# Presentation: 408852

## Electroweak results at the Tevatron

- Susana Cabrera for the CDF and D0 collaborations

- XXIIth International Workshop on Deep-Inelastic Scattering

## Electroweak Physics at Run II and Beyond SM

- WW/W/Z  cross sections

- W cross section

- R: Indirect Γ(W)

- W asymmetry

- Z’ resonances

- Anomalous TGC

- Higgs Mass constrain

-  Z Forward-Backward
- Asymmetry

- sin2(θW),
- Anomalous quark
-  couplings

- Lepton Universality

- W mass

- Bkgs top and Higgs

- Direct Γ(W)

- Z cross section

- Constrain PDFs

**Notes:**
The inclusive W & Z cross sections are the starting point of many other electroweak measurements.They help in understanding detector performance, specially important after the strong upgrade in both detectors CDF and D0, trigger and lepton Id efficiencies, energy scale...
With the ratios of W’s and Z’s combined we can extract an indirect measurement of the W width. With Ws we can test muon-electron universality.
With W’s and using the forward part of the detectors we can measure the W asymmetry and looking for anomalous quark couplings
With the Z’s and using the forward part of the detectors, we can look for bumps in the high mass region of the invarian mass distribution, many extensions of the SM predict the existence of the Z’
These topics will be covered in special talks dedicated to dearches for new physics in this parallel session.
The second par of the talk will be dedicated to the Diboson production, at least CDF has been very active on this subject. BY sutding this diboson processes we can look for anomnalous triple gauge couplings.

## TheTevatron collider in Run 2

- Increased instantaneous luminosity:
- Typical(moving target): 4-5 x 1031 cm–2 s-1
- Record: ~7.2 x 1031 cm–2 s-1
- Tevatron has delivered in total ~450 pb−1
- Medium term: FY2003
- Base goal: 230 pb−1 Design: 310 pb−1
- Long term, by the end of FY09
- Base goal: 4.4 fb−1 Design: 8.5 fb−1

- Tevatron is a proton-antiproton collider operating with Ebeam=980 GeV
- 36 p and p bunches  396 ns between bunch crossing.

**Notes:**
In Run1, ^X6 bunches with 3.5 microseconds
Tevatron plans to deliver 300 pb-1 in FY2004.
Typical luminosity is a moving target, in the last two weeks >5E31, E~80%,dead time<5%

## Run II Luminosity:CDF 

- ~350pb−1 on tape.
- Data taking efficiency  > 80%
-  Dead time typically <5%
-  L ~ 6% (from inel&
-  acceptance systematic)
_**Physics**_  Analyses:
- Between 64 and 200 pb-1 taken  Mar 2002 – Sep 2003

**Notes:**
Inclusive W & Z cross sections do not need all the statistics, high cross sections.
On the contraty DiBoson cross sections analysis need to use the whole dataset.
1.6% due to clc systematic error on CLC rate.
4.0% due to CLC acceptance sys
3.8% due to limited by knoledge of the pp inelastic cross section

## Run II Luminosity:DØ

- .

-         DØ data for Dis2004

- DØ has ~273pb−1 on tape.
- Data taking efficiency around 85% with full detector readout.
-  L ~ 6.5% (from inel)
-  L ~ 10% (2003 results)
- Between 14 and 160 pb-1 taken  July 2002 – Sep 2003

## CDF Run II Detector

- From Run I:
- Solenoid
- Central muon system
- Central calorimeter

- New For Run II:
- Front-end DAQ
- Trigger:Track (L1) and Displaced Track (L2)
- Silicon Tracker (8 Layers) (  2.0)
- Central Outer Tracker
-  (  1.0)
- Plug Calorimeters
- (1.0    3.6)
- Extended Muon Coverage (  1.5, gaps filled in)

**|********|= 1.**

**|********|=2.**

## e &  at CDF Run II 

- e &  at CDF Run II

- Central e: ||<1.2
- Et>20-25 GeV
- EM cluster + Drift chamber track,Pt>10 GeV
- Plug e: 1.2<||<2.0-2.8
- EM cluster (+ Silicon track)
- measured with Zee
- Trigger : 100%, Et>30 GeV
- ID  : >[80-94]%

