1st Workshop on Energy Scaling in Hadron-Hadron Collisions Fermilab 2009 From CDF to CMS Rick Field University of Florida Outline of Talk Outgoing Parton Extrapolating “min-bias” collisions Proton to the LHC. Studying <pT> versus Nchg in PT(hard) Initial-State Radiation AntiProton Underlying Event Outgoing Parton Underlying Event Final-State Radiation “min-bias” collisions and in Drell-Yan. LHC predictions! Summary. Fermilab Energy Scaling Workshop April 29, 2009 CDF Run 2 Rick Field – Florida/CDF/CMS CMS at the LHC Page 1 Charged Particle Density: dN/dh Charged Particle Density: dN/dh Charged Particle Density: dN/dh 5.0 2.0 PY Tune A generator level 4.0 3.0 2.0 PY64 Tune S320 PY64 Tune P329 1.0 Min-Bias 1.96 TeV Charged Particles (all PT) PY64 Tune P329 RDF Preliminary Charged Particle Density Charged Particle Density RDF Preliminary generator level 1.5 PY Tune A 1.0 PY64 Tune S320 0.5 Min-Bias 1.96 TeV Charged Particles (PT>0.5 GeV/c) 0.0 0.0 -8 -6 -4 -2 0 2 4 6 8 -8 -6 PseudoRapidity h -4 -2 0 2 4 6 8 PseudoRapidity h Charged particle (all pT) pseudo-rapidity Charged particle (pT>0.5 GeV/c) pseudodistribution, dNchg/dhdf, at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324. Fermilab Energy Scaling Workshop April 29, 2009 rapidity distribution, dNchg/dhdf, at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324. Rick Field – Florida/CDF/CMS Page 2 Charged Particle Density: dN/dh RDF LHC Prediction! Charged Particle Density: dN/dh Charged Particle Density: dN/dh 5.0 8.0 generator level 4.0 3.0 2.0 PY64 Tune S320 PY64 Tune P329 1.0 PY64 Tune P329 PY Tune A Charged Particle Density Charged Particle Density RDF Preliminary Min-Bias 1.96 TeV Charged Particles (all PT) 0.0 RDF Preliminary generator level 6.0 4.0 PY Tune A PY64 Tune S320 2.0 0.0 -8 -6 -4 -2 0 2 4 6 8 -8 -6 -4 -2 PseudoRapidity h 0 2 4 6 PseudoRapidity h “Minumum Bias” Collisions Proton Min-Bias 14 TeV Charged Particles (all PT) “Minumum Bias” Collisions AntiProton Tevatron Proton Proton LHC Charged particle (all pT) pseudo-rapidity distribution, dNchg/dhdf, at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324. Extrapolations of PYTHIA Tune A, Tune S320, and Tune P329 to the LHC. Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 3 8 Charged Particle Density: dN/dh Why is py64 Tune P329 higher than py Tune DWT?? RDF LHC Prediction! Charged Particle Density: dN/dh PY64 Tune P329 4.0 generator level PY Tune DWT 1.5 PY Tune A 1.0 0.5 Charged Particle Density RDF Preliminary generator level 3.0 PY64 Tune S320 2.0 PY64 Tune S320 Min-Bias 1.96 TeV Charged Particles (PT>0.5 GeV/c) 0.0 -8 -6 -4 PY Tune A PY64 Tune P329 generator level 3.0 PY64 Tune P329 PY64 Tune S320 2.0 PY Tune A 1.0 Min-Bias 14 TeV Charged Particles (PT>0.5 GeV/c) 0.0 1.0 -2 RDF Preliminary Charged Particle Density RDF Preliminary Charged Particle Density Charged Particle Density: dN/dh Charged Particle Density: dN/dh 4.0 2.0 0 2 4 6 -8 8 -6 PseudoRapidity h Charged Particles (PT>0.5 GeV/c) -4 Min-Bias 14 TeV -2 0 2 4 6 8 PseudoRapidity h 0.0 “Minumum Bias” Collisions Proton -8 -6 AntiProton Tevatron -4 -2 0 2 4 6 PseudoRapidity h 8 “Minumum Bias” Collisions Proton Proton LHC Charged particle (pT > 0.5 GeV/c) pseudo-rapidity distribution, dNchg/dhdf, at 1.96 TeV for inelastic non-diffractive collisions from PYTHIA Tune A, Tune S320, and Tune P324. Extrapolations of PYTHIA Tune A, Tune S320, and Tune P329 to the LHC. Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 4 Min-Bias Correlations Average PT versus Nchg Average PT (GeV/c) 1.4 CDF Run 2 Preliminary pyDW data corrected generator level theory “Minumum Bias” Collisions 1.2 Min-Bias 1.96 TeV pyA Proton 1.0 AntiProton ATLAS 0.8 Charged Particles (|h|<1.0, PT>0.4 GeV/c) 0.6 0 10 20 30 40 50 Number of Charged Particles Data at 1.96 TeV on the average pT of charged particles versus the number of charged particles (pT > 0.4 GeV/c, |h| < 1) for “min-bias” collisions at CDF Run 2. The data are corrected to the particle level and are compared with PYTHIA Tune A at the particle level (i.e. generator level). Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 5 Min-Bias: Average PT versus Nchg Beam-beam remnants (i.e. soft hard core) produces Average PT versus Nchg Average PT (GeV/c) 1.4 CDF Run 2 Preliminary Min-Bias 1.96 TeV data corrected generator level theory 1.2 low multiplicity and small <pT> with <pT> independent of the multiplicity. Hard scattering (with no MPI) produces large pyA multiplicity and large <pT>. pyAnoMPI 1.0 Hard scattering (with MPI) produces large 0.8 multiplicity and medium <pT>. ATLAS Charged Particles (|h|<1.0, PT>0.4 GeV/c) 0.6 0 5 10 15 20 25 30 35 40 This observable is sensitive to the MPI tuning! Number of Charged Particles “Hard” Hard Core (hard scattering) Outgoing Parton “Soft” Hard Core (no hard scattering) PT(hard) CDF “Min-Bias” = Proton + AntiProton Proton AntiProton Underlying Event Underlying Event Initial-State Radiation Final-State Radiation Multiple-Parton Interactions + Proton AntiProton Underlying Event Outgoing Parton Fermilab Energy Scaling Workshop April 29, 2009 Outgoing Parton PT(hard) Initial-State Radiation The CDF “min-bias” trigger picks up most of the “hard core” component! Outgoing Parton Underlying Event Final-State Radiation Rick Field – Florida/CDF/CMS Page 6 Average PT versus Nchg Average PT PT versus versus Nchg Nchg Average Average PT versus Nchg 2.5 2.5 CDF Run 2 Preliminary data corrected generator level theory 1.2 CDFRun Run22Preliminary Preliminary CDF Min-Bias 1.96 TeV Average Average PT PT (GeV/c) (GeV/c) Average PT (GeV/c) 1.4 pyA pyAnoMPI 1.0 0.8 ATLAS data corrected generator level theory generator level theory 2.0 2.0 HW HW pyAW pyAW "Drell-YanProduction" Production" "Drell-Yan 70<<M(pair) M(pair)<<110 110GeV GeV 70 1.5 1.5 JIM JIM 1.0 1.0 ATLAS ATLAS Charged Particles (|h|<1.0, PT>0.4 GeV/c) 0.6 ChargedParticles Particles(|h|<1.0, (|h|<1.0,PT>0.5 PT>0.5GeV/c) GeV/c) Charged excludingthe thelepton-pair lepton-pair excluding 0.5 0.5 0 5 10 15 20 25 30 35 40 00 55 10 10 Number of Charged Particles 15 15 20 20 25 25 30 30 Numberof ofCharged ChargedParticles Particles Number Drell-Yan Production Lepton “Minumum Bias” Collisions Proton AntiProton Proton AntiProton Underlying Event Underlying Event Anti-Lepton Data at 1.96 TeV on the average pT of charged particles versus the number of charged particles (pT > 0.4 GeV/c, |h| < 1) for “min-bias” collisions at CDF Run 2. The data are corrected to the particle leveland are compared with PYTHIA Tune A, Tune DW, and the ATLAS tune at the particle level (i.e. generator level). Particle level predictions for the average pT of charged particles versus the number of charged particles (pT > 0.5 GeV/c, |h| < 1, excluding the lepton-pair) for for Drell-Yan production (70 < M(pair) < 110 GeV) at CDF Run 2. Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 7 35 35 Average PT versus Nchg Z-boson production (with low pT(Z) and no MPI) No MPI! Average PT versus Nchg produces low multiplicity and small <pT>. 