Heavy Flavour Physics at the Tevatron

1. Heavy Flavour Physics at the Tevatron Zero to Z0 Conference: Fermilab, May 12-14 2004 Farrukh Azfar, Oxford University (CDF)

2. Overview of this presentation: Preliminary: 1) Tevatron performance, Beauty physics at hadron colliders 2) CDF and D0 detectors, relevance for B-physics Physics Results & Prospects: 3) Tests of Heavy Quark Expansion (HQE) Masses and Lifetimes of B hadrons. Hadronic Moments. 4) Search for Flavour Changing Neutral Current (FCNC), Rare decays… 5) Mixing and CP violation (CPV), Toward Bs-mixing & CKM angle g. 6) Conclusion and Summary

3. Tevatron pp collider upgrade & performance, integrated luminosity Run-IIa -Goals are Ldt=2fb-1 (x20 Run-I, 1992-96) Run-II Tevatron Upgrades: -Main Injector for Tevatron -Higher proton intensity -Anti-proton transfer efficiency increased -Anti-proton recycler (coming after autumn) CDF Performance Improvement: -Collision rate: 3.5 ms 396 ns - Bunches: 6x6 36x36 -Center of Mass energy: 1.81.96 TeV/c2 -Peak luminosity : 2.4x10317.2 x1031cm2s-1 (Below target by x2.5, but improving) Data taking efficiency~80-90% for CDF & D0 Results in this talk: CDF analyses ~65-250 pb-1 D analyses ~115-250 pb-1 290 pb-1on tape at CDF & D0

4. s(bb) at (4S) = 1nb (B-factories) (Compare bb production s(bb) at Z0 = 7nb (LEP) cross section) s(bb) at pp (1.96TeV/c2)=150mb(Tevatron Experiments) More B @ Tevatron but inelastic s is 103 x s(bb) -Select b-data online, key: right detector & triggers -Rewards: all B-hadrons e.g.B, B0, Bs, Bc , b … (unlike B-factories) & higher s than at Z0 Clever Online BSelection(Triggers): ”Traditional” Use leptons from e.g. BsDs+m-nCDF & D0 (single-lepton) & B J/yK*, J/ym+m-:CDF & D0 (di-lepton) ”Modern” long B lifetimeslarge impact parameter (IP) of daughter tracks : CDF (D0 in progress) SVT trigger: purely hadronic decays of B and Charm e.g. D0p+p-, BsDs+p-, Ds+f p+fK+K- (1st @ hadron machine!) CDF Apply High IP requirement in single-Lepton data as well Why Beauty at the Hadron-Hadron Colliders ?

5. CDF Detector The CDF & D0 Detectors in Run-II CDF & D0 Detectors are both Multi-purpose with: -Axial Solenoid -Inner Silicon micovertex detectors -Outer trackers -Calorimetry -Muon ID -Muon Triggering (CDF & D0) -High IP Track triggering (CDF) D0: Better calorimetry, better muon & tracking coverage CDF: Better momentum measurement, also can select high IP tracks, some Hadron ID with dE/dX, TOF D0 Detector

6. Physics Results, Testing HQE: B-hadron lifetimes, massesGoals, Techniques Goal: test the HQE Predicted B Lifetime hierarchy : tBc << tXb0 ~ tLb < tBd ~ tBs < t B- < t Xb- • Fully Reconstructed B from J/ym+m- di-muon trigger (e.g. BsJ/yf) or High IP trigger (e.g. BsK+K-) • Find vertex, 2-d distance: Lxy invariant mass: MB • momentum in 2-d: PtB Find proper time: ct = Lxy. MB/PtB • - Fit mass distribution only or mass and lifetime distributions • Partially Reconstructed e.g. Bsm+Ds-n, B+m+nD0 • 1-lepton (+High IP track CDF )trigger: • Missing n means: ct = Lxy.MB/PtB=Lxy(D0m+).MBK./Pt(m+D0) • -K= Pt(m+D0) /PtBfrom MC: high statistics but worsesct -Decays selected using SVT trigger have biased ct -”Turn-on” near low IP cut -”Turn-off” at high IP cut -Bias fix underway: Then measure Lifetimes in BsDs+p- etc….

