Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 1 1 st Workshop on Energy Scaling in Hadron-Hadron Collisions Rick Field University of Florida Outline of Talk CMS at the LHC CDF Run 2  The CDF 630 GeV “underlying event” data. Determining PARP(90).  Tuning the QCD Monte-Carlo model generators and some Min- bias comparisions. Fermilab 2009  Studying the “associated” charged particle densities in “min-bias” collisions. From Min-Bias to the Underlying Event  The latest “underlying event” studies at CDF for “leading Jet” and Z-boson events. Data corrected to the particle level. CDF-QCD Data for Theory R. Field, C. Group, & D. Kar

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 2 ParameterDefaultDescription PARP(83)0.5Double-Gaussian: Fraction of total hadronic matter within PARP(84) PARP(84)0.2Double-Gaussian: Fraction of the overall hadron radius containing the fraction PARP(83) of the total hadronic matter. PARP(85)0.33Probability that the MPI produces two gluons with color connections to the “nearest neighbors. PARP(86)0.66Probability that the MPI produces two gluons either as described by PARP(85) or as a closed gluon loop. The remaining fraction consists of quark-antiquark pairs. PARP(89)1 TeVDetermines the reference energy E 0. PARP(90)0.16Determines the energy dependence of the cut-off P T0 as follows P T0 (E cm ) = P T0 (E cm /E 0 )  with  = PARP(90) PARP(67)1.0A scale factor that determines the maximum parton virtuality for space-like showers. The larger the value of PARP(67) the more initial- state radiation. Hard Core Take E 0 = 1.8 TeV Reference point at 1.8 TeV Determine by comparing with 630 GeV data! Affects the amount of initial-state radiation! Tuning PYTHIA: Multiple Parton Interaction Parameters

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 3 “Transverse” Cones vs “Transverse” Regions  Sum the P T of charged particles in two cones of radius 0.7 at the same  as the leading jet but with |  | = 90 o.  Plot the cone with the maximum and minimum PT sum versus the E T of the leading (calorimeter) jet. Transverse Region: 2  /3=0.67  Transverse Cone:  (0.7) 2 =0.49  “Cone Analysis” (Tano, Kovacs, Huston, Bhatti)

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 4 Energy Dependence of the “Underlying Event”  Sum the P T of charged particles (p T > 0.4 GeV/c) in two cones of radius 0.7 at the same  as the leading jet but with |  | = 90 o. Plot the cone with the maximum and minimum PT sum versus the E T of the leading (calorimeter) jet.  Note that PYTHIA is tuned at 630 GeV with P T0 = 1.4 GeV and at 1,800 GeV with P T0 = 2.0 GeV. This implies that  = PARP(90) should be around 0.30 instead of the 0.16 (default).  For the MIN cone 0.25 GeV/c in radius R = 0.7 implies a PT sum density of dPT sum /d  d  = 0.16 GeV/c and 1.4 GeV/c in the MAX cone implies dPT sum /d  d  = 0.91 GeV/c (average PT sum density of 0.54 GeV/c per unit  -  ). “Cone Analysis” (Tano, Kovacs, Huston, Bhatti) 630 GeV PYTHIA P T0 = 2.0 GeV 1,800 GeV PYTHIA P T0 = 1.4 GeV

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 5 “Transverse” Charged Densities Energy Dependence  Shows the “transverse” charged PT sum density (|  | 0.4 GeV) versus P T (charged jet#1) at 630 GeV predicted by HERWIG 6.4 (P T (hard) > 3 GeV/c, CTEQ5L) and a tuned version of PYTHIA (P T (hard) > 0, CTEQ5L, Set A,  = 0,  = 0.16 (default) and  = 0.25 (preferred)).  Also shown are the PT sum densities (0.16 GeV/c and 0.54 GeV/c) determined from the Tano cone analysis at 630 GeV Lowering P T0 at 630 GeV (i.e. increasing  ) increases UE activity resulting in less energy dependence. Increasing  produces less energy dependence for the UE resulting in less UE activity at the LHC! Reference point E 0 = 1.8 TeV Rick Field Fermilab MC Workshop October 4, 2002!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 6 PYTHIA 6.2 Tunes ParameterTune AWTune DWTune D6 PDFCTEQ5L CTEQ6L MSTP(81)111 MSTP(82)444 PARP(82)2.0 GeV1.9 GeV1.8 GeV PARP(83)0.5 PARP(84)0.4 PARP(85) PARP(86) PARP(89)1.8 TeV PARP(90)0.25 PARP(62)1.25 PARP(64)0.2 PARP(67) MSTP(91)111 PARP(91)2.1 PARP(93)15.0 Intrinsic KT ISR Parameter UE Parameters Uses CTEQ6L All use LO  s with  = 192 MeV! Tune A energy dependence!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 7 PYTHIA 6.2 Tunes ParameterTune DWTTune D6TATLAS PDFCTEQ5LCTEQ6LCTEQ5L MSTP(81)111 MSTP(82)444 PARP(82) GeV GeV1.8 GeV PARP(83)0.5 PARP(84) PARP(85) PARP(86) PARP(89)1.96 TeV 1.0 TeV PARP(90)0.16 PARP(62) PARP(64) PARP(67) MSTP(91)111 PARP(91) PARP(93) Intrinsic KT ISR Parameter UE Parameters All use LO  s with  = 192 MeV! ATLAS energy dependence! Tune A Tune AW Tune B Tune BW Tune D Tune DW Tune D6 Tune D6T These are “old” PYTHIA 6.2 tunes! There are new tunes by Peter Skands (Tune S320, update of S0) Peter Skands (Tune N324, N0CR) Hendrik Hoeth (Tune P329, “Professor”)