- Drift chamber

- Loose :
- High Pt isolated track pointing to a  gap in the - coverage ||<1.2
- MIP requirements.
- Tight  :
- pointing to a  -stub ||<1.
-  measured with Z 
- Trigger : 88%-95%
- ID  : 85%-90%

-  e& mis-identification probability measured with dijet events
- Veto cosmics using timing information and track information.
- Veto  from jets (mostly b) using calorimeter-Iso and track-Iso

**Notes:**
Loose electrons: Ehad/Eem.
Tight electrons, additionally
E/P, shower profiles, track-showerMax matching 
ID  : tight e >80% , loose e >94%

## Overview of DØ Detector

- Excellent calorimetry, hermetic detector.
- Upgraded  system for better  -ID

**Notes:**
-track measured twice:
Toroidal spectrometer: position and timing information  after the magnet.
Precision Pt measured in central fiber tracke (before magnetic field)r
Track match: position and P.

18%/sqrt(E)+3,4%(linear term) (+1% run 1) we are workimg on increasing the calorimeter resolution

## W/Z Physics at the Tevatron.

- W/Z production: qq dominated.
- RunII: millions of Ws and 100ks of Zs.
- Leptonic decay modes to avoid high QCD background

- Zl+l-
- BR~3%

- Wl BR~11%

**Notes:**
With electrons andmuons we can do W/Zphysics at the Tevatron
W/Z production: qq dominated.
In RunII: millions of Ws and 100ks of Zs.
Leptonic decay modes to avoid high QCD background
BR ~11%  Br per leptonic W 
BR  ~3%   Br per leptonic mode for Z

W->lV: single charged lepton high pt and isolated, Missing Et fom the neutrino. Less redundandy in trigger. More difficult to control backgrounds and systematics, need to understand the hadronic recoil. Most interesting than Z’s (post-Lep) sigmaXBR 10 times larger than Z
It will ver necessary to understand the hadronic recoil fo rthe W mass measurement.
Pair of charge leptons high pt solated OC, redundancy in trigger, low backgrounds.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Z’s are well understood at LEP but excellent to understand the detector, W’s, sigmaX BR is 10 times bigger at the Tevatron and more unexplored.

## CDF BR(Ze+e-)

- CDF BR(Ze+e-)

- 66 < m(ll)/GeVc-2 < 116
- Small backgrounds from QCD, Z/W→τ less than 1.5%: 6218
- Systematics : ~5.7%(2003) ~2% (improved material description)

**L~***** *****72pb****-1**

| Number of candidates  |  | A x  |
| --- | --- | --- |
| Z/* e+ e−CC | 1730 |  |
| Z/* e+ e− CP | 2512 |  |

- (22.74 ± 0.48)%

- Extended
- coverage
- in the forward** **
** **  2.8

- BR(Zee)=250.53.8 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

******1****st**** e) ******** ******** 1.0**

******2****nd**** e) ******** ******** 2.8**

******e) ******** ******** 1.0**

**Notes:**
CC (tight-loose)
CP no track requirement on th eplug electron
Sources of systemaic errors..
Boson Pt uncertainty, PDF systematic, Pt/Et scale resolution uncertainty, material uncertainty, recoil energy
-------------------------------------------------------------------------------------------------------------------------------------------------
Winter2003: material description dominated CC
Winter2004: PDF CC  Material description CP
NLLO theory: allmass range,  WITHOUT gamma*, ALL MASS RANGE. Correction factor: 1.004 for the measu
rement  (account for the invarian mass cut and substracting gamma component)
SF  [σZ/σZ]MC=1.004

## DØ BR(Ze+e-)

- Z → e+ e− signal:
- 2 isolated central electrons ||<1.1 with Et>25 GeV
- No track match requirement, but shower shape and EmFrac requirements.
- 70 < m(ll)/GeVc-2 < 110
- QCD bkg shape from data, by fitting signal and bkg distributions.
- 1139 candidates after bkg substraction.
- A x =9.3%

