Recent results from theCollider Detector at Fermilab

(for the CDF collaboration)

Rob Snihur (McGill University)

CAP Congress 2007 – SaskatoonEnergy Frontier and Phenomenology I

June 19, 2007

Outline• CDF • Physics program• Higgs• Beyond the Standard Model

– MSSM Higgs – Large Extra Dimensions: Pierre-Hugues Beauchemin (this afternoon 14:15)

• Top quark– Mass: Sebastian Carron (next talk)– Production Mechanism: Shabnaz Pashapour (this session)

• QCD– Di-b-jet cross section: Greg Williams (this session)– Exclusive gamma-gamma– Z + jets

• Electroweak– W mass: William Trischuk (yesterday)– WZ production

• b physics– Bs mixing– Sigma b observation– Cascade b observation

• Summary

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Canadian CDF institutionsUmbrella organization: IPP

• University of Alberta– Bryan Caron, Andrew Hamilton,

James Pinfold, Long Zhang

• McGill University– Adrian Buzatu, Phillipe Roy, Rob Snihur,

Andreas Warburton, Greg Williams

• University of Toronto– Hugo Beauchemin, Sebastian Caron, Dan

MacQueen, Shabnaz Pashapour, Pierre Savard, Teresa Spreitzer , Pekka Sinervo, William Trischuk

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Tevatron

• Integrated luminosity: 3 fb-1 delivered, 2.5 fb-1 on tape• Projection: “base” = 4 fb-1, “design” = 8 fb-1

• Highest instantaneous luminosity = 292.3 x 1030

~5 interactions

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CDF

Upgrades for Run II:– New tracking system

• COT, silicon tracker

– New forward calorimetry– Tracking at trigger level

• Tracks at L1

• Displaced from PV@L2

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Some CDF results for Winter 2007

• QCD– b-bbar dijet production– Z+jets cross section measurement – Z b-bbar– Dijet production cross section

measurement (1.13 fb-1 )• B Physics

– Lifetime measurements:• B+, B0, Bs and B (1fb-1)

– Rare decay searches: • B++- K+, B0+- K*, Bs+-

(1fb-1)• Bhh

• Electroweak– Observation of WZ production– Evidence for ZZ production– W mass, width

• Top– Top mass in all-jets channel– Production cross section

(lepton+isolated track)– Search for W' in the single top sample– Top Production Mechanism (gg vs qq)– Top Charge

• New Phenomena– Search for Large Extra Dimensions– Search for New Particles Coupling to

Z+jets (b'->Z+b) in 1.1 fb-1

– SUSY trilepton combined limit - 0.7 to 1 fb-1

– High-mass dielectron (Z’ search) - 1.3 fb-1

• Higgs (fb-1)– H SUSY Higgs– HWW ME-based analysis – ZHllbb 2D-NN and MET fitter

analysis

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Tevatron: close to 2 publications / week

mb -

b -

nb -

pb -

fb -

100 120 140 160 180 200

- - -

Higgs Mass [GeV/c2]

Total Inelastic

bb

WZ

tt-

-

HiggsWH,ZH

jets (qq, qg, gg)ob

serv

ed

WZ, Single Top, ZZ

MW ~0.05%

Mtop ~1%

Bs–Bs OscillationDiscovery +

Precision Meas.

MHiggs < 144 GeVat 95% CL

-

Reach 10-19 m

Low Mass SUSY

Road to the Higgs!

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A direct path towards the Higgs

• Light or heavy Higgs?

• Strong b-tagging, large lepton coverage– X-section shows that

we must use channels with large BF (no )Production

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Higgs searches combined

• Last update in mid March (new CDF result on WW, ZH)

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Higgs WW• Matrix Element method• Expected background = 286.1 +- 23.3

background• Expected signal (160 GeV) = 3.9 +- 0.3• Observed 323 candidates• < 1.3 pb (95% C.L)• 10 Higgs mass hypotheses are shown

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ZH ll bb

• Both ee & uu channels• Small background

– Mostly Z+jets

• Neural network– Discriminates event kinematics

against Z+jets & tt background

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MSSM Higgs Tau Tau

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Exclusive gamma gammaAndrew Hamilton, Bryan Caron, James Pinfold

(University of Alberta)

