B, λB and Charm results from the Tevatron

Farrukh Azfar, Oxford University (CDF)

Physics in Collision: Zeuthen, June 27 2003

Overview of this presentation:

1) Tevatron performance & Beauty Physics at the Tevatron

2) CDF and D0 detectors and triggers

3) Data from various Triggers at CDF and D0

3) Physics Results : Masses and Lifetimes of B hadrons Tests of Heavy Quark Expansion (HQE)

4) Physics Results: Charm : masses, search for CP violation (CPV) & Flavour Changing Neutral Current (FCNC)

5) Physics Prospects: CP violation, Bs mixing (xs=ms/) and Bs width difference (s)

6) Conclusion and Summary

Tevatron pp collider upgrade & performance

Performance Improvement:-Collision rate: 3.5 s 396 ns-6x6 bunches 36x36 bunches-Center of Mass energy: 1.8 1.96 TeV/c2

-Peak luminosity : 2.4x1031 4.4 x1031cm2s-1

(Below target by x4, steadily improving)

Run-I (1992-1996) -Accumulated Ldt=110 pb-1

Run-IIa -Goals are Ldt=2fb-1 (x20 Run-I)

Run-II Tevatron Upgrades: Main Injector -New Injection stage for Tevatron -Higher proton intensity -Anti-proton transfer efficiency increased -Anti-proton recycler (work in progress)

Data taking performance CDF & D0

CDF integrated luminosity:-Delivered 230pb-1 of which-175pb-1 to tape, of which-70 pb-1 has important systems on(eg. Silicon) B-physics analyses

D0 efficiency:-50 pb-1 B-physics analyses

Physics Results in this talk are from ~70pb-1 @ CDF and ~50pb-1 @ D0

Why Beauty at the Tevatron ?

(bb) at (4S) = 1nb (B-factories)(bb) at Z0 = 7nb (LEP)(bb) at pp (1.96TeV/c2)=150b (Tevatron Experiments)

More B @ Tevatron but inelastic at tevatron is 103 x (bb) -Must select b-data online, key: appropriate detector &

triggers -Rewards: can produce all B-hadrons eg B, B0, Bs, Bc

, b …etc

(unlike B-factories) & higher than at Z0

Signatures for B Selection & use at CDF & D0:

-High PT leptons from b X or b eX (CDF & D0) -Di-leptons from B J/X, J/+(CDF & D0) -Utilize long B and charm lifetimes large impact

parameter (IP) of daughter tracks (CDF, D0 in progress)

The CDF & D0 Detectors in Run-IINew: Time of Flight (TOF): some hadron ID New: Silicon (SVT) online Si tracker: Select high IP tracks from b and c @ trigger level (First time at a hadron collider !)

Improvements over Run-I-Silicon Detector : 3-D tracking, 5 layers: B vertex, track IP resolution,-Faster Drift Chamber : Momentum measurement-Greater muon coverage : Select b, c New : 2T Super conducting MagnetNew: Silicon tracker (vertex, track IP resolution) New: Fiber tracker : MomentumNew: Si Track Trigger (displaced vertices) (Coming soon)Improvements over Run-I-Calorimetry and faster readout-Upgraded muon system.

CDF Detector

D0 Detector

D0 has a magnetic field, and is able to pursue a competitive B-physics program as well !

