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Heavy flavor results from CDF Run II Yuri Gotra University of Pittsburgh for the CDF Collaboration Deep Inelastic Scattering April 22-27, 2003 St Petersburg, Russia. Top Physics top production tt cross-section dilepton channel lepton + jets channel top mass Summary. Introduction

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Heavy flavor results from CDF Run IIYuri Gotra University of Pittsburghfor the CDF CollaborationDeep Inelastic Scattering April 22-27, 2003St Petersburg, Russia


Outline

Top Physics

top production

tt cross-section

dilepton channel

lepton + jets channel

top mass

Summary

Introduction

Bottom Physics

Triggers and data samples

Detector calibration

B masses

Lifetime: B0, B+, Bs J/yX

Dimuon B decays

Semileptonic B decays

Two body Bhh decays

Outline

Yuri Gotra - DIS 2003


B physics with run ii cdf
B physics with Run II CDF

Open wide spectrum of B hadrons

  • B, B0, Bs, Bc, b, b ...(unique)

    bb cross section is 50-100 mb

    ~O(105) larger than [email protected](4S)/Z0

    ~O(103) B’s per second at design luminosity (~10 B’s per second at (4S) factories)

    BUT:

    - B hadrons are hidden in a 103 larger

    background (inelastic(pp)  50 mb

    - Events more complicated than at (4S)

  • BRs for interesting processes: ~O(10-6)

  • S/B @ production (Tevatron): ~10-9

  • S/B @ production (B factory): ~10-6

  • Mean multiplicity of tracks/event: ~4 (4S)

  • Combinatoric background

  • - Events pile-up within the same beam crossing: problem for the trigger

  • - Typical S/B @ analysis level: ~O(0.5÷5)

    • B physics signatures:

    • QCD physics

    • - Quarkonium cross section and B fraction down to 0 GeV, polarization

    • - B cross section; fragmentation

    • CKM studies: CP violation and mixing

    • - Bs mixing, BsDs, lnDs

    • - |Vtd|: B0lnD

    • -DGs: BsJ/y , J/yh, lnDs, DsDs

    • - CP asymmetry: B0(Bs)hh

    • - : BsDsK+, BDK

    • - g:B0, BsKp, pp, KK

    • - b: B0J/yK0s

    • Properties of Bs, Bc, b, etc

    • - Production, mass, lifetime

    • Rare decays

    • - BK(*),B0, Bs

    • - Physics beyond the standard model:

    • Bse

    Solution: Vertex detector + trigger + Particle ID

    CDF

    CLEO

    Yuri Gotra - DIS 2003


    B triggers and data samples
    B Triggers and data samples

    Conventional

    New at CDF

    DiMuon (J/)

    2 central muons PT() > 1.5 GeV Run I: > 2 GeV Trigger on J/ymm

    Collected ~ 70 pb-1

    ~ 0.5MJ/ymm signal

    J/ modes down to low PT(J/)(~ 0 GeV)

    Displaced track + lepton (e, )

    1 muon/electron pT> 4 GeV 1 other track pT > 2 GeV SVT IP>120 mm M(l-Track) < 5 GeV

    Collected ~70 pb-1

    ~ 0.5M BlX signal

    Semileptonic modes

    2-Track Trig.

    2 Tracks with pT > 2 GeV SVT IP > 120 mm pT1+pT2 > 5.5 GeV

    Collected ~70 pb-1~ 0.5M D0Kp signalFully hadronic modes

    • - BS mixing

    • CP asymmetry in 2-body charmless decays

    - CP violation

    - Masses, lifetimes

    - Quarkonia, rare decays

    • - High statistics lifetime

    • tagging studies, mixing

    Secondary

    Vertex

    B

    Decay Length

    Lxy

    PT(B)  5 GeV

    Primary

    Vertex

    d = impact parameter

    Lxy  450 m

    Yuri Gotra - DIS 2003


    Detector calibration p scale b field correction

    Raw tracks

    Detector calibration:p scale & B-field correction

    MASS SCALE: MCDF = MPDG-M(PT)

    Use J/ to correct for B field and energy loss:

    (scale)/scale ~ 0.02%

    Sanity check with known signals:

    Add B scale correction

    1S

    Tune missing material

    Correct for material in GEANT

    2S

    3S

    Yuri Gotra - DIS 2003


    B masses in exclusive j y channels
    B masses in exclusive J/y channels

    M(Bs) is already the second best in the world (after CDF Run I)

    18.4 pb-1

    B0J/yK0*

    18.4/pb

    Prerequisite:momentum scale was

    precisely set (@0.02%) using J/

    sample (~200K events)

    BsJ/yf

    • BuJ/y K+

    • BdJ/y K0*(K0*K+p -)

    • BsJ/y f (fK+K-)

    Very good S/B

    More mass plots

    CDF2 (MeV/c2) DM/sCDF sCDF/sPDG

    Bu 5280.6 ±1.7 ±1.1 +0.8 4.0

    Bd5279.8 ±1.9 ±1.4 +0.24.8

    Bs5360.3 ±3.8 ± 2.11.9

    18.4 pb-1

    BJ/yK

    Bu

    2.1

    2.9

    • Statistics limited, but compare well w/PDG

    • Systematics already under control.