• 2 central EM showers with ET > 5 GeV

• 3 events observed, consistent with

• Background = 0.09 +- 0.04 events

• Significance = 3.7 • Cross section < 410 fb• May constrain exclusive

Higgs predictions at LHC

p

p

g

g

g

dijet, , c, Higgs

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Z + jets

• 1.1 fb-1

• Zee

• pT(jet) > 30 GeV|y(jet)| < 2.1

• NLO agrees with data

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First observation of WZ

Prob(background only) < 1.5 10-7 (5.1)

(WZ)=5.0+1.8-1.6(stat.+syst.)

pb

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First observation ofBs oscillations

• PRL 97, 24003 2006• Number of Bs decays

– 5600 fully reconstructed hadronic– 3100 partially reconstructed hadronic– 61500 partially reconstructed

semileptonic

ms=17.77±0.10(stat)±0.07(syst) ps-1 > 5 effect

• Same data set used for previous (spring 06) limit

• Improved selection• Improved analysis technique

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First observation of b

• Fully reconstructed decay modes

• Likelihood ratio (no bb states) = 2.6 x 10-19

m(Σb+)  = 5808+2.0-2.3(stat.) ± 1.7(syst.) MeV/c2

m(Σb¯) = 5816+1.0-1.0(stat.) ± 1.7(syst.) MeV/c2 

m(Σb*+) = 5829+1.6-1.8(stat.) ± 1.7(syst.) MeV/c2

m(Σb*¯) = 5837+2.1-1.9(stat.) ± 1.7(syst.) MeV/c2

0(*)bb

c pK

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Observation of b

• First ~2 fb-1 analysis• Use standard decay chain

to select candidate events• Use silicon hits to track • Topology similar to

B+ J/ K+• Significance = 7.8 • Mass = 5,792.9 +- 2.4(stat)

+- 1.7(syst) MeV/c2

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Example of Possible Fermilab Roadmap

ILC EDR + R&DILC System Test1-2 RF Units

Energy Frontier:

Beyond ILC/LHC Reach: R&D for higher energy lepton and hadron colliders

LHC LHC Upgrade

beams from Booster, Main Injector protonsMiniBooNE, SciBooNE, MINOS, MINERvA, NOvA

TevatronRunning

TevatronPhysics

Intensity Frontier: High Intensity Protons

ILC Construction

ILC Decision

ReconfiguringAccelerator

Complex

, , K, p beams

-

ILC CrymoduleIndustrialization

Running 2 GeV + 6 GeV Linac+ Recycler

+ Main InjectorRunning

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Summary• Broad physics program at CDF

– High pT– B physics

• New results on – SM & MSSM Higgs searches– QCD

• Exclusive gamma gamma production• Z + jets

– B physics• Bs oscillations• Sigma b observation

• More results presented at this conference– W mass– Large Extra Dimensions– B jet cross section– Top quark

• Mass• Gluon-gluon vs quark quark

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ISL Cooling: Physics Impact

• Five Layer SVX is core of system– B-tagging– Lifetime measurements– Silicon vertex triggers use SVX alone

• Layer 00– Improve vertex (eg B-tag) with point at beam pipe

• ISL– Not required for good B-tagging– High Lum point to help connect COT and SVX– High eta (||<2) tracking for forward electrons

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Single Top

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Tevatron Collisions• The hard scattering is not all

there is!– Parton Distribution Functions

(PDF): fraction of (anti)proton carried by incoming partons.

– Underlying Event (UE): extra stuff produce by spectator or multiple interactions.

– Initial and Final State Radiation (ISR, FSR): extra gluons radiating off the original/final partons.

– Jets: fragmentation of quark/gluons and recombination into hadrons reconstructed inside a cone.

.

All of these processes, and more, have an impact on what we measure

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Summary

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WH->lbb : Cut based AnalysesSingle b-tagged w/NN

CDF results:

Expect 95% C.L limit (mH =115 GeV)

< 2.2 pb (< 17 times over SM)

Observed limits:

< 3.4 pb( < 26 times over SM)

D0 results:

Expect 95% C.L limit (mH =115 GeV)

< 1.1 pb(< 9 times over SM)

Observed limits:

< 1.3 pb(< 11 times over SM)

Cross section limitRatio over SM

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Gluino vs. squark mass exclusion

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Chargino and Neutralino searches• Both experiments look for SUSY

signals– Chargino and neutralino are produced

with sizeable cross sections– More difficult search for squarks and

gluinos

R. Strohemer

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Non SM Higgs

• Non SM Higgs(es) have sizeable decay rate to pairs– Large efforts to bring up efficiency to trigger

on tau events (and to detect tau)

R. Strohemer