7. J/ym+m-, fK+K-(using di-muon (J/y) trigger): Run-I: ~60 at CDF. Run-II: D0~403, CDF~269 Largest sample of fully reconstructed Bs remains at the Tevatron Physics Results, HQE: BsJ/y f, Lifetime and Mass: CDF:M(Bs)=5366.010.73(stat)0.0.33 (sys)MeV/c2D0:M(Bs)=53605 MeV/c2 CDF: t(Bs)=1.3470.0990.013 ps & t(Bs)/t(Bd)= 0.89 0.072 D0: t(Bs) = 1.1900.180.014 ps (69 events, update in progress) Mass & Lifetime Results from assorted other fully reconstructed decays: CDF: t(LB)= 1.25±0.26±0.10 ps (bJ/y), M(LB)=5619.7±1.2±1.2 MeV/c2 Bs and LB mass measurements remain worlds best..

8. Physics Results (aside): Bs width difference DGs angular separation of CP eigenstates CDF & D0 fit 1 lifetime But: there are 2: tCP+,tCP- & DGBs=1/tCP+-1/tCP- DGs: predicted to be large ~10%, provides SM consistency check: DGs=A.DMBs If DMBs is large & DGs is small or vice-versasign of new physics Need to measure lifetime(s) : can do, and determine CP content: Use angular analysis…(CDF) and put them together (when we have higher statistics) Convenient basis: transversity Allows easy separation of CP content of BVV decays Analyse: Bs J/y f &Bd J/yK* as a check (J/ym+m-, fK+K-,K*(892)K+p-) PDF has 3 angles: f(QT ,FT, QK*) with amplitude parameters A,A A0 so that: A2=CP odd fraction & A2+A02=CP even fraction

9. Physics Results (aside): Bs width difference DGs angular separation of CP eigenstates Using 176 BsJ/yf & 993 BdJ/yK*(892) (as a check) Compatible with BaBar & Belle Polarization analysis indicates CP+ = 0.77±0.10: The larger the dominance of a CP eigenstate the greater the accuracy of DGs Analysis will be done at D0 as well !

10. Physics Results Testing HQE: Charged to Neutral B-Meson lifetime ratio (D0) D0: Charged to Neutral B-Meson Lifetime Ratio: t+/t0 Use: -B m+nD*(2010)-X: mostly Bd -B m+nD0X : mostly Bu± -Calculate ratio of events/lifetime bin N+/N0 ~e-(t+/t0-1)t (K-factor)st -Calculate expected ratio using all BRs in terms of k= t+/t0, and N(overall normalization) & Minimize c2 determine k and N D0 Result:t+/t0 = 1.093 ± 0.021 ± 0.022, N=1.001±0.012 BaBar: t(B+)/t(Bd)= 1.064 ±0.031 ±0.026 CDF: t(B+)/t(Bd)= 1.080 0.042Belle: t(B+)/t(Bd)= 1.091±0.023±0.014(B+J/yK+ & BdJ/yK*0) One of the World’s best single measurements

11. bJ/y (CDF) Physics Results Testing HQE: More B decays used: BdJ/y K* (D0) B+J/y K+(D0) B+J/y K+(CDF)

12. Physics Results: Hadronic Moments from D** decays 1) HQE:G(BXclnl)~GF2|Vcb|2 mb5.S(Cn/mb)n with Cn = <0|OnHQE|0> (non-perturbative, can extract from data) 2) Free parameters : L at O(1/mb), l1+l2 @ O(1/mb2) , etc…. 3) Moments M1,M2 of Xc invariant mass distribution: from B-decays: have expansions similar to 1) i.e..in terms of L & l1+l2 (sH=MXc2) 4) By finding pdf & hence M1, M2 ->constrain L, l1 , & improve Vcb measurements 5) Now First 2 pieces from D*, D0 are well known. f** (sH) comes from narrow & wide D**+higher order(resonant & non-resonant): |Vcb|incl= (41.9 ± 0.7exp ± 0.6theo) 10-3 containsL, l1

