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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma1 CDF hot topics Sandro De Cecco FNAL & INFN Roma 1
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma2 Outline Tevatron performances Recent and new results: – B s mixing – b-hadrons Lifetimes & s / s – b modes – Charmless B d,s decays – Rare decays Summary and perspectives CDF detector and B physics triggers
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma3 Tevatron performances CDF II has collected so far ~ 0.8 fb -1 out of >1 fb -1 delivered by Tevatron. Record peak luminosity is ~ 1.3∙10 32 cm -2 s -1 Around 600 pb -1 are available for B physics (good tracking detector conditions) Current analyses use 180 - 350 pb -1 of integrated luminosity 1 fb -1 ! Right on the track of stretched TeV plans
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma4 The CDF II detector CDF Tracking System Particle ID dE/dX in COT Time Of Flight detector Lepton ID Muons: CMU, CMP, CMX 1.1) Electrons: CEM (EM calorimeter) CPR (pre-shower detector)
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma5 B Physics at pp collider All B species produced: B u,B d,B s,B c, b, b … With production fractions: f u : f d : f s : f ≈ 4 : 4 : 1 : 1 Acceptance for other B is 20-40% BUT: (bb) << (pp) (~65 mb) B have to be selected with specific Triggers Primary Vertex Secondary Vertex I mpact P arameter ( ~100 m) L xy ~ 1 mm B decay b production is so large (~300 Hz @ 10 32 cm -2 Hz) that we could not even cope with writing it all to tape! trigger quasi-exclusively on specific decay modes Example: the Secondary Vertex Trigger SVT Online (L2) selection of displaced tracks based on Silicon detector hits. see talk by Mauro Dell’Orso
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma6 B physics triggers at CDF II 1-Displaced track + lepton (e, ) 120 m < I.P.(trk) < 1mm P T (lepton) > 4 GeV Semileptonic modes 2-Displaced tracks P T (trk) > 2 GeV 120 m < I.P.(trk) < 1mm p T > 5.5 GeV fully hadronic modes Di-Muon (J/ ) Pt( ) > 1.5 GeV J/ modes down to low Pt(J/ ) ~0 (Run II) Conventional at colliders (Run I) + With SVT trigger
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma7 Mixing
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma8 WA experimental limit: m s > 14.5 ps -1 (95%CL) (LEP+SLD+CDF 1) B s Mixing but: |V ts | >> |V td | m s >> m d Measuring m s / m d determines |V ts |/|V td | Lattice calculation error O(5%)
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma9 Δm s = 20.5 ± 3.2 ps -1 [14.4, 27.1] @ 95% CL m s = 18.9 ± 1.6 ps -1 [15.7, 23.0] @ 95% CL SM CKM-fit prediction for m s If m s > 30 ps -1 New Physics @ 3 (with all constraints) (Δm s not used) compatibility plot SM New Physics models can allow high m s
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma10 Analysis Strategy B s signal reconstruction – Flavour specific states B s decay time – proper time reconstruction – Lifetime measurement Initial flavour of the B s – Flavour tagging techniques – calibrate on B d mixing A B 0 Mixing perform a “Blind AMPLITUDE SCAN”: B 0 A-scan m d = 0.5 ps -1 ↔ A =1
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma11 Two different B s signatures: Fully reconstructed HADRONIC modes: SEMILEPTONIC modes: D P.V. B ,e s s D P.V. B s s Good proper time resolution High B s mass resolution Selected by Two Track Trigger (SVT) Missing momentum carried by the Diluted proper time resolution Selected by dedicated trigger (l+SVT):
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma12 Flavour tagging Opposite Side Same Side Same Side Kaon: for B 0 s is likely to have close in DR a K+. High D 2 is expected Soft Lepton (e, ) due to b ℓ X ℓ charge correlated to b-flavour Jet Charge: the sum of charges of the b-Jet tracks correlated to the b-flavour Used for today results NOT yet used HADRONICSEMILEPTONIC mdmd (0.503±0.063±0.015) ps -1 (0.498±0.028±0.015) ps -1 Tot. D 2 (1.12±0.23)%(1.43±0.09)% Muon Tag Calibrate the OS taggers on B 0 mixing
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma13 B s Amplitude Scan results Semileptonic Hadronic Sensitivity: 8.4 ps -1 Limit: m s > 7.9 ps -1 @ 95% CL Sensitivity: 0.4 ps -1 Limit: m s > 0 ps -1 @ 95% CL Semileptonic Hadronic Sensitivity: 8.4 ps -1 Limit: m s > 7.9 ps -1 @ 95% CL CDF winter ’05 Combined World Average + CDF Run II – Sensitivity: 18.2 18.6 ps -1 – Limit: 14.5 ps -1 see talk by Marco Rescigno
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma14 Near future for m s With the SAME data: Add new tagging algorithms Same Side Kaon Tag Add more channels Add signals from other triggers Improve decay time resolution with PV event by event With NEW data: Increased Luminosity (0.8fb -1 on tape!) Use new trigger strategies 2 SVT Tracks + tagging muon at trigger level (already in place since summer 2004) x4 statistics +20% better ct res. Hadronic analysis will begin to lead the sensitivity Start to “eat” interesting m s range (expect comb. sens. ~ 15ps -1 )
