The Tevatron Connection Rick Field University of Florida (for the CDF Collaboration) “Flavor Creation” Multiple Parton Interactions b-quark Outgoing Parton PT(hard) Proton Proton AntiProton Underlying Event AntiProton Underlying Event Underlying Event Underlying Event Initial-State Radiation b-quark The Tevatron Connection June 24, 2005 CDF Run 2 Rick Field - Florida/CDF Outgoing Parton Page 1 Jet Physics in Run 2 at CDF “Hard” Scattering Outgoing Parton Outline of Talk PT(hard) Proton AntiProton Underlying Event Underlying Event Initial-State Radiation Final-State Radiation Calorimeter Jet Constructing Jets in Run 2 at CDF (MidPoint and KT Algorithms). New from CDF: The KT-Jet Outgoing Parton High PT “jets” probe short distances! Inclusive Cross Section. New from CDF: The b-Jet Inclusive KT Algorithm Cross Section. New from CDF: The b-bbar Jet Cross Section and Correlations. Understanding and Modeling the “Underlying Event” in Run 2 at CDF. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 2 CDF-QCD Group CDF-QCD Group Learn more about how nature works. Compare with theory and work to provide information that will lead to improved Monte-Carlo models and structure functions. Our contributions will benefit to the colliders of the future! Some CDF-QCD Group Analyses! Jet Cross Sections and Correlations: JetClu, MidPoint, KT algorithms. DiJet Mass Distributions: Df distribution, compositness. Heavy Flavor Jets: b-jet and b-bbar jet cross sections and correlations. Z and W Bosons plus Jets: including b-jets. Jets Fragmentation: jet shapes, momentum distributions, two-particle correlations. Underlying Event Studies: charged particles and energy for jet, jet+jet, g+jet, Z+jet. Pile-Up Studies: modeling of pile-up. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Important for the LHC! Page 3 Jets at 1.96 TeV “Real Jets” “Theory Jets” Next-to-leading order parton level calculation 0, 1, 2, or 3 partons! Experimental Jets: The study of “real” jets requires a “jet algorithm” and the different algorithms correspond to different observables and give different results! Experimental Jets: The study of “real” jets requires a good understanding of the calorimeter response! Experimental Jets: To compare with NLO parton level (and measure structure functions) requires a good understanding of the “underlying event”! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 4 KT Algorithm Begin kT Algorithm: For each precluster, calculate di pT2,i For each pair of preculsters, calculate ( y y j ) 2 (fi f j ) 2 dij min( pT2 ,i , pT2 , j ) i D2 Find the minimum of all di and dij. Merge i and j yes Minumum is dij? no Move i to list of jets yes Any Preclusters left? Cluster together calorimeter towers by their kT proximity. Infrared and collinear safe at all orders of pQCD. No splitting and merging. No ad hoc Rsep parameter necessary to compare with parton level. Every parton, particle, or tower is assigned to a “jet”. No biases from seed towers. Favored algorithm in e+e- annihilations! Will the KT algorithm be effective in the collider environment where there is an “underlying event”? Raw Jet ET = 533 GeV KT Algorithm Raw Jet ET = 618 GeV no End Outgoing Parton PT(hard) Initial-State Radiation Proton AntiProton Underlying Event Underlying Event CDF Run 2 Outgoing Parton Final-State Radiation The Tevatron Connection June 24, 2005 Only towers with ET > 0.5 