CDF

CDF Status and Prospects

Stephen MillerUniversity of Michigan

5th International Conference on Hyperons, Charm and Beauty Hadrons

June 28, 2002

6/28/02 2

CDF CDF Run 2 Physics Program

• Broad range of physics topics includesTop - Mass, Cross section, Single top-

>Vtb

Electroweak - W mass, Di-boson production

QCD - High Et jets, photons,

Di-jets(Mjj)-> Compositeness

Charm - BR’s, Masses, Mixing

Bottom - Rare decays, CKM constraints, Lifetimes, Mixing

Higgs – Discovery/Exclusion

Exotics - Susy, Large Extra dimensions, Z’

• Improve Run 1 measurements (110 pb-1)Expect 2 fb-1 for Run 2a

Upgraded detector

New capabilities

6/28/02 3

CDF CDF B Physics Goals

• Measurement of CP Violation– B0→J/ψKs sin(2β)– B0→ππ sin(2α)– Bs →DsK sin(2γ)

• Bs mixing measurement– Δms |Vtd|/|Vts|

• Radiative B decays– B→K*γ, Bs →φγ, Λb →Λγ

• Rare B decays– B0→µµ

• Lifetimes, masses, BR’s– Bs , Bc , Λb (unique to Tevatron)

• b production

6/28/02 4

CDF Ingredients for a B Measurement

• e.g. Δms from Bs→Dsπ

• N depends on Luminosity Trigger cross section Reconstruction efficiency

• S+B/S Reconstructed mass resolution

• εD2 Flavor taggingTagging efficiency ε Dilution D = 1-2w (w is mistag rate)Particle id

• σt proper time resolutionvertex resolution σLxymomentum resolution σPt (negligible)

• limiting factor for Bs→Dslν mode

2( m )22

1 1 S B( x )

N D Ss t

s e

Flavor Tag B0J/Ks

Run I/ RunII

BsDs

Run I/ RunII

SameSide π/K 2.1 / 2.0 % 1.0 / 4.2%

SoftLepton 2.2 / 2.2 % 1.7 / 1.7 %

Jet Charge 2.2 / 3.0 % 3.0 / 3.0 %

Opp.Side K - / 2.4 % - / 2.4%

Total εD2 6.3 / 9.6 % 5.7 / 11.3 %

6/28/02 5

CDF Tevatron Upgrade

• Upgrade for higher Luminosity– Tevatron Run I

• 6x6 bunches with 3.5µs bunch spacing

– Tevatron Run II• 36x36 bunches with 396ns spacing

– Further upgrade to 132ns

– (fewer interactions per crossing)

– Main Ring replaced by Main Injector

– Recycler

– pbar source upgrade

6/28/02 6

CDF CDF Detector Upgrade

Components from Run 1Central and extension muon systemCentral & wall calorimetersSolenoid

New for Run 2Silicon tracker (more coverage, z measurements )Central tracker (shorter drift time, improved stereo)Time of flight (All New!)End plug calorimeter (complete replacement)Central muon detector (Gaps filled in)Forward muon detectors (1 < |η| < 2)Luminosity Monitor Front end electronics (Run 1 bunch spacing 3.5µs,

Run 2 spacing 396/132ns)Trigger (Higher rates, tracking at L1, svt tracks at

L2)Software (Fortran → C++/Java)

6/28/02 7

CDF Silicon

Layer 00 1 r-phi layer 1.4 cm from beamline

Fully integrated with DAQ

Improves impact parameter resolution

SVXII87 cm length (covers luminous region)

5 r-phi layers 3 r-z, 2 r-1.2° stereo

Used for SVT trigger

Intermediate Silicon Layer (ISL)r-phi and r-1.2° stereo all layers

1 layer |η| <1, 2 layers | η| <2

Gives tracks at higher eta

Cooling problems have limited use

but is being fixed

6/28/02 8

CDF Central Tracker

• COT – 8 superlayers (4 axial, 4 2° stereo)– 12 measurements/superlayer, 30K channels– Smaller cell size than Run 1 tracker

• needed for 132ns beam crossing period– Readout with Multi-hit TDCs– dE/dx encoded in pulse width

– Hit resolution ~ 175µm

COT working very well

6/28/02 9

CDF Tracking Performance

COT: 99.7% single track efficiencyCOT+SVXII tracks:

