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Alberto Cruz. On behalf of the CDF collaboration. XXXIV International Symposium on Multiparticle Dynamics. Chicago . Florida. Booster. CDF. DØ. Tevatron. p sou rce. Main Injector. Fermilab. Long Term Luminosity Projection (by end FY2009). Base Goal -> 4.4 fb-1

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Xxxiv international symposium on multiparticle dynamics

Alberto Cruz

On behalf of the CDF collaboration

XXXIV International Symposium on Multiparticle Dynamics


Fermilab

Chicago

Florida

Booster

CDF

Tevatron

p source

Main Injector

Fermilab


Tevatron

Long Term Luminosity Projection

(by end FY2009)

Base Goal -> 4.4 fb-1

Design -> 8.5 fb-1

Tevatron

  • proton-antiproton collisions

  • Main injector

  • (150 GeV proton storage ring)

  • antiproton recycler (commissioning)

    • Electron cooling this year

    • Operational on June’05

    • 40% increase in Luminosity

  • 36 bunches (396 ns crossing time)

Increasing Luminosity:

RUN IIa (2001~2005) ~1fb-1

RUN I (1992-95) ~0.1fb-1


Tevatron performance
Tevatron Performance

Recent Luminosity Record of 10.3x1031 sec-1cm-2 (July 16, 2004)


Cdf run ii data
CDF Run II Data

  • CDF Efficiency > 80%

    • DAQ runs with 5% to 10% dead time

    • Rest coming from very careful operation

    • of detector’s HV due to machine losses

    • (…to preserve silicon & trackers…)

CDF -> ~450 pb-1 on tape


Xxxiv international symposium on multiparticle dynamics

The Jet Algorithm Allows us to “see” the partons (or at least their fingerprints) in the final hadronic state.

In proton-antiproton collisions we can occasionally have a “hard” parton-parton scattering resulting in large transverse momentum outgoing partons.


Jet algorithms physics
Jet algorithms & physics least their fingerprints) in the final hadronic state.

  • Final state partons are revealed through collimated flows of hadrons called jets

  • Measurements are performed at hadron level & theory is parton level (hadron  parton transition will depend on parton shower modeling)

  • Precise jet search algorithms necessary to compare with theory and to define hard physics

  • Natural choice is to use a cone-based algorithm in - space (invariant under longitudinal boost)


Run ii midpoint algorithm
Run II -> MidPoint algorithm least their fingerprints) in the final hadronic state.

  • Define a list of seeds using CAL towers with E > 1 GeV

  • Draw a cone of radius R around each seed and form “proto-jet”

  • Draw new cones around “proto-jets” and iterate until stable cones

  • Put seed in Midpoint (-) for each pair of proto-jets separated by less than 2R and iterate for stable jets

  • Merging/Splitting

T

Cross section calculable in pQCD

Arbitrary Rsep parameter still

present in pQCD calculation …


Xxxiv international symposium on multiparticle dynamics

Comparison of JetClu and MidPoint for HERWIG MC least their fingerprints) in the final hadronic state.

Comparison of the JetClu to MidPoint cone algorithms

Differences between MidPoint and JetClu found to be due to “ratcheting”.

JetClu  0.5-2% higher ET jets


W z g jets production introduction
W/Z/ least their fingerprints) in the final hadronic state.g(+jets) production: introduction

  • QCD-wise, are W/Z/g cross sections of interest?

    • Smaller subset of diagrams, different mix of initial partons

      • Below is a set of LO diagrams for W/Z and W/Z/g + 1 jet

    • Inclusive distributions are not affected by jet finding uncertainties

  • More theoretical work is needed, e.g.:

    • W inclusive: known at the level of NNLO

    • W + 1 jet: known at the level of NLO

    • W + 2, 3, 4 jets: known at the level of LO

      • (MCFM does proved W + 2 jets at NLO, it just isn’t an event generator)


W jet s production jetclu r 0 4
W+jet(s) Production (JetClu R=0.4) least their fingerprints) in the final hadronic state.

  • Background to top and Higgs Physics

  • Stringent test of pQCD predictions

  • Test Ground for ME+PS techniques

  • (Special matching  MLM, CKKW to avoid

  • double counting on ME+PS interface)

Inclusive s (nb)

Run I (1.8 TeV):

LO: 1.76

NLO: 2.41

NNLO: 2.50

CDF I: 2.380.24

Run II (1.96 TeV):

LO: 1.94

NLO: 2.64

NNLO: 2.73

CDF II: 2.640.18

W + 1 parton +PS

W+ 2 partons

QCD corrections cover this difference.

40% higher than the RUNI result

Alpgen + Herwig

LO  large uncertainty


W jet s production jetclu r 0 41
W+ jet(s) Production (JetClu R=0.4) least their fingerprints) in the final hadronic state.

ME+PS implementation tested using the Nth jet spectrum in W+Njet events.

Dijet Mass in W+2jets

1st jet in W + 1p

Energy-scale

2nd jet in W + 2p

4th

3rd


Diphoton production
Diphoton Production least their fingerprints) in the final hadronic state.

  • General agreement with NLO predictions

Data: 2 isolated γs in central region, ET1,2 > 14, 13 GeV

  • Testing NLO pQCD and resummation methods

  • Signature of interesting physics

    • One of main Higgs discovery channels at LHC


Heavy flavour production
γ least their fingerprints) in the final hadronic state.+heavy flavour production

  • Probes heavy-quark PDFs

  • b/c-quark tag based on displaced vertices

  • Secondary vertex mass discriminates flavour

MC templates for b/c & (uds) used to extract b/c fraction in data


Xxxiv international symposium on multiparticle dynamics

γ least their fingerprints) in the final hadronic state.+heavy flavour production

γ+b-quark

γ+c-quark

Good agreement with LO pQCD

within still very large stat. errors

Validates quark flavour separation

using secondary vertex mass


Summary
Summary least their fingerprints) in the final hadronic state.

  • Tevatron and CDF are performing well

    • Data samples already significantly exceed those of Run I

    • On track for accumulating 4-8 fb-1 by 2009

  • Robust QCD program is underway

    • Jets, photons, W+jets, heavy flavors

      • Jet energy scale is the dominant systematics – improvements on the way

      • Heavy flavor identification is working well

    • Verifying and tuning tools: NLO calculations, Monte Carlo generators, resummation techniques, combining ME with PS

      • NLO does well for hard aspects

      • LO + Pythia give reasonable description of W+n jets

  • We don’t see any discrepancies.