**L~***** *****41.6pb****-1**

- Bkg
- Bkg+MC Signal
- Data

- BR(Zee)=250.53.8 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**Notes:**
Main systematics : Emid,PDF,Backgrounds...
Here we are sensitive almost to the Z peak and the mass reconstruccion is much better so: (0.983+-0.004)
What it is measured is the XS Zgamma* in certain Mll range.
SF  [σZ/σZ]MC=0.9830.004
------------------------------------
2.3+-1 is the fake rate, read method
Statistical error: authors decided to consider the statistical uncertainty on the background substraction as statistcal uncertainty, instead f of a systematic

## CDF BR(Z+-)

- Z → + − signal:
- Two  opposite charge ’s Pt>20GeV : Both: isolation + MIP +track quality
- 1st : + stub in CMUP or CMX.
- Cosmic veto: timing plus d0
- 66 < m(ll)/GeVc-2 < 116
- Small backgrounds from QCD, Z/W→τ, cosmics (μ)  less than 1.5% (13.3+13.5-11.8)
- Systematics : ~4.8%(2003) ~2.8%

**L~***** *****72pb****-1**

| Number of candidates  |  | A x  |
| --- | --- | --- |
| Z/*  μ+ μ− | 1785 | (10.18 ± 0.28)% |

- BR(Z)=250.53.8 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**Notes:**
Distance of closest approach.
Improved systematics: 4.8 % ->2.8 % (??? Main source ?)

##  DØ BR(Z+-)

- Z → + − signal: Two  opposite charge ’s Pt>15GeV , at least 1  isolated,cosmic veto: timing plus d0
- m(ll)/GeVc-2 > 30
- Very low Backgrounds: QCD bb  (0.6  0.3)% Z     (0.5  0.1)%
- 6126 candidates after bkg substraction A x =16.40%

**L~***** *****117pb****-1**

- BR(Z)=250.53.8 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**Notes:**
Correct from Z/gamma* to the pure Z propagator using MC
Starting to measure differential cross sections, good agreement data/MC
The analysis is sensitive to a very large mass range, and the resolutio for muons is not that good (the width of the Z peak is 8-9 GeV) SF 
NZ = Ncand • [σZ/σZ]MC=0.7860.013

MC PYTHIA CTEQ6 PDF it does not do a good job representing the Pt of the Z. We need to make a harder job and study all systematic uncertainties. But we can see there are not big discrepancies that could bias the cross section measuremen.

## Summary CDF & DØ BR(Zl+l-) 

##      CDF Wt and Z h+l− Signals

-      CDF Wt and Z h+l− Signals

- Count tracks in 10o  -cone and veto tracks in 30o isolation cone
- Reconstruct 0 candidates in Shower Max detector
- Combined mass < m()
-  Wt :  2345 in ~72 pb-1Background ~ 26 % (dominated QCD)

** ****L~***** *****72pb****-1**

**Notes:**
Update plot !!
Veto  Z’s, additional leptons.
Experimental signature of a hadronic tau decay is a narrow jet with low charged track multiplicity (one-prong, three-prong, 5 prong- not always the charged pions are reconstructed)
Hadronic tau selection: track isolation in a cone 10-30 degrees, combined visible mass < tau mass, calorimeter: cluster of towers: seed tower 6 GeV, number of shoulder towers>1 GeV
Lower than 6.     
W->taunu: tau jet, large MeT  QCD bkg dominates: 1 jet misidentified as a tau, and instrumental MET because eof a jet in acrack.
Tau(L3) +Met
Z->tautau (enutau) electron plus track,
-------------------------------------------------------------------------------
Invariant mass in 3d electron, tau, met(2d)

## DØ BR(Wl)

- 1 tight central e isolated Et>25 GeV Met>25 GeV

- 1 tight  isolated Pt>20 GeV Met>20 GeV

**L~***** *****41(e)pb****-1**

| Candidate events |  Bkg |  AX |
| --- | --- | --- |
| 8305 | ~11.8 % | 13.2% |

| Candidate events | Bkg | AX |
| --- | --- | --- |
| 27400 | ~5% | 18.4% |

**W ******** ****μ******

**W ******** e******

**L~***** *****17.3 (********) pb****-1**

- BR(Wl)=268740 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**Notes:**
Veto  Z’s, additional leptons

