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B-physics at CDF first results and perspectives

B-physics at CDF first results and perspectives. Sandro De Cecco INFN Roma 1 Universita’ di Roma “La Sapienza”, 11 giugno 2004. In this talk…. This talk won’t cover all B-physics studies going on at CDF. I will stress on B physics potentials of CDF which are complementary

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B-physics at CDF first results and perspectives

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  1. B-physics at CDFfirst results and perspectives Sandro De Cecco INFN Roma 1 Universita’ di Roma “La Sapienza”, 11 giugno 2004 Sandro De Cecco - INFN Roma 1

  2. In this talk… • This talk won’t cover all B-physics studies going on at CDF. • I will stress on B physics potentials of CDF which are complementary • to the B-factories outputs. • In particular I will concentrate on some information on CPV and HQ • that can be extracted from the study of Bs meson only accessible at • the Tevatron collider. • In this perspective, a selection of relevant new results will be described. • Future projections for Bs topics will be highlighted, relying on data and • current performances for extrapolations. Sandro De Cecco - INFN Roma 1

  3. Outline • Highlights on Bs physics • CDF detector and B-triggers • Selection of recent results in Leptonic & hadronic triggers data samples. • Projections for Bs mixing measurement & first studies. • CDF potential in relevant Bs decay channels, expected yields before next generation B-experiments. Sandro De Cecco - INFN Roma 1

  4. Babar/Belle + theory BS Babar/Belle/CLEO CDF/DØ + theory BS K-K+ Kp CDF Babar/Belle/CDF Babar/Belle/CDF/DØ CDF ? DS- K+ BdfKs0Babar/Belle/CDF?/DØ? CPV, the CKM picture CPV at Tevatron in the b-sector:unique opportunity to study Bs physics. Sandro De Cecco - INFN Roma 1

  5. B0s - B0s mixing • Explore one side of the CKM triangle • Key experimental issues: • B0s flavor ID at decay • B0s flavor ID at production (fl.tagging) • High Yield with good S/B. (trigger & reco.) • High resolution on proper decay time (Vertexing) World average limit Dms > 14.4/ps @ (95%CL) Sandro De Cecco - INFN Roma 1

  6. Bs Lifetime Difference: s Bssystem mass eigenstates BH and BLhaveDms = MH –MLand DG= GL-GH With BL=pBs + qBs(CP-even);and BH = pBs – q Bs(CP-odd) • s/Ms in SM does not depend on CKM parameters • s determines Ms up to QCD uncertainties (~20%) • Large Ms (hard to measure)  Large s (easy)  complementarity • Several methods available at Tevatron RunII: • Bs J/ (Vector-Vector): • Angular analysis to separate CP even/odd components Hadronic modes (being evaluated): • Bs K+K- • No angular analysis needed. ( direct CPV ? ) • Compare to Kp mixed mode (but suppressed!)~10,000 events in 6.5 fb-1 • Bs Dsp / DsDs: • Fit 2 exponential to known mixture of states • (ex. BsDs, BsDsl) • Compare with CP eigenstate (ex. BsDsDs)

  7. CP violation in B0s CP asymmetry in B0s J/  dominated by b(cc)s probesthe weak phase of Vts (angle s = 2s): Also plan to look at BsJ/(’) Expected to be small: sin(2s ) O(l2)  0.03 Complicated analysis:requires Dmsand angular analysis to disentangle CP even/odd final states CDF reach : s(sin(2 s )) 0.1 with 2fb–1 (0.06 with 8fb–1) If asymmetry observed with 2fb–1 signal for NEW Physics Sandro De Cecco - INFN Roma 1

  8. CPV in B0s J/  (2) Current experimental average of CP-asymmetry in B0d fKs is: S(fKs) = - 0.15 ± 0.33(hep-ex/0312024) This is 2.7s from sin2b = 0.736 ± 0.049 which is the SM prediction for this asymmetry to the percent level. Several analysys of this result, in the frame of NP (SUSY), allow it to be negative If this is true: In the Bs sector this would imply  High Dms ( > 70 ps-1)(hep-ph/0404001) (april fool?) ACP(B0s J/) i.e sin(2s)in the tagged sample will be: hopeless for CDF/D0 and very difficult even for LHCB – BTEV Nonetheless untagged time-evolution G(J/  ; t) will give information on CP violation in the Bs from the sign of cos(2s) (in SM ~ 1) through the dependence from DGs/Gs if this is sizeable O(10%) and measurable Recent Input from B-factories Sandro De Cecco - INFN Roma 1