GeV are shown Rick Field - Florida/CDF Page 5 Jet Corrections Calorimeter Jets: Particle Level Jets: Outgoing Parton PT(hard) Initial-State Radiation Proton AntiProton Underlying Event Outgoing Parton Underlying Event Final-State Radiation The Tevatron Connection June 24, 2005 We measure “jets” at the “hadron level” in the calorimeter. We certainly want to correct the “jets” for the detector resolution and effieciency. Also, we must correct the “jets” for “pile-up”. Must correct what we measure back to the true “particle level” jets! Do we want to make further model dependent corrections? Do we want to try and subtract the “underlying event” from the “particle level” jets. This cannot really be done, but if you trust the Monte-Carlo models modeling of the “underlying event” you can try and do it by using the Monte-Carlo models. Parton Level Jets: Do we want to use our data to try and extrapolate back to the parton level? This also cannot really be done, but again if you trust the MonteCarlo models you can try and do it by using the Monte-Carlo models. The “underlying event” consists of hard initial & final-state radiation plus the “beam-beam remnants” and possible multiple parton interactions. Rick Field - Florida/CDF Page 6 Jet Corrections Theory Experiment I believe we should correct the data back to what we measure (i.e. the particle level with an “underlying event”)! Calorimeter Jets: We measure “jets” at the “hadron level” in the calorimeter. We certainly want to correct the “jets” for the detector resolution and effieciency. should Also, we must(or correct the “jets” for “pile-up”. I believe we correct theory Must correct what calculate) the for what we we measure back to the true “particle level” jets! measure (i.e. the particle level anParticle Level Jets: with “underlying event”)! MC@NLO! Do we want to make further model dependent corrections? We need Do we want to try and subtract the “underlying event” from the “particle level” jets. This cannot really be done, but if you trust the Monte-Carlo models modeling of the “underlying event” you can try and do it by using the Monte-Carlo models. Parton Level Jets: Outgoing Parton PT(hard) Initial-State Radiation Proton Do we want to use our data to try and extrapolate back to the parton level? This also cannot really be done, but again if you trust the MonteCarlo models you can try and do it by using the Monte-Carlo models. AntiProton Underlying Event Outgoing Parton Underlying Event Final-State Radiation The Tevatron Connection June 24, 2005 The “underlying event” consists of hard initial & final-state radiation plus the “beam-beam remnants” and possible multiple parton interactions. Rick Field - Florida/CDF Page 7 Data at the “particle level”! KT Jet Cross-Section NLO parton level theory corrected to the “particle level”! Correction factors applied to NLO theory! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 8 Data at the “particle level”! KT Jet Cross-Section NLO parton level theory corrected to the “particle level”! 7 7 8 Correction factors applied to NLO theory! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 9 Data at the “hadron level”! KT Jet Cross-Section NLO parton level theory corrected to the “hadron level”! Theory and experiment agree very well! The KT algorithm works fine at the collider! Correction factors applied to NLO theory! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 10 Construct the invariant mass of particles pointing back to the secondary vertex! The b-Jet Inclusive Cross-Section 98 < pT(jet) < 106 GeV/c Monte-Carlo Templates Extract fraction of b-tagged jets from data using the shape of the mass of the secondary vertex as discriminating quantity (bin-by-bin as a function of jet pT). The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 11 The b-Jet Inclusive Cross-Section “Flavor Creation” b-quark Proton Inclusive b-Jet Cross Section AntiProton Underlying Event Underlying Event Initial-State Radiation b-quark “Flavor Excitation” b-quark Proton AntiProton Underlying Event Underlying Event b-quark Initial-State Radiation gluon, quark, or antiquark “Parton Shower/Fragmentation” Proton AntiProton Underlying Event Underlying Event Initial-State Radiation b-quark b-quark The data are compared with PYTHIA (tune A)! Data/PYA ~ 1.4 Comparison with MC@NLO coming soon! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 12 The b-bbar DiJet Cross-Section ET(b-jet#1) > 30 GeV, ET(b-jet#2) > 20 GeV, |h(b-jets)| < 1.2. Systematic Preliminary CDF Results: Uncertainty sbb = 34.5 1.8 10.5 nb QCD Monte-Carlo Predictions: PYTHIA Tune A CTEQ5L 38.71 ± 0.62nb HERWIG CTEQ5L 21.53 ± 0.66nb MC@NLO 28.49 ± 0.58nb “Flavor Creation” Proton Differential Cross Section as a function of the b-bbar DiJet invariant mass! b-quark AntiProton Underlying Event Underlying Event Initial-State Radiation Predominately Flavor creation! b-quark The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Large Systematic Uncertainty: Jet Energy Scale (~20%). b-tagging Efficiency (~8%) Page 13 The b-bbar DiJet Cross-Section ET(b-jet#1) > 30 GeV, ET(b-jet#2) > 20 GeV, |h(b-jets)| < 1.2. Preliminary CDF Results: sbb = 34.5 1.8 10.5 nb QCD Monte-Carlo Predictions: PYTHIA Tune A CTEQ5L 38.7 ± 0.6 nb HERWIG CTEQ5L 21.5 ± 0.7 nb MC@NLO 28.5 ± 0.6 nb MC@NLO + Jimmy 35.7 ± 2.0 nb Differential Cross Section as a function of the b-bbar DiJet invariant mass! JIMMY Runs with HERWIG and adds multiple parton interactions! “Flavor Creation” b-quark Initial-State Radiation JIMMY: MPI J. M. Butterworth J. R. Forshaw M. H. Seymour Adding multiple parton interactions (i.e. Jimmy) to enhance the “underlying event” increases the b-bbar jet cross section! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Proton AntiProton Underlying Event Underlying Event b-quark Final-State Radiation Page 14 b-bbar DiJet Correlations Tune A! b-jet direction Df “Toward” “Away” bbar-jet Differential Cross Section as a function of Df of the two b-jets! The two b-jets are predominately “back-toback” (i.e. “flavor creation”)! “Flavor Creation” Pythia Tune A agrees fairly well with the Df correlation! Proton b-quark AntiProton Underlying Event Underlying Event Initial-State Radiation Not an accident! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF b-quark Page 15 b-bbar DiJet Correlations Tune A! The two b-jets are predominately “backto-back” (i.e. “flavor creation”)! “Flavor Creation” b-quark Proton AntiProton Underlying Event Underlying Event Initial-State Radiation Differential Cross Section as a function of Df of the two b-jets! b-quark Pythia Tune A agrees fairly well with the Df correlation! “Flavor Creation” b-quark Initial-State Radiation Proton AntiProton Underlying Event Underlying Event b-quark Final-State Radiation Agrees very well with MC@NLO + HERWIG + JIMMY! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 16 b-Jet bbar-Jet Correlations Tune A! The two b-jets are predominately “backto-back” (i.e. “flavor creation”)! “Flavor Creation” b-quark Proton AntiProton Underlying Event Underlying Event Initial-State Radiation The “underlying event” is important in jet (and b-jet) Pythia Tune A agrees fairlyproduction well with the at Df the Tevatron! b-quark correlation! “Flavor Creation” Differential Cross Section as a function of Df of the two b-jets! b-quark Initial-State Radiation Proton AntiProton Underlying Event Underlying Event b-quark Final-State Radiation Agrees very well with MC@NLO + HERWIG + JIMMY! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 17 The “Underlying Event” in Run 2 at CDF Jet #1 Direction Df The “underlying event” consists of hard initial & final-state radiation plus the “beam-beam remnants” and possible multiple parton interactions. Outgoing Parton “Toward” PT(hard) Initial-State Radiation “Trans 1” “Trans 2” Proton AntiProton Underlying Event Underlying Event “Away” “Transverse” region is very sensitive to the “underlying event”! Outgoing Parton Final-State Radiation CDF Run 2 results: Two Classes of Events: “Leading Jet” and “Back-to-Back”. Two “Transverse” regions: “transMAX”, “transMIN”, “transDIF”. PTmax and PTmaxT distributions and averages. Df Distributions: “Density” and “Associated Density”. <pT> versus charged multiplicity: “min-bias” and the “transverse” region. Correlations between the two “transverse” regions: “trans1” vs “trans2”. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 18 The “Transverse” Regions as defined by the Leading Jet Jet #1 Direction “Transverse” region is very sensitive to the “underlying event”! Charged Particle Df Correlations 2p pT > 0.5 GeV/c |h| < 1 Away Region “Toward-Side” Jet Df Look at the charged particle density in the “transverse” region! Jet #1 Direction Transverse Region 1 Df “Toward” “Toward” “Transverse” “Transverse” “Away” “Trans 1” f Leading Jet “Trans 2” Toward Region Transverse Region 2 “Away” “Away-Side” Jet Away Region 0 -1 h +1 Look at charged particle correlations in the azimuthal angle Dfrelative to the leading calorimeter jet (JetClu R = 0.7, |h| < 2). o o o o o Define |Df| < 60 as “Toward”, 60 < -Df < 120 and 60 < Df < 120 as “Transverse 1” and o “Transverse 2”, and |Df| > 120 as “Away”. Each of the two “transverse” regions have o area DhDf = 2x60 = 4p/6. The overall “transverse” region is the sum of the two o transverse regions (DhDf = 2x120 = 4p/3). The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 19 Tuned PYTHIA 6.206 CDF Default! PYTHIA 6.206 CTEQ5L Tune B Tune A MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 1.9 GeV 2.0 GeV PARP(83) 0.5 0.5 PARP(84) 0.4 0.4 PARP(85) 1.0 0.9 PARP(86) 1.0 0.95 PARP(89) 1.8 TeV 1.8 TeV PARP(90) 0.25 0.25 PARP(67) 1.0 4.0 New PYTHIA default (less initial-state radiation) The Tevatron Connection June 24, 2005 1.00 "Transverse" Charged Density Parameter "Transverse" Charged Particle Density: dN/dhdf CDF Preliminary PYTHIA 6.206 (Set A) PARP(67)=4 data uncorrected theory corrected 0.75 Run 1 Analysis 0.50 0.25 CTEQ5L PYTHIA 6.206 (Set B) PARP(67)=1 1.8 TeV |h|<1.0 PT>0.5 GeV 0.00 0 5 10 15 20 25 30 35 40 45 50 PT(charged jet#1) (GeV/c) Plot shows the “Transverse” charged particle density versus PT(chgjet#1) compared