## CDF BR(Wl)

| Candidate events  |  | Estimated Bkg | Acceptance x efficiency |
| --- | --- | --- | --- |
| W  μ | 31,722 | (10.6 ± 0.4)% | (14.39 ± 0.32)% |
| W  e | 37,574 | ( 4.4 ± 0.8)% | (17.94 ± 0.35)% |

- 1 tight central e isolated Et>25 GeV Met>25 GeV

- 1 tight  isolated Pt>20 GeV Met>20 GeV

- BR(Wl)=268740 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**L~***** *****72pb****-1**

- Systematics : ~3.7%(2003) ~2.2%

**Notes:**
Diferencias systematics   Now PDF  winter2003: material description. 
Excellent agreement data-MC in the central.

## CDF BR(We) PLUG

- CDF BR(We) PLUG

| Candidates | 10461 |
| --- | --- |
| QCD bkg | 49562 247 |
| Z  | 8713 |
| W | 32423 |

- Electron: Plug EM cluster: Et>20, 1.1<||<2.8
- ID:Had/Em,E/P and cal-Iso.
- Silicon track matched with shower-max plug detector
- Met>20
- Trigger: Met>15 & Plug EM cluster: Et>20
- Main systematics: plug energy scale, PDF,material

- BR(Wl)=268740 pb (NNLO theory: Martin,Roberts,Stirling,Thorne)

**L~***** *****64pb****-1**

**Notes:**
Antonio Sidoti, results. (Already blessed)
Only electrons in the PLUG, demanding a silicon track 
DIFERENT TRIGGER: before hight Pt lepton (electron or muon) 

## Summary CDF & DØ BR(Wl) 

**Notes:**
Theory curves: Matsuura/van Neerven code with:
CTEQ4M MW=80.375 GeV, MZ=91.188 GeV, sin2(theta))=1-(MW/MZ)^2=0.2231
Pdf CTEQ4M (1334) scale M_V, Lambda=296 MeV ->Darien Wood

## Summary CDF & DØ 

- Summary CDF & DØ

| Channel  | Ncandidates & Purity |  | XA |
| --- | --- | --- | --- |
| CDF   We | 37.6K (95%) | 72 | 17.94% |
| CDFplug   We | 10.4K (90%) | 64 | 5.2% |
| DØ     We | 27.4K (90%) | 41 | 18.40% |
| CDF   W  | 31.7K (90%) | 72 | 14.39% |
| DØ     W  | 8.3K (88%) | 17 | 13.20% |
| CDF    Z ee | 4242 (1.5%) | 72 | 22.74% |
| DØ     Z ee | 1139(--) | 41 | 9.30% |
| CDF   Z  | 1785 (1.5%) | 72 | 10.18% |
| DØ     Z  | 6126 (1.1%) | 117 | 16.40% |

**Notes:**
Theory curves: Matsuura/van Neerven code with:
CTEQ4M MW=80.375 GeV, MZ=91.188 GeV, sin2(theta))=1-(MW/MZ)^2=0.2231
Pdf CTEQ4M (1334) scale M_V, Lambda=296 MeV ->Darien Wood

## Combining e and μ channels

- Assuming lepton universality, combine W and Z results
- correlated systematics effects accounted for

## Re & R R BR(W→lν) and Γ(W)

- Using NNLO calculation Γ(W→lν)=226.4 ±0.4 MeV (PDG):

**Notes:**
Z cross sections are corrected for gamma * exchange. 

## CDF & DØ BR(W→lν) and Γ(W)

- CDF & DØ BR(W→lν) and Γ(W)

|  | CDF(e+L=72pb-1 |  | D0(e) L=42pb-1 |
| --- | --- | --- | --- |
| R | 10.930.15stat0.13sys ‡ |  | 10.340.35stat0.49sys ‡
 |
| BR(Wll) |  | 0.1055  0.0038   | 0.1035  0.0062 |
|  |  |  |  |
| (W) | (2071 40) MeV |  | (2187 128) MeV |

**         ****‡****NNLO@1.96  : 10.66 ****±**** 0.05 (J.Stirling)**
- Using the NNLO calculation of ******(W********l********l****) **

**Current World Ave: 2092 ****±**** 40 MeV        LEP direct measurement : 2150 ****± 91 MeV**

**Notes:**
Z cross sections are corrected for gamma * exchange. 
D0 & CD indirect measurement of gamma(W)

## -e Universality in W Decays

- Calculate R separately for e and μ channels:

- From W  e and W  t  cross sections :

**Notes:**
We use the double ratio to test the Universality of the W couplings to electron and muons, under the assumption that the Z couplings are universal, this is well establish experimentally.
Many systematics are cancelled in this ratio,including PDF uncertainties.
Our result is dominated by the statistical error and by efficieny uncertainties,which are themselves statistical in nature.
Based on the measurements of Re and Rmu we find...