  9. The Tevatron pp collider Superconducting proton-synchrotron: 36p36p bunches, crossing each 396 ns at √s = 1.96 TeV Luminosity……………………………..: record peak L =7.2  1031 cm-2 s-1 # interactions / bunch-crossing……...: < N >poisson = 1.5 (at 5x 1031 cm-2s-1) Luminous region size………………...: 30 cm (beam axis) x 30 mm (transverse) Improved > 2x during last year Sandro De Cecco - INFN Roma 1

  10. Tevatron plans • RECYCLER had a first successful test • Plans beyond FY 05 depends on Recycler ring and electron cooling performances • Will see after aug./nov.04 shutdown Sandro De Cecco - INFN Roma 1

  11. Tevatron FY04 performance L (pb -1) FY04Design FY04 Base 1st May 2004 2003 1st Jan. 2004 2002 • Tevatron is working very well this year (Design plan): • Record Initial luminosity = 7.2 X 1031 sec-1 cm-2 • Weekly Integrated luminosity ~ 10 pb-1/w • ~350 pb-1 on tape, 100-200 pb-1 used for analysis so far Sandro De Cecco - INFN Roma 1

  12. The CDF II detector Completely new: Tracking System Sandro De Cecco - INFN Roma 1

  13. CDF II tracking system TOF:100ps resolution, 2 sigma K/ separation for tracks below 1.6 GeV/c (significant improvement of Bs flavor tag effectiveness) - charge) TIME OF FLIGHT CDF Roma COT: large radius (1.4 m) Drift chamber • 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 in Bs  Dsp ) Sandro De Cecco - INFN Roma 1

  14. b b g g b g q b b b b b q g g g q q Flavor Excitation Flavor Creation (gluon fusion) Flavor Creation (annihilation) Gluon Splitting B Physics at pp collider BB production mechanics in hadron collider: • Huge cross-section: 50-100 b • All B species produced: • Bu,Bd,Bs,Bc,b, b… • with production fractions: • fu : fd : fs : fL≈ 4 : 4 : 1 : 1 • BUT:(bb) << (pp) (~65 mb)  B events have to be selected with specific triggers • Trigger requirements:large bandwidth, background suppression, small dead-time Sandro De Cecco - INFN Roma 1

  15. CLEO CDF CLEO B physics at CDF • Typical  > 1 (B-factory ~0.56) • B hadrons are hidden in a x103larger background (inelastic(pp)  50 mb) • And events are much more“complicated” than at (4S) • Crucial detector components: • - Tracking system • Excellent pt resolution/Vertexing • - Trigger • Large bandwidth • Strong background reduction • - Particle identification Sandro De Cecco - INFN Roma 1

  16. ~ 1 mm b decays primary vertex secondary vertex Impact Parameter ( ~100mm) B physics triggers at CDF II With the NewSilicon Vertex Trigger Conventional at colliders (Run I) Di-Muon (J/) Pt() > 1.5 GeV J/ modes down to low Pt(J/)~0 (Run II) + Displaced track + lepton (e, ) I.P.(trk) > 120m Pt(lepton) > 4 GeV Semileptonic modes 2-Displaced tracks PT(trk) > 2 GeV pT> 5.5 GeV I.P.(trk) > 120(100) m fully hadronic modes - CP violation - Masses, lifetimes - Quarkonia, rare decays - High statistics lifetimes - Sample for tagging studies - BSmixing - Charmless decays Sandro De Cecco - INFN Roma 1

  17. COT track ( 2 parameters) 5 SVX coordinates beam spot d Impact Parameter (transverse projection) SiliconVertexTracker: thehadronic B trigger CDF Roma - Responsabilty • 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: s≈47 um ≈ 35 um + 30 um SVT resolution Beam spot size Impact parameter distribution Compare to offline ~ 46 mm Sandro De Cecco - INFN Roma 1