    • Precise measurements, soon!

    Yuri Gotra - DIS 2003


    B lifetimes 1

    Lxy

    B lifetimes (1)

    Crucial: precise Secondary Vertexing

    Silicon VerteX detector (SVX)

    c = Lxy / 

    PV

     = PT(B) / M(B)

    CDF Run I:full set of precise B-lifetime meas.

    Competitive with LEP

    • Inclusive: BlDX, BJ/X

    • Large statistics, but…

    • Final state not fully reconstructed

    • PT(B) has to be corrected from MC

    • Exclusive: BsJ/, b J/

    • Small systematics

    • Limited statistics

    Run II:x50 statistics( 2fb-1, wider silicon & lepton coverage, hadronic triggers)

    Improve measurements. Especially Bc, Bs, b down to ~0.01 ps

    Yuri Gotra - DIS 2003


    B lifetimes 2
    B lifetimes (2)

    Heavy Quark Expansion

    predicts lifetimes for

    different B hadron species

    t(Bc) << t(Xb0) ~ t(Lb)

    < t(B0) ~ t(Bs) < t(B-)

    < t(Xb-) < t(Wb)

    • t(B+)/t(B0) = 1.03÷1.07

    • t(Bs)/t(B0) = 1.00±0.01

    • t(Lb)/t(B0) = 0.9÷1.0

    B+/B0 and Bs/B0 measurements agree with prediction

    Small discrepancy forLb lifetimes

    • LEP + CDF Run I

    Yuri Gotra - DIS 2003


    Inclusive b j y x lifetime
    Inclusive B  J/y X Lifetime

    J/y

    B

    CDF July 2002 (18 pb-1):

    t=1.5260.0340.035 ps

    PDG 2002: t=1.6740.018 ps

    Inclusive B lifetime with J/y’s

    BJ/yX from ~ 28.000 J/y events

    c = J/y (prompt + non-prompt) + non-J/y

    c(B) = 458  10(stat)  11(syst) m

    PDG: 469 ± 4 μm

    Yuri Gotra - DIS 2003


    Exclusive b lifetimes

    MB,pB

    m-

    LB

    K+

    B+

    m+

    Exclusive BLifetimes

    B+gJ/y K+

    B0gJ/y K0* (K0* g K+p-)

    BsgJ/yf(fgK+K-)

    Unique to Tevatron

    uncertainties @ Run I level

    • Simultaneous fitting of

    • MB: Extract signal fraction

    • c: Extract the lifetime

    • c = LB / pBx MBPDG

    = 0.89  0.15

    = 1.11  0.09

    Yuri Gotra - DIS 2003


    Conventional way to b j y mm

    Background is subtracted

    Conventional way to B: J/y mm

    CDF triggers on stopped J/ymm: pT(m) 1.5 GeV/c, pT(J/y )  0

    CDF can measure cross section down to pT = 0

    (first at hadron collider)

    s(ppgJ/y; pT>0;|y|<0.6) = 240  1 (stat)  35/28 (syst) nb

    s(bJ/X): in progress

    Yuri Gotra - DIS 2003


    Exclusive b j y signals

    m

    m

    m

    Exclusive B  J/y Signals

    K+

    K+

    K+

    K-

    Bs

    p-

    B0

    B+

    m

    m

    m

    B+gJ/y K+

    ~ 640 signal events

    (>1000 events with loose selection)

    B0gJ/y K*0 (gKp)

    ~ 220 signal events

    Normalization mode for sin2banalysis

    BsgJ/yf (gKK)

    ~75 signal events

    Golden mode for

    DGsmeasurement

    Yuri Gotra - DIS 2003


    B b 0 from lepton displaced track

    Lepton

    D

    B

    SVT track

    n

    P.V.

