MonteCarlo Generators for CMS CDF Run 2 CMS

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Monte-Carlo Generators for CMS CDF Run 2 CMS Outline of Talk Not favored at

Monte-Carlo Generators for CMS CDF Run 2 CMS Outline of Talk Not favored at present! Æ Review briefly the CDF Run 1 and Run 2 PYTHIA 6. 2 tunes. Æ Discuss four NLO structure function CTEQ 6. 1 M PYTHIA 6. 2 tunes, Tune QK and Tune QKT, Tune QW and Tune QWT. UE&MB@CMS Perugia, Florida, Hamburg, Trieste Æ Introduce a new CTEQ 6 L tune Tune D 6 and Tune D 6 T. Æ Discuss a few early measurements at CMS. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS New CTEQ 6 L tune! 1

CDF Run 1 PYTHIA Tune A PYTHIA 6. 206 CTEQ 5 L Parameter Tune

CDF Run 1 PYTHIA Tune A PYTHIA 6. 206 CTEQ 5 L Parameter Tune B Tune A MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 1. 9 Ge. V 2. 0 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 1. 0 0. 9 PARP(86) 1. 0 0. 95 PARP(89) 1. 8 Te. V PARP(90) 0. 25 PARP(67) 1. 0 4. 0 New PYTHIA default (less initial-state radiation) FNAL-CMS MC Generator Meeting June 7, 2007 CDF Default! Run 1 Analysis Æ 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 (CTEQ 5 L, Set B (PARP(67)=1) and Set A (PARP(67)=4)). Old PYTHIA default (more initial-state radiation) Rick Field – Florida/CMS 2

CDF Run 1 PT(Z) UE Parameters PYTHIA 6. 2 CTEQ 5 L Parameter Tune

CDF Run 1 PT(Z) UE Parameters PYTHIA 6. 2 CTEQ 5 L Parameter Tune A 25 Tune A 50 MSTP(81) 1 1 1 MSTP(82) 4 4 4 PARP(82) 2. 0 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 0. 9 PARP(86) 0. 95 1. 8 Te. V PARP(90) 0. 25 PARP(67) 4. 0 MSTP(91) 1 1 1 PARP(91) 1. 0 2. 5 5. 0 PARP(93) 5. 0 15. 0 25. 0 ISR Parameter PARP(89) Æ Shows the Run 1 Z-boson p. T distribution (<p. T(Z)> ≈ 11. 5 Ge. V/c) compared with PYTHIA Tune A (<p. T(Z)> = 9. 7 Ge. V/c), Tune A 25 (<p. T(Z)> = 10. 1 Ge. V/c), and Tune A 50 (<p. T(Z)> = 11. 2 Ge. V/c). Vary the intrensic KT! Intrensic KT FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 3

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW UE

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW UE Parameters MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 2. 0 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 0. 9 PARP(86) 0. 95 PARP(89) 1. 8 Te. V PARP(90) 0. 25 PARP(62) 1. 0 1. 25 PARP(64) 1. 0 0. 2 PARP(67) 4. 0 MSTP(91) 1 1 PARP(91) 1. 0 2. 1 PARP(93) 5. 0 15. 0 ISR Parameters Tune used by the CDF-EWK group! Æ Shows the Run 1 Z-boson p. T distribution (<p. T(Z)> ≈ 11. 5 Ge. V/c) compared with PYTHIA Tune A (<p. T(Z)> = 9. 7 Ge. V/c), and PYTHIA Tune AW (<p. T(Z)> = 11. 7 Ge. V/c). Effective Q cut-off, below which space-like showers are not evolved. Intrensic KT The Q 2 = k. T 2 in as for space-like showers is scaled by PARP(64)! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 4

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW UE

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW UE Parameters MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 2. 0 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 0. 9 PARP(86) 0. 95 PARP(89) 1. 8 Te. V PARP(90) 0. 25 PARP(62) 1. 0 1. 25 PARP(64) 1. 0 0. 2 PARP(67) 4. 0 MSTP(91) 1 1 PARP(91) 1. 0 2. 1 PARP(93) 5. 0 15. 0 ISR Parameters Tune used by the CDF-EWK group! Also fits the high p. T tail! Æ Shows the Run 1 Z-boson p. T distribution (<p. T(Z)> ≈ 11. 5 Ge. V/c) compared with PYTHIA Tune A (<p. T(Z)> = 9. 7 Ge. V/c), and PYTHIA Tune AW (<p. T(Z)> = 11. 7 Ge. V/c). Effective Q cut-off, below which space-like showers are not evolved. Intrensic KT The Q 2 = k. T 2 in as for space-like showers is scaled by PARP(64)! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 5

Jet-Jet Correlations (DØ) Jet#1 -Jet#2 Df Distribution Df Jet#1 -Jet#2 Æ Mid. Point Cone