## Forward-backward asymmetry

**5438**** ****candidates in ~**** ****72**** ****pb****-1**

******(1****st**** e) ******** ******** 1.0**
******(2****nd**** e) ******** ******** 2.8**

- Unique at Tevatron (off Z pole)
- Directly probes V,A sin2W ,u,
-     d couplings to Z
- Sensitive to New Physics: agreement with SM prediction.

- p

**Notes:**
Tevatron is uniquely sensitive to Z-γ* interference at high invariant masses.
Shape of the Afb spectrum can be used to extract values for sin2(θW) and u, d couplings to Z
Agreement with SM prediction.

## Di-boson Production and TGC

- qq’W     TGC WW 

- qqZ   TGC  Z ZZ 

**Notes:**
ESTUDIAR CDF NOTE Y LA ULTIMA CHARLA DIBOSONES EN EL EWK MEETING, JUSTIFICAR LOS CORTES

ZZgamma

## DiBoson Production: W 

- DiBoson Production: W

**Shower Maximum Detector**

**Pre-shower Detector**

- W(e)
- Et(e) >25 GeV, cal-iso
- CDF |e|<1.1 DØ |e|<2. 3
- Et>25 GeV
- W()
- Pt()> 20 GeV,
- CDF ||<1.0 DØ ||<1.6
- Et>20 GeV

- CDF Et () >7 GeV DØ   Et () >8 GeV
- R(,l)>0.7 GeV
- |  |<1.1
- Cal & trk-iso

- Then:
- select
- 

**Notes:**
30<Mt(lepton,neutrino)<120

## CDF: W 

|  | N expected (L=202/pb) |
| --- | --- |
| N(W+g) MC | 180.51 ± 2.08 ± 11.2 |
| Tot Bkg | 75.12 ± 0.46 ± 15.00 |
| Total SM  | 255.63 ± 2.13 ± 26.43 |
| Data | 259 |

- (W)BR(Wl) = 19.7 1.7 (stat)  2.0 (sys)   1.1 (lumi) pb

- ·BRpp W ll  = 19.3  1.3 pb    NLO prediction (U. Baur):

| W+jet  | 49.52 ± 0.10 ± 14.95 |
| --- | --- |
| Z | 22.37 ± 0.38 ± 1.2 |
| Wg g | 3.23 ± 0.24 ± 0.17 |

**Notes:**
Test of gauge couplings ( as predicted by the SM) and a window 
on new physicsW+jet Bkg	49.52 ± 0.10 ± 14.95
Z	22.37 ± 0.38 ± 1.2
Wg g	3.23 ± 0.24 ± 0.17

## DØ W 

- DØ W

|  | (e) 162/pb | (82/pb) |
| --- | --- | --- |
| Total B | 87.17.5 | 37.10. |
| Total SM | 14217 | 6713 |
| data | 146 | 77 |

| W+jets  | 80.07.4 | 30.1 10.0 |
| --- | --- | --- |
| Z+   |      - | 4.72.0 |
| leX | 3.70.5 | 0.6 0.6 |
| W() | 3.41.1 | 0.9 0.3 |

- (W)BR(Wl) = 19.3 2.7 (stat)  6.1 (sys)   1.2 (lumi) pb

- ·BRpp W ll  = 16.4  0.4 pb    NLO prediction (U. Baur):

## DiBoson:  Z 

- DiBoson:  Z 

- First:
- Select
- Z l+l-

- Then:
- select
- 

- Et () >7 GeV
- R(,l)>0.7 GeV
- |  |<1.1
- Cal & trk-iso

- Z e+e-: Et(e) >25 GeV, |e|<2.8
- Z +-: Pt >20 GeV, ||<1.1
- Mll>40 GeV

- NON-SM !!