13. Reconstruct B- D**0 l- Find m and D**0 consistent with B parent (vertex). Use lepton + high IP track data. Physics Results : Hadronic Moments f**(sH) distribution Reconstruct D**0D*+- & D**0D+- decays are reconstructed, moments: m1, m2 calculated wrt f**(sH) In going from m to M assume: -lepton p in B rest frame >700 MeV -MD, MD* , Branching ratios from PDG -Only D** decays to 1p + D, D* M1 M2 from D, D* & D** best single measurement !

14. -Use high-mass di-muon data • -BRSM(Bsm+m- )=(3.8 ± 1.0) 10-9some extensions predict x103 BRSM • Variables: Mass, lifetime, Df from vertex & Isolation • 1 background event expected, 1 event seen: no excess->BR limit Rare B decays: B s(d)m+m- at CDF BR Upper Limit at 95% CL 7.5x10-7 Bsm+m- (World’s best) 1.9x10-7 Bdm+m- BR Upper Limit at 90% CL 5.8x10-7 (Bsm+m-) 1.5x10-7 (Bdm+m-) “Blind” analysis: cuts optimization before looking at the signal mass region Bd result: Belle: 1.6x10-7 & BaBar 2.0x10-7 Submitted to PRL

15. Physics Results Bsm+m- limits from D0: -Use MC for signal data, background for cut optimisation: -Expect 7.3  1.8 background events in signal region The analysis has not been unblinded yet (signal region still hidden). It is still being optimized (without bias) and expected to improve … 180 pb-1 Expected limit (Feldman/Cousins): Br(Bs  + -) < 9.1  10-7 @ 95 % CL (stat only) Br(Bs  + -) < 1.0  10-6 @ 95 % CL (stat + syst) (expected signal has been normalised to B  J/ K for BR limit calculation)

16. Rare Decays: Bsff :Observation & BR (SVT Trigger) CDF 1) Bsff decays via second order weak decay 2) SUSY coupling could enhance the SM BR (10-5) 3) Comparison of angular distributions of various B VV decays can determine a and g First “observation” (4.8s) ! Blind analysis 1) Normalization Mode: BsJ/y f 2) Relative Efficiencies from MC 3) N(Bs J/y f) is corrected for: Reflections from Bd J/y K* 4) J/y  m+m-fK+K-BsJ/y f BRs taken from PDG BR= (1.4 ± 0.6 ± 0.2 ± 0.5 (BR))x10-5 (SM 3.7x10-5) Upper Limit : <2.7x10-5 @ 95% CL

17. -Mixing: tag B-flavour at birth, decay to flavour specific state: asymmetry: Amix~Cos(Dmd,st) -CPV: tag B at birth, decay to CP eigenstate: asymmetry(t) Acpv~Acpv,direct.Cos(Dmd,st)+Acpv,mixing.Sin(Dmd,st) Mixing and CP violation (CPV) in Bd,s decays, basics: Issues: Tagging Flavour Correctly… ....& being able to tag at all Statistical power: N tagged events = eD2N pure events Opposite side tagging Same side tagging Concept:Look for B on opposite side of B of interest -Look for m,e -Use weighted jet-charge Disadvantages: Opposite B not in acceptance (60%) or mixes (B0) Concept: Look for p± (K±) from hadronization of B (Bs) of interest, Higher e Check algorithms in known b-flavour decays eg B± J/yK± Prepare for Bs mixing by first doing Bd mixing

18. 250 pb-1 -Data sample: lepton triggers -Bdm+D*(2010)-X (D*-D0p-,D0 K+p-) -Find m+, D0,p- consistent with B -Select events within |DM(D*-,D0)PDG- DM(D*-,D0)|<0.04GeV/c2 -Opposite-side m tags flavour -Use PDG BRs to calculate expected & observed asymmetry(t) -DMd & Purity are free parameters & fit Proof of principle: Bd mixing at D0 Preliminary results: md = 0.506  0.055 0.049 ps-1 Consistent with world average: 0.502  0.007 ps-1 Tagging efficiency: 4.8  0.2 % Tagging Purity: 73.0  2.1 % First D0 mixing Measurement !!