Data Samples: The J/ at CDF and D0 (Run-II)

0.5M at CDF (70 pb-1) 75K at D0, completely new capability ! (40 pb-1)

Two Fully Reconstructed B-hadron J/states at CDF &D0

B J/ KS: CDF:220, D0:45 (Run-II) (D0 had none in Run-I)

B J/ : CDF:53, D0:16 (Run-II)

Data Samples: B and Charm Using the high Impact Parameter (IP) (Hadronic) trigger

Select events by requiring : -2 tracks with IP>100 m - 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/ trigger

Data Samples: B(+)l+D decays using “hybrid” triggerOne lepton (PT>3 GeV/c) & one high IP (>120m)track:-High IP track means we can go lower in lepton PT-Statistics much higher than Run-I (lower PT thresholds)(x4-5 increase in statistics)

Used for:1) High statistics lifetime and mixing analyses 2) calibration samples for tagging (B+ l+D) Drawback: worse vertex resolution due to missed neutrinoSome numbers:BlD0X (D0K): ~10000 events, BlD+X (D+K): ~5,000 events also Bs decays (later)

Physics Results: lifetime, mass, from fully reconstructed BJ/ X modes: Standard Technique :

Data from J/ di-muon trigger: - Reconstruct vertex - Calculate decay proper time, mass & errors- Fitting for Mass:fit mass only- Fitting for Lifetime:Fit mass and lifetime distributions in single step

An Example B+ J/ K+ at CDF

Technique applied to several decays : B+ J/ K+, B0 J/ K0* (K0* K), Bs J/ ( KK) & bJ/ (p)

( , ) . ( , ) (1 ). ( , )

( , ) 1

total s signal s backround

total

F m t f F t m f F t m

F m t dmdt

Probability Density Function and normalization:

Physics Results: Bs J/, Lifetime and Mass:J/ +- and K+K- (using di-muon (J/) trigger): 1) Run-I: we had ~60 at CDF.2) Run-II: we have ~136 at D0 and CDF : World’s largest sample of fully reconstructed Bs decays remains at the Tevatron

CDF: M(Bs) = 5365.5 1.29(stat)0.94 (sys) MeV/c2, D0: M(Bs) = 5360 5CDF: (Bs) = 1.26 0.2 (stat) 0.02(sys) ps, D0 lifetime analysis in progress

Fit has one lifetime (width) but this mode contains two lifetimes: CP even and CP odd BsWith higher statistics we can use angular variables & disentangle CP states & fit two lifetimes (widths)

Why is the width difference interesting ?-Bs width difference s: predicted to be large ~10% -SM : s=A.xs (xs=Bs mixing Parameter)-If xs is large and s is small or vice-versa sign of new physics-SM CP violation in Bs J/ ~3% if extra-SM CP violation phase =Sin2 then s,measured = s,SM.Cos2sand CPV are complementary

Physics Results: B, lepton+displaced track and purely hadronic data samples (have shown J/ mode already)b cl [pK] l Protons are easiest to separate using Time of Flight

Particle ID in left plot using TOF and dE/dX

b c [pK] Lifetime in hadronic, hadron+lepton modes requirecorrection for IP cut bias & missing Expect results this summer

Note on BA search for CP violation in Baryon decays is plannedusing B p

Physics Results:Testing HQE: A summary of results:

CDF (70 pb-1): (B+ )= 1.570.070.02 ps using (B+ J/K+) (B0 )=1.42 0.090.02 ps using (Bd J/K*0) B+)/Bd)= 1.11 0.09 (Run-II)Bs)/Bd)= 0.89 0.15 (Run-II) D0 (40 pb-1): (B+ )=1.76 0.24 ps using (B+J/K+) BELLE (PRL 88 171801 2002) using BdD(*)-(+), J/KS,J/K*0 and B+D0+, J/K+

B+)/Bd)= 1.091±0.023±0.014

BABAR : fully reconstructed decays

Bd D(*)-(+,a1+), J/KS,J/K*0 and B+ D0+, J/K+

B+)/Bd)= 1.082±0.026±0.012

BABAR : partially reconstructed decays(BD,D* l )B+)/Bd)= 1.064 ±0.031 ±0.026

HQE Predicted B Lifetime hierarchy : Bc << b0 ~ b < Bd ~ Bs < B- < b-

Physics Results:Testing HQE: A summary of results:(B+)/Bd)) surpasses theory: 1.067 0.027 (HQE) (@ both Tevatron and B-factories)(Bs)/Bd)) doesn’t (yet): 0.998 0.015 (HQE)