2.5 Average PT (GeV/c) CDF Run 2 Preliminary data corrected generator level theory 2.0 HW High pT Z-boson production produces large pyAW multiplicity and high <pT>. "Drell-Yan Production" 70 < M(pair) < 110 GeV Z-boson production (with MPI) produces large 1.5 multiplicity and medium <pT>. JIM 1.0 ATLAS Charged Particles (|h|<1.0, PT>0.5 GeV/c) excluding the lepton-pair 0.5 0 5 10 15 20 25 30 35 Number of Charged Particles Drell-Yan Production (no MPI) High PT Z-Boson Production Lepton Initial-State Radiation Outgoing Parton Final-State Radiation Drell-Yan = Proton AntiProton Underlying Event Underlying Event Anti-Lepton + + Drell-Yan Production (with MPI) Proton Proton Lepton AntiProton Z-boson AntiProton Underlying Event Underlying Event Anti-Lepton Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 8 Average PT(Z) versus Nchg No MPI! Average PT versus Nchg PT(Z-Boson) PT(Z-Boson) versus versus Nchg Nchg 80 80 2.5 data corrected generator level theory 2.0 CDF CDF Run Run 22 Preliminary Preliminary HW Average PT(Z) (GeV/c) Average PT (GeV/c) CDF Run 2 Preliminary pyAW "Drell-Yan Production" 70 < M(pair) < 110 GeV 1.5 JIM 1.0 ATLAS generator level theory data corrected generator level theory 60 60 pyAW pyAW HW HW "Drell-Yan "Drell-Yan Production" Production" 70 70 << M(pair) M(pair) << 110 110 GeV GeV 40 40 JIM JIM 20 20 Charged Particles (|h|<1.0, PT>0.5 GeV/c) excluding the lepton-pair ATLAS ATLAS Charged Charged Particles Particles (|h|<1.0, (|h|<1.0, PT>0.5 PT>0.5 GeV/c) GeV/c) excluding excluding the the lepton-pair lepton-pair 00 0.5 0 5 10 15 20 25 30 35 00 55 Outgoing Parton Lepton Initial-State Radiation Proton Proton AntiProton Underlying Event Underlying Event 15 15 20 20 25 25 30 30 35 35 40 40 Number Number of of Charged Charged Particles Particles Number of Charged Particles High PDrell-Yan Production T Z-BosonProduction 10 10 Predictions for the average PT(Z-Boson) versus the number of charged particles (pT > 0.5 GeV/c, |h| < 1, excluding the lepton-pair) for for Drell-Yan production (70 < M(pair) < 110 GeV) at CDF Run 2. Anti-Lepton Z-boson Data on the average pT of charged particles versus the number of charged particles (pT > 0.5 GeV/c, |h| < 1, excluding the lepton-pair) for for Drell-Yan production (70 < M(pair) < 110 GeV) at CDF Run 2. The data are corrected to the particle level and are compared with various Monte-Carlo tunes at the particle level (i.e. generator level). Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 9 Average PT versus Nchg PT(Z) < 10 GeV/c Average Charged PT versus Nchg Average Average Charged Charged PT PT versus versus Nchg Nchg CDF Run Preliminary CDF CDF Run Run 22 2 Preliminary Preliminary data corrected generator level generator level theory theory generator level theory 1.2 1.2 1.2 pyAW pyAW pyAW 1.0 1.0 1.0 HW HW HW 0.8 0.8 0.8 "Drell-Yan Production" "Drell-Yan "Drell-Yan Production" Production" 70 M(pair) 110 GeV 70 70 << < M(pair) M(pair) << < 110 110 GeV GeV PT(Z) 10 GeV/c PT(Z) PT(Z) << < 10 10 GeV/c GeV/c CDF Run 2 Preliminary JIM JIM Average PT (GeV/c) Average PT (GeV/c) AveragePT PT(GeV/c) (GeV/c) Average 1.4 1.4 1.4 Average PT versus Nchg 1.4 ATLAS ATLAS Drell-Yan PT > 0.5 GeV PT(Z) < 10 GeV/c data corrected generator level theory 1.2 pyAW No MPI! 1.0 Min-Bias PT > 0.4 GeV/c 0.8 Charged Particles (|h|<1.0, PT>0.5 GeV/c) Charged Charged Particles Particles (|h|<1.0, (|h|<1.0, PT>0.5 PT>0.5 GeV/c) GeV/c) excluding the lepton-pair excluding excluding the the lepton-pair lepton-pair Charged Particles (|h|<1.0) pyA 0.6 0.6 0.6 0.6 00 0 55 5 10 10 10 15 15 15 20 20 20 25 25 25 30 30 30 35 35 35 0 Number of Charged Particles Number Number of of Charged Charged Particles Particles Drell-Yan Production 10 20 30 40 Number of Charged Particles Lepton Proton AntiProton Underlying Event Underlying Event Remarkably similar behavior! Perhaps indicating that