19. CDF Run-I Dmd (all methods) = 0.495 ± 0.026 ± 0.025 ps-1 Proof of principle CDF (Run-II) DMd measurement First Run-II mixing result: same side tagging (SST) Find fragmentation p from B, track near B with lowest relative PT B+J/y K+, D0p+ to check tag, B0J/y K*0, Dp for Dmd -1.1KB0J/yK*0 (J/y data) -4.9K B0Dp (SVT Trigger!) DMd=0.55±0.10 ps-1 Dilution (D) =12.4 % eD2=1.0±0.5 Work on jet-charge & opposite side muon Tagging continues

20. Physics Prospects: Toward Bs mixing at CDF : fully reconstructed decays : B0s Ds Decays we plan to use: B0s Ds, B0s Ds Proper time resolution: t = 67 fs  t  PT/PT First observation of mode BsDs+p-with(Ds+fp+, f K+K-) !“Flagship” Mode for Bs mixing ! -Need to tag initial B flavour -projection awaits final eD2 -Currently have reconstructed onlyDsfp -Reconstruct with more Ds decays eg:K*0K, + to improve yields…

21. Use leptons (CDF: lepton+high IP track) & select Bsm+Ds-X Physics Prospects: Toward Bs mixing semi-leptonic decays: Find lepton+Ds-fp-f K+K- lepton has charge opp. to Ds Plots have different mass resolution and S/B • Also Lifetime measurement provides valuable constraint on DGBs: • t=(tcp+2+tcp-2 )/(tcp++tcp-) as in B0s Ds

22. MC - u W d u,c,t b b d u W - u W s u,c,t b s b u W Lumi~180pb-1 Physics Prospects: CP violation in Bh+h- (SVT data) decays determining angleg (CDF), Method: Bh+h- from hadronic trigger Data ! (891 events) Tree > penguin in Bp+p- vice-versa in BsK+K- Four unknowns In Asymmetry(t): d=ratio of penguin/tree hadronic matrix elements q= phase of d g,b= weak phases Constrain b from B-factories, measure g by fitting asymmetry (t) Proposed by: R.Fleischer, PLB459 1999 306 dE/dx check: Use D*±D0p, D0 Kp 1st Stage Statistically SeparateBd p+p-, Bd K+p-, Bs K+p-, BsK+K- - Use: M vs a=(1-p1/p2)q1:6 distinct shapes for p+p- K+K-, (Bd,Bs) K+p-,p+K- -Use: dE/dX distinguishes Kp to 1.16s in the future use DmBdDmBs too…

23. hep-ph/0404009 SM check by comparison with ACP in Bd BR(Bd+-) BR(BsK+K-) U-Spin relationship 58°<<72° dir ACP(Bd+-) Physics Prospects: CP violation in Bh+h- decays determining angleg (CDF) Yields (Results from 65 pb-1) Bdp+p- 14817 BdKp 3914 BsKp 311 BsK+K- 9017 (BsK+K- First Observation !) Results use 65 pb-1 sample, 1.16s dE/dX Kp separation: Update with dE/dX (1.4s) & 180 pb-1 underway ! Sanity check (spot on !): Measure Ratio of Branching Ratios CDF :G(Bdp+p-)/G(Bd K+p-) = 0.26 ±0.11±0.055, PDG: Ratios of BRs (CDF) & ACP(Bdp+p-) (B-factories): Check SM consistency (D.London) Finally we expect: (Fleischer method) (2fb-1):() =±10(stat) ±3(syst SU(3) breaking)