Preliminary resolutions:σd0 ≈ 23µmσLxy ≈ 60µm

includes beam spot resolution of ≈ 35µm

Still can improve alignments Numbers don’t include L00

Calibration of E-loss and B fieldUse J/ψ mass for calibration

Cross checked with other particles

Energy loss correction depends on material 0.56 g/cm2 layer added to detector descriptionB field scaled by 0.13%

dEdx measurement from COT hits

Eloss+BfieldImproved ElossE-loss default

No E-loss

6/28/02 10

CDF Time of Flight

• Detector– 216 scintillator bars

• 2.8 m length

• 4x4 cm^2 cross section

– Coverage to |η| < 1

• PerformanceGoal of 100 ps time resolution gives

2 σ K/π separation for p<1.6 GeV/c

2 σ K/p separation for p<2.7 GeV/c

2 σ π/p separation for p<3.2 GeV/c

Preliminary Calibration

σ 110 ps

6/28/02 11

CDF Time of Flight (cont)

φ→KK reconstructionUsing generic sample of tracks

6/28/02 12

CDF Calorimeter

• Detector– Scint+Pb/Fe Towers with

EM/Hadronic sections• Covers 15° in phi, 0.11 in η

– 2-d strip/wire chamber at EM shower max

• In Central region

• Crucial for low energy electrons in trigger and analysis

• Performance– Fully commissioned

– Used for trigger and analysis

– Energy scale calibrated to ~1%

6/28/02 13

CDF Muon Detectors

• Central & Extension Muon Detectors– System commissioned and aligned– 95% live– Triggering on muon track stubs

• Forward Muon Detectors (New)– System commissioned– 98% live– Alignment underway– Will be added to trigger

6/28/02 14

CDF DAQ and Trigger

• L1 Trigger – Calorimeter towers (Em and Hadronic Et)– SumEt, Missing Et– Muons– Tracks

• Pt> 1.5 GeV. Matching for e, µ selection

• L2 Trigger – Calorimeter clusters (plus isolation)– Track matched to Shower Max (electron id)– SVT tracks -> displaced tracks select b,

charm– Processors calculate Lxy, (transverse) mass

• L3 Trigger – Farm of 240 dual processor PC’s– All data available for making decision – Uses full reconstruction (offline code) 50 Hz

~20MB/s

300-500 Hz

45 kHz

6/28/02 15

CDF Physics Goals and the Trigger

B and Charm Physics– SVT tracks: Hadronic Bs, B→ππ, Charm

• Displaced impact parameter, 2-D vertex, Lxy cut– Lepton + SVT: Semileptonic B, Radiative B– Dileptons: B→J/ψX

• QCD – Jets– Diffractive triggers

• Top– High Et lepton: W→lν– All Hadronic: ttbar→ 6 jets

• Higgs– High Et lepton: HW production– B-tagging (d0 cut) for H→bbar– H→ττ

• Exotics– High Et photons– Missing Et– Tau’s (cluster+ isolated track)– B-tagging

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6/28/02 16

CDF Silicon Vertex Trigger (SVT)

• Silicon based tracking at L2– New capability at hadron collider

• SVX readout on L1A– SVX chip digitizes and stores every 132 ns– Fast parallel readout over optical fiber

• Track roads seeded by L1 XFT tracks• Lookup tables match to pattern of hits

– Finds tracks with pt > 2 GeV– Currently match to 4 layers– Will change pattern to 4/5

• Track fit gives d0, curvature, phi0, χ2– σd0 ≈35µm, σc ≈6x10-6 cm-1 σphi0 ≈1mrad – Correction required for beam offset

• Beam spot measurement fed back to Tevatron to control beam position

– Information available but not yet used

6/28/02 17

CDF Hadronic B Trigger

• Physics goals– B→ππ, Bs →KK : CKM angle γ

– Bs →Dsπ, Ds πππ : Bs mixing• Ds→φπ,K*K, KsK

– Charm BR’s, masses

• Selection– L1: 2 opposite charge tracks, Pt >

2GeV, Δφ cut, • dominates L1A bandwidth

– L2: 2 svt tracks d0 > 100µm, Lxy cut

– Yield for B events lower than expected• Will improve with SVX fixes and more

efficient track patterns in SVT

Lxy

Beam spot

secondary vertex

R

PT

6/28/02 18

CDF Lepton + SVT Track Trigger

Physics goalsSemileptonic B decays

B cross sectionFragmentation fractionLife time, B+/B0

Bs and b (Bc)Bs mixing (need ~ fb-1)

