# Presentation: 700170

## CDF Status  

- April 4, 2003
- Luciano Ristori

- The CDF Collaboration

- 112 countries
-  59 institutions
-  706 physicists

- North America

- Europe

- Asia

- 3 Natl. Labs
- 28 Universities
- 2 Universities

- 1 Research Lab
- 6 Universities
- 1 University
- 4 Universities
- 2 Research Labs
- 1 University
- 1 University
- 1 University

- 4 Universities
- 1 Research Lab
- 1 University
- 3 Universities

## Outline

- Overview of detector and offline operations
- Highlights of Run 2 physics analyses
- QCD with jets
- Electroweak physics with W and Z bosons
- Re-discovering the top quark
- Beauty and charm
- New phenomena searches

**Detector and Offline**** Operations**

##  The CDF Detector showingRun 2a Upgrades

**Cherenkov**
**Luminosity Monitor**

- New
- L1, L2, L3
- Triggers
- DAQ System
- Monitoring

- Store # 2271 February 24-25, 2003

- 10.84 pb-1 delivered
- 10.75 pb-1 written to tape
- 989 % eff. for store

- Time into store

- Integrated
- luminosity

- delivered
- recorded

- DAQ run
- ~ 16 hours

- Silicon Detectors
- integrated quickly
- after Tevatron scraping

- Integrated
- Luminosity
- pb-1

- Data
- Recording
- Efficiency

- ~180 pb-1 delivered

- ~130 pb-1 recorded
- (including early data
- used for commissioning)

- 90% efficiency

- ~ commissioning

- physics

- March 2003

- March 2002

- 85 pb-1 QCD
- 72 pb-1 EW
- 56 pb-1 top tagged

## Trigger Table and Rates

- Complete physics trigger table
-  ~140 triggers (e, , , , , jets, displaced track)
- Dynamically prescaling some hadronic B triggers of lower purity
- L1, L2, L3 trigger rates
-  With luminosity of ~ 3 x1031 cm-2 s-1
-      L1 = 11.5 kHz
-      L2 = 250 Hz
-      L3 = 50 Hz
-      Total trigger dead time  < 1%
- L1 rate limitation at 12 kHz
-     is being removed

##  Central Outer Tracker (COT)  used to select high Pt tracks at L1 Extremely Fast Tracker (XFT)

- Use COT axial
- track segments

- XFT Pt turn on

- Measured XFT Pt/Pt2 = 1.65%
- Measured angular resolution 5.1 mrad.

- Stable data taking: since June shutdown
- >90 % of the Silicon is integrated

-  Now working on minimizing:
**inefficiency at the beginning of each store**
**Error rate**
-  Upcoming Challenges
**Higher trigger rates**
**A good maintenance plan for stable operations in the years to come**

| Sub-detector | Running % | S/N r (z) |
| --- | --- | --- |
| L00 | 97.0 % | S/N 10:1 |
| SVXII | 92.5 % | S/N 14:1(12:1) |
| ISL | 89.0 % | S/N 12/1(12:1) |

- Silicon Trackers

## Improvement of Silicon Coverage

**June 2002**

**March 2003**

- phi

- z

**Silicon Vertex trigger (SVT)**
**Selects secondary vertices at L2**

- sigma ~ 50 um ~ 43 um + 25 um

- SVT resolution

- beam spot size

- This distribution is the convolution of the actual transverse size of the beam spot with the impact parameter resolution of the SVT

- Impact parameter distribution

- Impact parameter do
- measured at L2

- cm

## Offline data processing

- L3 Farm: 8 output streams split based on L3 decisions
- 230 dual CPU’s, 20 Mbytes/s to tape, event size 300 Kbytes
- Offline production: split into 35 datasets
- 170 dual CPU’s, 3-5 seconds/event, event size 200Kbytes
- 35 datasets split on L3 trigger bits
- Process 5 million events/day sustained, 10 million/day peak
- Data analysis system
- 300 dual Athlon CPU’s (1.4-1.7 MHz) with ~ 100 Tbytes of disk
- Robotic tape storage (StorageTeK) accessed over network
- Data handling via Enstore (tapes) and DCACHE (disk)

## Offline data processing

- Monte Carlo event simulation
- Have used excess processing capacity on reconstruction farms
- Moving to a distributed model of MC event generation in US, UK, Canada, Italy, Germany, ...)
- Physics analysis for Winter Conferences
- All physics quality data up to January 2003 shutdown reprocessed