    B+/B0 from lepton+displaced track

    high statistics semileptonic B samples

    Excellent calibration samples for

    B+/B0lifetime, tagging and B0 mixing

    BglD0X (D0gKp):~10,000 events

    BglD*+X (D*+gD0p):~1,500 events

    BglD+X (D+gKpp):~5,000 events

    Run II yields significantly larger,

    lower lepton pT threshold possible

    thanks to i.p. trigger

    Yuri Gotra - DIS 2003


    B s from lepton displaced track
    Bs from lepton + displaced track

    BsDsl[] l[[KK] ]lONLY @ Tevatron

    Yield/Lumi ~ Run I x 3, S/N ~ Run I x 2

    • HIGH STATISTICS SAMPLE:

    • Inclusive lifetime: 

    • Mixing (moderate xs):

    • good S/N, limited time resolution: back-up sample

    385  22 Ds

    (muon only)

    Systematics of trigger bias

    Efficiency vs c

    ARBITRARY UNITS

    MC

    Lifetime: stat. ~ 0.07 ps (PDG:0.057 ps)

    Future: Bs mixing (low ms case)

    Yuri Gotra - DIS 2003


    B from lepton displaced track
    bfrom lepton+displaced track

    Yield/Lumi = 4 x Run I, S/N ~ 2 x Run I

    bcl[pK]l

    • Branching Ratio

    • Measure 

    • Q2 = m(l)

    • important for theory

    • Experimental challenge:

    • disentangle from decays through excited baryons

    Time of flight

    dE/dx +

    Lifetime: stat. ~ 0.12 ps (PDG:0.08)

    Future: semileptonic form factor

    Yuri Gotra - DIS 2003


    B c and b
    Bc and b

    Lb  L+c l -n

    Lb J/y L (L p)

    Run I:

    ~20 eventsBcJ/ye/

    Run I:

    M(Bc) = 6.400.390.13 GeV/c2

    t(Bc) = 0.46 +0.18 0.03 ps

    t(Lb) = 1.32  0.15 0.07 ps

    -0.16

    Run II data

    53  11

    65 pb-1

    Lb J/y L

    Also hadronic modes:

    LbLc (Lc pK)

    LbpD0p(D0 K)

    LbpK / p

    Run II: better Mass, Lifetime, BR

    Also exclusive channels:BcJ/ p

    and fully hadronic:BcBsp

    Yuri Gotra - DIS 2003


    Physics with b 0 h h
    Physics with B0 h+h-

    300 eventsin 65 pb-1: first charmless B’s at hadronic collider

    B0 h+h-is a mixture (1:4:2:0.5) of

    Bdpp;BdKp;BsKp;BsKK;tree, BR~5x10-6penguin, BR~1.5x10-5

    • Strategy for disentangling channels:

    • Invariant mass shape (M ~25 MeV/c2)

    • Kinematical variables

    • Particle Identification

    • COT dE/dx

    • Oscillation of CP asymmetry

    ( inv.mass)

    CDF II simulation

    —sum

    BdK

    BsKK

    Bd

    BsK 

    • Can soon perform interesting measurements:

      • Relative B. Ratios: Bdpp/Kp; BsKK/Kp

      • Direct CP asymmetries in BdKp (self tagging)

      • CP asymmetries in Bdpp(with b-tagging)

    • Later on: CKM angle

    Yuri Gotra - DIS 2003


    Physics with the hadronic trigger
    Physics with the hadronic trigger

    open access to fully

    hadronic D and B signals

    D

    D

    D’s from

    Primary Vertex

    have d 0

    B

    d(D)

    D-mesons Impact Parameter (d)

    used to discriminate the two components

    D mesons I.P. (d) distribution

    B fraction

    D0K16.4  0.7 %

    D*D011.4  1.4 %

    DK11.3  0.5 %

    Ds34.8  2.8 %

    Reconstructed large (0.5M) D mesons:

    D K, D0K, D*D0, Ds 

    D0KK, D0p

    Measured prompt D vs. Dfrom B

    Yuri Gotra - DIS 2003


    Physics with b 0 s j
    Physics with B0s J/

    • largest fully reconstructed sample

    • in the world:7411 events

    • Yield/Lumi = 2 x RunI

    • Expected in 2 fb-1:  4000 events

    • CP asymmetry measures the weak

      phase of Vts (angles = 2s )

      Expected to be very small in SM:

      s 2o sin(2s ) O(l2)  0.03

      Complicated analysis: requires xsand angular analysis to disentangle CP even/odd final states

      CDF II reach : s(sin(2 s ))  0.1 with 2 fb–1 (0.03÷0.06 with 10 fb–1)

    • If asymmetry observed with 2fb–1 signal for NEW Physics

    • We also want to measure the lifetime difference between two Bs mass eigen states:s = BsH - BsL

      Current limit (LEP):s/s < 0.31 (S.M.:DG/G = 0.05 ÷ 0.20)

    • Expected uncertainty: (s/ s) = 0.05

    Yuri Gotra - DIS 2003


    More b g j y signals
    More BgJ/ysignals

    B0gJ/yK0s

    ~220 events

    B+gJ/yK+

    • Two track trigger data (65 pb-1)