Tevatron: Projection: (Bs)/Bd) ) and (Bd)/b)) <1% in Run-II important test for HQE

Current B lifetime is below HQE prediction, with B J/can have unambiguous determination

These results also give us confidence that vertexing works very well this is a crucial ingredient for Bs mixing and CP violation studies (more later)

Physics Results: Charm physics at CDF: Ds±-D ±

mass difference

Ds± - D± mass difference

2400 Ds and 1600 D in only

11.6 pb-1 of datam = 99.28 ± 0.43 ± 0.27MeV/c2

In agreement with old world average:99.2 ± 0.5 MeV/c2 (PDG: CLEO2, E691)and with recent BaBar result:98.4 ±0.1 (stat) ±0.3 (syst) Mev/c2

First Run-II publication from CDF-comparable with recent results1) Data Selected from the hadronic trigger2) Both Ds

±,D± decay to ±with K+K-

3) Kinematics of both decays ~identical4) Simply measure difference

Physics Results: Charm physics at CDF: Search for Flavour Changing Neutral Current decay D0+-

SM predicts a branching ratio (BR) of O(~10-13) for D0+-

Some R-parity violating SUSY models predict branching ratios upto O(~10-6)

CDF Result: BR(D0+) < 2.4x10-6 better than most recent world average:( PDG 90%CL: < 4.1 x 10-6 )

Technique:1) D0+- BR is well known ~ identical

acceptance to D0 +-

2) Use D0*±D0± to tag D0 in D0K-+ (thus no

K vs ambiguity)3) See how many s fake s per PT5) Look for D0 +- in same sample6) Subtract D0+- faking D0+-

0 events found in 2searchwindow

A similar analysis of the rare decay Bs establishes a 4sensitivity to signal for branching ratios >3.3x10-6

Physics Results: Charm physics at CDF: Search for CP violation (CPV) in Charm decays:1) c and u quarks don’t couple to t box diagram contributions are tiny2) CPV in charm decays due to interference in decay (direct CPV) 3) SM prediction O(0.1-1%) CP violation effects in Charm DecaysHow: Compare rate of Decay of D0, D0 to CP eigenstates f=K+K- and +-

0 0

0 0

( ) ( )( ) ( )CPD f D fAD f D f

Method Using data from Hadronic Trigger-Collect D*±D0± : sign of tags flavour of D-Search for D0 K+K-, D0 +-, D0 +- & D0 K+K- -Correct for tracking efficiency for + vs - from D*±D0±

-Count number of decays in each mode after corrections

Physics Results: Charm physics at CDF: Search for CP violation in Charm decays:

…8320 D*±D0±, D0 K+K-

3697 D*±D0±, D0 +-

First attempt at measuring CPV at CDF in Run-II

93560 D*±D0±

with D0+-

Cross-check: Measure Ratio of Branching Ratios @CDF(D0 +-)/(D0 +-)=9.38±0.18±0.10% (D0 +-)/(D0 +-)=3.686 ± 0.076 ±0.036%

FOCUS: (D0 +-)/(D0 +-)=9.93±0.14±0.14% (D0 +-)/(D0 +-)=3.53±0.12±0.06%CDF accuracy is comparable and consistent with FOCUS (2003) and World average 2.88±0.15 (PDG)

ACP(D0 (+-))=2.0±1.7±0.6% (PDG 0.5±1.6%)ACP(D0 (+-))=3.0±1.9±0.6%(PDG 2.1±2.6%)

CLEO Result (2001)

ACP(D0 (+-))= 0.0±2.2±0.8% ACP(D0 (+-))= 1.9 ±3.2±0.8%

Mixing and CP violation (CPV) in B decays

Same side taggingOpposite side taggingConcept: Look for charged tracks around reconstructed Bof interest, Higher

