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News and CommunicationsM. Cobal, University of Udine

- Summary of recent results from CDF and DO- Plans for the future- Requests from the Speaker Committe

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Tevatron- Introduction

Luminosity goal: 4.4-8.5 fb-1 by FY 2009

Record: 6.8x1031cm-2s-1

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Two detectors

CDF underwent serious upgrades:

New tracking system COT, new silicon tracker

(6-7 layers DS+1 SS) New forward calorimetry Tracking at trigger level

Tracks at L1 Displaced from PV@L2

D0: change of philosophy

New tracking system Based on a 2T solenoid New 8 layers (fiber)

tracker Secondary vertices

capability (SVX) Improved muon

coverage New features at trigger

level

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Data taking…7x1031…

Accelerator delivers.. Detectors use:

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Top (ttbar and single top)

A summary: Single top process would measure |Vtb|2 directly...

<13.7 pb (combined)<8.5 pb (t-channel)

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Top – Cross-section

A number of channels explored by D0

Nice comparison with past and theory…

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Top Cross-Section

Look for top content in W+jets sample

SLT

kinematic

Svx tag

soft tag

NN on kinematic variables

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Top Cross Section

A summary:

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Top Cross Section

A number of channels explored by D0

Nice comparison with past and theory…

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Combined value will be calculated soon

Cross Section: all the results

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Top Quark Mass

Recent Updates

Run I data (revisited), ~125 pb-1

mt  = 180.1 3.6 3.9(syst) GeV/c2

Run II data, ~126 pb-1  

mt=175.0 +17.4-16.9 8.4 (syst)

GeV/c2

Run II data, ~102 pb-1

mt=177.5 +12.7-9.4 7.1 (syst)

GeV/c2

Run II measurements will be more precise than Run I results soon

In the meantime Run I Tevatron average was re-done with D0’s new update

Run II data, ~126 pb-1   Lepton + Jets

mt=177.8 +4.5-5.0 6.2 (syst) GeV/c2 Likelihood Method

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Top Quark Mass

New Run I Combination

mHiggs  = 117 +67 –45 GeV/c2

Or

mHiggs  < 251 GeV/c2 (95% CL)

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Top mass and Higgs: Where we are

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M. Mangano,IFAE, Apr 2004

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Look in: http://www-d0.fnal.gov/www_buffer/pub/

publications.html#ACCEPTED

Paper Category: ACCEPTED

An Improved Measurement of the Top Quark MassNature {}{}{2004}. Not yet. PS

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Top Quark Properties

Single Top Production

t < 8.5 pb-1 @ 95% CL

Without Systematics With Systematics

s (pb) <6.4 <13.8

t (pb) <9.0 <19.8

s+t (pb) <7.9 <15.8

Sensitivity already better than Run I

t-channel search

s+t < 13.7 pb-1 @ 95% CL

Combined search

Direct Measurement of B(tWb)

3-jet 4-jet

1-tag 12 19

2-tag 2 2

49.039.054.0)(

WbtB

Measurement of W Helicity

New Run I measurement:F0 = 0.56 0.31(stat+mt) 0.07 (syst)

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Latest Results! (Blessed on 28/04/04..)

Study of top quark decay branching ratio Channel: dilepton, study of ratio: BR(t->τνb)/BRSM(t->τνb)

Limit: < 5.0 @ 95% C.L. With 193 pb-1 Top quark mass Channel: single lepton+jets, method: vertex b-tag (SECVTX) and templates Mass: 174.9 +7.1-7.7 (stat) +- 6.5 (syst) GeV/c2

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Tevatron only (di-lepton events or lepton+jet ) from W decays

Status of inputs (preliminary):mmtt=(178.0 =(178.0 2.7 2.7 (stat) (stat) 3.3 3.3 (syst)(syst)) GeV/c) GeV/c22

(latest Tevatron updated combination – RunI data)(latest Tevatron updated combination – RunI data) mmtt=(175 =(175 17 17 (stat) (stat) 8 8 (syst)(syst)) GeV/c) GeV/c22

(CDF di-leptons – RunII data)(CDF di-leptons – RunII data) mmtt=(178=(178+13+13

-9-9 (stat) (stat) 7 7 (syst)(syst)) GeV/c) GeV/c22

(CDF lepton+jets – RunII data)(CDF lepton+jets – RunII data) mmtt=(=(174.9174.9 +7.1+7.1

-7.7-7.7 (stat) (stat) 6.5 6.5 (syst)(syst)) GeV/c) GeV/c22

(CDF lepton+jets – RunII data)(CDF lepton+jets – RunII data) Matter of statistics (also for the main systematics) and optimized use of the Matter of statistics (also for the main systematics) and optimized use of the available information. Each experiment expects 500 b-tagged tt l+jets events/fb available information. Each experiment expects 500 b-tagged tt l+jets events/fb Mtop ~ 2-3 GeV/cMtop ~ 2-3 GeV/c22 for the Tevatron combined (2-4/fb) for the Tevatron combined (2-4/fb)

mmt t 2.5 GeV ; 2.5 GeV ; mmW W 30 MeV 30 MeV mmHH/m/mH H 35% 35%

Near future of Mtop

In 2009 (if upgrade is respected) from Tevatron: Mtop = 1.5 GeV !!

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What is left before the LHC starts?

Cover topics still open: cross section, couplings, exotic, resonances,

Define a strategy for validation of the MC input models (e.g: UE modeling and subtraction, jet fragmentation properties, jet energy profiles, b-fragmentation functions..)see M. Mangano talk at IFAE 2004

Explore the effects of changing detector parameters in evaluating the top mass.

Perform commissioning studies with top events Contribute to simulation validation …

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M. Mangano,IFAE, Apr 2004

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M. Mangano,IFAE, Apr 2004

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M. Mangano,IFAE, Apr 2004

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Communications

Speaker needed

BEACH (Beauty, Charm and Hyperons) conference in Chicago.(june 27th-july 3rd)

We have two ATLAS talks confirmed. For one of them there are 2 options:"LHC top physics" and "LHC electroweak physics" The talk will be 15 and 20-25 minutes (plus questions). What we would like from the top and/or SM groups are suggestions for this talk:both of title/topic and possible speakers. It is conceivable we may be able to get a third (short=10') talk on whichever of SM/top we don't choose for the longer talk, but this is not guaranteed.

http://capp.iit.edu/beach04/