    • Reconstruct hadronic B decays

      • B+gJ/yK+(J/ygl+l-): 311±25

        normalization mode

    First steps towards

    sin(2b) measurement

    Yuri Gotra - DIS 2003


    Hadronic b c signal
    Hadronic bc signal

    bc[pK]

    40 events in 65 pb-1,largest fully reconstructed hadronic channel

    NO PID YET

    pK Mass [GeV]

    • Measure mass, lifetime, polarization, t(Lb)/t(B0)

    • More channels to be added

      • LbgLcppp, pD0p

      • LcgLppp

    pK Mass [GeV]

    Yuri Gotra - DIS 2003


    Ingredients for b 0 s mixing

    Lxy

    c =

    

    Ingredients for B0s mixing

    ms/md

    a

    Nunmix(t) – Nmix(t)

    Amix(t) =

    = Dcos(mst)

    g

    b

    Nunmix(t) + Nmix(t)

    • Reconstruct the final state(use fully rec. B0sD-s π+(3π))

      with good S/B (thanks to precise tracking, vertexing, PID)

    ;  = PT(B) / M(B)

    2. Measure proper decay time:

    Current limit:

    ms 14.4 ps-1

    Error on B momentum, ~ 15% (semileptonic)

    negligible (~ 0.5%) for

    fully reconstructed final states

    60 fs (SVX II detector)

    45 fs (also Layer 00 is used)

    3. Identify the flavor of Bsat production: B-flavor tagging algorithms

    Yuri Gotra - DIS 2003


    First steps towards b 0 s mixing
    First steps towards B0s mixing

    Collect more data

    and understand tagging

    Bs Ds(*)  []   [[KK] ] 

    Fully reconstructed

    Bs is consistent with

    BdD-+control sample

    More channels to be added

    BsDs, DsK*K, K0sK, 

    Yuri Gotra - DIS 2003


    Angle from b 0 h h

    u

    W+

    p+

    b

    d

    B0

    p

    u

    d

    d

    b

    ms/md

    a

    Angle  from B0h+h-

    g

    b

    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

    B0 +

    Bs K+K

    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 for BsK+K(Dmdreplaced byDms)

    The 4 asymmetries: function of, and P/T amplitude ratio

    Parameters: from fit of meas. ofACP(t) for Bdand BsKK

    Expected (2fb-1) accuracy:() = ±10(stat) ±3(syst)

    (SU(3) breaking effects)

    Yuri Gotra - DIS 2003


    B physics prospects with 2fb 1
    B physics prospects(with 2fb-1)

    Both competitive and complementary to B-factories

    The B physics potential is great and we expect:

    • Bs mixing:BsDsπ(Ds3π)(xs up to 60, with xd meas. one side of U.T.), direct and mixing asymmetries in two body decays

    • Angle :B0J/yKs(refine Run I measurement up to (sin2)  0.05)

    • CP violation, angle: B0ππ(πK), BsKK(Kπ), at ~10° possible

    • Angle sand s/s:BsJ/y(probe for New Physics)

    • Precise Lifetimes, Masses, BRfor all B-hadrons: Bs, Bc, b…

      (CDF observed: BcJ/y e().

      Now hadronic channels BcBsX can be explored)

    • HF cross sections (beauty and charm)

      By the end of Run IIb (~2008): 5 the statistics of Run IIa !

    • Stringent tests of SM … or evidence for new physics !

    Yuri Gotra - DIS 2003


    Why do we care about top
    Why do we care about Top?

    The Discovery of the top quark in 1995 was no big surprise. What was surprising is that its mass is almost 40 times that of the b quark, and tantalizingly close to the scale of EWSB.

    The Fermilab Tevatron has been the only place, and will be until the LHC turns on in ~2008, to study the top quark.

    Everything we know about top is based on ~100 events from the Tevatron Run I.

    • tt measurement: (Precision test of QCD, Probe for physics beyond SM)

    • Top mass:

    • Fundamental parameter of Standard Model (SM)

    • Affects predictions of SM via radiative corrections (BB mixing, W and Z mass, measurements of MW, mt constrains MH)

    • Large mass of top quark (Yukawa coupling  1,

    • may provide clues about electroweak symmetry

    • breaking)

      With 30 times more top events, as expected in Run IIa:

      • Why is top so heavy ?

      • Is it or the third generation special ?

      • Is top involved with EWSB ?

      • Is it connected to new physics ?

    Yuri Gotra - DIS 2003


    Production and decay of top quark
    Production and Decay of Top Quark

    At the Tevatron, top quarks are primarily produced in pairs via strong interaction. Single production via weak interaction not yet observed

    ttop ~ 4 x 10-25 s

    L-1~ (100 MeV)-1 ~10-23 s

    Top decays as free quark!