Look for ,e from B decayLook for ± (K±) from hadronization of B (Bs)

Concept:Look forB on opposite sideof B of interest -Look for ,e -Look for or K-Use weighted jet-charge Disadvantages: Opposite B not in acceptance (60%) or mixes (B0)

Key Issues: Tagging Flavour Correctly… ...& being able to tag at all

tagnowrongcorrect

wrongcorrect EfficiencyNNN

NN

wrongcorrect

wrongcorrectDilution NNNN

D

Statistical power: D2 N events count for D2N pure events

CDF: D2 working on using TOF to do Kaon tagging& first mixing analyses to quote a final numberD0: D2 = 3.1 % Jet Charge, D2 = 4.7 % Lepton

Sharpen algorithms on B± decays (where b-flavour is known eg B± J/K± )

Mixing and CP violation (CPV) at Hadron colliders: Run-I, CDF were able to do 2 measurement of sin2 & competitive xd (md/) measurements: can do tagging in hadron collider environmentSin2=0.79±0.39(stat)±0.16(sys) (CDF 1996)

Sin2=0.76 ±0.067(stat)±0.034(sys) (BaBar 2002)

Sin2=0.719±0.07(stat)±0.035(sys) (Belle 2002)CDF: In Run-II with 40-50 x more Bd J/KS decays can get (sin2)~0.05: D0: Similar statistics

Can’t be competitive with BaBar and BELLERedo the measurement because:-It’s an important benchmark -Gives credence to other CPV measurements eg. in B h+h- & Bs J/

Physics Prospects: Toward Bs mixing at CDF : fully reconstructed decays

First observation of mode BsDs+-

with (Ds+ , K+K-) ! Decays we plan to use:B0

s Ds,

B0s Ds

Proper time resolution:t = 45 fs t PT/PT

Plan to increase statistics from:. More efficient online SVT (Silicon Tracker) utilizing any 4/5 Si layers . Dynamic pre-scaling of trigger at Level2 (hadronic trigger) (x2-4). Reconstruct with more Ds decays eg: K*0K, +

-Need to tag initial B flavour-projection awaits final D2

Aside: Physics Results: Ratio of branching ratiosof BsDs

± ± to BdD ± ±

Interest in Bs Ds± ± is mostly due to Bs mixing but:we’ve alsomeasured the ratio of branching ratios (Bs Ds± ±)/(Bd D±± )

Normalization mode is Bd D ± ± , D± K± Kinematically ~Bs Ds ± ±, Ds ± ± , K+K-Using: -numbers of Bs and Bd in our signals-efficiencies from Monte-Carlo-D ±, Ds ± BR are from PDG, obtain:

( )0.44 0.11( ) 0.11( ) 0.07( )

( )s s s

d d

f BR B Dstat BR syst

f BR B D

Using fs/fd =0.273±0.034 from PDG obtain:

( ) 1.61 0.40( ) 0.40( ) 0.26( ) 0.20( )

s s s

d d

BR B D fstat BR syst PDGBR B D f

…we’re beginning to fill in PDG section on the Bs

Use new “hybrid” displaced track+single lepton trigger Decays included: Accounting for missed

neutrinoBs Ds

l, Ds*l (Ds, K*0K, +)

expect ~40K events in 2 fb-1

t is worse due to missed (K factor) :t = 60 fs t K/K, K/K ~ 14%If one Bs lifetime is fit in any flavour specific mode: fit = (BsCP+

2+BsCP-2)/(BsCP++BsCP-) from which s can be determined as

well

Carlo Monte from )(

)()(

)()()(

)()(

st

st

st

ssxy

st

ssxy

BPDlP

K

KDlP

BMBLBP

BMBLct

Physics prospects:Back to Bs mixing at CDF: partially reconstructed decays

Physics Prospects: CP violation in Bh+h- decays determining angle CDF), Method:

u-b

W

uud-

b dW

u,c,t

b su,c,t bW

usW

Five observables,

Four unknowns:d=ratio of penguin/tree hadronic matrix elementsphase of d = weak phases