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## CDF:  Z 

|  | e + μ |
| --- | --- |
| N(Z+g MC) | 65.76 ±3.76  |
| N(background) | 4.70 ± 1.34 |
| Total | 70.46 ±4.00  |
| data | 69 |

- (Z)BR(Zll) =5.3 0.6 (stat)  0.4 (sys)  0.3 (lumi) pb

| Z+jet  | 4.44 ± 1.33 |
| --- | --- |
| Others | 0.26 ± 0.2 |

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## CDF:  WW (Two approaches)

- _Dileptons: l__+__,l__-__: identified e,___
-  Reject 76<Mll<106 & ET / ET <3
-  ET>25
-  No High Et jets
-  Opposite sign & Isolation

- _(Identified e,____) + track_
- Reject ET / ET <5.5 in all Mll
- ET>25
- Njets<=1
- Opposite sign & Isolation

- High S/B

- Increased acceptance

- Two complementary approaches

-  DY, Z
-  WZ/ZZ, Z
-  top dilepton
-  Fakes

- 	 ET / ET  Bkg with instrumental ET

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## CDF:  WW  cross section 

|  | l+track |  e,  |
| --- | --- | --- |
| WW | 16.30.4 | 11.3 1.3 |
| DY | 1.80.3 | 1.82 0.4 |
| WZ+ZZ
W | 2.40.1
- | 0.76 0.06
1.050.19 |
| Fakes | 9.10.8 | 1.080.49 |
| Bkg | 15.10.9 | 4.770.70 |
| WW+Bkg | 31.51.0 | 16.11.6 |
| Data | 39 | 17 |

- NLO (MFCM, Ellis& Campbell) WW=12.50.8 pb

- e,

- l+track

**Notes:**
L+track assuming BR 10.8 %

## CDF:  WW  Beyond SM 

**Anoumalous TGC WWZ/WW******

**gg********H********WW 140<M****H****<180GeV/c****2**

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling
A scalar favours small deltaphi or delta(opening angle)
Search for any scalar particle giving 2 leptons , Met in the final state, ej: gg->H->WW

## CDF:  WW e candidate

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## W mass prospects

**direct **
**extraction**
** ****of ********(W)**

**W ****→ ****μν**

**Z ****→ ****μμ**

- Data
- Simulation
- Total background

- momentum scale
**J/********GeV)******
****** ****GeV)******
****** ********high Pt)**

- Data
- Simulation

**M************(GeV/c****2****)**

**M************(********) (GeV/c****2****)**

- direct
- extraction
-  of (W)

- CDF Run I (μ)                            mW = 80.465  ± 100(stat) ± 103(sys) MeV
- CDF Run II for 250/pb estimate (μ):  =    X  ±   55(stat) ±   80(sys) MeV

- Calorimeter:
- right energy scale
- and resolution

**Notes:**
It is a difficult measurement, we need to now very well the recoil of the W (everything in the calorimeter except the lepton)
Pieces:
Proper generation: including NLO QCD and NLO QED radiation in the MC.
We have reprocessed the data set with a new tracking reconstruccion, we are full of expectations !!!

Correct modelled the detector response:
Mt=sqrt(2 pt Et-miss (1-cos(deltaphi)) ->dphi azimuthal angle between the pt of the charge lepton and the direction of the missing transverse energy
Right tracking resolution-> can affect the direction .
Calorimeter response: energy scale and resolution.
3) Correct modelled of the underlying event
4)Right tracking:
Alignment->cosmics
Momemtum scale resolution: calibrate:
J/psi 2-5 GeV 10 milion
Upsilon 8-10 GeV
Z: high Pt 
5) Gamma direct extraction from the left parte,
The deviation from the briet wigner is due to the non reconstrutionof the Pz of the Met

## Conclusions

- Electroweak measurements at the Tevatron:
- Benchmarks to understand the  CDF & DØ detectors.
- Important backgrounds for Top and Higgs physics.
- Ideal scenario to test the Standard Model.
- Please  tune in to the talks:
-  Higgs (S.Beauceron) SUSY (K.Kurca) Leptoquarks (D.Ryan) and other (A.Pompos) searches at the Tevatron.
- Diboson Production cross section measurements  anomalous TGC.
- Expect full set of publications based on 200 /pb  between now and the end of 2004.

