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Charm and Beauty Physics at Fermilab Robert K. Kutschke Fermilab International Conference on Flavor Physics Zhang-Jia-Jie, Hunan, P.R. China June 4, 2001.

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Presentation on theme: "Charm and Beauty Physics at Fermilab Robert K. Kutschke Fermilab International Conference on Flavor Physics Zhang-Jia-Jie, Hunan, P.R. China June 4, 2001."— Presentation transcript:

1 Charm and Beauty Physics at Fermilab Robert K. Kutschke Fermilab International Conference on Flavor Physics Zhang-Jia-Jie, Hunan, P.R. China June 4, 2001 1.Introduction 2.D 0  D 0 Mixing and DCSD 3.Some Dalitz plots. 4.A few lifetimes.  c +  pK -   6.P-wave charm. 7.B Physics at the Tevatron. http://home.fnal.gov/~kutschke/talks/Misc/icfp01.pdf

2 R. K. Kutschke, FermilabICFP2001, June 4, 2001.2 Charm Experiments: Fixed Target E791 – 1990/91 500 GeV/c   Target: Pt, C. Follows: E516,E691,E769 SELEX (E781) – ran 1996/97 600 GeV/c     540 GeV/c p,  + Targets: C, Cu. Goal: charmed baryons FOCUS (E831) – 1996/97 300 GeV/c (max)  Target: BeO. Upgraded E687. Will not include: Charmonium: Fixed target, Tevatron, anti- p accumulator ring: E835. Production physics.

3 R. K. Kutschke, FermilabICFP2001, June 4, 2001.3 At Fermilab   BeO charm 

4 R. K. Kutschke, FermilabICFP2001, June 4, 2001.4 RICH Beam TRD

5 R. K. Kutschke, FermilabICFP2001, June 4, 2001.5 Very open trigger.

6 R. K. Kutschke, FermilabICFP2001, June 4, 2001.6 Properties of Fixed Target Exp’ts. Segmented Targets Si  -strip detectors Downstream magnets and tracking systems: Momentum measurement Vee’s Cerenkov based PID SELEX: RICH FOCUS,791: Threshold EM Calorimetry: FOCUS,SELEX: Pb Glass E791: Pb liquid scint. Hadronic calorimetery. Muon chambers: FOCUS, E791 only. High bandwidth trigger/daq. 791: Very open trigger. Others more selective.

7 R. K. Kutschke, FermilabICFP2001, June 4, 2001.7 Vertexing is the Key BeO tarsil | primary vtx | secondary vtx Decays / 200  m BackgroundSubtracted Golden Mode Charm Golden Modes: D +  K -     D 0  K -   D 0  K -      

8 R. K. Kutschke, FermilabICFP2001, June 4, 2001.8 SM Expectations for D 0 Mixing u c u c q = d, s, b d, s, b = q W W K +, π + K –, π – Short distance effects from box diagram. Highly suppressed: GIM mechanism Long distance effects from common intermediate states.

9 R. K. Kutschke, FermilabICFP2001, June 4, 2001.9 If CP is Conserved Diagonalize this: These have definite mass and lifetime: M 1, M 2,  1  2  Define: Exp’t: x < 0.03Exp’t: -0.06 < y < 0.01

10 R. K. Kutschke, FermilabICFP2001, June 4, 2001.10 Cartoon of  m and  Rate Mass

11 R. K. Kutschke, FermilabICFP2001, June 4, 2001.11 Time Evolution D 0  CP+ (eg K + K - ) D 0  CP - D 0  non-CP eigenstate ( eg. K -  , K -     Method 1: Compare lifetimes measured in K + K - and K -    This measures y.

12 R. K. Kutschke, FermilabICFP2001, June 4, 2001.12 D 0  K -     Mixing Tag initial flavor using D *+  D 0    Look for “wrong sign” decays: SM expectation ( expansion for small x and y): # of oscillations/mean lifetime = x/2 . Method 2: Measure time dependence of wrong sign K 

13 R. K. Kutschke, FermilabICFP2001, June 4, 2001.13 D 0  K +   : DCSD and Mixing DCSD: Doubly Cabbibo Suppressed Decay Wrong sign hadronic modes: both mixing and DCSD. t in units of mean lifetime;  relative phase between dcsd and mixing amplitudes. Method 3: Measure time dependence of wrong sign K +   : SM prediction:

14 R. K. Kutschke, FermilabICFP2001, June 4, 2001.14 Charm Mixing: Theory Predictions From compilation of H.N.Nelson hep-ex/9908021 Triangles are SM x Squares are SM y Circles are NSM x Predictions encompass 15 orders magnitude for R mix (but only 7 orders of x or y!)