Constrain Sin2 from B-factories, & CDF/D0 results and measure

Tree and penguin graphs for B & BsK+K-

-CP Asymmetry in B = Sin2() (without penguin) -CP Asymmetry in BsK+K- = Sin2without penguin) -Assume SU(3) symmetry: replace s-d Hadronic matrix element ratios : penguin/tree same for both modes

Tree > penguin in B vice-versa in BsK+K-

Proposed by: R.Fleischer, PLB459 1999 306

Physics Prospects: CP violation in Bh+h- decays determining angle CDF)

B h+h- from hadronic triggerIncludes BBsK+K-

BsK± ±, and Bd K± ±

Monte-Carlo plot below shows: Bd Bs K+K- Bs K± ±,

& Bd K± ± (From Monte-Carlo)-all pile up in the same region

Must disentangle contributions from each mode to signalTo do this we (will) use: -dE/dx based K and identification -Kinematical variable separation M vs =(1-p1/p2)q1 -Width of signal -Frequency of oscillation in CP asymmetry

Physics Prospects: CP violation in Bh+h-: angle CDF)

Back to projection of measurement:Expected (2fb-1) accuracy: () =±10(stat) ±3(syst) (syst: SU(3) breaking)

M vs a for each Bh+h- mode dE/dx calibration using D*± D0, D0 K±± ( from D* unambiguously distinguishes K, from D0)

Sanity check: Measure Ratio of Branching RatiosCDF : (Bd -)/(Bd K+-) = 0.26 ±0.11±0.055, PDG: 0.13 0.010.29 0.12 0.02

Yield for each mode:Bd Bd K± ±Bs K± ±Bs K+K- First observation !

Method works ! Confirmed by Sanity check against ratio of branching ratiosHave first observation of Bs K+K-Its a CP Eigenstate: Can use thisTo measure s as well !!

Conclusions:1) CDF & D0 are in the first phase (<200pb-1) of data

taking expect to: a) Test HQE especially with B and Bs b) Search for CPV and FCNC in Charm & B rare decays c) Establish tagging and lifetime measurement

techniques with new data

2) Next phase (>200pb-1 &<500pb-1) will: a) set limits on (or measure) Bs mixing b) search for CPV in the neutral B system

3) Final Phase (end Run-IIa) (>500pb-1 and <2fb-1) measure: a) Bs width difference s & mixing parameter xs c) CKM angle d) search for CPV in B p

e) ……and search for unexpectedly large CPV in Bs J/ Pursue in the first phases a program partially in parallel to

and in the last phase complementary to the B-factories

Backup Slides

Aside: Physics Results: Ratio of branching ratiosof BsDs

to BdDInterest in BsDs

is mostly due to Bs mixing but:we’ve alsomeasured the ratio of branching ratios (BsDs

)/(BdD)Normalization mode is Bd D, D K

Kinematically ~BsDs, Ds

, K+K-

( ) ( ) ( ) ( )( ) ( ) ( )

s s s s s s

d d d d

N B f Br B D Br D Br K KN B f Br B D Br D K

Ratio of Bs to Bd signals is:

Where are determined from Monte-CarloD, Ds

BR are from PDG, obtain:( )

0.44 0.11( ) 0.11( ) 0.07( )( )

s s s

d d

f BR B Dstat BR syst

f BR B D

Using fs/fd =0.273±0.034 from PDG obtain:

( ) 1.61 0.40( ) 0.40( ) 0.26( ) 0.20( )

s s s

d d

BR B D fstat BR syst PDGBR B D f

…we’re beginning to fill in PDG section on the Bs

Physics Results: Average B-hadron lifetime from partially reconstructed BJ/X decays.