    BR(tWb) @100%

    CDF Run I:Ldt 109 pb-1(~300 top candidates)

    Main “usable” top event topologies:

    Dilepton: tt  lnlnbb2 high-PT leptons, 2 bjets, large Missing ET (BR 5% e+m)

    Lepton + Jets:tt  lnqqbb1 high-PT lepton, 4 jets (2 b's), large missing ET (BR 30% e+m)

    All-hadronic:tt  qqqqbb6 jets (BR 44%)

    Yuri Gotra - DIS 2003


    S tt dilepton cross section

    µ2

    µ1

    -

    N

    N

    Jet1

    obs

    bkg

    s

    =

    (

    t

    t

    )

    Jet2

    ×

    ò

    A

    L

    b

    l-

    tt = 13.2  5.9stat  1.5sys  0.8lum pb

    [email protected] s=1.96 TeV for

    Mtop = 175 GeV: 6.70+0.71–0.88 pb

    p

    p

    b

    l+

    stt:dilepton cross section

    • Event selection

      • 2 High PT (PT>20 GeV) oppositely charged leptons (e,m).

      • Both isolated: ICAL< 0.1

      • Veto Z’s, cosmics, and conversions

      • Neutrinos: large missing ET > 25 GeV

      • at least 2 jets with ET > 10 GeV

      • Total transverse energy of the event > 200 GeV

    • BR~5%, detection efficiency ~ 11%

    • 5 candidate events in 72 pb-1

    • (Run I: 9 events) tt = 8.2  4 pb

    • Backgrounds: Drell-Yan, Z0->tt, WW : 0.30±0.12

    • Disadvantageslow yield, difficult to measure Mtop accurately

    • Advantageshigh S/B ~8

    Yuri Gotra - DIS 2003


    S tt lepton jets cross section

    b

    Jet3

    Jet2

    Lego view

    Jet1

    Jet4

    l-

    p

    µ

    p

    tt = 5.3  1.9stat  0.8sys  0.3lum pb

    q

    b

    q

    stt: lepton + jets cross section

    • Event selection

    • One high momentum, central, isolated lepton, PT > 20 GeV/c, e or m.

    • Veto Z’s, cosmics, and conversions.

    • Neutrinos: large missing ET > 20 GeV

    • 3 or more jets with ET > 15 GeV

    • At least 1 jet with secondary vertex tag

    • 15 observed events in 57.5 pb-1

    • Backgrounds from Wbb,Wcc, mistags, Wc, non-W (fake lepton): 3.8 ± 0.5

    • Lower S/B1:6 for W+ 3 jets

    • b-tagging improves S/B3:

    • Higher statistics

    • Essential for Mtop (2 b-tags jets)

    Run 1

    Run 2

    Yuri Gotra - DIS 2003


    Top mass lepton 4 jets

    W+

    b-jet

    n

    X

    t

    t

    jet

    W-

    jet

    b-jet

    Top mass: lepton + 4 jets

    • METHOD

    • Use 2C constrained fitting technique with constraints

    • m(ln) = m(qq) = mW

      • m(lnb) = m(qqb)

      • PDG: MW, W, t

  • 24 combinations:

  • 12 correspond to the jet-parton match

  • every combination has 2 solutions for neutrino PZ

  • Choose combination with lowest 2.

  • Improvements to DMtop:

    • Statistics:

    • Increased b-tag acceptance

    • events with b-tag reduce combinatorics

    • Choose best measured events

    • Jet Energy Scale:

    • Use control samples (Zbb, Wqq) to reduce systematics

    • Jet energy flow techniques

  • 5 vertices

    20 constraints

    Yuri Gotra - DIS 2003


    Top mass
    Top mass

    Run I CDF+D0 combined: mt=174.3 5.1 GeV/c2

    dominated by jet energy measurement

    • Run 2a expectations:

      • DMtop = 2-3 GeV

    Use a continuous likelihood method to extract top mass and statistical uncertainty

    Mtop is the minimum of the log-likelihood distribution

    top corresponds to a change of 0.5 units in the log-likelihood

    Yuri Gotra - DIS 2003


    Physics with large top samples
    Physics with large top samples

    • top quark mass measurements (within 2-3 GeV/c2)

    • tt pair production cross section (within 8%)

    • single top production cross section

    • tt spin correlations, studies of top polarization

    • rapidity of tt system

    • mass of tt system

    • soft gluon radiation in tt events

    • W helicity in top decays

    • single top production  |Vtb|

    • any anomalies in the above studies

    • rare decays…

    • NEW PHYSICS ?