MPIProton playing an important role in both processes. “Minumum Bias” Collisions AntiProton Anti-Lepton Predictions for thepTaverage pT ofparticles chargedversus particles theofnumber charged(p particles (pT > 0.5 Data the average of charged theversus number chargedofparticles |h|GeV/c, < 1, |h| T > 0.5 GeV/c, < 1, excluding the lepton-pair) forDrell-Yan for Drell-Yan production < M(pair) 110 GeV, PT(pair) 10 GeV/c) at excluding the lepton-pair) for for production (70 <(70 M(pair) < 110< GeV, PT(pair) < 10<GeV/c) at CDF CDF Run Run 2. The2.data are corrected to the particle level and are compared with various Monte-Carlo tunes at the particle level (i.e. generator level). Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 10 LHC Predictions “Minumum Bias” Collisions Proton AntiProton Charged Particle Density: dN/dh 4.0 RDF Preliminary Charged Particle Density I believe we are now in a position to make some predictions at the LHC! PY64 Tune P329 generator level 3.0 PY64 Tune S320 2.0 PY Tune A 1.0 Min-Bias 14 TeV Charged Particles (PT>0.5 GeV/c) The amount of activity in “min-bias” collisions. Outgoing Parton Underlying Event 1.6 “Toward” “Transverse” “Away” The amount of activity in the “underlying event” in hard scattering events. Drell-Yan Production -2 0 2 4 6 8 "Transverse" Charged Particle Density: dN/dhdf If the LHC data are not in the range shown here then we learn new physics! “Transverse” Final-State Radiation -4 PseudoRapidity h "Transverse" Charged Density AntiProton Outgoing Parton -6 f Initial-State Radiation Underlying Event -8 PTmax Direction PT(hard) Proton 0.0 PY Tune DWT RDF Preliminary generator level 1.2 0.8 PY64 Tune P329 PY Tune A PY Tune DW PY64 Tune S320 0.4 Min-Bias 14 TeV Charged Particles (|h|<1.0, PT>0.5 GeV/c) 0.0 0 5 10 15 20 25 PTmax (GeV/c) Z-BosonDirection f Lepton "Toward" Charged Particle Density: dN/dhdf “Toward” RDF Preliminary AntiProton Underlying Event Underlying Event “Transverse” “Transverse” “Away” Anti-Lepton The amount of activity in the “underlying event” in DrellYan events. "Toward" Charged Density Proton 1.6 PY Tune DWT PY Tune DW generator level 1.2 0.8 PY64 Tune P329 PY64 Tune S320 70 < M(pair) < 110 GeV 0.4 Drell-Yan 14 TeV Charged Particles (|h|<1.0, PT>0.5 GeV/c) 0.0 0 25 50 75 100 125 150 Lepton-Pair PT (GeV/c) Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS Page 11 Summary However, I believe that the better fits to the LEP fragmentation data at high z will lead to small improvements Outgoing Parton of Tune A at the Tevatron! We are making good progress in understanding and modeling the “underlying event”. PT(hard) Initial-State Radiation Proton The new Pythia pT ordered tunes (py64 S320 and py64 P329) are very similar to Tune A and Tune DW. At present the new tunes do not fit the data better than Tune A and Tune DW. However, the new tune are theoretically preferred! AntiProton Underlying Event Underlying Event Outgoing Parton Final-State Radiation Hard-Scattering Cut-Off PT0 All tunes with the default value PARP(90) = 0.16 are wrong and are overestimating the activity of min-bias and the underlying event at the LHC! This includes all the ATLAS tunes! Need to measure “Min-Bias” and the “underlying event” at the LHC as soon as possible to see if there is new QCD physics to be learned! Fermilab Energy Scaling Workshop April 29, 2009 Rick Field – Florida/CDF/CMS PYTHIA 6.206 = 0.25 (Set A)) 4 PT0 (GeV/c) It is clear now that the default value PARP(90) = 0.16 is not correct and the value should be closer to the Tune A value of 0.25. 5 3 2 = 0.16 (default) 1 100 1,000 10,000 100,000 CM Energy W (GeV) UE&MB@CMS Page 12