24. CDF & D0 are completing 1st phase (~250pb-1) of data taking : • a) Current s(t(Bu+)/t(Bd0) ) surpasses theoretical accuracy. Also tests of vertexing & tracking (for future DMBs and CPV) • b) Search for FCNC set limits on rare BRs • c) Prepare for Bs mixing: Establish by measuring Bd mixing first ! • 2) Next phase (>250pb-1 &<500pb-1) will: • a) set limits on (or observe) Bs mixing • b) set limits on DGBs • c) search for CPV in the neutral B system • d) Continue to improve limits of Rare Decay BRs • 3) Final Phase (end Run-IIa) (>500pb-1 and <2fb-1) all of the previous &: • a) Achieve better than 1% accuracy on s(t(Bs)/t(Bd) ) & s(t(Bd)/t(Lb)) • b) Measure Bs mixing parameter xs expect to measure d(DGs)~5% • c) Measure CKM angle g • d) ……and search for unexpectedly large CPV in BsJ/yf • Last phase will be mostly complementary to the B-factories Conclusions:

25. Backup Slides

26. Aside: Physics Results: Ratio of branching ratiosof BsDsp toBdDp Interest in BsDsp is mostly due to Bs mixing but:we’ve also measured the ratio of branching ratios G(BsDsp)/G(BdDp) Normalization mode is BdDp, D Kp+p- Kinematically ~BsDsp, Ds fp, fK+K- Ratio of Bs to Bd signals is: Where e are determined from Monte-Carlo D, Ds BR are from PDG, obtain: Using fs/fd =0.273±0.034 from PDG obtain: …we’re beginning to fill in PDG section on the Bs

27. 0.5M Charm decays at CDF 10-20% come from B: Great Potential for B and Charm Physics, opens at least as many avenues as J/y trigger Data Samples: B and Charm from the hadronic trigger Some charm is prompt D from direct charm: Points back to beam spot ..Some charm is from B D from B has a impact Parameter wrt beam spot An example of B reconstructed Using data from this trigger: ..to separate prompt Ds from Ds coming from B Prompt Charm D0K86.5  0.4 % (stat) D*D087.6  1.1 % (stat) DK89.1  0.4 % (stat) Ds72.4  3.4 % (stat) We have B and tons of Charm as well !

28. Signal lifetime is modelled by : Complete likelihood function: Complete event probability density Background shape from side-bands Physics Results:Average B-hadron lifetime from partially reconstructed BJ/yX decays This is a “sanity check” of our BJ/y sample: Obtain Average B hadron tB From all BJ/y (+other stuff) decays: B is not fully reconstructed D0 Inclusive B Lifetime Partially reconstructed B -Correct for missed daughters: F(PT) (from by Monte-Carlo) -tB is an estimate -it is the average lifetime of all hadrons decaying to J/y Results from D0 and CDF tB=1.5610.0240.074 ps D0 (40 pb-1) tB=1.5260.0340.035 ps CDF (18 pb-1) Both consistent with: PDG: tB= 1.564  0.014

29. Bs width difference DGs and angular variable separation Two CP states: transversity • One lifetime(width) has been fit in this mode • But contains two distinct lifetimes: CP+ & CP- Bs, significant lifetime (width) difference: • DGs=1/tB1-1/tB2 • 2) Extract DGs : fit two lifetimes, use single angle to separate CP+ and CP- Bs: (Transversity angle q) • SM prediction forDGs ~0.10Gs alsoDGs= A.xs (xs = Bs mixing parameter)ifDGsis smalland xs is large or vice-versaSign of new physics • CDF prediction for 2fb-1 d(DGs)~0.05 Two CP states: lifetime Total function and normalization Current limit (LEP):s / s <0.31, from branching ratio of BsDs±(*)Ds(*) Note: SM CP violation in this mode: O(3%), if large new physics CP asymmetry = sin2e  DGs, measured= DGs,SM.Cos2e (complementary)