      ~800 b-tagged tt lepton+jets events in 2pb-1

    • With larger samples (later this year) we will be able to extend our Run I searches for extensions to the SM

    Yuri Gotra - DIS 2003


    Summary
    Summary

    Run II CDF collected ~100 pb-1 of data for heavy flavor physics

    (Run I total: 110 pb-1)

    • Detector is well calibrated, mass scales and vertexing resolution are understood, Run I physics signals are re-established. Some of the systematic uncertainties are still conservative. Will be reduced in future Impact parameter trigger: huge/clean semileptonic/all hadronic B signals

    • The SVT  great success:

      • unique @ hadron collider

      • CDF as Charm/B factory

  • Forward detectors  diffractive physics

  • Great heavy flavor physics potential, we have results on:

    • Masses, lifetimes, production cross sections competitive with Run I

  • We are preparing for high luminosity:

    • Promising perspectives for flagship analyses: studies of Bs, Bc, CP violation, Bs mixing, s, b, charmless B-decays and other topics unique to Tevatron are in progress.

  • Lots of heavy flavors at CDF, stay tuned for new exiting results

    Yuri Gotra - DIS 2003


    Heavy flavor results from CDF Run II: B physics

    • Run II CDF collected ~100 pb-1 of data for heavy flavor physics

    • Masses, lifetimes, production cross sections competitive with Run I

    • studies of Bs, Bc, CP violation, Bs mixing, s, b etc are in progress

    Lepton + displaced track

    Two track trigger

    Dimuon trigger

    Bs lnDsX

    Lb Lcp

    Bs J/y f

    Lifetime

    Mass

    CDF2 (MeV/c2)sCDF/sPDG

    Bu 5280.6 ±1.7 ±1.1 4.0

    Bd5279.8 ±1.9 ±1.4 4.8

    Bs5360.3 ±3.8 ± 1.9

    Yuri Gotra - DIS 2003


    Heavy flavor results from CDF Run II: top quark

    • We have reestablished the presence of the top quark in Run II

    • Cross sections in dilepton and lepton plus jets channels are in agreementwith the SM expectations

    • The tt events show mass compatible with the run I measurement

    • The Fermilab Tevatron has been the only place, and will be until the LHC turns on in ~2008, to study the top quark

    Dileptonstt = 13.2  5.9stat  1.5sys  0.8lum pb

    tt = 5.3  1.9stat  0.8sys  0.3lum pb

    Lepton plus jets

    Yuri Gotra - DIS 2003


    Backup slides
    Backup Slides

    Yuri Gotra - DIS 2003


    Our machinery at fermilab

    Chicago

    Booster

    CDF

    Tevatron

    p source

    Main Injector

    (new)

    Our machinery at Fermilab

    Run II: proton-antiproton collisions ats=1.96 TeV

    Yuri Gotra - DIS 2003


    Tevatron p p collider

    Jan 03

    Mar 02

    Tevatron p+p- collider

    Main Injector (new injection stage for Tevatron)

    Ability to accelerate and deliver higher intensity of protons

    More efficient anti-proton production

    Collision rate: 396 ns crossing time

    (36x36 bunches)  ~ 2M collisions/sec

    Center of Mass energy: 1.96 TeV

    CDF Integrated Luminosity

    130 pb-1 (delivered)

    100 pb-1 (to tape)

    B/Charm: ~ 70 pb-1

    Today: luminosity ~4.0 x 1031cm-2s-1

    4 to 7 pb-1/week delivered

    Goal: luminosity: ~1032 cm-2s-1

    16 pb-1/week delivered

    In this talk: results with 70 pb-1 for CDF

    commiss

    Yuri Gotra - DIS 2003


    What is new at the tevatron
    What is New at the Tevatron

    • Main Injector: new injection stage, more efficient anti-p transfer to Tevatron ring

    • Recycler: new storage ring for reuse anti-p (still commissioning, ready 2004)

    • Higher collision rate: 396ns crossing time (36x36 bunches) ( 132ns, 108x108)

      major upgrades in detector, electronics and trigger !!!

    • Slightly higher C.M. energy: 1.8  1.96 TeV

    • Higher Inst. Luminosity: 5-10 times higher than in Run 1

    • Run plans: Run 2a: L = 5-8  1031cm2 s1

      • (L = 10-20  1031cm2 s1 , with Recycler)

    • Total integrated L = 2fb1

    • Run 2b: Total integrated L = 6 - 10fb1

    2005

    …2008

    Yuri Gotra - DIS 2003


    Tevatron status and goals
    Tevatron status andgoals

    10–6f 0B NpNpb(6 r r)

    L

    H ( l /  *) (1031 cm-2s-1)

    =

    2 *( p+  pb)

    Accelerator parameters:

    Integrated Luminosity (fb-1)

    Yuri Gotra - DIS 2003


    Tevatron performance
    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

    Yuri Gotra - DIS 2003



    Cdf detector overview

    CDF Detector overview

    CDF Detector Overview

    New Central Tracker (COT)