Radiative B decays b→sγ (γ→ee)Sample for flavor tagging studies

Selection 4 GeV e, + 2 GeV SVT track

Run I single 8 GeV e, Lower B Et threshold

Run1 10 GeV vs Run2 6 GeV

~ 3 x SVT x Run I yieldRadiative decays

Large Run II inner materialX2.5 gain in acceptance~10 Bd ->K* γ / 100 pb-1~few Bs-> φγ / 100 pb-1

Lepton + D yield D0 D* Ds

Run I /100 pb-1 1800 230 60

Run II /7pb-1 350 120 30

Run II / Run I 2.7 7.5 7.0

6/28/02 19

CDF Di-lepton Trigger

• Physics Goals– B→ J/ψX

• sin(2β), lifetimes

– rare decays B→ll(X)

• Selection– 1.5 GeV dimuon

– 2 GeV dielectron

– 2-3X Run I yield• Run I: 2 GeV muon, 5 GeV electron

6/28/02 20

CDF Charm Physics

6/28/02 21

CDF Charm Yields

• Hadronic trigger gives large charm sample

Large percentage of D’s from direct production

With 2 fb-1 expect 10-100x samples of charm from Fixed Target experiments

Decay Mode Yield 50pb-1

D0→Kπ 300K

D0→KK 20K

D0→ ππ 10K

D+→Kππ 200K

Ds→KKπ 10K

D*+→ D0π D0→Kπ 80K

Λc →pKπ 300

6/28/02 22

CDF Charm Measurements

• Physics Prospects– Production cross sections

• for D0, D+, D*+, Ds, Λc

• can separate prompt from direct production

– Mass measurements

• mDs - mD+ , for Ds, D+ →φπ

– D0– D0 mixing search

– CP Violation searches

– Rare/Forbidden Decays

T

d

dP

6/28/02 23

CDF B Physics Prospects

• Collecting large sample of J/ψ, hadronic and semileptonic b decays

(Quoted errors below assume 2fb-1)

• Broad program of measurements– Lifetimes

• Measure cτ with error of .01 ps B0 ,B+; .03 ps Bs ; .04ps Λb

– b production – Δmd mixing measurement– b hadron masses– Branching ratios– Rare Decays

• Bs ,Bc , Λb measurements unique to Tevatron

J/ψ→µµ Sample

6/28/02 24

CDF B Prospects (cont)

• Bs mixing– All pieces necessary for measurement

are working• TOF, Hadronic trigger, SVX, L00

– Hadronic yields lower than expected• Working on improving trigger and

reconstruction efficiency

• sin(2β) from B→ J/ψKs

– will collect large sample of events• Use J/ψ→µµ and ee modes

– next step to optimize flavor tags– with 2fb-1 will have competitive

measurement• σ sin(2β) ≈ 0.06

6/28/02 25

CDF B Prospects (cont)

• Bs lifetime difference ΔΓs

– Use Bs→J/ψφ mode

– Fit lifetime and transversity angle of decay

• Separates CP even/odd states

– Error on ΔΓs/Γ of 0.05-0.08

• CP asymmetry in B0→ππ – Hadronic trigger collecting B0→hh

sample

– Use PID to separate B→Kπ , B→KK

– Error on asymmetry of 0.09

• γ from Bd→ππ , Bs→KK– Difference in asymmetries only from

CKM phases γ and β• Assume SU(3) symmetry

– Uses simultaneous fit of time dependent asymmetry

– Expect σγ ≈ 10°• Requires measurement of β

• Search for CP violation in Bs→J/ψφ – Asymmetry very small in Standard

Model• Test for new physics

– Error on asymmetry of 0.1 to 0.2• (depending on value of xs)

6/28/02 26

CDF Summary

• The CDF detector is working well and collecting data for physics

• Hadronic trigger greatly extends B and Charm Physics capabilities

• CDF will collect a very large Charm sample– Expect first charm measurements later this summer

– Broad charm physics program for Run 2

• B physics program has all the pieces in place– B triggers collecting samples

– Detector providing good reconstruction

– Particle ID working for flavor tagging

• Lots of interesting B measurements to come