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma15 NEW: additional semileptonic B decays From the same data (360 pb -1 ) used in mixing analysis: Use SVT trigger (2 displaced and 2 GeV tracks) Select e and offline Allow lower LEPTON P T (4 2GeV) Increase the overall acceptance of more than X 3 At low Lepton P T, expect more backgrounds from B DDX decays
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma16 more semileptonic B s for m s analysis + 4GeV-lepton + 1 displaced track trigger 2 displaced track trigger Additional new sample overlap with the one already used ~ 20% Effective ~ X 3 more semileptonic B s yield to be used for MIXING Expect significant sensitivity increase in semileptonic m s search
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma17 b-hadron lifetimes and s / s
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma18 Full statistics sample still under study. Statistical uncertainty expected: Lifetimes in semileptonic B decays Largest statistics B sample More complicated background 13,300 Signal events 260 pb -1 (B + ) = 1.653±0.029±0.032 ps, (B 0 ) = 1.473±0.036±0.054 ps (B+)/ (B0) = 1.123±0.040±0.040 http:// www-cdf.fnal.gov/physics/new/bottom/050224.blessed-bsemi-life / B+B+ 0.017 ps B0dB0d 0.025 ps B0sB0s 0.03 ps bb 0.037 ps @ ~400 pb -1
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma19 Lifetimes in fully reconstructed modes (B + ) = 1.661±0.027±0.013 ps (B 0 ) = 1.511±0.023±0.013 ps (B s ) = 1.598±0.097±0.017 ps Test for our ability to understand SVT trigger biases Very clean samples Prerequisite for mixing fits KK CDF ’05 preliminary result
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma20 Result (260 pb -1 ) –1/4 heavy - 3/4 light state –Lifetime - heavy ~ 2 x light Lifetime difference measures “same” CKM element as m (oscillation frequency) Exciting!! Need more data –~ 5 % sensitivity by 2009 – m s = 10 ps -1 S / S = 7% Test still possible CP violation effect in B s mixing B s J/ and s s B S J/ + - K + K - B VV decays: Heavy and Light state decay with distinct angular distributions and different lifetimes.
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma21 b-Barions
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma22 b modes http://www-cdf.fnal.gov/physics/new/bottom/050407.blessed-lbbr / C. Tarantino, hep-ph/0310241 Oct 2003 b c X Lifetimes are an important experimental reference: –Overlap with B factories understanding of detector/trigger/analysis biases –Further test on species not produced at B factories: b c NEW: b Branching ratios: Exp. Theo.
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma23 b Updated knowledge Mass m = 5619.9 1.7 MeV/c 2 (4.1 2.0) x 10 -3 c l (5.5 1.8) % pK + p < 2.2 x 10 -5 c (2593) + l seen c (2625) + l seen c ++ l seen c 0 l seen c + seen b mass Colors: -PDG2004 -CDF contribution beyond current PDG2004
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma24 CP violation and charmless B decays
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma25 Charmless B hh’ Difficult competition with B factories for t-dependent tagged measurements Interesting B physics measurement of B s BR and A CP (B 0 K ) Signals overlap within mass resolution Kinematic and dE/dX to disentangle components in a combined fit: see talk by Simone Donati Future: measure B s lifetime in the CP even mode KK extract s / s
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma26 Charmless B VV decays Bd→K*Bd→K* ~125 events~44 events Measured BR( B s ) with 8 events (180 pb -1 ) Update with 360 pb -1 Will go soon for Polarization Amplitude analysis Expected significance similar to B-factories B s → see talk by Simone Donati ~225 events B s → J/ TTT data overlap with 2 trigger: ~20% Future: measure s / s in B s penguin mode
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma27 Search for B s,d see talk by Sinead Farrington NEW Results (360 pb -1 ): BR(B s ) < 1.6×10 -7 @ 90% CL < 2.1×10 -7 @ 95% CL BR(B d ) < 3.9×10 -8 @ 90% CL < 5.1×10 -8 @ 95% CL These are currently world best limits SM: BR(Bs ) < 3.8∙10 -9 Sensitive to new physics Ex.:
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma28 … and also at BEAUTY 05: Other VERY INTERESTING results from TEVATRON Heavy Flavour physics on: – B c meson at CDF and D0 – X(3872) at CDF and D0 see talk by William Wester see talk by Ulrich Kerzel
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma29 Conclusions CDF performed the first B s mixing analysis in run II We foresee a substantial update with new samples, new data collected and improved tagging power for winter 2006 Working to have world class measurements on b-hadron lifetimes and lifetime difference s / s Perform complementary studies in the field of charmless B decays: B d,s hh, B d,s VV, help digging the penguin sector Huge CDF legacy of knowledge in Beauty to next generation B physics experiments.
