flight distance distributions is used to extract the relative yields for both prompt  cJ and  cJ from B decays

27. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL27 Results on  c1 )/  c2 ) New level of precision for measurement of  c1 )/  c2 ) Should provide nice constraint on models of production mechanisms Result for prompt  cJ : for 4 < p T (  cJ ) < 20 GeV/c ● Color Octet predicts 5/3 (counting of Spin states)

28. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL28 Conclusion The unprecedented integrated luminosity delivered by the Tevatron in conjunction with CDF’s high bandwidth trigger allows us to perform Charm studies we did not anticipate. New “Charming” results: ● First measurement of charm meson pair cross section in an hadron collider environment probes open charm production:  gluon splitting underestimated ● Polarization measurements of J/  and  ’ instigates new theory approach to charmonium production ● New level of precision for measurement of  (  c1 )/  (  c2 ) provides new trial to models of charmonium production Charm Physics at the Tevatron has its beauty

29. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL29 Acknowledgements Contact persons for the presented CDF analyses: ● Charm meson pair cross Sections Burkard Reisert, reisert@fnal.govreisert@fnal.gov ● J/  and  ’ polarization Min-Jeong Kim mjkim@fnal.govmjkim@fnal.gov Kwangzoo Chung kchung@andrew.cmu.edukchung@andrew.cmu.edu ● Relative  c1  c2 production Patrick Lukens ptl@fnal.govptl@fnal.gov

30. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL30 Backup slides ● Tevatron, CDF & Trigger

31. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL31

32. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL32

33. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL33 Heavy Quark Production in Higher Orders Example Feynman Diagrams Calculations with massive quarks –incoming charm (?) –charm in final state parton shower (?) All shown example graphs can be interpreted as higher order flavor creation Flavor Creation (a 2 s ) Gluon Splitting (a 3 s ) Flavor Excitation (a 3 s ) Gluon Radiation (a 3 s ) Interference Term (a 4 s ) Gluon Radiation (a 3 s )

34. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL34 Tevatron Run II Physics Goals: ● Properties of top quark ● Precision Electroweak Physics ● CKM, B s Mixing ● Searches for new phenomena ● Tests of QCD New world record ISR @ √s=62 GeV

35. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL35 Collider Detector at Fermilab Silicon Microstrip Tracker Time-of-Flight Drift Chamber Plug Calorimeter Muon Muon System Solenoid Central Calorimeter Fwd Calorimeter |  | to 5.5 Scint based |  | to 3.6 1.0<|  |<2.0 Old New Partially New

36. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL36 CDF Trigger & DAQ System CDF Detector L1 trigger L2 trigger L3 farm disk/tape 42 L1 buffers 4 L2 buffers 1.7 MHz crossing rate 25 kHz L1 accept 500 Hz L2 accept 100 Hz L3 accept Hardware tracking for p T  1.5 GeV Refined Muon-track matching Electron-track matching Missing E T, sum-E T Silicon tracking Dedicated hardware Hardware + CPU Linux farm (>200 CPUs) Jet finding Full event reconstruction Refined electron/photon finding The trigger is the key to heavy flavour physics at hadron colliders Muon-track matching

37. 29 September 2006CDF Charm Studies at Beauty 2006, Burkard C. Reisert, FNAL37 Triggers for Beauty & Charm Physics Di-Muon (J/  ) P T (  ) > 1.5 GeV J/  (2S) modes Down to low P T (J/  ) (~ 0 GeV) Two Track Trigger P T (trk)>2 GeV IP(trk) >100  m Fully hadronic modes Displaced track(s) + lepton (e,  ) IP(trk)>120  m P T (lepton) >4GeV Semileptonic modes  (2s), X(3872)  J/  (quarkonia) B s  J/ , B u,d J/  K s (*)  b  J  (masses, lifetimes, mixing calibration) B s,d   (rare decays) B c (lifetime B  J/  lX, mass B  J/  ) 2-body charmless decays (B 0,B s,  b ) B s mixing (hadronic) Charm physics - inclusive cross sections - D 0   Heavy quark production B s mixing (semileptonic) Tagging, lifetime Primary Vertex Secondary Vertex Decay Length L xy d=impact parameter