15 R. K. Kutschke, FermilabICFP2001, June 4, 2001.15 FOCUS y CP Measurement Phys. Lett. B485:62 N=10331 N=119738 Assumes CP invariance. y CP =y if nature conserves CP D 0  K - K + : CP + D 0  K -    0.5 (CP + +CP - ) Signal and sideband regions shown. Strong clean up and PID cuts. Slice into time bins, subtract BG and efficiency correct. Deal with reflections.

16 R. K. Kutschke, FermilabICFP2001, June 4, 2001.16 Acceptance Corrections: = ( t – n  ), where n is the detachment cut. f( ) is very flat and is essentially same for K - K + and K -  . Derived from MC: fiducial volume, absorbtion.  fs: no need to convolute resolution.

17 R. K. Kutschke, FermilabICFP2001, June 4, 2001.17 FOCUS y CP Measurement Points: background subtracted, f(t ’ ) corrected yields Lines: Fit results.  (D 0 ) = 409.2 ± 1.3 (stat only); cuts optimized for y, not  Binned Max. Likelihood Fit Non-parametric treatment of the backgrounds. y CP =(3.42 ± 1.39 ± 0.74)%

18 R. K. Kutschke, FermilabICFP2001, June 4, 2001.18 E791 y CP Measurement PRL. 83 (1999) p.32 y CP =(0.8 ± 2.9 ± 1.0)%  KK  K   0.04 ± 0.14 ± 0.05 ps -1

19 R. K. Kutschke, FermilabICFP2001, June 4, 2001.19 Comparison of y Results Experimenty CP (%) Lifetime D 0  K  (fs) E7910.8 ± 2.9 ± 1.0413 ± 3 ± 4 FOCUS3.42 ±1.39 ± 0.74409.2 ± 1.3 (Stat. Only) BELLE (Preliminary)1.16 + 1.67  414.5 ± 1.7 (Stat. Only) CLEO (Preliminary)  1.1 ± 2.5 ± 1.4  ± 3.6 (Stat. Only) SELEX407.9 ± 6.0 ± 4.3 World Average1.77 ± 1.00412.6 ± 2.8 (PDG 2K) World Average

20 R. K. Kutschke, FermilabICFP2001, June 4, 2001.20 FOCUS: Wrong Sign D 0  K +   D*  D mass difference M(K  Tight particle ID + extra hard cuts if M(K  )  M(  K). Phys. Rev. Lett. 86:2955

21 R. K. Kutschke, FermilabICFP2001, June 4, 2001.21 FOCUS R WS Measurement FOCUS: R ws = (0.404  0.085  0.025)% CLEO: R ws = (0.332 +0.063 –0.065  0.040)% Yield = 36770  195 Yield = 149  31 Points: Fitted D 0 yield from previous page.

22 R. K. Kutschke, FermilabICFP2001, June 4, 2001.22 Interpretation of R WS Measurement Time integrated R WS depends on detachment cuts! Depends on t, not. Not a good observable: may vary between experiments! <> is average over true distribution of times. We believe x is small from semi-leptonic decays. Determine  t /  and  (t /  ) 2  using MC Measure R WS : 3 unknowns r DCS,.

23 R. K. Kutschke, FermilabICFP2001, June 4, 2001.23 Interpretation of R WS Measurement r DCS (%) Using measured R WS, for small x, solve for the allowed region in the r DCS - plane.

24 R. K. Kutschke, FermilabICFP2001, June 4, 2001.24 Comparison of Mixing Results Preliminary! No compelling signal. If  is small, FOCUS y CP can be compared directly to CLEO. Both consistent with zero but they have opposite sign! If opposite sign, implies large . Other measurements: E791: y CP = (0.8 ± 2.9 ± 1.0)% BELLE(prelim): E791 Kl : PRL 77:2384,1996. CLEO: PRL 84:5038, 2000.

