# Presentation: 944093

##   High mass bump searches in  Drell-Yan spectrum at CDF

- Drell-Yan & Signatures for New Physics
- Present Limits and Run II reaches
- First Run II Data
- Future Plans

- Supervisor: Todd Huffman, Oxford University
- Advisor: 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

## 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

## CDF Detector - what’s new

- Muon System

- Old
- Partially New
- New

- Barrel Muon Chamber

- Solenoid

- Silicon Microstrip Tracker

- Time-of-Flight

- Plug Calorimeter

- Central
- Calorimeter

## Drell-Yan (DY)

-  functions (pdfs) of the protons at the scale Q2 = M*/ Z2

- For */Z production :   q  fq q(x1)q(x2)

- Low background at high dilepton invariant mass
- Distinctive signatures:
- two oppositely charged leptons produced
- have a high transverse momentum
- are isolated
- originate from a single interaction point

## 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)

## Run 1 Z' limits

- set 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 Dimensions

- ADD model
- 	***references

- New parameters:
- String Scale: Ms = MPl(4+n)
- A Factor:  ( = ±1)

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

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

## ADD model and RS model limits 

- Effective Planck Scale lower limit (95% C.L.)
- 0.9-1.5 TeV Run I
- 1.3-2.5 TeV Run IIa, 1.7-3.5 TeV LHC
- Range corresponds to number of extra dimensions n=7-2. (hep-ph/9909218)

- 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 I

## 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 dimuons
- 	as 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 data

- Run II officially began on March 1st 2001
- Started taking “physics quality” data from June 2001

- Zee

-  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

-  = 3.0

- ToF

- Silicon Tracker
- Fiber Tracker
- Drift Chamber

- Scintillator
- EM Cal.
- Hadronic Cal.

- Solenoid Coil
- Toroid
- Steel 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 

- 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

-             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)