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 8 Charged Particle Density: dN/d   Charged particle (all p T ) pseudo-rapidity distribution, dN chg /d  d , at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324.  Charged particle (p T >0.5 GeV/c) pseudo- rapidity distribution, dN chg /d  d , at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324.

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 9  Use the maximum p T charged particle in the event, PTmax, to define a direction and look at the the “associated” density, dN chg /d  d , in “min-bias” collisions (p T > 0.5 GeV/c, |  | < 1). “Associated” densities do not include PTmax! Highest p T charged particle!  Shows the data on the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | < 1, not including PTmax) relative to PTmax (rotated to 180 o ) for “min-bias” events. Also shown is the average charged particle density, dN chg /d  d , for “min-bias” events. It is more probable to find a particle accompanying PTmax than it is to find a particle in the central region! CDF Run 2 Min-Bias “Associated” Charged Particle Density

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 10  Shows the data on the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | 0.5, 1.0, and 2.0 GeV/c. Transverse Region  Shows “jet structure” in “min-bias” collisions (i.e. the “birth” of the leading two jets!). Ave Min-Bias 0.25 per unit  -  PTmax > 0.5 GeV/c PTmax > 2.0 GeV/c CDF Run 2 Min-Bias “Associated” Charged Particle Density Rapid rise in the particle density in the “transverse” region as PTmax increases!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 11  Shows the data on the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | 0.5 GeV/c and PTmax > 2.0 GeV/c compared with PYTHIA Tune A (after CDFSIM).  PYTHIA Tune A predicts a larger correlation than is seen in the “min-bias” data (i.e. Tune A “min-bias” is a bit too “jetty”). PTmax > 2.0 GeV/c PTmax > 0.5 GeV/c Transverse Region PY Tune A CDF Run 2 Min-Bias “Associated” Charged Particle Density

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 12 Min-Bias “Associated” Charged Particle Density  Shows the “associated” charged particle density in the “toward”, “away” and “transverse” regions as a function of PTmax for charged particles (p T > 0.5 GeV/c, |  | < 1, not including PTmax) for “min-bias” events at 1.96 TeV from PYTHIA Tune A (generator level).  Shows the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | 0.5, 1.0, 2.0, 5.0, and 10.0 GeV/c from PYTHIA Tune A (generator level). “Toward” Region “Transverse” ~ factor of 2!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 13 Min-Bias “Associated” Charged Particle Density  Shows the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | 0.5 GeV/c for PYTHIA Tune A, Tune S320, Tune P320 (generator level).  Shows the  dependence of the “associated” charged particle density, dN chg /d  d , for charged particles (p T > 0.5 GeV/c, |  | 2.0 GeV/c for PYTHIA Tune A, Tune S320, Tune P320 (generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 14 Min-Bias “Associated” Charged Particle Density  Shows the “associated” charged particle density in the “toward”, “away” and “transverse” regions as a function of PTmax for charged particles (p T > 0.5 GeV/c, |  | < 1, not including PTmax) for “min-bias” events at 1.96 TeV from PYTHIA Tune A and Tune S320 at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 15 Min-Bias “Associated” Charged Particle Density  Shows the “associated” charged particle density in the “transverse” region as a function of PTmax for charged particles (p T > 0.5 GeV/c, |  | < 1, not including PTmax) for “min-bias” events at 1.96 TeV from PYTHIA Tune A, Tune S320, Tune N324, and Tune P329 at the particle level (i.e. generator level). Tevatron LHC  Extrapolations of PYTHIA Tune A, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC. RDF LHC Prediction!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 16 QCD Monte-Carlo Models: High Transverse Momentum Jets  Start with the perturbative 2-to-2 (or sometimes 2-to-3) parton-parton scattering and add initial and final- state gluon radiation (in the leading log approximation or modified leading log approximation). “Hard Scattering” Component “Underlying Event”  The “underlying event” consists of the “beam-beam remnants” and from particles arising from soft or semi-soft multiple parton interactions (MPI).  Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event” observables receive contributions from initial and final-state radiation. The “underlying event” is an unavoidable background to most collider observables and having good understand of it leads to more precise collider measurements!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 17 QCD Monte-Carlo Models: Lepton-Pair Production  Start with the perturbative Drell-Yan muon pair production and add initial-state gluon radiation (in the leading log approximation or modified leading log approximation). “Underlying Event”  The “underlying event” consists of the “beam-beam remnants” and from particles arising from soft or semi-soft multiple parton interactions (MPI).  Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event” observables receive contributions from initial-state radiation. “Hard Scattering” Component

