Review of the QCD Monte-Carlo Tunes Rick Field University...

Oregon Terascale Workshop February 23, 2009

Rick Field – Florida/CDF/CMS

Northwest Northwest TerascaleTerascale WorkshopWorkshopParton Showers and Event Structure at the LHCParton Showers and Event Structure at the LHC

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying EventUnderlying Event

Initial-State Radiation

Final-State Radiation

Rick FieldUniversity of Florida

CMS at the LHCCDF Run 2

Outline of TalkReview some of what we have learned about “min-bias” and the “underlying event” in Run 1 at CDF.

Review the various PYTHIA “underlying event” QCD Monte-Carlo Model tunes.

Show some extrapolations to the LHC.

Show some things I do not understand about the CDF data.

University of Oregon February 23, 2009

Review of the QCD Monte-Carlo Tunes



QCD MonteQCD Monte--Carlo Models:Carlo Models:High Transverse Momentum JetsHigh 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

PT(hard)

Outgoing Parton

Outgoing Parton



Hard Scattering

PT(hard)

Outgoing Parton

Outgoing Parton



Proton AntiProton

Underlying Event Underlying Event

Proton AntiProton


“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.



QCD MonteQCD Monte--Carlo Models:Carlo Models:High Transverse Momentum JetsHigh 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

PT(hard)

Outgoing Parton

Outgoing Parton



Hard Scattering

PT(hard)

Outgoing Parton

Outgoing Parton



Proton AntiProton


Proton AntiProton



“Jet”

“Jet”



Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event”observables receive contributions from initial and final-state radiation.

“Jet”

The “underlying event” is an unavoidable background to most collider observables and having good understand of it leads to

more precise collider measurements!



QCD MonteQCD Monte--Carlo Models:Carlo Models:LeptonLepton--Pair ProductionPair 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).

Proton AntiProton


Proton AntiProton


Lepton-Pair Production

Lepton

Anti-Lepton



Lepton

Anti-Lepton




Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event”observables receive contributions from initial-state radiation.

“Jet” “Hard Scattering” Component



QCD MonteQCD Monte--Carlo Models:Carlo Models:LeptonLepton--Pair ProductionPair 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).

Proton AntiProton


Proton AntiProton



Lepton

Anti-Lepton



Lepton

Anti-Lepton




Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event”observables receive contributions from initial-state radiation.

“Jet”

Proton AntiProton

High PT Z-Boson Production

Z-boson

Outgoing Parton

Initial-State Radiation Final-State Radiation


Z-boson

Outgoing Parton






ProtonProton--AntiProtonAntiProton CollisionsCollisionsat the at the TevatronTevatron

Elastic Scattering Single Diffraction

M

σtot = σEL + σSD+σDD+σHC

Double Diffraction

M1

M2

Proton AntiProton

“Soft” Hard Core (no hard scattering)

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying Event Underlying Event Initial-StateRadiation

Final-StateRadiation

“Hard” Hard Core (hard scattering)

Hard Core

1.8 TeV: 78mb = 18mb + 9mb + (4-7)mb + (47-44)mb

The “hard core” component contains both “hard” and

“soft” collisions.



ProtonProton--AntiProtonAntiProton CollisionsCollisionsat the at the TevatronTevatron

Elastic Scattering Single Diffraction

M

σtot = σEL + σSD+σDD+σHC

Double Diffraction

M1

M2

Proton AntiProton

“Soft” Hard Core (no hard scattering)

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying Event Underlying Event Initial-StateRadiation

Final-StateRadiation

“Hard” Hard Core (hard scattering)

Hard Core

1.8 TeV: 78mb = 18mb + 9mb + (4-7)mb + (47-44)mb

The CDF “Min-Bias” trigger picks up most of the “hard core” cross-section plus a small amount of single &

double diffraction.

The “hard core” component contains both “hard” and

“soft” collisions.

Beam-Beam Counters3.2 < |η| < 5.9

CDF “Min-Bias” trigger1 charged particle in forward BBC

AND1 charged particle in backward BBC



-1 +1

φ

2π

0 η

1 charged particle

dNchg/dηdφ = 1/4π = 0.08

Study the charged particles (pT > 0.5 GeV/c, |η| < 1) and form the charged particle density, dNchg/dηdφ, and the charged scalar pT sum density, dPTsum/dηdφ.

Charged ParticlespT > 0.5 GeV/c |η| < 1

ΔηΔφ = 4π = 12.6

1 GeV/c PTsum

dPTsum/dηdφ = 1/4π GeV/c = 0.08 GeV/c

dNchg/dηdφ = 3/4π = 0.24

3 charged particles

dPTsum/dηdφ = 3/4π GeV/c = 0.24 GeV/c

3 GeV/c PTsum

0.236 +/- 0.0182.97 +/- 0.23Scalar pT sum of Charged Particles(pT > 0.5 GeV/c, |η| < 1)

PTsum(GeV/c)

0.252 +/- 0.0253.17 +/- 0.31Number of Charged Particles(pT > 0.5 GeV/c, |η| < 1)Nchg

Average Densityper unit η-φAverageCDF Run 2 “Min-Bias”

Observable

Divide by 4π

CDF Run 2 “Min-Bias”

Particle DensitiesParticle Densities



Shows CDF “Min-Bias” data on the number of charged particles per unit pseudo-rapidity at 630 and 1,800 GeV. There are about 4.2 charged particles per unit η in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).

Charged Particle Pseudo-Rapidity Distribution: dN/dη

0

1

2

3

4

5

6

7

-4 -3 -2 -1 0 1 2 3 4

Pseudo-Rapidity η

dN/d

η

CDF Min-Bias 1.8 TeVCDF Min-Bias 630 GeV all PT

CDF Published

<dNchg/dη> = 4.2

Charged Particle Density: dN/dηdφ

0.0

0.2

0.4

0.6

0.8

1.0

-4 -3 -2 -1 0 1 2 3 4

Pseudo-Rapidity η

dN/d

ηd φ

CDF Min-Bias 630 GeVCDF Min-Bias 1.8 TeV all PT

CDF Published

<dNchg/dηdφ> = 0.67

Convert to charged particle density, dNchg/dηdφ, by dividing by 2π. There are about 0.67 charged particles per unit η-φ in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).