Results from D0 and CDFB=1.5610.0240.074 ps D0 (40 pb-1)

B=1.5260.0340.035 ps CDF (18 pb-1)

Both consistent with: PDG: B = 1.564 0.014

D0 Inclusive B Lifetime

This is a “sanity check” of our BJ/sample: Obtain Average B hadron From all B J/y (+other stuff) decays: B is not fully reconstructedIf Fully reconstructed B-ct = c.(time in B rest frame)-Lxy = 2-d decay length-MB = mass -PT = transverse momentumIf Partially reconstructed B-Correct for missed daughters: F(PT) (from by Monte-Carlo)-B is an estimate -it is the average lifetime of all hadrons decaying to J/

( )xyT T

Mct LP F P

T

BT

BT P

PMMPF )(

B

xy BT

Mct LP

Signal lifetime is modelled by :

Complete likelihood function:

( / )

( , , ) ( , )

( , , ) . ( , , ) (1 ). ( )

Bt

signal B t tB

B t signal B t background

eF t g t

F t f F t f F t

Complete event probability density

Background shape from side-bands

CDF Integrated Luminosity

Mar 02

commissioning

Data used for Today’s results Mar 02 – Jan 03 130 pb-1 (delivered) 100 pb-1 (to tape) B/Charm: ~ 70 pb-1

Jan 03

Physics Prospects: Bs width difference using Bs J/

Two CP states: lifetime

Two CP states: transversity

Total function and normalization

21

22

( ,1) 0.375(1 cos )

( , 2) 0.75(sin )

F

F

1 1 1 2( , , ) [ . ( , , ). ( ,1) (1 ). ( , , ). ( , 2)]. ( , , )signal CP t B CP t B m BF m t f F t F f F t F F m M

( , , ) . ( , , ) (1 ). ( , , )total s signal s backroundF m t f F m t f F m t ( , , ) 1totalF m t dmdtd

1

2

( / )

1 11

( / )

2 22

( , , ) ( , )

( , , ) ( , )

B

B

t

t B tB

t

t B tB

eF t g t

eF t g t

Current limit (LEP): s / s <0.31, from branching ratio of BsDs±(*)Ds(*)

Note: SM CP violation in this mode: O(3%), if large new physicsCP asymmetry = sin2 s, measured= s,SM.Cos2complementary)

One lifetime(width) has been fit in this mode

1) But contains two distinct lifetimes: CP+ & CP- Bs, significant lifetime (width) difference:

s=1/B1-1/B2

2) Extract s : fit two lifetimes, use single angle to separate CP+ and CP- Bs: (Transversity angle

3) SM prediction for s ~0.10s also s = A.xs (xs = Bs mixing parameter) if s is small and xs is large or vice-versa Sign of new physics

3) CDF prediction for 2fb-1 (s)~0.05

Physics Results: lifetime, mass, from fully reconstructed B J/ X modes: Standard Technique :

Data from J/ di-muon trigger: 1) Reconstruct vertex according to decay topology2) Calculate decay proper time mass & errors3) If fitting for mass:fit mass only4) If fitting for lifetime:Fit mass and lifetime using bi-variate Probability density function (PDF) in likelihood 2

2

( / )

( )( )

( , , ) ( , )

( , , )2

( ) ( , , )

( , ) ( , , ). ( , , )

( , ) . (1 ). ( , )

( , ) 1

B

B

m

t

t B tB

m M

m Bm

signal m B

signal t B m B

total s signal s backround

total

eF t g t

eF m M

F m F m M

F m t F t F m M

F m t f F f F t m

F m t dmdt

1) Signal Lifetime :

2) Signal Mass :

4) Signal pdf in mass and lifetime:

6) Normalization : mass and lifetime

3) Signal for Mass only analyses:

5) Signal for lifetime analysis:

An Example B+ ->J/ K+ at CDF

Both the mass and lifetime distributions are fit in a single step. Technique is applied to :B+ J/ K+, B0 J/ K0* (K0* K),

Bs J/ ( KK), bJ/ (p)

Probability Density Function (pdf)

B physics prospects(with 2fb-1)

Bs mixing: Bs →Dsπ(Ds3π) (xs up 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, angle γ : B0→ ππ(πK), Bs → KK(Kπ) Angle s and s/ s : Bs→ J/ψ (probe for New Physics)

Precise Lifetimes, Masses, BR for 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 !!