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 18 “Towards”, “Away”, “Transverse”  Look at correlations in the azimuthal angle  relative to the leading charged particle jet (|  | < 1) or the leading calorimeter jet (|  | < 2).  Define |  | 120 o as “Away”. Each of the three regions have area  = 2×120 o = 4  /3.  Correlations relative to the leading jet Charged particles p T > 0.5 GeV/c |  | < 1 Calorimeter towers E T > 0.1 GeV |  | < 1 “Transverse” region is very sensitive to the “underlying event”! Look at the charged particle density, the charged PTsum density and the ETsum density in all 3 regions! Z-Boson Direction

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 19 Event Topologies  “Leading Jet” events correspond to the leading calorimeter jet (MidPoint R = 0.7) in the region |  | < 2 with no other conditions. “Leading Jet”  “Leading ChgJet” events correspond to the leading charged particle jet (R = 0.7) in the region |  | < 1 with no other conditions. “Charged Jet” “Inc2J Back-to-Back” “Exc2J Back-to-Back”  “Inclusive 2-Jet Back-to-Back” events are selected to have at least two jets with Jet#1 and Jet#2 nearly “back- to-back” (  12 > 150 o ) with almost equal transverse energies (P T (jet#2)/P T (jet#1) > 0.8) with no other conditions.  “Exclusive 2-Jet Back-to-Back” events are selected to have at least two jets with Jet#1 and Jet#2 nearly “back- to-back” (  12 > 150 o ) with almost equal transverse energies (P T (jet#2)/P T (jet#1) > 0.8) and P T (jet#3) < 15 GeV/c. subset Z-Boson  “Z-Boson” events are Drell-Yan events with 70 < M(lepton-pair) < 110 GeV with no other conditions.

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 20 “transMAX” & “transMIN”  Define the MAX and MIN “transverse” regions (“transMAX” and “transMIN”) on an event-by-event basis with MAX (MIN) having the largest (smallest) density. Each of the two “transverse” regions have an area in  -  space of 4  /6.  The “transMIN” region is very sensitive to the “beam-beam remnant” and the soft multiple parton interaction components of the “underlying event”.  The difference, “transDIF” (“transMAX” minus “transMIN”), is very sensitive to the “hard scattering” component of the “underlying event” (i.e. hard initial and final-state radiation). Area = 4  /6 “transMIN” very sensitive to the “beam-beam remnants”!  The overall “transverse” density is the average of the “transMAX” and “transMIN” densities. Z-Boson Direction

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 21 “Back-to-Back” ObservableParticle LevelDetector Level dN chg /d  d  Number of charged particles per unit  -  (p T > 0.5 GeV/c, |  | < 1) Number of “good” charged tracks per unit  -  (p T > 0.5 GeV/c, |  | < 1) dPT sum /d  d  Scalar p T sum of charged particles per unit  -  (p T > 0.5 GeV/c, |  | < 1) Scalar p T sum of “good” charged tracks per unit  -  (p T > 0.5 GeV/c, |  | < 1) Average p T of charged particles (p T > 0.5 GeV/c, |  | < 1) Average p T of “good” charged tracks (p T > 0.5 GeV/c, |  | < 1) PT max Maximum p T charged particle (p T > 0.5 GeV/c, |  | < 1) Require Nchg ≥ 1 Maximum p T “good” charged tracks (p T > 0.5 GeV/c, |  | < 1) Require Nchg ≥ 1 dET sum /d  d  Scalar E T sum of all particles per unit  -  (all p T, |  | < 1) Scalar E T sum of all calorimeter towers per unit  -  (E T > 0.1 GeV, |  | < 1) PT sum /ET sum Scalar p T sum of charged particles (p T > 0.5 GeV/c, |  | < 1) divided by the scalar E T sum of all particles (all p T, |  | < 1) Scalar p T sum of “good” charged tracks (p T > 0.5 GeV/c, |  | < 1) divided by the scalar E T sum of calorimeter towers (E T > 0.1 GeV, |  | < 1) “Leading Jet” Observables at the Particle and Detector Level