to the QCD hard scattering predictions of two tuned versions of PYTHIA 6.206 (CTEQ5L, Set B (PARP(67)=1) and Set A (PARP(67)=4)). Old PYTHIA default (more initial-state radiation) Rick Field - Florida/CDF Page 20 Run 1 b-quark Azimuthal Correlations PYTHIA Tune A (more initial-state radiation) PYTHIA Tune B (less initial-state radiation) b-quark Correlations: Azimuthal Df Distribution b-quark Correlations: Azimuthal Df Distribution 0.01000 0.01000 1.8 TeV PT1 > 15 GeV/c PT2 > 10 GeV/c |y1| < 1 |y2| < 1 PYTHIA 6.206 CTEQ5L PARP(67)=1 ds/df (mb/deg) ds/df (mb/deg) 1.8 TeV PT1 > 15 GeV/c PT2 > 10 GeV/c |y1| < 1 |y2| < 1 0.00100 0.00010 0.00100 0.00010 "Away" "Toward" "Away" "Toward" PYTHIA 6.206 CTEQ5L PARP(67)=4 0.00001 0.00001 0 30 60 90 120 150 180 0 30 60 Df (degrees) PY62 (67=1) Total Flavor Creation Flavor Excitation 90 120 150 180 Df (degrees) Shower/Fragmentation PY62 (67=4) Total Flavor Creation Flavor Excitation Shower/Fragmentation b-quark direction Predictions of PYTHIA 6.206 (CTEQ5L) with PARP(67)=1 (new default, Tune B) and PARP(67)=4 (old default, Tune A) for the azimuthal angle, Df, between a b-quark with PT1 > 15 GeV/c, |y1| < 1 and bbar-quark with PT2 > 10 GeV/c, |y2|<1 in proton-antiproton collisions at 1.8 TeV. The curves correspond to ds/dDf (mb/o) for flavor creation, flavor excitation, shower/fragmentation, and the resulting total. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Df “Toward” “Away” bbar-quark Page 21 Run 1 b-quark Azimuthal Correlations PYTHIA Tune A (more initial-state radiation) b-quark Correlations: Azimuthal Df Distribution b-quark Correlations: Azimuthal Df Distribution 0.01000 0.010000 1.8 TeV PT1 > 15 GeV/c PT2 > 10 GeV/c |y1| < 1 |y2| < 1 HERWIG 6.4 CTEQ5L 0.001000 0.00100 ds/df (mb/deg) ds/df (mb/deg) 1.8 TeV PT1 > 15 GeV/c PT2 > 10 GeV/c |y1| < 1 |y2| < 1 0.00010 "Flavor Creation" CTEQ5L HERWIG 6.4 0.000100 PYTHIA 6.206 PARP(67)=4 PYTHIA 6.206 PARP(67)=1 0.000010 "Away" "Toward" 0.00001 30 60 90 120 150 180 Df (degrees) HW64 Total "Away" "Toward" 0 Flavor Creation Flavor Excitation 0.000001 0 30 60 Predictions of HERWIG 6.4 (CTEQ5L) for the azimuthal angle, Df, between a b-quark with PT1 > 15 GeV/c, |y1| < 1 and bbar-quark with PT2 > 10 GeV/c, |y2|<1 in proton-antiproton collisions at 1.8 TeV. The curves correspond to ds/dDf (mb/o) for flavor creation, flavor excitation, shower/fragmentation, and the resulting total. 90 120 150 180 Df (degrees) Shower/Fragmentation b-quark direction PYTHIA Tune B (less initial-state radiation) Df “Toward” “Away” “Flavor Creation” bbar-quark The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 22 CDF Run I Analysis Azimuthal Correlations b-quark Correlations: Azimuthal Df Distribution b-quark Correlations: Azimuthal Df Distribution 0.1000 0.01000 1.8 TeV PT1 > 15 GeV/c PT2 > 10 GeV/c |y1| < 1 |y2| < 1 1.8 TeV ds/df (mb/deg) 1/s ds/df (mb/deg) CDF Preliminary Data 0.0100 PYTHIA 6.206 CTEQ5L PARP(67)=4 0.00100 0.00010 0.0010 "Away" "Toward" "Away" "Toward" 0.00001 0 0.0001 0 30 60 90 Df (degrees) 120 150 30 60 90 120 150 180 Df (degrees) 180 PY62 (67=4) Total Flavor Creation Flavor Excitation Run I preliminary uncorrected CDF data for the Preliminary CDF Run 1 bazimuthal angle, Df, between a b-quark |y1| < 1 and bbarbbar quark Df! quark |y2|<1 in proton-antiproton collisions at 1.8 TeV. Shower/Fragmentation b-quark direction Df “Toward” PYTHIA Tune