•CDF Detector

•Drell-Yan & Signatures for New Physics

•Present Limits and Run II reaches

•First Run II Data

•Future Plans

Supervisor: Todd Huffman, Oxford UniversityAdvisor: Kaori Maeshima, FNAL

Presented work by Tracey Pratt, Oxford and Koji Ikado, Waseda University

By Tracey Pratt

April 02

High mass bump searches in Drell-Yan spectrum at CDF

CDF at Fermilab

CDF CDF

D0

Tevatron

Main Injector

pp collisions

CDF Run I and Run II overview

Run I consisted of Run 1a (88/89) and Run 2b (92-95)

In total 110pb-1 of data was collected

Centre of mass energy 1.8 TeV

Since the shutdown in 1996, the Tevatron and CDF have undergone major upgrades

Run II started in June 2001

Centre of mass energy 2 TeV

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Drell-Yan (DY)

Low background at high dilepton invariant massDistinctive signatures:

•two oppositely charged leptons produced

•have a high transverse momentum

•are isolated

•originate from a single interaction point

qq */ Z l+l-

p p

l+ l-

*/ Z

q q

New Physics Searches with DY

New Gauge Bosons (Z')

Extra Dimensions

Quark-lepton Compositeness

Technicolor (T , T )

Looking for deviations to the Standard Model at high invariant mass

Run I Drell-Yan (DY)

•AFB smaller than SM

• AFB dips beyond 200 GeV/c2

X 88/89 CDF Run 1 dileptons (ee+ 4pb-1)

o 92-95 CDF Run 1 dimuons (107.4pb-1)

Invariant Mass in GeV/c2

0 100 200 300 400

101

100

10-1

10-2

10-3

10-4

Z and

only

d2/dMdy

Run 1 Z' limitsset limits for Z' ll, with 110pb-1, in both dielectron and dimuon channels

CDF Run I (110pb-1), for MZ > 600 GeV/c2 (Z ).BR(Z ->ll) is 40 fb.

which excludes MZ with Standard Model coupling < 690 GeV/c2

(Phys. Rev. Lett.79: 2192-2197, 1997))

Run II Extrapolated limits

Extrapolating from Run I, with 2 fb-1, the predicted Z' mass reach could be extended to

900 GeV/c2 with s =1.8 TeV assuming Standard Model couplings

and to about

1000 GeV/c2 with s =2.0 TeV

Extra DimensionsADD model

***references

New parameters:

1. String Scale: Ms = MPl(4+n) 2. A Factor: ( = ±1)

RS model L.Randall and R.Sundrum, Phys. Rev. Lett. 83,3370 (1999), Phys. Rev. Lett. 83,4690 (1999)

New parameters:

1. First graviton excitation mass: m1

2. A Ratio: k/MPl

Graviton Exchange - modifies the rate and angular distribution of high-mass Drell-Yan events

ADD model and RS model limits

SM predictionQuantum Gravity Model for Ms valuesCDF results for dimuon samples

Effective Planck Scale lower limit (95% C.L.)0.9-1.5 TeV Run I1.3-2.5 TeV Run IIa, 1.7-3.5 TeV LHCRange corresponds to number of extra dimensions n=7-2. (hep-ph/9909218)

Mll (GeV)

RS model

10 -2

10 -4

10 –6

10 -8

200 400 600 800 1000 1200

d/dM (pb/GeV) 1

0.70.50.30.20.1

700 GeV KK graviton

Compactification scales R-1 (TeV) 0.9 Run 1 at 95% C.L., 1.2 Run II, 6.7 LHC(one large extra dimension) (hep-ph/9905311)

Run IK/MPl

Compositeness

Compositeness

Quark-lepton contact interaction was searched for in Run I in the dimuon and dielectron channels, by looking for an excess of dileptons compared to the Drell-Yan prediction.

Run Ib dielectron data set the limits on the compositeness scale to - > 3.8 TeV and + > 2.6 TeV. In Run II we expect to be able to explore up to limits of approximately 5 TeV.

(Where +/- corresponds to the constructive / destructive interference with the dominant up-quark contribution to the cross-section.)

(Phys. Rev. Lett.79: 2198-2203, 1997))

Run II

Run II officially began on March 1st 2001

Started taking “physics quality” data from June 2001

CDF Upgrade improvements for Drell-Yan measurements•Dielectron channel New plug calorimeter •Dimuon channel Increased muon chamber coverage Improved Dimuon Background Rejection in run II

Time-Of-Flight (ToF) Detector in CDF

216 scintillator bars located just outside the COT

Expected time resolution is 100 ps.

ToF Cosmic-Ray Rejection

~ 2L/c for CR dimuons ~ 0 for interaction dimuonsas for dielectrons

For high mass dimuon sample the

dominant background at high invariant mass is from cosmic rays

Above plots are from uncalibrated ToF. Calibration work is in progress.

Expected time resolution is 100 ps.

Tupper – Tlower

Run II dataRun II officially began on March 1st 2001

Started taking “physics quality” data from June 2001

Zee Z

Total Luminosity So Far

~2 week shutdown in June to install 2 new stochastic cooling tanks in the pbar accumulator, aim is to give us higher luminosity and a smaller transverse pbar beam size

Future Plans

It is hoped that approximately 50-70 pb-1 data will be collected by Summer 2002

And 150 pb-1 by end of 2002.

We hope to find new physics or set new limits using the dilepton channels.

The END

That’s All Folks!

Run 1 limits on Z' production

CDF Run II Detector

Key:

= 1.0

= 1.5

= 2.0

= 3.0ToF

Silicon TrackerFiber Tracker Drift Chamber

ScintillatorEM Cal.Hadronic Cal.

Solenoid CoilToroidSteel Shielding

CDF Upgrades for Run II New Silicon tracking System: SVX II: 5 layers, 96cm, r-phi and r-z

ISL: 2 additional layers, covers |eta| < 2

L00 :

(Addition of stereo capability to SVX, 3D Vertex and ~ 2 more acceptance)

New central drift chamber: (And strengthened COT stereo capabilities, maintain Run 1 track eff and resolution) Improved and integrated tracking system

New deadtimeless Trigger (track trigger moved to Level 1 and use Silicon info at L2)

Improved Calorimeter: resolution, efficiency and coverage

New Plug calorimeter, out to || = 2.

Extra Muon coverage

Luminosity monitor

Electronics

Higher center of mass energy

Addition of a ToF detector

ADD model

SM predictionQuantum Gravity Model for Ms valuesCDF results for dimuon samples

ADD model: Effective Planck Scale lower limit 0.9-1.5 TeV Run I (at 95% C.L.)1.3-2.5 TeV Run IIa and 1.7-3.5 TeV LHC

Range corresponds to number of extra dimensions n=7-2. (hep-ph/9909218)

Extra Dimensions

Tevatron

700 GeV KK graviton

K/MPl

Mll (GeV)

RS model

10 -2

10 -4

10 –6

10 -8

200 400 600 800 1000 1200

d/dM (pb/GeV) 1

0.70.50.30.20.1

RS model

RS model: Compactification scales R-1 (TeV) 0.9 Run 1 at 95% C.L.,

1.2 Run II, 6.7 LHC

(one large extra dimension) (hep-ph/9905311)