25 R. K. Kutschke, FermilabICFP2001, June 4, 2001.25 E791: D +        Dalitz Plot PRL 86, 770 (2001). 0 21 0 1 2 S 13 (GeV 4 /c 2 ) S 12 (GeV 4 /c 2 ) Non-Resonant 2-3 Symmetrized Resonances included: Fit 1Fit 2  = Light Scalar

26 R. K. Kutschke, FermilabICFP2001, June 4, 2001.26 E791: Unbinned Max Likelihood Fit Fit 2: With   2 / = 138/162 0123 M2(-+)M2(-+) PRL 86, 770 (2001). 0 21 0 1 2 S 13 (GeV 4 /c 2 ) S 12 (GeV 4 /c 2 ) (GeV 4 /c 2 ) N/0.05 (GeV 2 /c 4 ) Fit 1: Without   2 / =254/162 120 80 40 80 40 0 0 Two entries/event Symmetrized

27 R. K. Kutschke, FermilabICFP2001, June 4, 2001.27 Need a light isoscalar to fit the data:  Fit 1 Fit 2  + - 46.3  9.0  2.1 - 205.7  8.0  5.2  + 20.8  2.4 33.6  3.2  2.2 0. (fixed) NR 38.6  9.7 7.8  6.0  2.7 150.1  11.5 57.3  19.5  5.7 f 0 (980)  + 7.4  1.4 6.2  1.3  0.4 151.8  16.0 165.0  10.9  3.4 f 2 (1270)  + 6.3  1.9 19.4  2.5  0.4 102.6  16.0 57.3  7.5  2.9 f 0 (1370)  + 10.7  3.1 2.3  1.5  0.8 143.2  9.7 105.4  17.8  0.6  0 (1450)  + 22.6  3.7 0.7  0.7  0.3 45.8  14.9 319.1  39.0  10.9 Fit Fraction Phase (degrees) M(  ) = 478  24  17  (  ) = 324  42  21 both in MeV/c 2 Can other groups see it? Is it in other channels?

28 R. K. Kutschke, FermilabICFP2001, June 4, 2001.28 E791: D s +         Dalitz plot Phys. Rev. Lett. 86 (2001) p. 765. f 0 (1370) f 0 (980) Other resonances present:   (770),   (1450), f 2 (1270). Mass and width measurements for the f(980) and f(1370).

29 R. K. Kutschke, FermilabICFP2001, June 4, 2001.29 SELEX:  c and D 0 Lifetimes  c +  p K -    D 0  K -    D 0  K -       } +CC No  c - Reduced Proper time: t R = [L-L Min ] M/pc L Min = 8  L Sideband regionsSignal regions Binned lifetime analysis OK since  t R 

30 R. K. Kutschke, FermilabICFP2001, June 4, 2001.30 BG sub,  corrected data. Background Acceptance function. SELEX:  c and D 0 Lifetimes  (  c ) = 198.1  7.0  5.6 fs  (D 0 ) = 407.9  6.0  4.3 fs Reduced Proper time: t R = [L-L MIN ] M/pc Simultaneous Max Likelihood fit to the binned signal and sideband t R distributions.

31 R. K. Kutschke, FermilabICFP2001, June 4, 2001.31 Observation of  c +  pK -   SELEX FOCUS 0.234±0.047±0.0220.20±0.04±0.02 c+c+

32 R. K. Kutschke, FermilabICFP2001, June 4, 2001.32 Additional Results:  c +  pK -   FOCUS: SELEX:

33 R. K. Kutschke, FermilabICFP2001, June 4, 2001.33 Observation of the D s2 * at Focus Preliminary FOCUS First observation of the D + K S 0 mode! D0K+D0K+ D+KS0D+KS0 There are some real K S 0 in the sideband sample. D s2 * has L=1 between quarks.

34 R. K. Kutschke, FermilabICFP2001, June 4, 2001.34 Simultaneous Fits to D 0 K + and D + K S 0 Spectra 1.D S2 Signal: D-wave Rel. BW 2.Smooth background shape 3.MC D S1 feeddown shape 4.MC D S2 feeddown shape. Significance is not stable with cut variations! Terms in the fit: Simultaneous: M and  same. Errors are statistical only PDG: M = 2573.5 ± 1.7 MeV/c 2  =  ± 5 MeV/c 2 Preliminary First observation of D + K S 0 mode

35 R. K. Kutschke, FermilabICFP2001, June 4, 2001.35 Observation of the D S1 at FOCUS Preliminary 1.D S1 Signal: Non Rel BW, convoluted with a gaussian. 2.Smooth background shape. 3.D S2 * Signal: D-wave Rel BW. Terms in the fit: Errors are statistical only PDG:  = 525.35 ± 0.34 MeV/c 2  < 2.3 MeV/c 2 @ 90 % CL.

36 R. K. Kutschke, FermilabICFP2001, June 4, 2001.36 Charm Summary E791 still going strong 10 years after data taking. Weak decays, production, strong interaction physics in Dalitz plots, rare decay physics. FOCUS and SELEX are now starting to publish. Expect lots more to come: lifetimes, Dalitz plots, charm spectroscopy, mixing and DCSD, rare decays, production … One recent highlight is the new level of precision available for measurements of mixing and DCSD. If it’s real, it’s interesting.