Jet-Jet Correlations (DØ) Jet#1 -Jet#2 Df Distribution Df Jet#1 -Jet#2 Æ Mid. Point Cone Algorithm (R = 0. 7, fmerge = 0. 5) Æ L = 150 pb-1 (Phys. Rev. Lett. 94 221801 (2005)) Æ Data/NLO agreement good. Data/HERWIG agreement good. Æ Data/PYTHIA agreement good provided PARP(67) = 1. 0→ 4. 0 (i. e. like Tune A, best fit 2. 5). FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 6

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune DW Tune

CDF Run 1 PT(Z) PYTHIA 6. 2 CTEQ 5 L Parameter Tune DW Tune AW UE Parameters MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 1. 9 Ge. V 2. 0 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 1. 0 0. 9 PARP(86) 1. 0 0. 95 PARP(89) 1. 8 Te. V PARP(90) 0. 25 PARP(62) 1. 25 PARP(64) 0. 2 PARP(67) 2. 5 4. 0 MSTP(91) 1 1 PARP(91) 2. 1 PARP(93) 15. 0 ISR Parameters Æ Shows the Run 1 Z-boson p. T distribution (<p. T(Z)> ≈ 11. 5 Ge. V/c) compared with PYTHIA Tune DW, and HERWIG. Tune DW uses D 0’s perfered value of PARP(67)! Intrensic KT Tune DW has a lower value of PARP(67) and slightly more MPI! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 7

“Transverse” Nchg Density UE Parameters PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW

“Transverse” Nchg Density UE Parameters PYTHIA 6. 2 CTEQ 5 L Parameter Tune AW Tune DW Tune BW MSTP(81) 1 1 1 MSTP(82) 4 4 4 PARP(82) 2. 0 Ge. V 1. 9 Ge. V 1. 8 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 0. 9 1. 0 PARP(86) 0. 95 1. 0 1. 8 Te. V PARP(90) 0. 25 PARP(62) 1. 25 PARP(64) 0. 2 PARP(67) 4. 0 2. 5 1. 0 MSTP(91) 1 1 1 PARP(91) 2. 5 2/5 PARP(93) 15. 0 ISR Parameter PARP(89) Intrensic KT Three different amounts of MPI! Æ Shows the “transverse” charged particle density, d. N/dhdf, versus PT(jet#1) for “leading jet” events at 1. 96 Te. V for PYTHIA Tune A, Tune AW, Tune DW, Tune BW, and HERWIG (without MPI). Three different amounts of ISR! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 8

New PYTHIA 6. 2 Tunes Use LO as with L = 192 Me. V!

New PYTHIA 6. 2 Tunes Use LO as with L = 192 Me. V! UE Parameters ISR Parameter Tune DW Tune D 6 Tune QW Tune QK PDF CTEQ 5 L CTEQ 6. 1 MSTP(2) 1 1 MSTP(33) 0 0 0 1 PARP(31) 1. 0 1. 8 MSTP(81) 1 1 MSTP(82) 4 4 PARP(82) 1. 9 Ge. V 1. 8 Ge. V 1. 1 Ge. V 1. 9 Ge. V PARP(83) 0. 5 PARP(84) 0. 4 PARP(85) 1. 0 PARP(86) 1. 0 PARP(89) 1. 8 Te. V PARP(90) 0. 25 PARP(62) 1. 25 PARP(64) 0. 2 PARP(67) 2. 5 MSTP(91) 1 1 PARP(91) 2. 1 PARP(93) 15. 0 NLO Structure Function! K-factor (T. Sjostrand) Tune A energy dependence! Intrinsic KT FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 9

New PYTHIA 6. 2 Tunes Use LO as with L = 192 Me. V!

New PYTHIA 6. 2 Tunes Use LO as with L = 192 Me. V! UE Parameters ISR Parameter Tune DWT ATLAS Tune D 6 T Tune QWT Tune QKT PDF CTEQ 5 L CTEQ 6 L CTEQ 6. 1 MSTP(2) 1 1 1 MSTP(33) 0 0 1 1 1 PARP(31) 1. 0 1. 8 MSTP(81) 1 1 1 MSTP(82) 4 4 4 PARP(82) 1. 9409 Ge. V 1. 8387 Ge. V 1. 1237 Ge. V 1. 9409 Ge. V PARP(83) 0. 5 0. 5 PARP(84) 0. 4 0. 5 0. 4 PARP(85) 1. 0 0. 33 1. 0 PARP(86) 1. 0 0. 66 1. 0 PARP(89) 1. 96 Te. V 1. 0 Te. V 1. 96 Te. V PARP(90) 0. 16 PARP(62) 1. 25 1. 0 1. 25 PARP(64) 0. 2 1. 0 0. 2 PARP(67) 2. 5 1. 0 2. 5 MSTP(91) 1 1 1 PARP(91) 2. 1 1. 0 2. 1 PARP(93) 15. 0 NLO Structure Function! K-factor (T. Sjostrand) ATLAS energy dependence! Intrinsic KT FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 10