30. Physics Results: lifetime, mass, from fully reconstructed B J/y X modes: Standard Technique : Probability Density Function (pdf) Data from J/ym+m- di-muon trigger: 1) Reconstruct vertex according to decay topology 2) Calculate decay proper time mass & errors 3) If fitting for mass:fit mass only 4) If fitting for lifetime:Fit mass and lifetime using bi-variate Probability density function (PDF) in likelihood 1) Signal Lifetime : 2) Signal Mass : An Example B+ ->J/y K+ at CDF 3) Signal for Mass only analyses: 4) Signal pdf in mass and lifetime: 5) Signal for lifetime analysis: Both the mass and lifetime distributions are fit in a single step. Technique is applied to : B+gJ/y K+, B0gJ/y K0* (K0* g Kp), Bsg J/yf (fgKK), LbgJ/yL (Lgpp) 6) Normalization : mass & lifetime

31. B physics prospects(with 2fb-1) Both competitive and complementary to B -factories • Bs mixing: Bs →Dsπ(Ds3π)(xsup to 60, with xd meas. one side of U.T.) • Angle : B0→ J/ψ Ks(refine Run1 meas. up to (sen2)  0.05) • CP violation, angleγ: B0→ ππ(πK), Bs→ KK(Kπ) • Angle s and s/ s : Bs→ J/ψ(probe for New Physics) • Precise Lifetimes, Masses, BRfor all B-hadrons: Bs, Bc, Λb … (CDF observed: Bc → J/ψ e(). Now hadronic channels Bc → Bs X can be explored) • HF cross sections (beauty and charm) • Stringent tests of SM … or evidence for new physics !!

32. Signal lifetime is modelled by : Complete likelihood function: Complete event probability density Background shape from side-bands Physics Results:Average B-hadron lifetime from partially reconstructed BJ/yX decays. This is a “sanity check” of our BJ/y sample: Obtain Average B hadron tB From all BJ/y (+other stuff) decays: B is not fully reconstructed If Fully reconstructed B -ct= c.(time in B rest frame) -Lxy = 2-d decay length -MB = mass -PT = transverse momentum D0 Inclusive B Lifetime If Partially reconstructed B -Correct for missed daughters: F(PT) (from by Monte-Carlo) -tB is an estimate -it is the average lifetime of all hadrons decaying to J/y Results from D0 and CDF tB=1.5610.0240.074 ps D0 (40 pb-1) tB=1.5260.0340.035 ps CDF (18 pb-1) Both consistent with: PDG: tB= 1.564  0.014

33. 1 B 1   » ) + ( sin (2 ) e D N S 2 ms/md a Sin(2) in B0J/y Ks g b N(B0)(t) - N(B0)(t) ACP(t) = =Dsin(2b)sin(Dmd t) N(B0)(t) + N(B0)(t) In Run1 measured: B0  J/ Ks ; J/   sin(2b)=0.79±0.39±0.16 (400 events) sin(2b)=0.91±0.32±0.18 (+60 B0   (2S) Ks) With 2fb-1 can refine this measurement Although: no way to compete with B-Factories ! N(J/ Ks) from scaling Run I data: • x 20 luminosity 8,000 • x 1.25 tracks at L1 trigger 10,000 • x 2 muon acceptance 20,000 • Trigger on J/  e+e+ 10,000 Stat. Error: Expect: s(sin2b)  0.05 Systematic ~ 0.5xStatistical (scales with control sample statistics) Combined eD2: from 6.3% to 9.1%(Kaon b-tag) Same S/B = 1

34. Tevatron Performance 3.8 x 1031 • Tevatron operations • Startup slow, but progress steady ! • Now:L ~3.5 x 1031 cm-2s-1 • integrating ~ 6. pb-1/week • … still factor 2-3 below planned values • additional improvements (~10-20%) expected from Jan. 3weeks shutdown Initial Luminosity July ‘01 Now • CDF operations • Commissioning: Summer 2001 • Physics data since February 2002 • Running with >90% Silicon integrated • since July 2002 On-tape Luminosity 110 pb -1 • Luminosity (on-tape): • ~20pb-1until June (analyses in this talk) • Additional 90pb-1 July – December • Reach 300- 400 pb-1 by October 2003 July ‘02 Feb ‘02