    ToF counter for K/p separation

    Placed right before the Solenoid

    New Plug Calorimeter

    1.3 < |h| < 3.5

    Muon Detector

    More Coverage

    SVX: Acceptance increase

    |z0| < 30 g 45 cm

    L00: Vertex resolution

    ISL: |h| < 2.0

    Forward Calorimeter

    3.5 < |h| < 5.1

    Yuri Gotra - DIS 2003


    Cdf detector in run ii
    CDF Detector in Run II

    Inherited from Run I:

    Central Calorimeter (||<1)

    Solenoid (1.4T)

    Partially New:

    Muon system(extended to ||~1.5)

    Completely New:

    Tracking System

    - 3D Silicon Tracker(up to ||~2)

    - Faster Drift Chamber

    Time-of-Flight(particle ID)

    Plug and Forward Calorimeters

    DAQ & Trigger system(Online Silicon Vertex Tracker: trigger

    on displaced vertices, first time at hadron collider)

    Yuri Gotra - DIS 2003


    Quadrant of cdf ii tracker
    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 Layer 00)

    LAYER 00: 1 layer of radiation-hard silicon at very small radius (1.5 cm)

    (achievable: 45 fs proper time resolution inBsDsp )

    Yuri Gotra - DIS 2003


    Cdf ii trigger system
    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

    Yuri Gotra - DIS 2003


    Cdf trigger system overview

    Crossing: 396 ns: 2.5 MHz

    Level 1: hardware

    Calorimeter, Muon, Track

    15kHz (reduction ~x200)

    Level 2: hardware + CPU

    Cal cluster, Silicon track

    300 Hz (reduction ~x5)

    Level 3: Linux PC farm

    ~ Offline quantities

    50 Hz (reduction ~ x6)

    CDF Trigger System Overview

    Yuri Gotra - DIS 2003


    Silicon vertex tracker svt

    Level 2: Silicon Vertex Trigger

    Use silicon detector information

    Good IP resolution

    Trigger on displaced track

    beamline reconstruction

    update every ~ 30 seconds

    IP resolution: ~ 50 mm

    35mm beam size + 35mm SVT

    Increase physics sensitivity of the

    Run II CDF

    CDF as “Charm Factory”

    Millions of D’s per 100 pb-1

    Collect Hadronic B sample

    No Lepton required in final state

    Bs physics (mixing in Dsp)

    Higgs/new particles decaying heavy (b and c) quarks

    f

    z

    Silicon Vertex Tracker (SVT)

    Yuri Gotra - DIS 2003


    Svt triggering on impact parameters

    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

    Yuri Gotra - DIS 2003


    B triggers conventional
    B triggers: conventional

    Needspecialized triggers

    (bb) /(pp)  10-3

    CDF Run I, 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 I:

    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

    Yuri Gotra - DIS 2003


    B triggers new
    B triggers: New !!

    Secondary

    Vertex

    CDF 2, displaced tracks triggers:

    B

    Decay Length

    Lxy

    PT(B)  5 GeV

    Trigger on tracks significantly

    displaced from primary vertex

    Primary

    Vertex

    Lxy  450m

    <d>  100 m

    Made possible by SVT:

    precise meas. of track impact parameter at Level 2

    2D Secondary Vertices reconstructed online !

    d = impact parameter

    • Two displaced tracks(d > 100m, Lxy cut,  cut)

      • All hadronic B decays: B (KK), b  p(K), Bs Ds(3) ...

      • Lots of prompt charm mesons !!!

    • Lepton plus displaced track

      • Semileptonic decays at Lower PT ( 4 GeV/c)

      • Rare B decays …

    Yuri Gotra - DIS 2003


    All hadronic b triggers
    “All Hadronic B triggers”

    • Level 1: 2 XFT tracks

    • PT > 2 GeV

      •  < 135º

      • PT1 + PT2 > 5.5

    “Multi-body decays”

    “Two body decays”

    1/100

    h+

    Level 2

    h-

    B0

    D

    d > 100 mm

    20º <  < 135º

    Lxy  200 m

    dB < 140 mm

    d > 120 mm

    2º <  < 90º

    Lxy  200 m

    B

    B0  p p

    B0  K p

    Bs K K

    Bs p K

    Lb  p p(K)

    Bs Dsp

    Bs Dsp p p

    B D K/p

    + Lots of

    prompt charm decays

    1/1000

    Level 3

    SAME with refined tracks

    & Mass cuts

    Yuri Gotra - DIS 2003


    Xft performance
    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/  

    Yuri Gotra - DIS 2003


    Svt performance
    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%

    Yuri Gotra - DIS 2003


    Tof performance
    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

    Yuri Gotra - DIS 2003


    Cdf j y cross section
    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; |y|<0.6) =240  1 (stat) 35/28(syst) nb

    Yuri Gotra - DIS 2003


    B 0 s mixing expectations with 2fb 1
    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 !