Δη = 1

Δφ = 1

ΔηxΔφ = 1

0.67

CDF Run 1 CDF Run 1 ““MinMin--BiasBias”” DataDataCharged Particle DensityCharged Particle Density

I will talk about “min-bias” and “pile-up” tomorrow!



Shows CDF “Min-Bias” data on the number of charged particles per unit pseudo-rapidity at 630 and 1,800 GeV. There are about 4.2 charged particles per unit η in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).

Charged Particle Pseudo-Rapidity Distribution: dN/dη

0

1

2

3

4

5

6

7

-4 -3 -2 -1 0 1 2 3 4

Pseudo-Rapidity η

dN/d

η

CDF Min-Bias 1.8 TeVCDF Min-Bias 630 GeV all PT

CDF Published

<dNchg/dη> = 4.2


0.0

0.2

0.4

0.6

0.8

1.0

-4 -3 -2 -1 0 1 2 3 4

Pseudo-Rapidity η

dN/d

ηd φ

CDF Min-Bias 630 GeVCDF Min-Bias 1.8 TeV all PT

CDF Published

<dNchg/dηdφ> = 0.67

Convert to charged particle density, dNchg/dηdφ, by dividing by 2π. There are about 0.67 charged particles per unit η-φ in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).

Δη = 1

Δφ = 1

ΔηxΔφ = 1

0.67

There are about 0.25 charged particles per unit η-φ in “Min-Bias”collisions at 1.96 TeV (|η| < 1, pT > 0.5 GeV/c).

0.25

CDF Run 1 CDF Run 1 ““MinMin--BiasBias”” DataDataCharged Particle DensityCharged Particle Density

I will talk about “min-bias” and “pile-up” tomorrow!



Charged Jet #1Direction

Δφ

“Transverse” “Transverse”

“Toward”

“Away”

“Toward-Side” Jet

“Away-Side” Jet

Look at charged particle correlations in the azimuthal angle Δφ relative to the leading charged particle jet.Define |Δφ| < 60o as “Toward”, 60o < |Δφ| < 120o as “Transverse”, and |Δφ| > 120o as “Away”.All three regions have the same size in η-φ space, ΔηxΔφ = 2x120o = 4π/3.


Δφ

“Toward”


“Away”

-1 +1

φ

2π

0 η

LeadingJet

Toward Region

Transverse Region

Transverse Region

Away Region

Away Region

Charged Particle Δφ Correlations PT > 0.5 GeV/c |η| < 1

Look at the charged particle density in the “transverse” region!“Transverse” region

very sensitive to the “underlying event”!

CDF Run 1 Analysis

CDF Run 1: Evolution of Charged JetsCDF Run 1: Evolution of Charged Jets““Underlying EventUnderlying Event””



Compares the average “transverse” charge particle density with the average “Min-Bias”charge particle density (|η|<1, pT>0.5 GeV). Shows how the “transverse” charge particle density and the Min-Bias charge particle density is distributed in pT.

"Transverse" Charged Particle Density: dN/dηdφ

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PT(charged jet#1) (GeV/c)

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CDF Min-BiasCDF JET20

CDF Run 1data uncorrected

1.8 TeV |η|<1.0 PT>0.5 GeV/c

Charged Particle Jet #1 Direction

Δφ

“Toward”


“Away”

Run 1 Charged Particle DensityRun 1 Charged Particle Density““TransverseTransverse”” ppTT DistributionDistribution



Compares the average “transverse” charge particle density with the average “Min-Bias”charge particle density (|η|<1, pT>0.5 GeV). Shows how the “transverse” charge particle density and the Min-Bias charge particle density is distributed in pT.

CDF Run 1 Min-Bias data<dNchg/dηdφ> = 0.25

PT(charged jet#1) > 30 GeV/c“Transverse” <dNchg/dηdφ> = 0.56

Factor of 2!

“Min-Bias”


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CDF Min-BiasCDF JET20


1.8 TeV |η|<1.0 PT>0.5 GeV/c

Charged Particle Density

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

0 2 4 6 8 10 12 14

PT(charged) (GeV/c)C

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N/d

ηd φ

dPT

(1/G

eV/c

)


1.8 TeV |η|<1 PT>0.5 GeV/c

Min-Bias

"Transverse"PT(chgjet#1) > 5 GeV/c

"Transverse"PT(chgjet#1) > 30 GeV/c

Run 1 Charged Particle DensityRun 1 Charged Particle Density““TransverseTransverse”” ppTT DistributionDistribution



Plot shows average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus PT(charged jet#1) compared to the QCD hard scattering predictions of ISAJET 7.32 (default parameters with PT(hard)>3 GeV/c) .The predictions of ISAJET are divided into two categories: charged particles that arise from the break-up of the beam and target (beam-beam remnants); and charged particles that arise from the outgoing jet plus initial and final-state radiation (hard scattering component).

Beam-BeamRemnants

ISAJETCharged Jet #1Direction

Δφ

“Toward”


“Away”

“Hard”Component


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CDF Run 1Datadata uncorrectedtheory corrected

1.8 TeV |η|<1.0 PT>0.5 GeV

Isajet

"Remnants"

"Hard"

ISAJET 7.32ISAJET 7.32““TransverseTransverse”” DensityDensity

ISAJET uses a naïve leading-log parton shower-model which does

not agree with the data!



Plot shows average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus PT(charged jet#1) compared to the QCD hard scattering predictions of HERWIG 5.9 (default parameters with PT(hard)>3 GeV/c).The predictions of HERWIG are divided into two categories: charged particles that arise from the break-up of the beam and target (beam-beam remnants); and charged particles that arise from the outgoing jet plus initial and final-state radiation (hard scattering component).

Beam-BeamRemnants

HERWIG


Δφ

“Toward”


“Away”


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CDF Run 1Datadata uncorrectedtheory corrected

1.8 TeV |η|<1.0 PT>0.5 GeV

Herwig 6.4 CTEQ5LPT(hard) > 3 GeV/c

Total "Hard"

"Remnants"

“Hard”Component

HERWIG uses a modified leading-log parton shower-model which does agrees better with the data!