  18. @ high Lumi.: Dynamic PreScale of had. trigger Sandro De Cecco - INFN Roma 1

  19. B(s) physics from Di-Muon triggers Sandro De Cecco - INFN Roma 1

  20. Exclusive BsJ/f Lifetime CDF RunII preliminary results (in ps) Sandro De Cecco - INFN Roma 1

  21. B Lifetime summary • Accurate measurements from Tevatron, still statistics-dominated • Theory errors are still smaller than experiment • HQET:t(B+)/t(B0) = 1.067 ± 0.027 • t(Bs)/t(B0) = 0.998 ± 0.015 • t(Lb)/t(B0) = 0.90 ± 0.05 • More B hadrons coming:Bc , b Sandro De Cecco - INFN Roma 1

  22. Polarization amplitudes of BsJ/YF and BdJ/YK* Both channels are Vector–Vector final states:  The Helicity amplitudes of the 2 Vectors are correlated • Measurement for Bd is to be compared to the B-factories results • and gives confidence on Bs: • Analysis of BsJ/YF polarization is the first step toward • DGs/Gs and CPV. • Measure the angular distributions of decay products in transversity basis • The convenience of transversity basis ( A0 ; A|| ; A┴) instead of Helicity (H-;H0;H+) is to separate CP even ( A0 ; A|| ) from CP-odd ( A┴ ) eigenstates. Sandro De Cecco - INFN Roma 1

  23. BVV in transversity basis z QT QK* FT B K* J/Y transversity plane In the J/Y rest frame the transversity plane is defined by K* (Kp) or f (KK) decay products and transversity axis z is orthogonal to it. Sandro De Cecco - INFN Roma 1

  24. Transversity amplitudes Angular distribution: Amplitude parametrization: from measurable distributions of : cosQK ; cosQTand FK Sandro De Cecco - INFN Roma 1

  25. Results: BsJ/YF BdJ/YK* NB=176±16 NB=993±58 • Based on 180 pb-1 of integrated Luminosity. • Data collected with Di-Muon (J/Ym+m-) trigger. • About 1000 Bd and 180 Bs candidates pass selection cuts. • BsJ/YF (FK+K-) and BdJ/YK* (K0*K+p-) • Polarization amplitudes measured with an un-binned Likelihood fit. Sandro De Cecco - INFN Roma 1

  26. BdJ/YK* angular distributions FT cosQT • Main systematic: • K-p misidentification (no PID used) • Detector acceptance sculpting on • angular distributions cosQK Sandro De Cecco - INFN Roma 1

  27. BsJ/YFangular distributions FT cosQT • Main systematic: • Assumption (on limited statistics) • of equal number of Bs and Bs •  reduced form of angular distributions. • Detector acceptance sculpting on • angular distributions. cosQK Sandro De Cecco - INFN Roma 1

  28. Polarization results summary: BdJ/YK* BsJ/YF • Results are consistent with previous measurements • BsJ/YFmostly CP-even state: (A02+A||2) ~ 80%↔ mostlyBsL •  This is helpful for CPV analysis •  Lifetime measurement dominated by GsL • if DG/G sizeable  CDF starts to be sensible to this effect. Sandro De Cecco - INFN Roma 1

  29. Rare B decays Sandro De Cecco - INFN Roma 1

  30. Search for rare B decays: Bs(d)m+m- • SM prediction: BR(Bsm+m-) = (3.8 ± 1.0) 10-9 • Several extensions to the SM predict an enhancement of this branching ratio by 1 to 3 orders of magnitude • If there is not excess we can already constrain several SUSY models! Discriminating variables “Blind” analysis:cuts were optimized before looking at the signal mass region Sandro De Cecco - INFN Roma 1

  31. Rare B decays: Bs(d)m+m- Final B mass distribution • No excess has been found • Limits on the Branching fractions have been set Submitted to PRL Slighly better results than Belle and BaBar @ 90% CL Best world result 1.6 X 10-7 2.0 X 10-7 Sandro De Cecco - INFN Roma 1