Both competitive and complementary to B -factories

Sin(2) in B0J/Ks N(B0)(t) - N(B0)(t) N(B0)(t) + N(B0)(t)

=Dsin(2)sinmd t

ACP(t) =

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

In Run1 measured:sin(2)=0.79±0.39±0.16

B0 J/ Ks ; J/ (400 events)(+60 B0 (2S) Ks)

sin(2)=0.91±0.32±0.18

Combined D2: from 6.3% to 9.1% (Kaon b-tag)

Same S/B = 1

Expect: s(sin2b) 0.05

With 2fb-1 can refine this measurementAlthough: no way to compete with B-Factories !

)) (2 sin( S B

ND1

2 1

Stat. Error:

Systematic ~ 0.5xStatistical

(scales with control sample statistics)

ms/md

Tevatron Performance

July ‘01

Now

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 valuesadditional improvements (~10-20%) expected from Jan. 3weeks shutdownCDF operations

• Commissioning: Summer 2001• Physics data since February 2002• Running with >90% Silicon integrated since July 2002

Initial Luminosity 3.8 x 1031

110 pb -1

July ‘02

On-tape Luminosity

Luminosity (on-tape): ~20pb-1 until June (analyses in this talk) Additional 90pb-1 July – December Reach 300- 400 pb-1 by October 2003

Feb ‘02

Quadrant of CDF II Tracker

LAYER 00: 1 layer of radiation-hard silicon at very small radius (1.5 cm) (achievable: 45 fs proper time resolution in Bs Ds )

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)~150m• 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: ~30m (~20 m with Layer00)

TOF: 100ps resolution, 2 sigma K/ separation for tracks below 1.6 GeV/c (significant improvement of Bs flavor tag effectiveness)

TIME OF FLIGHT

CDF II Trigger System3 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. pT/p2T = 2% (GeV-1)

• azimuthal angle res. = 8 mrad

SVT: “Silicon Vertex Tracker” precise 2D Silicon+XFT tracking at Level 2

• impact parameter res. d = 35 m Offline accuracy !!

CAL COT MUON SVX CES

XFT XCES

XTRP

SVTL2

CAL

L1CAL

GLOBALL1

L1MUON

L1TRACK

GLOBALLEVEL 2 TSI/CLK

CDF II can trigger on secondary vertices !! Select large B,D samples !!

Matched to L1 ele. and muonsenhanced J/ samples

SVT: Triggering on impact parameters

d

beam spot

COT track ( 2 parameters) 5 SVX coordinates

Impact Parameter (transverse projection)

• Combines COT tracks (from XFT) with Silicon Hits (via patternmatching) • Fits track parameters in the transverse plane (d, , PT) with offline res.• All this in ~15s !• Allows triggering on displaced impact parameters/vertices• CDF becomes a beauty/charm factory

~150 VME boards

B triggers: conventional

Suffer of low BR and not fully rec. final state

Need specialized 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

Now enhanced, thanks to XFT (precise tracking at L1) :• Reduced (21.5 GeV/c) and more effective PT thresholds • Increased muon and electron coverage• Also J/ ee

Nevertheless, many important measurements by CDF 1: B0

d mixing, sin(2), B lifetimes, Bc observation, …

XFT performance

XFT: L1 trigger on tracks better than design resolution

pT/p2T = 1.65% (GeV-1)