HERWIG 6.4HERWIG 6.4““TransverseTransverse”” DensityDensity



"Transverse" Charged Particle Density

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

0 2 4 6 8 10 12 14

PT(charged) (GeV/c)C

harg

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ensi

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N/d

ηd φ

dPT

(1/G

eV/c

)

CDF Datadata uncorrectedtheory corrected

1.8 TeV |η|<1 PT>0.5 GeV/c

PT(chgjet#1) > 5 GeV/c

PT(chgjet#1) > 30 GeV/c

Herwig 6.4 CTEQ5L

Herwig PT(chgjet#1) > 5 GeV/c<dNchg/dηdφ> = 0.40

Herwig PT(chgjet#1) > 30 GeV/c“Transverse” <dNchg/dηdφ> = 0.51


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1.8 TeV |η|<1.0 PT>0.5 GeV

Herwig 6.4 CTEQ5LPT(hard) > 3 GeV/c

Total "Hard"

"Remnants"

Compares the average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus PT(charged jet#1) and the pT distribution of the “transverse” density, dNchg/dηdφdPT with the QCD hard scattering predictions of HERWIG 6.4 (default parameters with PT(hard)>3 GeV/c. Shows how the “transverse” charge particle density is distributed in pT.

HERWIG has the too steep of a pTdependence of the “beam-beam remnant”

component of the “underlying event”!

HERWIG 6.4HERWIG 6.4““TransverseTransverse”” PPTT DistributionDistribution



MPI: Multiple PartonMPI: Multiple PartonInteractionsInteractions

PYTHIA models the “soft” component of the underlying event with color string fragmentation, but in addition includes a contribution arising from multiple parton interactions (MPI) in which one interaction is hard and the other is “semi-hard”.

Proton AntiProton

Multiple Parton Interaction

initial-state radiation

final-state radiation outgoing parton

outgoing parton

color string

color string

The probability that a hard scattering events also contains a semi-hard multiple partoninteraction can be varied but adjusting the cut-off for the MPI. One can also adjust whether the probability of a MPI depends on the PT of the hard scattering, PT(hard) (constant cross section or varying with impact parameter). One can adjust the color connections and flavor of the MPI (singlet or nearest neighbor, q-qbar or glue-glue).Also, one can adjust how the probability of a MPI depends on PT(hard) (single or double Gaussian matter distribution).

+

“Semi-Hard” MPI “Hard” Component


final-state radiation outgoing jet Beam-Beam Remnants

or

“Soft” Component

Proton AntiProton

“Hard” Collision


final-state radiation outgoing parton

outgoing parton



A scale factor that determines the maximum parton virtuality for space-like showers. The larger the value of PARP(67) the more initial-state radiation.

1.0PARP(67)

Determines the energy dependence of the cut-offPT0 as follows PT0(Ecm) = PT0(Ecm/E0)ε with ε = PARP(90)

0.16PARP(90)

Double-Gaussian: Fraction of the overall hadronradius containing the fraction PARP(83) of the total hadronic matter.

0.2PARP(84)

Determines the reference energy E0.1 TeVPARP(89)

Probability 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.

0.66PARP(86)

Probability that the MPI produces two gluons with color connections to the “nearest neighbors.

0.33PARP(85)

Double-Gaussian: Fraction of total hadronicmatter within PARP(84)

0.5PARP(83)

DescriptionDefault Parameter

Hard Core


Color String

Color String


Color String

Hard-Scattering Cut-Off PT0

1

2

3

4

5

100 1,000 10,000 100,000CM Energy W (GeV)

PT0

(GeV

/c)

PYTHIA 6.206

ε = 0.16 (default)

ε = 0.25 (Set A))

Take E0 = 1.8 TeV

Reference pointat 1.8 TeV

Determine by comparingwith 630 GeV data!

Affects the amount ofinitial-state radiation!

Tuning PYTHIA:Tuning PYTHIA:Multiple Parton Interaction ParametersMultiple Parton Interaction Parameters




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PT(charged jet#1) (GeV/c)"T

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CTEQ3L CTEQ4L CTEQ5L CDF Min-Bias CDF JET20

1.8 TeV |η|<1.0 PT>0.5 GeV

Pythia 6.206 (default)MSTP(82)=1

PARP(81) = 1.9 GeV/c


Default parameters give very poor description of the “underlying event”!

Note ChangePARP(67) = 4.0 (< 6.138)PARP(67) = 1.0 (> 6.138)

0.160.160.16PARP(90)

1,0001,0001,000PARP(89)

4.0

2.1

1.9

1

1

6.125

1.0

2.1

1.9

1

1

6.158

1.04.0PARP(67)

1.91.55PARP(82)

1.91.4PARP(81)

11MSTP(82)

11MSTP(81)

6.2066.115Parameter

Plot shows the “Transverse” charged particle density versus PT(chgjet#1) compared to the QCD hard scattering predictions of PYTHIA 6.206 (PT(hard) > 0) using the defaultparameters for multiple parton interactions and CTEQ3L, CTEQ4L, and CTEQ5L.

PYTHIA default parameters

PYTHIA 6.206 DefaultsPYTHIA 6.206 DefaultsMPI constant

probabilityscattering



Old PYTHIA default(more initial-state radiation)New PYTHIA default

(less initial-state radiation)

0.50.5PARP(83)

0.40.4PARP(84)

0.250.25PARP(90)

0.951.0PARP(86)

1.8 TeV1.8 TeVPARP(89)

4.0

0.9

2.0 GeV

4

1

Tune A

1.0PARP(67)

1.0PARP(85)

1.9 GeVPARP(82)

4MSTP(82)

1MSTP(81)

Tune BParameter

Old PYTHIA default(more initial-state radiation)New PYTHIA default

(less initial-state radiation)

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)).


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CDF Preliminarydata uncorrectedtheory corrected

CTEQ5L

PYTHIA 6.206 (Set A)PARP(67)=4

PYTHIA 6.206 (Set B)PARP(67)=1

Run 1 Analysis

Run 1 PYTHIA Tune ARun 1 PYTHIA Tune APYTHIA 6.206 CTEQ5L

CDF Default!




Δφ

“Toward”


“Away”


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CDF Run 1 Min-BiasCDF Run 1 JET20

CDF Run 1 Datadata uncorrected

1.8 TeV |η|<1.0 PT>0.5 GeV

Shows the data on the average “transverse” charge particle density (|η|<1, pT>0.5 GeV) as a function of the transverse momentum of the leading charged particle jet from Run 1.

Compares the Run 2 data (Min-Bias, JET20, JET50, JET70, JET100) with Run 1. The errors on the (uncorrected) Run 2 data include both statistical and correlated systematic uncertainties.Shows the prediction of PYTHIA Tune A at 1.96 TeV after detector simulation (i.e. after CDFSIM).