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma30 Backup slides
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma31 SVT: the hadronic B trigger ≈ 47 m ≈ 35 m + 30 m SVT resolution Beam spot size Online Impact parameter Available at Level 2 trigger (20µs latency) convolution of transverse size of the beam spot with the impact parameter resolution of the SVT: Impact Parameter distribution Offline ~ 45 m d beam spot COT track ( 2 parameters) 5 SVX coordinates Impact Parameter (transverse projection) Primary Vertex Secondary Vertex I mpact P arameter ( ~100 m) L xy ~ 1 mm B decay
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma32 HadronicSemileptonic m s : systematic Uncertainties Physics background at low m s Prompt background at high m s Dilution scale factors and templates systematic limited from control sample statistics **Systematic errors are negligible with respect to statistical in both cases**
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma33 Heavy Flavour Production from H b X in 37 pb -1 of data! PRD 71, 032001 (2005) P t > GeV/c (y<1) b D0D0 5.5 13.3 0.2 0.5 D* + 6.0 5.2 0.1 0.8 D+D+ 6.0 4.3 0.1 0.7 DsDs 8.0 0.75 0.05 0.22 PRL 91, 241804 (2003) bb cc with first 6.5 pb -1 !
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma34 Excited Heavy Flavor states B**(L=1) B –B J/ K and D modes –Important to understand impact for Same Side Kaon tagging mixing
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma35 Welcome back to B c Hep-ex/0505076 http://www-cdf.fnal.gov/physics/new/bottom/050330.blessed-bc-jpsimu/ 106 events 46.0 7.3 events First signal of fully reconstructed B c Direct mass measurement! Mode that gave the first evidence of the B c (CDF Run I) Large yield, no clean resonance though!
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma36 Lifetimes: J/ modes This was the starting point: Clean unbiased sample Precision measurement Reference for biased (e.g. displaced track) triggers Test for the understanding of: Detector Analysis technique Sample composition http://www-cdf.fnal.gov/physics/new/bottom/040428.blessed-lft2/
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma37 Lifetime in the hadronic B s modes Decay time actually measure transverse quantities: – L xy, P T (B) Un-binned likelihood fit Used: and Combinatorial background ct template from high mass sideband
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma38 Hadronic B-lifetimes results (B + ) = 1.66 ± 0.03 ± 0.01 ps (B 0 ) = 1.51 ± 0.02 ± 0.01 ps (B s ) = 1.60 ± 0.10 ± 0.02 ps Systematic summary (B + ) / (B 0 ) = 1.10 ± 0.02 ± 0.01 (B s ) / (B 0 ) = 1.06 ± 0.07 ± 0.01 ± (stat) ± (syst) (B + ) = 1.653 ± 0.014 ps (B 0 ) = 1.534 ± 0.013 ps (B s ) = 1.469 ± 0.059 ps World Average lifetimes (exp.): (B + ) / (B 0 ) = 1.06 ± 0.02 (B s ) / (B 0 ) = 1.00 ± 0.01 Theory prediction (see Cecilia Tarantino CKM05): CDF
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma39 Lifetime in the semileptonic B s modes c = 455.9 11.9 mc = 422.6 25.7 mc = 413.8 20.1 m Combined ℓ-D s lifetime result: 445.0 9.5 m (W.A.: 438 17 m) statistical err.only, NOT for Averages (DØ ’05: 426 13 17 m) Real D s backgrounds: prompt and physics
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Beauty 05, Assisi 20-06-2005 Sandro De Cecco - FNAL & INFN Roma40 HQET: baryon lifetimes and B moments B lifetimes Vcb Dominant uncertainty comes from HQET extraction! CDF can probe HQET and constrain it! b lifetime C. Tarantino, hep-ph/0310241 Oct 2003 LO NLO LO NLO LO NLO http://www-cdf.fnal.gov/physics/new/bottom/030710.blessed-lambdab-lifetime/
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