New PYTHIA 6. 2 Tunes 1. 96 Te. V 14 Te. V PT 0(MPI)

New PYTHIA 6. 2 Tunes 1. 96 Te. V 14 Te. V PT 0(MPI) Ge. V s(MPI) mb Tune DW 1. 9409 351. 7 3. 1730 549. 2 Tune DWT 1. 9409 351. 7 2. 6091 829. 1 ATLAS 2. 0046 324. 5 2. 7457 768. 0 Tune D 6 1. 8387 306. 3 3. 0059 546. 1 Tune D 6 T 1. 8387 306. 3 2. 5184 786. 5 Tune QK 1. 9409 259. 5 3. 1730 422. 0 Tune QKT 1. 9409 259. 5 2. 6091 588. 0 Æ Average charged particle density and PTsum density in the “transverse” region (p. T > 0. 5 Ge. V/c, |h| < 1) versus PT(jet#1) at 1. 96 Te. V for PY Tune DW, Tune D 6, and Tune QK. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 11

New PYTHIA 6. 2 Tunes 1. 96 Te. V 14 Te. V PT 0(MPI)

New PYTHIA 6. 2 Tunes 1. 96 Te. V 14 Te. V PT 0(MPI) Ge. V s(MPI) mb Tune DW 1. 9409 351. 7 3. 1730 549. 2 Tune DWT 1. 9409 351. 7 2. 6091 829. 1 ATLAS 2. 0046 324. 5 2. 7457 768. 0 Tune D 6 1. 8387 306. 3 3. 0059 546. 1 Tune D 6 T 1. 8387 306. 3 2. 5184 786. 5 Tune QK 1. 9409 259. 5 3. 1730 422. 0 Tune QKT 1. 9409 259. 5 2. 6091 588. 0 Æ Average charged particle density and PTsum density in the “transverse” region (p. T > 0. 5 Ge. V/c, |h| < 1) versus PT(jet#1) at 14 Te. V for PY Tune DWT, Tune D 6 T, and Tune QKT. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 12

PYTHIA 6. 2 Tunes LHC Min-Bias Predictions Æ Shows the predictions of PYTHIA Tune

PYTHIA 6. 2 Tunes LHC Min-Bias Predictions Æ Shows the predictions of PYTHIA Tune A, Tune DWT, and the ATLAS tune for the charged particle density d. N/dh and d. N/d. Y at 14 Te. V (all p. T). Æ PYTHIA Tune A and Tune DW predict about 6 charged particles per unit h at h = 0, while the ATLAS tune predicts around 9. Æ PYTHIA Tune DWT is identical to Tune DW at 1. 96 Te. V, but extrapolates to the LHC using the ATLAS energy dependence. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 13

PYTHIA 6. 2 Tunes LHC Min-Bias Predictions Æ Shows the predictions of PYTHIA Tune

PYTHIA 6. 2 Tunes LHC Min-Bias Predictions Æ Shows the predictions of PYTHIA Tune A, Tune DWT, and the ATLAS tune for the charged particle p. T distribution at 14 Te. V (|h| < 1) and the average number of charged particles with p. T > p. Tmin (|h| < 1). Æ The ATLAS tune has many more “soft” particles than does any of the CDF Tunes. The ATLAS tune has <p. T> = 548 Me. V/c while Tune A has <p. T> = 641 Me. V/c (100 Me. V/c more per particle)! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 14

New PYTHIA 6. 2 Tunes 14 Te. V (p. T > 0. 5 Ge.

New PYTHIA 6. 2 Tunes 14 Te. V (p. T > 0. 5 Ge. V/c, |h| < 1) <Nchg> <PTsum> (Ge. V/c) <PT> (Ge. V/c) Tune DWT 6. 268 7. 091 1. 131 Tune D 6 T 5. 743 6. 467 1. 126 Tune QKT 5. 361 6. 115 0. 982 Numbers for p. T > 0. 5 Ge. V/c, |h| < 1. Æ Pseudo. Rapidity distribution, d. N/dh, for charged particles with p. T > 0. 5 Ge. V/c at 14 Te. V for PY Tune DWT, Tune D 6 T, and Tune QKT. Note this is “hard core” (i. e. MSEL=1, PT(hard) = 0) with no trigger and with only stable particles (i. e. MSTJ(22)=1). Tune D 6 T uses CTEQ 6 L (i. e. LHAPDF = 10042) and Tune QKT uses CTEQ 6. 1 M (i. e. LHAPDF = 10100 or 10150 which are the same). FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS We now have CTEQ 6 L Tune D 6 T! 15