Run 1 Run 1 vsvs Run 2: Run 2: ““TransverseTransverse””Charged Particle DensityCharged Particle Density“Transverse” region as defined by the leading “charged particle jet”




Δφ

“Toward”


“Away”


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CDF Run 1 Datadata uncorrected

1.8 TeV |η|<1.0 PT>0.5 GeV


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|η|<1.0 PT>0.5 GeV

CDF Preliminarydata uncorrected

Shows the data on the average “transverse” charge particle density (|η|<1, pT>0.5 GeV) as a function of the transverse momentum of the leading charged particle jet from Run 1.

Compares the Run 2 data (Min-Bias, JET20, JET50, JET70, JET100) with Run 1. The errors on the (uncorrected) Run 2 data include both statistical and correlated systematic uncertainties.


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CDF Run 2


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CDF Run 2 Preliminary

|η|<1.0 PT>0.5 GeV/c


Excellent agreement between Run 1 and 2!


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CDF Run 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A

|η|<1.0 PT>0.5 GeV/c

CDF Preliminarydata uncorrectedtheory corrected

PYTHIA Tune A was tuned to fit the “underlying event” in Run I!

Shows the prediction of PYTHIA Tune A at 1.96 TeV after detector simulation (i.e. after CDFSIM).

Run 1 Run 1 vsvs Run 2: Run 2: ““TransverseTransverse””Charged Particle DensityCharged Particle Density“Transverse” region as defined by the leading “charged particle jet”



-1 +1

φ

2π

0 η

Leading Jet

Toward Region

Transverse Region

Transverse Region

Away Region

Away Region

Jet #1 Direction

Δφ


“Toward”

“Away”


“Away-Side” Jet

““TowardsTowards””, , ““AwayAway””, , ““TransverseTransverse””

Look at correlations in the azimuthal angle Δφ relative to the leading charged particle jet (|η| < 1) or the leading calorimeter jet (|η| < 2).Define |Δφ| < 60o as “Toward”, 60o < |Δφ| < 120o as “Transverse ”, and |Δφ| > 120o as “Away”. Each of the three regions have area ΔηΔφ = 2×120o = 4π/3.

Jet #1 Direction Δφ

“Toward”


“Away”

Δφ Correlations relative to the leading jetCharged particles pT > 0.5 GeV/c |η| < 1Calorimeter towers ET > 0.1 GeV |η| < 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



Event TopologiesEvent Topologies“Leading Jet” events correspond to the leading calorimeter jet (MidPoint R = 0.7) in the region |η| < 2 with no other conditions.


“Toward”


“Away”

“Leading Jet”

“Leading ChgJet” events correspond to the leading charged particle jet (R = 0.7) in the region |η| < 1 with no other conditions.

ChgJet #1 Direction Δφ

“Toward”


“Away”


“Toward”


“Away”

Jet #2 Direction

“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” (Δφ12 > 150o) with almost equal transverse energies (PT(jet#2)/PT(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” (Δφ12 > 150o) with almost equal transverse energies (PT(jet#2)/PT(jet#1) > 0.8) and PT(jet#3) < 15 GeV/c.

subset

subset

Z-Boson Direction

Δφ

“Toward”


“Away”

Z-Boson“Z-Boson” events are Drell-Yan events with 70 < M(lepton-pair) < 110 GeVwith no other conditions.



Charged Particle Density Charged Particle Density ΔφΔφ DependenceDependence

Look at the “transverse” region as defined by the leading jet (JetClu R = 0.7, |η| < 2) or by the leading two jets (JetClu R = 0.7, |η| < 2). “Back-to-Back” events are selected to have at least two jets with Jet#1 and Jet#2 nearly “back-to-back” (Δφ12 > 150o) with almost equal transverse energies (ET(jet#2)/ET(jet#1) > 0.8) and with ET(jet#3) < 15 GeV.


0.1

1.0

10.0

0 30 60 90 120 150 180 210 240 270 300 330 360

Δφ (degrees)C

harg

ed P

artic

le D

ensi

ty


Charged Particles (|η|<1.0, PT>0.5 GeV/c)

30 < ET(jet#1) < 70 GeV

"Transverse" Region

Jet#1


“Toward”


“Away”

Jet #1 Direction

Δφ

“Toward”


“Away”

Jet #2 Direction

Shows the Δφ dependence of the charged particle density, dNchg/dηdφ, for charged particles in the range pT > 0.5 GeV/c and |η| < 1 relative to jet#1 (rotated to 270o) for 30 < ET(jet#1) < 70 GeV for “Leading Jet” and “Back-to-Back” events.


0.1

1.0

10.0

0 30 60 90 120 150 180 210 240 270 300 330 360

Δφ (degrees)C

harg

ed P

artic

le D

ensi

ty

Back-to-BackLeading JetMin-Bias



30 < ET(jet#1) < 70 GeV

"Transverse" Region

Jet#1

Refer to this as a “Leading Jet” event

Refer to this as a “Back-to-Back” event

Subset



Charged Particle Density Charged Particle Density ΔφΔφ DependenceDependence

Jet #1 DirectionΔφ

“Toward”


“Away”

Jet #1 Direction

Δφ

“Toward”


“Away”

Jet #2 Direction

Shows the Δφ dependence of the charged particle density, dNchg/dηdφ, for charged particles in the range pT > 0.5 GeV/c and |η| < 1 relative to jet#1 (rotated to 270o) for 30 < ET(jet#1) < 70 GeV for “Leading Jet” and “Back-to-Back” events.

“Leading Jet”

“Back-to-Back”

Charged Particle Density: dN/dηdφ272

276 280 284 288292

296300

304308

312

316

320

324

328

332

336

340

344

348

352

356

360

4

8

12

16

20

24

28

32

36

40

44

48

5256

6064

6872

7680848892

96100104108112

116120

124128

132

136

140

144

148

152

156

160

164

168

172

176

180

184

188

192

196

200

204

208

212

216

220

224

228

232236

240244

248252

256 260 264 268


30 < ET(jet#1) < 70 GeV


"Transverse" Region

"Transverse" Region

Jet#1

Back-to-BackLeading Jet

0.5

1.0

1.5

2.0

Polar Plot



““transMAXtransMAX”” & & ““transMINtransMIN””

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 η-φ space of 4π/6.