A (with more initial state radiation) agreed better with the CDF Run 1 data! Thus we choose Tune A over Tune B as the CDF default! “Away” bbar-quark Now Published! Phys. Rev. D71, 092001 (2005) The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 23 Refer to this as a “Leading Jet” event Charged Particle Density Df Dependence Run 2 Jet #1 Direction Df Charged Particle Density: dN/dhdf “Toward” “Transverse” CDF Preliminary “Transverse” “Away” Refer to this as a “Back-to-Back” event Jet #1 Direction Df “Toward” “Transverse” Charged Particle Density Subset 10.0 30 < ET(jet#1) < 70 GeV Back-to-Back Leading Jet Min-Bias data uncorrected "Transverse" Region 1.0 Jet#1 Charged Particles (|h|<1.0, PT>0.5 GeV/c) “Transverse” 0.1 “Away” 0 30 60 90 120 150 180 210 240 270 300 330 360 Df (degrees) Jet #2 Direction Look at the “transverse” region as defined by the leading jet (JetClu R = 0.7, |h| < 2) or by the leading two jets (JetClu R = 0.7, |h| < 2). “Back-to-Back” events are selected to have at least two jets with Jet#1 and Jet#2 nearly “back-to-back” (Df12 > 150o) with almost equal transverse energies (ET(jet#2)/ET(jet#1) > 0.8) and ET(jet#3) < 15 GeV. Shows the Df dependence of the charged particle density, dNchg/dhdf, for charged particles in the range pT > 0.5 GeV/c and |h| < 1 relative to jet#1 (rotated to 270o) for 30 < ET(jet#1) < 70 GeV for “Leading Jet” and “Back-to-Back” events. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 24 “Transverse” PTsum Density PYTHIA Tune A vs HERWIG “Leading Jet” Jet #1 Direction Df "AVE Transverse" PTsum Density: dPT/dhdf “Toward” “Transverse” “Transverse” “Away” “Back-to-Back” Jet #1 Direction Df “Toward” “Transverse” “Transverse” "Transverse" PTsum Density (GeV/c) 1.4 Leading Jet CDF Preliminary 1.2 data uncorrected theory + CDFSIM PY Tune A 1.0 0.8 0.6 0.4 Back-to-Back HW 0.2 1.96 TeV Charged Particles (|h|<1.0, PT>0.5 GeV/c) 0.0 0 50 100 150 200 250 ET(jet#1) (GeV) “Away” Jet #2 Direction Now look in detail at “back-to-back” events in the region 30 < ET(jet#1) < 70 GeV! Shows the average charged PTsum density, dPTsum/dhdf, in the “transverse” region (pT > 0.5 GeV/c, |h| < 1) versus ET(jet#1) for “Leading Jet” and “Back-to-Back” events. Compares the (uncorrected) data with PYTHIA Tune A and HERWIG after CDFSIM. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 25 Charged PTsum Density PYTHIA Tune A vs HERWIG HERWIG (without multiple parton interactions) does not produces enough PTsum in the “transverse” region for 30 < ET(jet#1) < 70 GeV! Charged PTsum Density: dPT/dhdf Charged PTsum Density: dPT/dhdf 100.0 Charged Particles 30 < ET(jet#1) < 70 GeV (|h|<1.0, PT>0.5 GeV/c) Back-to-Back PY Tune A Charged PTsum Density (GeV/c) Charged PTsum Density (GeV/c) 100.0 10.0 1.0 CDF Preliminary Jet#1 "Transverse" Region data uncorrected theory + CDFSIM Charged Particles 30 < ET(jet#1) < 70 GeV (|h|<1.0, PT>0.5 GeV/c) Back-to-Back HERWIG 10.0 "Transverse" Region 1.0 CDF Preliminary 0.1 0.1 0 30 60 90 120 150 180 210 240 270 300 330 360 0 30 60 90 120 Df (degrees) 150 180 210 240 270 300 330 360 330 360 Df (degrees) Data - Theory: Charged PTsum Density dPT/dhdf Data - Theory: Charged PTsum Density dPT/dhdf 2 2 data uncorrected theory + CDFSIM 1 Back-to-Back 30 < ET(jet#1) < 70 GeV PYTHIA Tune A CDF Preliminary Data - Theory (GeV/c) CDF Preliminary Data - Theory (GeV/c) Jet#1 data uncorrected theory + CDFSIM 0 -1 "Transverse" Region Charged Particles (|h|<1.0, PT>0.5 GeV/c) data uncorrected theory + CDFSIM 1 30 < ET(jet#1) < 70 GeV Back-to-Back HERWIG 0 -1 "Transverse" Region Charged Particles (|h|<1.0, PT>0.5 GeV/c) Jet#1 Jet#1 -2 -2 0 30 60 90 120 150 180 210 240 270 300 330 360 0 30 90 120 150 180 210 240 270 300 Df (degrees) Df (degrees) The Tevatron Connection June 24, 2005 60 Rick Field - Florida/CDF Page 26 Tuned JIMMY versus PYTHIA Tune A JIMMY: MPI J. M. Butterworth J. R. Forshaw M. H. Seymour JIMMY Runs with HERWIG and adds multiple parton interactions! Charged PTsum Density: dPT/dhdf Charged PTsum Density: dPT/dhdf 100.0 Charged Particles 30 < ET(jet#1) < 70 GeV (|h|<1.0, PT>0.5 GeV/c) Leading Jet PY Tune A Charged PTsum Density (GeV/c) Charged PTsum Density (GeV/c) 100.0 10.0 1.0 CDF Preliminary Jet#1 "Transverse" Region data uncorrected theory + CDFSIM 0.1 RDF Preliminary generator level PYA TOT Charged Particles (|h|<1.0, PT>0.5 GeV/c) JIMMY tuned to agree with PYTHIA Tune A! PT(jet#1) > 30 GeV/c JM TOT JM 2-to-2 10.0 "Transverse" Region JM ISR JM MPI 1.0 Jet#1 0.1 0 30 60 90 120 150 180 210 240 270 300 330 360 0 30 Df (degrees) 60 90 120 150 180 210 240 270 300 330 360 Df (degrees) (left) Shows the Run 2 data on the Dfdependence of the charged scalar PTsum density (|h|<1, pT>0.5 GeV/c) relative to the leading jet for 30 < ET(jet#1) < 70 GeV/c compared with PYTHIA Tune A (after CDFSIM). (right) Shows the generator level predictions of PYTHIA Tune A and a tuned version of JIMMY (PTmin=1.8 GeV/c) for the Df dependence of the charged scalar PTsum density (|h|<1, pT>0.5 GeV/c) relative to the leading jet for PT(jet#1) > 30 GeV/c. The tuned JIMMY and PYTHIA Tune A agree in the “transverse” region. (right) For JIMMY the contributions from the multiple parton interactions (MPI), initial-state radiation (ISR), and the 2-to-2 hard scattering plus finial-state radiation (2-to-2+FSR) are shown. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 27 JIMMY (MPI) versus HERWIG (BBR) Charged PTsum Density: dPT/dhdf ETsum Density: dET/dhdf 2.5 0.8 generator level 0.6 JM MPI HW BBR RDF Preliminary PT(jet#1) > 30 GeV/c RDF Preliminary generator level ETsum Density (GeV) Charged PTsum Density (GeV/c) 1.0 "Transverse" Region 0.4 0.2 0.0 0 30 60 90 PT(jet#1) > 30 GeV HW BBR 2.0 1.5 1.0 0.5 Jet#1 Charged Particles (|h|<1.0, PT>0.5 GeV/c) JM MPI Jet#1 "Transverse" Region All Particles (|h|<1.0, PT>0 GeV/c) 0.0 120 150 180 210 240 270 300 330 360 0 30 Df (degrees) 60 90 120 150 180 210 240 270 300 330 360 Df (degrees) (left) Shows the generator level predictions of JIMMY (MPI, PTmin=1.8 GeV/c) and HERWIG (BBR) for the Df dependence of the charged scalar PTsum density (|h|<1, pT>0.5 GeV/c) relative to the leading jet for PT(jet#1) > 30 GeV/c. (right) Shows the generator level predictions of JIMMY (MPI, PTmin=1.8 GeV/c) and HERWIG (BBR) for the Df dependence of the scalar ETsum density (|h|<1, pT>0 GeV/c) relative to the leading jet for PT(jet#1) > 30 GeV/c. The “multiple-parton interaction” (MPI) contribution from JIMMY is about a factor of two larger than the “Beam-Beam Remnant” (BBR) contribution from HERWIG. The JIMMY program replaces the HERWIG BBR is its MPI. The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 28 Tuned JIMMY versus PYTHIA Tune A Tuned JIMMY produces more ETsum than PYTHIA Tune A! ETsum Density: dET/dhdf Charged