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 22 “Leading Jet” Overall Totals (|  | < 1)  Data at 1.96 TeV on the overall number of charged particles (p T > 0.5 GeV/c, |  | 0.5 GeV/c, |  | < 1) and the overall scalar ET sum of all particles (|  | < 1) for “leading jet” events as a function of the leading jet p T. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A at the particle level (i.e. generator level).. Nchg = 30 PTsum = 190 GeV/c ETsum = 330 GeV ETsum = 775 GeV!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 23 “Leading Jet” “Towards”, “Away”, “Transverse”  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “leading jet” events as a function of the leading jet p T for the “toward”, “away”, and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A at the particle level (i.e. generator level).  Data at 1.96 TeV on the charged particle scalar p T sum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “leading jet” events as a function of the leading jet p T for the “toward”, “away”, and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A at the particle level (i.e. generator level).  Data at 1.96 TeV on the particle scalar E T sum density, dET/d  d , for |  | < 1 for “leading jet” events as a function of the leading jet p T for the “toward”, “away”, and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A at the particle level (i.e. generator level). Factor of ~4.5 Factor of ~16 Factor of ~13

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 24 Charged Particle Density  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z-Boson” and “Leading Jet” events as a function of the leading jet p T or P T (Z) for the “toward”, “away”, and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the particle level (i.e. generator level). HERWIG + JIMMY Tune (PTJIM = 3.6)

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 25 Charged PTsum Density  Data at 1.96 TeV on the charged scalar PTsum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” and “Leading Jet” events as a function of the leading jet p T or P T (Z) for the “toward”, “away”, and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 26 The “TransMAX/MIN” Regions  Data at 1.96 TeV on the charged particle density, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z-Boson” and “Leading Jet” events as a function of P T (Z) or the leading jet p T for the “transMAX”, and “transMIN” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the particle level (i.e. generator level).  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “leading jet” events as a function of the leading jet p T and for Z-Boson events as a function of P T (Z) for “TransDIF” = “transMAX” minus “transMIN” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and HERWIG (without MPI) at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 27 The “TransMAX/MIN” Regions  Data at 1.96 TeV on the charged scalar PTsum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” and “Leading Jet” events as a function of P T (Z) or the leading jet p T for the “transMAX”, and “transMIN” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the particle level (i.e. generator level).  Data at 1.96 TeV on the charged scalar PTsum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “leading jet” events as a function of the leading jet p T and for Z-Boson events as a function of P T (Z) for “TransDIF” = “transMAX” minus “transMIN” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and HERWIG (without MPI) at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 28 Charged Particle Charged Particle  Data at 1.96 TeV on the charged particle average p T, with p T > 0.5 GeV/c and |  | < 1 for the “toward” region for “Z-Boson” and the “transverse” region for “Leading Jet” events as a function of the leading jet p T or P T (Z). The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the particle level (i.e. generator level). The Z-Boson data are also compared with PYTHIA Tune DW, the ATLAS tune, and HERWIG (without MPI)

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 29 Z-Boson: “Towards”, Transverse”, & “TransMIN” Charge Density  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” events as a function of P T (Z) for the “toward” and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 30 Z-Boson: “Towards”, Transverse”, & “TransMIN” Charge Density  Data at 1.96 TeV on the charged scalar PTsum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z-Boson” events as a function of P T (Z) for the “toward” and “transverse” regions. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator level).

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 31 Z-Boson: “Towards” Region  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” events as a function of P T (Z) for the “toward” region. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator level). HW without MPI DWT

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 32 Z-Boson: “Towards” Region  Data at 1.96 TeV on the average p T of charged particles with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” events as a function of P T (Z) for the “toward” region. The data are corrected to the particle level (with errors that include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator level). DWT HW (without MPI) almost no change!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 33 Z-Boson: “Towards” Region  Data at 1.96 TeV on the density of charged particles, dN/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z- Boson” events as a function of P T (Z) for the “toward” region from PYTHIA Tune AW, Tune DW, Tune S320, and Tune P329 at the particle level (i.e. generator level). Tevatron LHC  Extrapolations of PYTHIA Tune AW, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC. RDF LHC Prediction!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 34 Z-Boson: “Towards” Region  Data at 1.96 TeV on the charged PTsum density, dPT/d  d , with p T > 0.5 GeV/c and |  | < 1 for “Z-Boson” events as a function of P T (Z) for the “toward” region from PYTHIA Tune AW, Tune DW, Tune S320, and Tune P329 at the particle level (i.e. generator level). Tevatron LHC  Extrapolations of PYTHIA Tune AW, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC. RDF LHC Prediction!

Fermilab Energy Scaling Workshop April 28, 2009 Rick Field – Florida/CDF/CMSPage 35 1 st Workshop on Energy Scaling in Hadron-Hadron Collisions  Rick Field Talk 3 Wednesday at 9:00am From CDF to CMS Peter’s favorite observable: versus Nchg Summary & Conclusions & Predictions!