The “transMIN” region is very sensitive to the “beam-beam remnant” and the soft multiple parton interaction components of the “underlying event”.


“Toward”

“TransMAX” “TransMIN”

“Away”

Jet #1 Direction

Δφ


“Toward”

“Away”


“Away-Side” Jet

Jet #3

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 = 4π/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




“Toward”


“Away”

Jet #1 Direction

Δφ

“Toward”


“Away”

Jet #2 Direction

“Back-to-Back”

Scalar pT sum of “good” charged tracks (pT > 0.5 GeV/c, |η| < 1)

divided by the scalar ET sum of calorimeter towers (ET > 0.1 GeV, |η| < 1)

Scalar pT sum of charged particles (pT > 0.5 GeV/c, |η| < 1)

divided by the scalar ET sum of all particles (all pT, |η| < 1)

PTsum/ETsum

Scalar ET sum of all calorimeter towers per unit η-φ

(ET > 0.1 GeV, |η| < 1)

Scalar ET sum of all particles per unit η-φ

(all pT, |η| < 1)dETsum/dηdφ

Maximum pT “good” charged tracks(pT > 0.5 GeV/c, |η| < 1)

Require Nchg ≥ 1

Maximum pT charged particle(pT > 0.5 GeV/c, |η| < 1)

Require Nchg ≥ 1PTmax

Average pT of “good” charged tracks(pT > 0.5 GeV/c, |η| < 1)

Average pT of charged particles(pT > 0.5 GeV/c, |η| < 1)<pT>

Scalar pT sum of “good” charged tracks per unit η-φ

(pT > 0.5 GeV/c, |η| < 1)

Scalar pT sum of charged particles per unit η-φ

(pT > 0.5 GeV/c, |η| < 1)dPTsum/dηdφ

Number of “good” charged tracksper unit η-φ

(pT > 0.5 GeV/c, |η| < 1)

Number of charged particlesper unit η-φ

(pT > 0.5 GeV/c, |η| < 1)dNchg/dηdφ

Detector LevelParticle LevelObservable“Leading Jet”

Observables at theObservables at theParticle and Detector LevelParticle and Detector Level



CDF Run 1 PCDF Run 1 PTT(Z)(Z)

Shows the Run 1 Z-boson pT distribution (<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA Tune A (<pT(Z)> = 9.7 GeV/c), Tune A25 (<pT(Z)> = 10.1 GeV/c), and Tune A50 (<pT(Z)> = 11.2 GeV/c).

Z-Boson Transverse Momentum

0.00

0.04

0.08

0.12

0 2 4 6 8 10 12 14 16 18 20

Z-Boson PT (GeV/c)

PT D

istr

ibut

ion

1/N

dN

/dPT

CDF Run 1 DataPYTHIA Tune APYTHIA Tune A25PYTHIA Tune A50

CDF Run 1published

1.8 TeV

Normalized to 1

σ = 1.0

σ = 2.5

σ = 5.0

25.015.05.0PARP(93)

5.02.51.0PARP(91)

111MSTP(91)

4.0

0.25

1.8 TeV

0.95

0.9

0.4

0.5

2.0 GeV

4

1

Tune A50

4.0

0.25

1.8 TeV

0.95

0.9

0.4

0.5

2.0 GeV

4

1

Tune A25

0.5PARP(83)

0.4PARP(84)

0.25PARP(90)

0.95PARP(86)

1.8 TeVPARP(89)

4.0

0.9

2.0 GeV

4

1

Tune A

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

ParameterUE Parameters

ISR Parameter

Intrensic KT

PYTHIA 6.2 CTEQ5L

Vary the intrensic KT!




Shows the Run 1 Z-boson pT distribution (<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA Tune A(<pT(Z)> = 9.7 GeV/c), and PYTHIA Tune AW(<pT(Z)> = 11.7 GeV/c).

4.04.0PARP(67)

0.21.0PARP(64)

15.05.0PARP(93)

2.11.0PARP(91)

11MSTP(91)

1.25

0.25

1.8 TeV

0.95

0.9

0.4

0.5

2.0 GeV

4

1

Tune AW

0.5PARP(83)

0.4PARP(84)

0.25PARP(90)

0.95PARP(86)

1.8 TeVPARP(89)

1.0

0.9

2.0 GeV

4

1

Tune A

PARP(62)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

The Q2 = kT2 in αs for space-like showers is scaled by PARP(64)!

Effective Q cut-off, below which space-like showers are not evolved.

UE Parameters

ISR Parameters

Intrensic KT

PYTHIA 6.2 CTEQ5LZ-Boson Transverse Momentum

0.00

0.04

0.08

0.12

0 2 4 6 8 10 12 14 16 18 20

Z-Boson PT (GeV/c)

PT D

istr

ibut

ion

1/N

dN

/dPT

CDF Run 1 DataPYTHIA Tune APYTHIA Tune AW

CDF Run 1published

1.8 TeV

Normalized to 1

Tune used by the CDF-EWK group!



JetJet--Jet Correlations (DJet Correlations (DØØ))Jet#1-Jet#2 Δφ Distribution

Δφ Jet#1-Jet#2

MidPoint Cone Algorithm (R = 0.7, fmerge = 0.5) L = 150 pb-1 (Phys. Rev. Lett. 94 221801 (2005))Data/NLO agreement good. Data/HERWIG agreement good.Data/PYTHIA agreement good provided PARP(67) = 1.0→4.0 (i.e. like Tune A, best fit 2.5).




Shows the Run 1 Z-boson pT distribution (<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA Tune DW, and HERWIG.4.02.5PARP(67)

0.20.2PARP(64)

15.015.0PARP(93)

2.12.1PARP(91)

11MSTP(91)

1.25

0.25

1.8 TeV

0.95

0.9

0.4

0.5

2.0 GeV

4

1

Tune AW

0.5PARP(83)

0.4PARP(84)

0.25PARP(90)

1.0PARP(86)

1.8 TeVPARP(89)

1.25

1.0

1.9 GeV

4

1

Tune DW

PARP(62)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

UE Parameters

ISR Parameters

Intrensic KT

PYTHIA 6.2 CTEQ5L Z-Boson Transverse Momentum

0.00

0.04

0.08

0.12

0 2 4 6 8 10 12 14 16 18 20

Z-Boson PT (GeV/c)

PT D

istr

ibut

ion

1/N

dN

/dPT

CDF Run 1 DataPYTHIA Tune DWHERWIG

CDF Run 1published

1.8 TeV

Normalized to 1

Tune DW has a lower value of PARP(67) and slightly more MPI!