37 R. K. Kutschke, FermilabICFP2001, June 4, 2001.37 B Physics at CDF in Run I sin2     First fully reconstructed B s. Measurements of mixing in B d sector. Limits on mixing in the B s sector: Amplitude analysis of B 0  J/  K* 0 and B s  J/  . Lifetimes: B +, B 0, B s,  b. First observation of B c. Production cross-section and differential cross-sections.

38 R. K. Kutschke, FermilabICFP2001, June 4, 2001.38 B Physics at CDF in Run I … Limits on rare decays. Onia production. b quark fragmentation functions. J/  and  c, both prompt and from B’s. B Physics at D0 in Run I Limits on rare decays. Production cross-section and differential cross-sections. J/ , both prompt and from B’s.

39 R. K. Kutschke, FermilabICFP2001, June 4, 2001.39 B Physics at the Tevatron: Run II… Commissioning runs started in March 2001. Goal: start real data taking Sept. 2001. Will run until significant lumi at LHC ( 15 fb -1 ?). Huge luminosity upgrade Run I:  100. pb -1 best year Run II: 2000. pb -1 /year ( design lumi ) Upgraded detectors CDF and D0: Main physics goals: Higgs, SUSY, Precision top, etc These require excellent b tagging. B physics is an important part of these programs New dedicated B detector  2006: BTeV Workshop: http://www-theory.fnal.gov/people/ligeti/Brun2/

40 R. K. Kutschke, FermilabICFP2001, June 4, 2001.40 CDF Run II Upgrades Layer 00 on beam pipe  b : 50  m  35  m TOF:  t = 25 ps K/  Sep. at 2  to 1.6 GeV/c Electronics, Trigger and DAQ upgraded

41 R. K. Kutschke, FermilabICFP2001, June 4, 2001.41 Scintillating Fiber Tracker

42 R. K. Kutschke, FermilabICFP2001, June 4, 2001.42 2 ndry vertex trigger at Level 1 Stage I approval received June 2000.

43 R. K. Kutschke, FermilabICFP2001, June 4, 2001.43 Some Comparisons Compare to e + e - B-factories: + About 4 orders of magnitude more rate. + Access to B s, B c, and b baryons. - Poorer S/B; at e + e - initial state well understood. BTeV vs CDF and D0: + BTeV is a dedicated b experiment. + Much better K/  p particle ID. ± More aggressive trigger. - CDF and D0 are running now.

44 R. K. Kutschke, FermilabICFP2001, June 4, 2001.44 Sensitivity to B s Mixing CDF has sensitivity out to  60 for 2 fb -1. D0 has sensitivity out to  30, for 2 fb -1. This will be one of the first important b physics measurements of Run II.  (x s )  0.2 for all interesting values of x s.

45 R. K. Kutschke, FermilabICFP2001, June 4, 2001.45 Other Projections for 2 fb -1 CDF: Errors on B -, B 0, B s and  b  lifetimes will decrease 5x. B s lifetime difference CDF: B s  J/  and D s (*)+ D s (*)- BTeV: B s  J/    J/  D s   sin2  (CDF,D0)  sin2  (BTeV) BaBar now =±0.2 stat Projects to ±0.04 stat for 500 fb -1 at PEP II. B s  D s K CDF:  sin   by end of Run II  BTeV:  

46 R. K. Kutschke, FermilabICFP2001, June 4, 2001.46 Other Projections for 2 fb -1 B s  J/   :  sin2  s  (BTeV) CDF looking at this too. BTeV: a lot of charm will pass the b trigger. High precision measurments, or limits, on x, y, r DCs, rare decays. CDF and D0 have not evaluated how much charm they get. B 0        BTeV: O(1000) diluted flavor tagged events. Compares to a few tens for B-factory at their design lumi. BTeV: Learning how to do Dalitz plot fits with resolution effects, efficiency and backgrounds.

47 R. K. Kutschke, FermilabICFP2001, June 4, 2001.47 B Physics at the Tevatron Summary During Run I B physics was an afterthought but it still produced a wealth of B physics, competitive in many places with CLEO, LEP, SLD. Run II detectors have B physics designed in. Great things are expected. Will be competitive with the B-factories in many areas and will exceed them in others. BTeV will come online near the end of Run II and will carry the B physics program to the end of the decade. It will also have a signficant charm program.


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