The Evolution of Charged Jets and the “Underlying Event” “Transverse” region very sensitive to

The Evolution of Charged Jets and the “Underlying Event” “Transverse” region very sensitive to the “underlying event”! Charged Particle Df Correlations PT > 0. 5 Ge. V/c |h| < 1 Look at the charged particle density in the “transverse” region! CDF Run 1 Analysis Æ Look at charged particle correlations in the azimuthal angle Df relative to the leading charged Æ Æ particle jet. Define |Df| < 60 o as “Toward”, 60 o < |Df| < 120 o as “Transverse”, and |Df| > 120 o as “Away”. All three regions have the same size in h-f space, Dhx. Df = 2 x 120 o = 4 p/3. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 16

CDF Run 2 Min-Bias “Associated” Charged Particle Density “Associated” densities do not include PTmax!

CDF Run 2 Min-Bias “Associated” Charged Particle Density “Associated” densities do not include PTmax! Highest p. T charged particle! Æ Use the maximum p. T charged particle in the event, PTmax, to define a direction and Æ is “associated” more probable to findd. N a chg particle look at the It the density, /dhdf, in “min-bias” collisions (p. T > 0. 5 accompanying PTmax than it is to Ge. V/c, |h| < 1). find a particle in the central region! Shows the data on the Df dependence of the “associated” charged particle density, d. Nchg/dhdf, for charged particles (p. T > 0. 5 Ge. V/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180 o) for “min-bias” events. Also shown is the average charged particle density, d. Nchg/dhdf, for “min-bias” events. FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 17

CDF Run 2 Min-Bias “Associated” Rapid rise in the particle Charged Particle Density density

CDF Run 2 Min-Bias “Associated” Rapid rise in the particle Charged Particle Density density in the “transverse” region as PTmax increases! PTmax > 2. 0 Ge. V/c Transverse Region Ave Min-Bias 0. 25 per unit h-f Transverse Region PTmax > 0. 5 Ge. V/c Æ Shows the data on the Df dependence of the “associated” charged particle density, d. Nchg/dhdf, for charged particles (p. T > 0. 5 Ge. V/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180 o) for “min-bias” events with PTmax > 0. 5, 1. 0, and 2. 0 Ge. V/c. Æ Shows “jet structure” in “min-bias” collisions (i. e. the “birth” of the leading two jets!). FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 18

CDF Run 2 Min-Bias “Associated” Charged Particle Density PY Tune A PTmax > 2.

CDF Run 2 Min-Bias “Associated” Charged Particle Density PY Tune A PTmax > 2. 0 Ge. V/c Transverse Region PTmax > 0. 5 Ge. V/c Æ Shows the data on the Df dependence of the “associated” charged particle density, d. Nchg/dhdf, for charged particles (p. T > 0. 5 Ge. V/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180 o) for “min-bias” events with PTmax > 0. 5 Ge. V/c and PTmax > 2. 0 Ge. V/c compared with PYTHIA Tune A (after CDFSIM). Æ 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”). FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 19

Tune Summary Tevatron LHC Æ PYTHIA Tune DW is very similar to Tune A

Tune Summary Tevatron LHC Æ PYTHIA Tune DW is very similar to Tune A except that it fits the CDF PT(Z) distribution and it uses the DØ prefered value of PARP(67) = 2. 5 (determined from the dijet Df distribution). Æ PYTHIA Tune DWT is identical to Tune DW at 1. 96 Te. V but uses the ATLAS energy extrapolation to the LHC (i. e. PARP(90) = 0. 16). Æ PYTHIA Tune D 6 and D 6 T are similar to Tune DW and DWT, respectively, but use CTEQ 6 L (i. e. LHAPDF = 10042). Æ PYTHIA Tune QK and QKT uses the NLO PDF CTEQ 6. 1 M (i. e. LHAPDF = 10100 or 10150 which are the same) and use the “K-factor” to get the right amount of MPI. Not favored at present! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 20

Next Round of Tunes? Torbjorn has made comparing. LHC tunes easy! Tevatron Æ I

Next Round of Tunes? Torbjorn has made comparing. LHC tunes easy! Tevatron Æ I do not believe that we should continue to produce PYTHIA 6. 2 tunes! Æ We need one good PYTHIA 6. 2 tune as a “reference tune” for the LHC (like tune DWT) to compare with early CMS data. Æ Depending on what we see early on at CMS, we might make one new PYTHIA 6. 2 tune, BUT we need to start tuning the new Monde-Carlo generators (PYTHIA 6. 4, PYTHIA 8. 0, Sherpa, HERWIG + JIMMY, etc. ) Æ We need to be able to easily validate the tunes within the CMS software framework. I hope Steve Mrenna will take charge of this effort! FNAL-CMS MC Generator Meeting June 7, 2007 Rick Field – Florida/CMS 21