Tune DW uses D0’s perfered value of PARP(67)!



MIT Search Scheme: Vista/SleuthMIT Search Scheme: Vista/SleuthExclusive 3 Jet Final State Challenge

Bruce Knuteson

Markus Klute

KhaldounMakhoul

GeorgiosChoudalakis

Ray Culbertson

ConorHenderson

Gene Flanagan

Exactly 3 jets(PT > 20 GeV/c, |η| < 2.5)

At least 1 Jet (“trigger” jet)(PT > 40 GeV/c, |η| < 1.0)

CDF Data

PYTHIA Tune A

Normalized to 1

Order Jets by PTJet1 highest PT, etc.

R(j2,j3)



3Jexc R(j2,j3) Normalized3Jexc R(j2,j3) NormalizedExclusive 3-Jet Production: R(j2,j3)

0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)

Data R(j2,j3)pyAWpyDWpyBW

CDF Run 2 Preliminarydata uncorrected

generator level theory

Let Ntrig40 equal the number of events with at least one jet with PT > 40 geV and |η| < 1.0 (this is the “offline” trigger).

Let N3Jexc20 equal the number of events with exactly three jets with PT > 20 GeV/cand |η| < 2.5 which also have at least one jet with PT > 40 GeV/c and |η| < 1.0.

Let N3JexcFr = N3Jexc20/Ntrig40. The is the fraction of the “offline” trigger events that are exclusive 3-jet events.

The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune AW (PARP(67)=4), Tune DW (PARP(67)=2.5), Tune BW (PARP(67)=1).

PARP(67) affects the initial-state radiation which contributes primarily to the region R(j2,j3) > 1.0.

Normalized to N3JexcFr

Proton AntiProton


Outgoing Parton

Outgoing Parton



“Jet 1”

“Jet 2”

“Jet 3”

R > 1.0

The data have more 3 jet events with small R(j2,j3)!?



Proton AntiProton


Outgoing Parton

Outgoing Parton




0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)

Data R(j2,j3)pyDWhw05



“Jet 3”

Exclusive 3-Jet Production: R(j2,j3)

0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)

Data R(j2,j3)pyDWpyDWnoFSR






The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune DW (PARP(67)=2.5) and HERWIG (without MPI).

Final-State radiation contributes to the region R(j2,j3) < 1.0.


“Jet 1”

“Jet 2” If you ignore the normalization and normalize all the distributions to one then the data prefer Tune BW, but I believe this is misleading.R < 1.0



Proton AntiProton


Outgoing Parton

Outgoing Parton




0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)




“Jet 3”


0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)










“Jet 1”



0.00

0.20

0.40

0.60

0.80

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)

CDF Datahw05pyDWpyBW



Normalized to 1



Proton AntiProton


Outgoing Parton

Outgoing Parton




0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)




“Jet 3”


0.00

0.04

0.08

0.12

0.16

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)










“Jet 1”



0.00

0.20

0.40

0.60

0.80

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

R(j2,j3)

dN/d

R(j2

,j3)

CDF Datahw05pyDWpyBW



Normalized to 1

I do not understand the excess number of events

with R(j2,j3) < 1.0.Perhaps this is related to the

“soft energy” problem??I will show you a lot more on Thursday!



PYTHIA 6.2 TunesPYTHIA 6.2 Tunes

15.0

2.1

1

4.0

0.2

1.25

0.25

1.8 TeV

0.95

0.9

0.4

0.5

2.0 GeV

4

1

CTEQ5L

Tune AW

15.0

2.1

1

2.5

0.2

1.25

0.25

1.8 TeV

1.0

1.0

0.4

0.5

1.8 GeV

4

1

CTEQ6L

Tune D6

CTEQ5LPDF

1.25PARP(62)

0.2PARP(64)

15.0PARP(93)

2.1PARP(91)

1MSTP(91)

0.5PARP(83)

0.4PARP(84)

0.25PARP(90)

1.0PARP(86)

1.8 TeVPARP(89)

2.5

1.0

1.9 GeV

4

1

Tune DW

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

Intrinsic KT

ISR Parameter

UE Parameters

Uses CTEQ6L

All use LO αswith Λ = 192 MeV!

Tune A energy dependence!




15.0

2.1

1

2.5

0.2

1.25

0.16

1.96 TeV

1.0

1.0

0.4

0.5

1.8387 GeV

4

1

CTEQ6L

Tune D6T

5.0

1.0

1

1.0

1.0

1.0

0.16

1.0 TeV

0.66

0.33

0.5

0.5

1.8 GeV

4

1

CTEQ5L

ATLAS

CTEQ5LPDF

1.25PARP(62)

0.2PARP(64)

15.0PARP(93)

2.1PARP(91)

1MSTP(91)

0.5PARP(83)

0.4PARP(84)

0.16PARP(90)

1.0PARP(86)

1.96 TeVPARP(89)

2.5

1.0

1.9409 GeV

4

1

Tune DWT

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

Intrinsic KT

ISR Parameter

UE Parameters


ATLAS energy dependence!




15.0

2.1

1

2.5

0.2

1.25

0.16

1.96 TeV

1.0

1.0

0.4

0.5

1.8387 GeV

4

1

CTEQ6L

Tune D6T

5.0

1.0

1

1.0

1.0

1.0

0.16

1.0 TeV

0.66

0.33

0.5

0.5

1.8 GeV

4

1

CTEQ5L

ATLAS

CTEQ5LPDF

1.25PARP(62)

0.2PARP(64)

15.0PARP(93)

2.1PARP(91)

1MSTP(91)

0.5PARP(83)

0.4PARP(84)

0.16PARP(90)

1.0PARP(86)

1.96 TeVPARP(89)

2.5

1.0

1.9409 GeV

4

1

Tune DWT

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

Intrinsic KT

ISR Parameter

UE Parameters



Tune A

Tune AW Tune B Tune BW

Tune D

Tune DW Tune D6Tune D6T




15.0

2.1

1

2.5

0.2

1.25

0.16

1.96 TeV

1.0

1.0

0.4

0.5

1.8387 GeV

4

1

CTEQ6L

Tune D6T

5.0

1.0

1

1.0

1.0

1.0

0.16

1.0 TeV

0.66

0.33

0.5

0.5

1.8 GeV

4

1

CTEQ5L

ATLAS

CTEQ5LPDF

1.25PARP(62)