35. Quadrant of CDF II Tracker TOF:100ps resolution, 2 sigma K/ separation for tracks below 1.6 GeV/c (significant improvement of Bs flavor tag effectiveness) TIME OF FLIGHT COT: large radius (1.4 m) Drift C. • 96 layers, 100ns drift time • Precise PT above 400 MeV/c • Precise 3D tracking in ||<1 (1/PT) ~ 0.1%GeV –1; (hit)~150m • dE/dx info provides 1 sigma K/ separation above 2 GeV • SVX-II + ISL: 6 (7) layers of double-side silicon (3cm < R < 30cm) • Standalone 3D tracking up to ||= 2 • Very good I.P. resolution: ~30m (~20 m with Layer00) LAYER 00: 1 layer of radiation-hard silicon at very small radius (1.5 cm) (achievable: 45 fs proper time resolution inBs Dsp )

36. CDF II Trigger System 3 levels: 5 MHz (pp rate) 50 Hz (disk/tape storage rate) almost no dead time (< 10%) • XFT: “EXtremely Fast Tracker” • 2D COT track reconstruction at Level 1 • PT res. DpT/p2T = 2% (GeV-1) • azimuthal angle res. Df = 8 mrad • SVT: “Silicon Vertex Tracker” • precise 2D Silicon+XFT tracking at Level 2 • impact parameter res. d = 35 m • Offline accuracy !! CAL MUON CES COT SVX XFT XCES Matched to L1 ele. and muons XTRP enhanced J/ samples L1 CAL L1 TRACK L1 MUON GLOBAL L1 SVT L2 CAL CDF II can trigger on secondary vertices !! Select large B,D samples !! GLOBAL LEVEL 2 TSI/CLK

37. COT track ( 2 parameters) 5 SVX coordinates beam spot d Impact Parameter (transverse projection) SVT: Triggering on impact parameters ~150 VME boards • Combines COT tracks (from XFT) with Silicon Hits (via pattern • matching) • Fits track parameters in the transverse plane (d, , PT)with offline res. • All this in ~15ms ! • Allows triggering on displaced impact parameters/vertices • CDF becomes a beauty/charm factory

38. B triggers: conventional Needspecialized triggers (bb) /(pp)  10-3 CDF Run1, lepton-based triggers: • Di-leptons (, PT 2 GeV/c): B  J/ X, J/   • Single high PT lepton ( 8 GeV/c): B  l  D X Suffer of low BR and not fully rec. final state Nevertheless, many important measurements by CDF 1: B0d mixing, sin(2), B lifetimes, Bc observation, … • Now enhanced, thanks to XFT (precise tracking at L1) : • Reduced (21.5 GeV/c) and more effective PT thresholds • Increased muon and electron coverage • Also J/  ee

39. XFT performance Efficiency curve: XFT threshold at PT=1.5 GeV/c  = 96.1 ± 0.1 % (L1 trigger) XFT: L1 trigger on tracks better than design resolution pT/p2T = 1.65% (GeV-1)  = 5.1 mrad Offline track XFT track 11 pb-1 53.000 J/  

40. SVT performance • I.P. resolution as planned • d = 48 m = 35m  33 m intrinsic D0  Kp used as online monitor of the hadronic SVT triggers transverse beam size • Efficiency S/B  1 90% soon 80%

41. TOF performance • TOF resolution (110ps) within 10% of design value Background reduction in KK: Low PT (< 1.5 GeV/c) track pairs before and after a cut on TOF kaon probability x20 bkg reduction, 80% signal efficiency with TOF PID S/N = 1/2.5 S/N = 1/40

42. CDF J/y cross section 0<pt<0.25 GeV 5.0<pt<5.5 GeV 10.0<pt<12.0 GeV s(ppgJ/y; pT>0; |h|<0.6) =240  1 (stat) 35/28(syst) nb