  32. R. Dermisek et al., hep-ph/0304101 SO(10) 7.510-7 Bs m+m-implications for SUSY CDF BR limits vs. luminosity (Expected/Obs.) BR = ~10-7 @ 500pb-1 R. Arnowitt et al., PLB 538 (2002) 121, new plot by B.Dutta R-parity violating Sandro De Cecco - INFN Roma 1

  33. B(s) physics from Hadronic triggers Sandro De Cecco - INFN Roma 1

  34. Charmless B decays Sandro De Cecco - INFN Roma 1

  35. B(s) hh’B(s) Pseudoscalar VectorB(s) Vector Vector Sandro De Cecco - INFN Roma 1

  36. Bhh decays at the Tevatron • Bd, BdK, BsK, BsKK “Penguin” “Tree” /K /K Bd/s Bd/s /K /K direct CP CP from mixing alone dir mix Bd  ACP(t) =ACPcos(mdt)+ACPsin(mdt)  Bd K ACP = (N+ - N-)/(N+ + N-)  Bs K ACP = (N+ - N-)/(N+ + N-)  Bs KK ACP(t) =ACPcos(mst)+ACPsin(mst) dir dir Bs channels never observed dir mix Sandro De Cecco - INFN Roma 1

  37. Reconstruction of Charmless 2-body • Specific trigger path optimized forBhh NB = 870 Montecarlo Bdpp BdKp BsKK BsKp NB = 1770 • min(|d01|,|d02|)  150 m • Lxy(B0)  300 m • |dB0|  80 m , d01 · d02 < 0 • I(B0) > 0.5 (ISOLATION) • For further back.reduction Need to separate contributions ! Sandro De Cecco - INFN Roma 1

  38. B0d pp B0d K-p+ B0d K+p- B0s K+p- B0s K-p+ B0s KK K  Separation of B0h+h- contributions CDF Roma Use Mvs (1-p1/p2)q1 Use dE/dx calibrated on D* (K/p separation 1.4pT>2GeV) … Fit the fractions Sandro De Cecco - INFN Roma 1

  39. BsK BsKK Bd K Bd  B  h+h'- results with 65 pb-1 • BR(Bd pp) / BR(BdKp)=0.26 ± 0.11(stat) ± 0.06(syst) • Consistent with B-factories results(0.250.06) • Direct ACP(BdKp) = 0.02 ± 0.15(stat) ± 0.02(syst) • fs·BR(BsKK) /fd·BR(BdKp) = 0.74±0.20(stat)±0.22(syst) • First evidence ofBs K+K-(CDF’s largest fully reconstructed Bs sample!) Update on 185pb-1 coming out soon x4 statistics and smaller syst (mainly dEdx) Sandro De Cecco - INFN Roma 1

  40. BsKK Bdpp hep-ph/0404009 B  h+h'- future measurements Expected yields • BsKp BR & ACP measurement • Limits on Bspp, BdKK • Lifetime in BsKK : s • ACP in Bdpp,BsKK Bs+Bd BRs’ alone provide, via U-spin simmetry, information ong(R. Fleischer hep-ph/0306270)and checks of CKM model(Matias&London, hep-ph/0404009) Longer time-scale: time dependent ACP in BsKK measurexs independently of penguin pollution (Fleischer and Matias: PRD669 (2002) 054009) Sandro De Cecco - INFN Roma 1

  41. u W+ p+ b d B0 p u d d b time-dep study: Angle  from B0h+h- B0 +has two (comparable) decay amplitudes: Penguin Tree W+ d p+ u u,c,t B0 g d u p d direct CP CP from mixing alone ACP(t) =ACPdircos(Dmd t) +ACPmixsin(Dmd t) ACPdir, ACPmixfunctions of, , d,(d ei  P / Tdecay amplitude) R. Fleischer(PLB 459 (1999) 306): Assume U-spin symmetry (d  s) Similar relation holds forBs  K+K(Dmdreplaced byDms) The 4 asymmetries can be expressed as function of, andP/Tamplitude ratio Parameters can be extracted from fit of meas. ofACP(t)forBdandBsKK Sandro De Cecco - INFN Roma 1