0.2PARP(64)

15.0PARP(93)

2.1PARP(91)

1MSTP(91)

0.5PARP(83)

0.4PARP(84)

0.16PARP(90)

1.0PARP(86)

1.96 TeVPARP(89)

2.5

1.0

1.9409 GeV

4

1

Tune DWT

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

Intrinsic KT

ISR Parameter

UE Parameters



Tune A

Tune AW Tune B Tune BW

Tune D

Tune DW Tune D6Tune D6T

These are “old” PYTHIA 6.2 tunes! There are new 6.4 tunes byArthur Moraes (ATLAS)Hendrik Hoeth (MCnet)Peter Skands (Tune S0)




5.0

2.0

1

2.74

0.12

2.97

0.17

1.0

0.91

0.82

0.5

0.84

2.1 GeV

4

1

CTEQ5L

Tune H(6.418)

15.0

2.1

1

2.5

0.2

1.25

0.16

1.96 TeV

1.0

1.0

0.4

0.5

1.8387 GeV

4

1

CTEQ6L

Tune D6T

5.0

1.0

1

1.0

1.0

1.0

0.16

1.0 TeV

0.66

0.33

0.5

0.5

1.8 GeV

4

1

CTEQ5L

ATLAS

CTEQ5LPDF

1.25PARP(62)

0.2PARP(64)

15.0PARP(93)

2.1PARP(91)

1MSTP(91)

0.5PARP(83)

0.4PARP(84)

0.16PARP(90)

1.0PARP(86)

1.96 TeVPARP(89)

2.5

1.0

1.9409 GeV

4

1

Tune DWT

PARP(67)

PARP(85)

PARP(82)

MSTP(82)

MSTP(81)

Parameter

Intrinsic KT

ISR Parameter

UE Parameters


Q2 ordered showers, old MPI!



JIMMY at CDFJIMMY at CDFThe Energy in the “Underlying

Event” in High PT Jet Production

“Transverse” <Densities> vs PT(jet#1)


“Toward”


“Away”

"Transverse" PTsum Density: dPT/dηdφ

0.0

0.4

0.8

1.2

1.6

0 50 100 150 200 250 300 350 400 450 500

PT(particle jet#1) (GeV/c)

"Tra

nsve

rse"

PTs

um D

ensi

ty (G

eV/c

) PY Tune A

HW

1.96 TeV

Charged Particles (|η|<1.0, PT>0.5 GeV/c) CDF Run 2 Preliminary


MidPoint R = 0.7 |η(jet)| < 2

"Leading Jet"

JIMMY Default

JM325

"Transverse" ETsum Density: dET/dηdφ

0.0

1.0

2.0

3.0

4.0

0 100 200 300 400 500


"Tra

nsve

rse"

ETs

um D

ensi

ty (G

eV) 1.96 TeV

All Particles (|η|<1.0)

HW

PY Tune A

MidPoint R = 0.7 |η(jet)| < 2CDF Run 2 Preliminarygenerator level theory

"Leading Jet"

JIMMY Default

JM325JIMMY: MPI

J. M. ButterworthJ. R. Forshaw

M. H. Seymour

JIMMY was tuned to fit the energy density in the “transverse” region for

“leading jet” events!JIMMY

Runs with HERWIG and adds multiple parton interactions!

PT(JIM)= 2.5 GeV/c.

PT(JIM)= 3.25 GeV/c.

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton






JIMMY at CDFJIMMY at CDFThe Energy in the “Underlying

Event” in High PT Jet Production

“Transverse” <Densities> vs PT(jet#1)


“Toward”


“Away”

"Transverse" PTsum Density: dPT/dηdφ

0.0

0.4

0.8

1.2

1.6

0 50 100 150 200 250 300 350 400 450 500


"Tra

nsve

rse"

PTs

um D

ensi

ty (G

eV/c

) PY Tune A

HW

1.96 TeV

Charged Particles (|η|<1.0, PT>0.5 GeV/c) CDF Run 2 Preliminary


MidPoint R = 0.7 |η(jet)| < 2

"Leading Jet"

JIMMY Default

JM325


0.0

1.0

2.0

3.0

4.0

0 100 200 300 400 500


"Tra

nsve

rse"

ETs

um D

ensi

ty (G

eV) 1.96 TeV

All Particles (|η|<1.0)

HW

PY Tune A

MidPoint R = 0.7 |η(jet)| < 2CDF Run 2 Preliminarygenerator level theory

"Leading Jet"

JIMMY Default

JM325JIMMY: MPI

J. M. ButterworthJ. R. Forshaw

M. H. Seymour

JIMMY was tuned to fit the energy density in the “transverse” region for

“leading jet” events!JIMMY

Runs with HERWIG and adds multiple parton interactions!

PT(JIM)= 2.5 GeV/c.

PT(JIM)= 3.25 GeV/c.

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton




The Drell-Yan JIMMY TunePTJIM = 3.6 GeV/c,JMRAD(73) = 1.8JMRAD(91) = 1.8



Z-Boson Direction Δφ

“Toward”


“Away”

Charged Particle DensityCharged Particle Density

Data at 1.96 TeV on the density of charged particles, dN/dηdφ, with pT > 0.5 GeV/c and |η| < 1 for “Z-Boson”and “Leading Jet” events as a function of the leading jet pT or PT(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).