- 300 million

- 200 million

- Events processed
- by offline
- reconstruction

- Red: events from DAQ
- Blue: events reconstructed

- Feb. 2002

- Feb. 2003

## Physics Analyses

- QCD
- Electroweak
- Top
- Beauty and Charm
- Exotics

- Integrated Luminosity for Physics

- Total data recorded to tape (~130 pb-1) includes that taken early in Run 2 when detector was not fully commissioned.
- Data acquired over past year ~ 100 pb-1
-  As of end of January 2003    Ldt for physics:
- Jet measurements			85 pb-1
- High Et electrons			72 pb-1
- Top lepton plus jets with B tags	56 pb-1
- Since October 2002 the silicon detectors are integrated into physics data taking 98% of the time _for clean stores_.
- Now working on improving recorded data -> physics data efficiency

## QCD Physics with Jets

-    Jet structure
-    High Et probes with inclusive jets
-    Particle searches with di-jets

## Jet structure

- Measure ET with
- calorimeter towers
- and
- tracking chambers

- Study (r) and jet energy flow
- Compare to PYTHIA(6.203) 2->2 processes
- plus CDF detector simulation

## Jet structure 

- Central Jets
- Good agreement with PYTHIA
- and detector simulation

- Forward Jets
- New plug calorimeter
- Needs some simulation tuning.

- CDF Run II Preliminary

## Inclusive high Et jets

- CDF Run II Preliminary

- Inclusive jet ET
- in  bins

- Corrected Et spectra
- compared to NLO (EKS) predictions
- With CTEQ6.1 PDF’s

**Di-jet studies**

-  ET = 538 GeV
-   = 0.20

- ET = 528 GeV
-  = -0.55

- Dijet Mass = 1146 GeV

- > 500 GeV cross section larger by x3
- Due to increased COM energy

## Particle Searches with Di-jets

**Particle Searches with Di-jets**

- CDF Run II Preliminary

**Electroweak Physics**

-  W and Z boson production
-  e+ e- forward-backward asymmetry

## Clean signals of inclusive W and Z bosons are the first step in CDF’s precision electroweak physics program

Measurements based upon 72 pb-1 of data : 
W ->  e ,  and  
Z  ->  e e and 

The W ->  channel allows clean study of tau lepton identification

- Clean signals of inclusive W and Z bosons are the first step in CDF’s precision electroweak physics program
- Measurements based upon 72 pb-1 of data :
- W ->  e ,  and 
- Z  ->  e e and 
- The W ->  channel allows clean study of tau lepton identification

**W and Z boson inclusive production**

- Charged
- particle
- multiplicity
- from W -> 
- candidates

- Compare (W)*BR(W->)
- to           (W)*BR(W->e)
-   g**** / ge   =  0.99 _+_ 0.04

- W -> 

- W -> e

-  Backgrounds low
-  Detector simulation
-          reproduces data

- Z ->  

- Z ->  e e

## W, Z production and (W)

- W* BR(We) = 2.64±0.01stat±0.09syst ± 0.16lum  nb
- W* BR(W) = 2.64±0.02stat±0.12syst ± 0.16lum nb
- W* BR(W) = 2.62±0.07stat±0.21syst ± 0.16lum nb

- NNLO Prediction
- 2.69 nb

- Z* BR(Zee)  =  267 ± 6stat ± 15syst ±  0.16lum   pb
- Z* BR(Z) =  246 ± 6stat ± 12syst ±  0.15lum   pb
- Z* BR(Z)  =   in progress

- NNLO Prediction
- 252 pb

- Measure R(e) = (W)*BR(W->e )/ (Z)*BR(Z->e e) and R()

- (W) = 2.29 _+_ 0.12 GeV    from R(e)
- (W) = 2.11 _+_ 0.09 GeV    from R()

- PDG value
- 2.11 _+_ 0.04 GeV

## e+e- forward-backward asymmetry

- Data:  e_**+**_  with Et > 20 GeV, || < 3.0

- SM ZGRAD, Pythia with CTEQ5L

- Sensitive to new
- neutral gauge bosons

**Top Physics**

-  top pair production using eee ~ 0.05   (t t)
-  top pair production using e,  + jets	 ~ 0.30   (t t)
-  first look at top mass in Run 2

## Top physics in Run 2

- 85%

- 15%

- 26%

- 70%

- 4%

-  ~ 7 pb

-  ~ 3.4 pb

-  Major focus of Run 2
-  World’s knowledge based on ~ 100 events
-  Top is special among known particles

## Measurement based on channels with ee++e ~ 0.05*7pb
Kinematics selection cuts:
e and  central and isolated with ET > 20 GeV
At least 2 jets with ET > 10 GeV within || < 2.0
Missing Et > 25 GeV
HT (scalar sum of ET , leptons, jets) > 200 GeV
plus various background rejection cuts ( Z veto, jets and leptons away from ET ...)