PTsum Density: dPT/dhdf RDF Preliminary generator level PYA TOT 100.0 Charged Particles (|h|<1.0, PT>0.5 GeV/c) PYA TOT PT(jet#1) > 30 GeV/c JM TOT JM 2-to-2 10.0 "Transverse" Region JM ISR JM MPI All Particles (|h|<1.0, PT>0 GeV/c) JM TOT ETsum Density (GeV) Charged PTsum Density (GeV/c) 100.0 1.0 PT(jet#1) > 30 GeV JM 2-to-2 JM ISR JM MPI 10.0 "Transverse" Region 1.0 Jet#1 RDF Preliminary Jet#1 generator level 0.1 0.1 0 30 60 90 120 150 180 210 240 270 300 330 360 0 30 60 90 120 150 180 210 240 270 300 330 360 Df (degrees) Df (degrees) (left) Shows the generator level predictions of PYTHIA Tune A and JIMMY (PTmin=1.8 GeV/c) for the Df dependence of the charged scalar PTsum density (|h|<1, pT>0.5 GeV/c) relative to the leading jet with PT(jet#1) > 30 GeV/c. JIMMY and PYTHIA Tune A agree in the “transverse” region.. (right) Shows the generator level predictions of PYTHIA Tune A and JIMMY (PTmin=1.8 GeV/c) for the Df dependence of the scalar ETsum density (|h|<1, pT>0) relative to the leading jet for PT(jet#1) > 30 GeV/c. The tuned JIMMY produces a lot more ETsum (pT>0) in the “transverse” region than does PYTHIA Tune A! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 29 Tuned JIMMY versus PYTHIA Tune A Tuned JIMMY produces more ETsum than PYTHIA Tune A! ETsum Density: dET/dhdf Charged PTsum Density: dPT/dhdf RDF Preliminary generator level PYA TOT 100.0 Charged Particles (|h|<1.0, PT>0.5 GeV/c) PYA TOT PT(jet#1) > 30 GeV/c JM TOT JM 2-to-2 10.0 "Transverse" Region JM ISR JM MPI All Particles (|h|<1.0, PT>0 GeV/c) JM TOT ETsum Density (GeV) Charged PTsum Density (GeV/c) 100.0 1.0 PT(jet#1) > 30 GeV JM 2-to-2 JM ISR JM MPI 10.0 "Transverse" Region 1.0 The next step is toRDF study Preliminary the energy in the “transverse region”. We will have results of onPYTHIA this soon! (left) Shows the generator level predictions Tune A and JIMMY (PTmin=1.8 GeV/c) for Jet#1 Jet#1 generator level 0.1 0.1 0 30 60 90 120 150 180 210 240 270 300 330 360 0 30 60 90 120 150 180 210 240 270 300 330 360 Df (degrees) Df (degrees) the Df dependence of the charged scalar PTsum density (|h|<1, pT>0.5 GeV/c) relative to the leading jet with PT(jet#1) > 30 GeV/c. JIMMY and PYTHIA Tune A agree in the “transverse” region.. (right) Shows the generator level predictions of PYTHIA Tune A and JIMMY (PTmin=1.8 GeV/c) for the Df dependence of the scalar ETsum density (|h|<1, pT>0) relative to the leading jet for PT(jet#1) > 30 GeV/c. The tuned JIMMY produces a lot more ETsum (pT>0) in the “transverse” region than does PYTHIA Tune A! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 30 Summary The KT algorithm works fine at the Tevatron and theory/data (CTEQ61M) look flat! KT Algorithm b-jet direction Df “Toward” “Away” We have measured the inclusive b-jet section, b-bbar jet cross section and correlations, and everything is as expected - nothing goofy! “Flavor Creation” bbar-jet Jet #1 Direction CDF Run 2 b-quark Df Initial-State Radiation “Toward” Proton AntiProton Underlying Event “Trans 1” Underlying Event “Trans 2” “Away” b-quark Final-State Radiation “Underlying event” important in jet (and b-jet) production! We are making good progress in understanding and modeling the “underlying event”. We now have PYTHIA tune A and JIMMY tune A! Energy density in the “transverse region” coming soon! The Tevatron Connection June 24, 2005 Rick Field - Florida/CDF Page 31