= 5.1 mrad

XFT track

Offlinetrack

Efficiency curve: XFT threshold at PT=1.5 GeV/c = 96.1 ± 0.1 % (L1 trigger)

53.000 J/

11 pb-1

SVT performance

D0 K used as online monitor of the hadronic SVT triggers

I.P. resolution as plannedd = 48 m = 35 m 33 m

Efficiency

80%

90%

soon

transverse beam size

intrinsic

S/B 1

TOF performance TOF resolution (110ps)

within 10% of design value

with TOF PIDS/N = 1/40

S/N = 1/2.5

Background reduction in KK:Low PT (< 1.5 GeV/c) track pairsbefore and after a cut on TOF kaon probabilityx20 bkg reduction, 80% signal efficiency

CDF J/cross section

0<pt<0.25

GeV 5.0<pt<5.5 GeV10.0<pt<12.0 GeV

(ppJ/; pT>0; ||<0.6) =240 1 (stat) 35/28(syst) nb

Lots of charm from hadronic triggers:

Foresee a quite interesting charm physics program:• D cross sections, • CP asymmetries and Mixing in D sector, Rare decays, …

56320490K mass

D0 K

KK mass mass

D0 KK D0

5670180 2020110

(DKK)/(DK) = 11.17 0.48(stat) 0.98 (syst) %(D )/(DK) = 3.37 0.20(stat) 0.16(syst) %

Relative Br. Fractions of Cabibbo suppressed D0 decays :

Already competitivewith CLEO2 results(10fb-1 @ (4S))

!!!!!

With ~10 pbWith ~10 pb-1-1 of “hadronic trigger” data: of “hadronic trigger” data:

O(107) fully reconstructed decays in 2fb-1

Data Samples: B and Charm from the hadronic trigger

Prompt CharmD0K 86.5 0.4 % (stat)D*D0 87.6 1.1 % (stat)DK 89.1 0.4 % (stat)Ds 72.4 3.4 % (stat)

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/ trigger

Some charm is prompt

..to separate prompt Ds from Ds coming from B

An example of B reconstructed Using data from this trigger:

D from direct charm:Points back to beam spot

D from B has a impactParameter wrt beam spot

We have B and tons of Charm as well !

..Some charm is from B

B0s mixing: expectations with 2fb-1

Signal: 20K ( only) - 75K (all) events• with SVT hadronic trigger• BR (Ds ) = 0.3 % ; BR (Ds ) = 0.8 %

Resolution: (c) = 45 fs (with Layer00) D2 = 11.3% (with TOF)

S/B: 0.5-2 (based on CDF I data)

5 sensitivity up to: Xs = 63 (S/B = 2/1) Xs = 53 (S/B = 1/2)

S.M. allowed range: 20. < Xs < 35.Can do a precise measurement… or evidence for new physics !

xs = ms(B0s)Bs Ds, Ds

Ds , K*K,

2( m )22

1 1 S B( x )N D S

s ts e

Physics Results: Average B-hadron lifetime from partially reconstructed BJ/X decays.

Results from D0 and CDFB=1.5610.0240.074 ps D0 (40 pb-1)

B=1.5260.0340.035 ps CDF (18 pb-1)

Both consistent with: PDG: B = 1.564 0.014

D0 Inclusive B Lifetime

This is a “sanity check” of our B J/sample: Obtain Average B hadron From all B J/(+other stuff) decays: B is not fully reconstructed

Partially reconstructed B-Correct for missed daughters: F(PT) (from by Monte-Carlo)-B is an estimate -it is the average lifetime of all hadrons decaying to J/

( )xyT T

Mct LP F P

T

BT

BT P

PMMPF )(

Signal lifetime is modelled by :

Complete likelihood function:

( / )

( , , ) ( , )

( , , ) . ( , , ) (1 ). ( )

Bt

signal B t tB

B t signal B t background

eF t g t

F t f F t f F t

Complete event probability density

Background shape from side-bands