- 		Backup slides

## Electron Reconstruccion

- Central electron: ||<1.2
- EM cluster + COT track
- Plug electron: 1.2<||<1.8
- EM cluster (+ Silicon track)
- Isolation: fraction of E in a cone 0.4
- Loose electrons: Et>20-25 GeV,
- Pt>10 GeV, Ehad/Eem,  track quality and fiducial requirements.
- Tight electrons: +E/P, shower profiles, track:showerMax matching
-  measured with Zee
- Trigger : 100%, Et>30 GeV
- ID  : tight e >80% , loose e >94%

-        Calorimeter  + tracking information

- Large fractional energy deposit in EM sector. Track match requirement.
- Isolation: fraction of energy in hollow cone between 0.2 –0.4
- Shower shape distribution,E/P
-  measured with Zee
- Trigger : 100% above 30 GeV
- ID  > 90%, track matching included.
- E/P:75-80%

- Mis-identification probability measured with dijet events

**Notes:**
For all EWK measurements electrons and muons are essencial.

## Muon  Reconstruccion 

- Muon  Reconstruccion

- Loose muon:
- High Pt isolated track pointing to a  gap in the muon coverage ||<1.2
- MIP requirements.
- Tight muon:
- High Pt isolated track pointing to a muon stub ||<1.
-  measured with Z 
- Trigger : 88%(CMUP)-95%(CMX)
- ID  : 85%(CMUP)-90%(CMX)

-  Calorimeter  + tracking  +   stub information.

- -track measured twice:
- Toroidal spectrometer: position and timing information before & after the magnet.
- Precision Pt measured in central fiber tracker
- Track match: position and P.
-  measured with Z  
- Trigger : 50% (single )
- Tracking   > 95%.
- Isolation:91%

- Mis-identification probability measured with dijet events
- Veto cosmics using timing information and track information.
- Veto  from jets (mostly b) using isolation: calorimeter (CDF & DØ)and track (DØ)

##  DØ Z  th+tl− Signals

-  DØ Z  th+tl− Signals

- Z    ( )  (   + n0)

- Backgrounds
-   - QCD  from bb or /K decay
-   - W   or  + jet
-   - Z  

- L = 68 pb-1

-  visible mass (GeV)

**Notes:**
1 tau decay into muon and neutrinos and the other hadronic 1 prong decay
D0 has also proof they can obsevre tautau resonances, they observe a small number of events compatible with SM predictions

## CDF:  WW (III)

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## CDF:  WW (IV)

**Notes:**
probes EW boson self-coupling: direct consequence of SU(2)xU(1) gauge theory
 NEW PHYSICS, e.g. composite W modifies coupling

## TheTevatron collider in Run 2

- Tevatron is a proton-antiproton collider operating with Ebeam=980 GeV
- 36 p and p bunches  396 ns between bunch crossing.
-  Run 1: 6x6 bunches with 3.5s
- Increased instantaneous luminosity:
- Typical: 4-5 x 1031 cm–2 s-1
- Record: 6.1 x 1031 cm–2 s-1
- Tevatron has delivered ~430 pb−1
- Long term, by the end of FY09
- Base goal: 4.4 fb−1
- Design: 8.5 fb−1

## CDF Run II Detector

- From Run I:
- Solenoid
- Central muon system
- Central calorimeter

- New For Run II:
- Front-end DAQ
- Trigger:Track (L1) and Displaced Track (L2)
- Silicon Tracker (8 Layers) (  2.0)
- Central Outer Tracker
-  (  1.0)
- Plug Calorimeters
- (1.0    3.6)
- Extended Muon Coverage (  1.5, gaps filled in)

## Overview of DØ Detector

- New Inner tracking (silicon tracker, scintillating fiber tracker,preshowers)  with 2T superconducting solenoid
- Excellent calorimetry, hermetic detector.
- Upgraded  system for better  -ID
- Faster readout electronics, new trigger and DAQ.