- Measurement based on channels with ee++e ~ 0.05*7pb
- Kinematics selection cuts:
- e and  central and isolated with ET > 20 GeV
- At least 2 jets with ET > 10 GeV within || < 2.0
- Missing Et > 25 GeV
- HT (scalar sum of ET , leptons, jets) > 200 GeV
- plus various background rejection cuts ( Z veto, jets and leptons away from ET ...)

**Top studies from di-leptons**

- (tt) acceptance = 0.52+0.05%
- Signal/background ~ 8

- Data: 5 events
- SM tt +backg.
-         = 2.8 _+_ 0.3

## Top studies from di-leptons

- Di-muon top candidate
- with a B jet tag

## Kinematics of di-lepton tt candidates

**Kinematics of di-lepton tt candidates**

- (t t) =
- 13.2 _+_ 5.9stat _+_ 1.5sys

- (t t) =
- 8.4

- Run 1
- p p at 1.80 TeV

- Run 2 preliminary
- p p at 1.96 TeV

- + 4.5

- - 3.5

- pb

- Expect x 1.35

## Top studies from lepton plus jets

**Top studies from lepton plus jets**

- Measurement based on e and  plus jets channels ~ 0.30*7pb
- Select W->e   and   using standard cuts
- e and  central and isolated with ET > 20 GeV
- Missing Et > 20 GeV
- Select jets with ET > 15 GeV within || < 2.0
- Use silicon SVXII detector to tag the jets with b decays
- Backgrounds determined from data and SM Monte Carlo simulations
- Fake W’s
- W bb, W cc and fake tags
- W c
- WW   WZ
- Z-> 
- Z bb    Z cc
- Single top

## Top studies from lepton plus jets

- W events with b tagged jets
- from 57.5 pb-1 of data

- Data = 15 events
- Background =3.8 _+_ 0.5

- Use excess events in > 3 jets bins
- to measure the top cross section

- (t t) =
- 5.3 _+_ 1.9stat _+_ 0.8sys _+_ 0.8lum

## First Look at top mass in Run 2

- Sample: ejets
- 24 combinations
- 12 correspond to the jet-parton match
- every combination has two solutions for pz
- with 1 b-tagged jet goes down to 12
- with 2 b-tagged jets to 4
- Impose Mt=Mt , M(j,j)=M(l,)=MW,
- 2-C fit applied, lower  is chosen for top mass
- Model the shape of the reconstructed top mass
-       distribution and the background
- Extract top quark mass using maximum Likelihood

**Top Mass from e/m + jets channel**

-        33 events without b-tagging
-   4 jets with Et > 15 GeV
- 13 t t events plus 20 background events

-           11 events with a b-tagging
-     3 jets Et > 15, 4th jet Et > 8 GeV)
- 9 t t events plus 2 background events

**Heavy Flavor Physics**

-     Lots of charm particles ...
-     Establishing robust beauty signals ...

**First CDF Run II Publication****Submitted**

- M(Ds-D+) = 99.28 _+_ 0.43(stat) _+_ 0.27(syst)

## Cabibbo suppressed D0 decays

## Search for FCNC decay D0  +-

- Normalization
- Do -> +

- Blind search for
- Do -> +

- SM prediction
- BR(Do -> +) ~ 10-13
-  clean territory for new
- physics search

- Select events using
- the SVT
- two-track-trigger

- Pt > 2 GeV/c
- 120 |do| < 1 mm

- BR(Do -> +) < 3.1 x10-6   95% CL
- (factor of 2 below previous best limit)

## B physics basics ...

- (B+) = 1.57 _+_ 0.07 _+_0.02 ps

- (Bo) = 1.42 _+_ 0.09 _+_0.02 ps

## Exclusive beauty meson decays

## B  h+ h-

**B ******** h****+**** h****-**

- A mixture of:
- Bd  
- Bd  K
- Bs  K
- Bs  KK

## Bs  Ds 

**B****s**** ******** D****s**** ******

## Beauty baryon decays

- b -> c -

- b -> J/ 

**New Phenomena Searches**

- Z’
- Randell Sundrum Graviton
- Leptoquarks
- Doubly charged Higgs bosons

## Z’ and RS-Graviton Search

- Run II 650 GeV/c2  Run I 640 GeV/c2

## Lepto-quarks and H++

- M(LQ) > 230 GeV/c2 @ 95% CL
- Run I > 220 GeV/c2
- 0 events observed
- (Scalar) LQLQeejj

- Same sign dielectrons-10% mass bin
- 0 Events Observed
- Background Z,dijet,W/Z+jet

**Summary & Conclusions**

- All detector components are recording physics quality data
- Have re-established the Tevatron Collider physics program
- Early results demonstrate the broad physics potential of Run II
- From charm particles to top quarks and beyond ...
- Summer Conferences 2003 (Lepton-Photon, etc.)
- Look for many measurements that will supercede Run I results