43. D0 K D0 KK D0  5670180 2020110 56320490 K mass KK mass  mass Lots of charm from hadronic triggers: With ~10 pb-1 of “hadronic trigger” data: Relative Br. Fractions of Cabibbo suppressed D0 decays : Already competitive with CLEO2 results (10fb-1 @ (4S)) !!!!! (DKK)/(DK) = 11.17  0.48(stat)  0.98 (syst) % (D )/(DK) = 3.37  0.20(stat)  0.16(syst) % O(107) fully reconstructed decays in 2fb-1 •  Foresee a quite interesting charm physics program: • D cross sections, • CP asymmetries and Mixing in D sector, Rare decays, …

44. B0s mixing: expectations with 2fb-1 xs = ms(B0s) Bs Ds, Ds  Ds  , K*K,  • Signal: 20K (fp only) - 75K (all) events • with SVT hadronic trigger • BR (Ds ) = 0.3 % ; BR (Ds   ) = 0.8 % • Resolution: • (c)= 45 fs (with Layer00) • eD2 = 11.3% (with TOF) • S/B: 0.5-2 (based on CDF I data) S.M. allowed range: 20. < Xs < 35. 5s sensitivity up to: Xs = 63 (S/B = 2/1) Xs = 53 (S/B = 1/2) Can do a precise measurement … or evidence for new physics !

45. 75K at D0, completely new capability ! (40 pb-1) 0.5M at CDF (70 pb-1) Data Samples: The J/ym+m- t CDF and D0 (Run-II) Two Fully Reconstructed B-hadronJ/y states at CDF &D0 BJ/y KS:CDF:220, D0:45 (Run-II) (D0 had none in Run-I) LBJ/yL :CDF:53, D0:16 (Run-II)

46. Data Samples: B and Charm Using the high Impact Parameter (IP) (Hadronic) trigger Select events by requiring : -2 tracks with IP>100 mm - track PT > 2GeV/c - sum 2-track PT > 5.5 GeV/c 0.5M Charm decays at CDF 10-20% come from B: Great Potential for B and Charm Physics, opens at least as many avenues as J/y trigger

47. Select events with 1 lepton (PT>3 GeV/c) & 1 high IP (>120mm)track: -High IP track means we can go lower in lepton PT ->Much higher than Run-I due to lower PT thresholds (x4-5 increase) Used for: 1) High statistics lifetime and mixing analyses 2) calibration samples for tagging (B+l+nD) Drawback: worse vertex resolution due to missed neutrino Some numbers: BglD0X (D0gKp):~10000 events, BglD+X (D+gKpp):~5,000 events also Bs decays (later) Data Samples: B(+)l+uD decays using “hybrid” trigger

48. Physics Results: Lifetimes from partially reconstructed decay Decays included:Accounting for missed neutrino Bs  Dsl, Ds*l (Ds, K*0K, +) expect ~40K events in 2 fb-1 st is worse due to missed u (K factor) : t = 60 fs  t  K/K, K/K ~ 14% If one Bs lifetime is fit in any flavour specific mode: tfit = (tBsCP+2+tBsCP-2)/(tBsCP++tBsCP-) from which DGs can be determined as well Use new “hybrid” displaced track+single lepton trigger

49. Physics Results:LB, lepton+displaced track and purely hadronic data samples (have shown J/y mode already) Protons are easiest to separate using Time of Flight Particle ID in left plot using TOF and dE/dX b cl  [pK] l Lifetime in hadronic, hadron+lepton modes require correction for IP cut bias & missing  Expect results after this summer b cp [pK] p Note on LB A search for CP violation in Baryon decays is planned using LBpp

50. Mixing and CPviolation (CPV) at Hadron colliders Proof of principle: Run-I, CDF were able to do2smeasurementof sin2b & competitive xd (Dmd/G) measurements: can tag b-flavours in hadron collider environment Sin2b=0.79±0.39(stat)±0.16(sys) (CDF 1996) CDF have not repeated this measurement yet…cannot compare to B-factories… CDF: In Run-II with 40-50 x more BdJ/yKS decays can get d(sin2b)~0.05: D0: Similar statistics Can’t be competitive with BaBar (insert current) and BELLE (insert current) Redo the measurement because: -It’s an important benchmark -Gives credence to other CPV measurements eg. in Bh+h- & BsJ/yf