  42. BPV & BVV charmless decays • QCD Factorizationprovides a predictive framework for calculating PV and VV two body charm-less decays rate (less good at CP violation parameters…) • Recently many authors have combined all the available data to fit for the CKM angle g: • D.Du hep-ph/0311135 • N. deGroot et. Al hep-ph/0305263 • Beneke and Neubert Nucl Phys B651, 225 • These fits are as useful in constraining g as all other experimental inputs! • Theorist are now opening the Bs field: • D.Du et al hep-ph/0211154 (PP, PV) • Y.Yang et al hep-ph/0309136 (VV) • This is a call for CDF and the hadronic trigger : • Mostly these are rate measurement! • Provide several crucial tests of QCDF • Improve overall confidence • In many respects the same physics motivating Bhh study can be done replacing K*+with K+ , or Ks with K*0, and p0 with r . Examples are: • Bs K*+K*- , Bs K*+K- , Bs K*-K+ , BsK*+p- , Bs K*0 K*0 , Bs  K*0Ks CDF can recover in part the lack of efficient p0 detection or Ks trigger efficiency! Sandro De Cecco - INFN Roma 1

  43. BPV & BVV charmless decays • Rich dynamic revealed by Vector-Vector decays • Angular correlations  additional observables (CKM studies) • Many Bd,umodes are being measured at B-factories • BVV charmless : • Study polarization and CP violation • Hints for some NP(?) contribution in bs penguin dominated decays: • if NP effects in fKs is true, also visible in: • Bd,ufK*ACPand/or angular distributions(hep-ph/0309282) • Bsfftime dependent CP asymmetry (hep-ph/0208091) • First results (BaBar-Belle) on polarization unexpectedly small: • fL(fK* ) << fL(r+r-) How canCDF contribute ? Sandro De Cecco - INFN Roma 1

  44. Atwood Soni grid • Atwood and Soni (hep-ex/010683) proposed a method based on the study of angular correlation in pure penguin decays (third column) compared to a tree-penguin decays which can give g (bs transitions) or a (bd transitions) Many of the interesting decay color suppressed ! • Easy analysis  do not need tagging! • A lot of useful modes are accessible to CDF with SVT trigger, probably CDF can be successful with high luminosity • Bs modes can give additional constraint to the Bd,u modes available at B-factories Sandro De Cecco - INFN Roma 1

  45. Bs VV charmless decays QCDF predictions (hep-ph/0309136) • Rich harvest of interesting and unseen decays from Bs (hep-ph/0309136) • Only the p0-less shown in the table here • Measure them all! • Interesting ACP possible for self tagging modes: • K*0r0 bd bs Pure penguin Sandro De Cecco - INFN Roma 1

  46. B± → K± Sandro De Cecco - INFN Roma 1

  47. BR and ACP for B±→  K± CDF Roma • BRand direct CP asymmetry measurement • Luminosity used:180 ± 10 pb-1 • Performed a multidimensional un-binned fit to mB, m,  helicity and dE/dx PID information. Legend: total PDF signal comb. BG phys. BG B±→ f0K± B±→ K*0± B±→ K±K-K+ B±→ K±-+ • Yield result from fit:N = 47±8 • S/N = 1, main resonant background contribution from B±→ f0K± Sandro De Cecco - INFN Roma 1

  48. BR for B±→  K± CDF Roma BR is measured relative to normalization mode B+J/Y K+ : Using the PDG value: Which is already comparable precision with B-factories Sandro De Cecco - INFN Roma 1

  49. ACP for B±→  K± CDF Roma From multidimensional fit, direct CP asymmetry is also extracted: • BaBar [hep-ex/0309025], • Belle [hep-ex/0307014], • CLEO [Phys. Rev. Lett 86, 3718 (2001)]. • The Heavy Flavor Averaging Group mean has been superimposed. Sandro De Cecco - INFN Roma 1

  50. Bs   Sandro De Cecco - INFN Roma 1

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