    Yuri Gotra - DIS 2003


    Projections for xs reach with 2fb-1

    Optimistic: S/B =2/1

    Conservative: S/B =1/2

    Xs = 42-63

    Xs = 32-53

    MC simulation: accounts also for SVT cuts on proper time acceptance,

    non-Gaussian tails in proper time resolution function

    Yuri Gotra - DIS 2003


    Sin 2 in b 0 j y k s

    1

    B

    1

    »

    )

    +

    (

    sin

    (2

    )

    e

    D

    N

    S

    2

    ms/md

    a

    Sin(2) in B0J/yKs

    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

    Yuri Gotra - DIS 2003


    Disentangling b 0 h h contributions
    Disentangling B0h+h-contributions

    Use M vs a=(1-p1/p2)q1

    B0d pp

    B0d K-p+

    B0d K+p-

    B0s K+p-

    B0s K-p+

    B0s KK

    Expected fraction res. (MC 65 pb-1)

    B0dKp(0.6): 0.062 (stat)

    B0 dpp(0.15):  0.056 (stat)

    B0sKK(0.2):  0.045 (stat)

    B0 sKp(0.05): 0.036 (stat)

    ACP(B0dKp): 0.14 (PDG-2002: 0.06)

    Use K/ separation dE/dx 1.16

    Yuri Gotra - DIS 2003


    B flavor tagging
    B Flavor Tagging

    “Identify the flavor of B at production”

    OST (opposite side tagging):

    B’s produced in pairs  measure flavor of opposite B

    JETQ:sign of the weighted average charge

    of opposite B-Jet

    SLT:identify the soft lepton from semileptonic decay of opposite B

    SST (same side tagging):

    B0 (B0) is likely to be accompanied close by a + ()

    Search for the track with minimum PTREL

    b

    d

    d

    u

    u

    B0

    +

    D2 “tagging effectiveness”  2%

    Figure of merit:

    = tagging efficiency ;

    D = “Dilution” = 1 – 2Pmistag

    Effective size of sample is reduced byD2

    Yuri Gotra - DIS 2003


    New at cdf kaon b taggers
    NEW at CDF: “Kaon b-taggers”

    • Exploit K/ separation of new TOF

    • Well suited for strange B mesons

    b

    s

    s

    u

    u

    B0s

    Same Side K: aB0s(B0s) is likely to be accompanied

    close by aK+(K) from fragmentation

    K+

    Opposite Side K: due to bcs it is more likely that a B meson

    contains in final state a K than a K+

     to identify a B0s look for a K from the decay of the opposite B

    Run II Projections

    Yuri Gotra - DIS 2003


    B flavor tagging1

    Statistical uncertainty for tagging efficiency

    A typical tagging:e=0.1, D=0.4, eD2=1.6%

    1000 events:eD2=1.6+0.7% (44%)

    100K events:eD2=1.60+0.07% (4.4%)

    We can’t study/optimize the flavor tagging with ~O(1000) events of the B signal events

    B g J/yK: ~ 1000 events/100pb-1

    B g Dp: ~ 500 events/100pb-1

    Solution: Use Semileptonic B decays in the lepton + track dataset

    ~200K semileptonic B signal events

    High B purity

    Lepton Charge = Decay flavor of B

    B Flavor Tagging

    No charm contamination

    Yuri Gotra - DIS 2003


    Top properties
    Top Properties

    • Top pairs: s(tt) ~ 8 pb

      • W helicity in top events

      • t-tbar spin correlations

      • Top PT

      • QCD tests

      • Top Drell-Yan via ds/dM of tt

      • New physics in X tt

      • Anomalous couplings,

      • new particles

    • Single top: s(tb) ~ 3 pb

      • |Vtb|

      • QCD tests

      • New physics?

    Yuri Gotra - DIS 2003


    Top production numbers
    Top production numbers

    Yuri Gotra - DIS 2003


    L jets channel backgrounds
    l+jets channel BACKGROUNDS

    • Mistags:

    • fake rate matrix(Et,) from inclusive jet data per jet : neg-rate=#tagged jets

    • with Lxy<0 / #taggable jets

    • is applied to every single taggeable jet found in W+jets sample

    Wbb,Wcc Wc: [Evt Fraction] [Efficiency] [N W+jet]

    Event Fraction: heavy flavor fraction

    in W+jets events from Run 1

    Efficiency:b-tagging rate from Run 2

    MC, Scale Factor applied

    N W+jets in Run 2 data.

    Non-W: from data, isolation vs Et method

    WW,WZ,Z->,Single top from MC

    Yuri Gotra - DIS 2003


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