“Toward”


“Away”


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200

PT(jet#1) (GeV/c)

Ave

rage

Cha

rged

Den

sity

CDF Run 2 Preliminarydata corrected

pyA generator level

"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2


"Away"

"Toward"

"Transverse"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

Ave

rage

Cha

rged

Den

sity


pyAW generator level"Away"

"Transverse"

"Toward"

"Drell-Yan Production"70 < M(pair) < 110 GeV

Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair

Proton AntiProton


Z-boson

Outgoing Parton


Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton







“Toward”


“Away”




“Toward”


“Away”


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200

PT(jet#1) (GeV/c)

Ave

rage

Cha

rged

Den

sity


pyA generator level



"Away"

"Toward"

"Transverse"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

Ave

rage

Cha

rged

Den

sity



"Transverse"

"Toward"



Proton AntiProton


Z-boson

Outgoing Parton


Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton





0.0

0.3

0.6

0.9

1.2

0 20 40 60 80 100 120 140 160 180 200

PT(jet#1) or PT(Z-Boson) (GeV/c)

"Tra

nsve

rse"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"

"Away" Charged Particle Density: dN/dηdφ

0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200


"Aw

ay"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"




“Toward”


“Away”




“Toward”


“Away”


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200

PT(jet#1) (GeV/c)

Ave

rage

Cha

rged

Den

sity


pyA generator level



"Away"

"Toward"

"Transverse"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

Ave

rage

Cha

rged

Den

sity



"Transverse"

"Toward"



Proton AntiProton


Z-boson

Outgoing Parton


Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton





0.0

0.3

0.6

0.9

1.2

0 20 40 60 80 100 120 140 160 180 200


"Tra

nsve

rse"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200


"Aw

ay"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

"Aw

ay"

Cha

rged

Den

sity





JIM

HW

pyAW

HERWIG + JIMMYTune (PTJIM = 3.6)




“Toward”


“Away”




“Toward”


“Away”


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200

PT(jet#1) (GeV/c)

Ave

rage

Cha

rged

Den

sity


pyA generator level



"Away"

"Toward"

"Transverse"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

Ave

rage

Cha

rged

Den

sity



"Transverse"

"Toward"



Proton AntiProton


Z-boson

Outgoing Parton


Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton





0.0

0.3

0.6

0.9

1.2

0 20 40 60 80 100 120 140 160 180 200


"Tra

nsve

rse"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"


0

1

2

3

4

0 20 40 60 80 100 120 140 160 180 200


"Aw

ay"

Cha

rged

Den

sity




"Leading Jet"

"Z-Boson"


0

1

2

3

0 20 40 60 80 100

PT(Z-Boson) (GeV/c)

"Aw

ay"

Cha

rged

Den

sity





JIM

HW

pyAW

HERWIG + JIMMYTune (PTJIM = 3.6)

H. Hoeth, MPI@LHC08



“Leading Jet”

The The ““TransverseTransverse”” RegionRegion

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Shows the Data - Theory for the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).


“Toward”


“Away”


0.0

1.0

2.0

3.0

4.0

5.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

rse"

ETs

um D

ensi

ty (G

eV) CDF Run 2 Preliminary

data correctedgenerator level theory


Stable Particles (|η|<1.0, all PT)

PY Tune A

HW



“Leading Jet”

The The ““TransMAXTransMAX/MIN/MIN”” RegionsRegions

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMAX” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMIN” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for “transDIF” = “transMAX”-”transMIN. 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).


“Toward”


“Away”

"TransMAX" ETsum Density: dET/dηdφ

0.0

2.0

4.0

6.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsM

AX"

ETs

um D

ensi

ty (G





PY Tune A

HW

"TransMIN" ETsum Density: dET/dηdφ

0.0

1.0

2.0

3.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

MIN

" ET

sum

Den

sity

(GeV

)





PY Tune A

HW

"TransMAX/MIN" ETsum Density: dET/dηdφ

0.0

2.0

4.0

6.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

rse"

ETs

um D

ensi

ty (G





PY Tune A

HW

"transMAX"

"transMIN"



“Leading Jet”

The The ““TransverseTransverse”” RegionRegion

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Shows the Data - Theory for the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).


“Toward”


“Away”


0.0

1.0

2.0

3.0

4.0

5.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

rse"

ETs

um D

ensi

ty (G





PY Tune A

HW


-0.4

0.0

0.4

0.8

1.2

1.6

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

Dat

a - T

heor

y (G

eV)





HWPY Tune A

0.4 density corresponds to 1.67 GeV in the

“transverse” region!



“Leading Jet”

The The ““TransMAXTransMAX/MIN/MIN”” RegionsRegions

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMAX” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMIN” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for “transDIF” = “transMAX”-”transMIN. 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).


“Toward”


“Away”

"TransMAX" ETsum Density: dET/dηdφ

0.0

2.0

4.0

6.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsM

AX"

ETs

um D

ensi

ty (G





PY Tune A

HW

"TransMIN" ETsum Density: dET/dηdφ

0.0

1.0

2.0

3.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

MIN

" ET

sum

Den

sity

(GeV

)





PY Tune A

HW

"TransMAX/MIN" ETsum Density: dET/dηdφ

0.0

2.0

4.0

6.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

"Tra

nsve

rse"

ETs

um D

ensi

ty (G





PY Tune A

HW

"transMAX"

"transMIN"

"TransDIF" ETsum Density: dET/dηdφ

0.0

1.0

2.0

3.0

4.0

5.0

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

Tran

sMA

X - T

rans

MIN

(GeV

)




PY Tune A

HWStable Particles (|η|<1.0, all PT)



“Leading Jet”

The Leading Jet MassThe Leading Jet Mass

Data at 1.96 TeV on the leading jet invariant mass for “leading jet” events as a function of the leading jet pTfor the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Shows the Data - Theory for the leading jet invariant mass for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).


“Toward”


“Away”

Leading Jet Invariant Mass

0

10

20

30

40

50

60

70

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

Jet M

ass

(GeV

)




PY Tune A

HW



“Leading Jet”

The Leading Jet MassThe Leading Jet Mass

Data at 1.96 TeV on the leading jet invariant mass for “leading jet” events as a function of the leading jet pTfor the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).

Shows the Data - Theory for the leading jet invariant mass for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).


“Toward”


“Away”


0

10

20

30

40

50

60

70

0 50 100 150 200 250 300 350 400

PT(jet#1) (GeV/c)

Jet M

ass

(GeV

)




PY Tune A

HW


-4.0

0.0

4.0

8.0

12.0

0 50 100 150 200 250 300 350 400

PT(jet#1 uncorrected) (GeV/c)

Dat

a - T

heor

y (G

eV)




HW PY Tune A

Off by ~2 GeV



The The ““Underlying EventUnderlying Event”” ininHigh PHigh PTT Jet Production (LHC)Jet Production (LHC)

Charged particle density in the “Transverse”region versus PT(jet#1) at 1.96 TeV for PY Tune AW and HERWIG (without MPI).

Charged particle density in the “Transverse”region versus PT(jet#1) at 14 TeV for PY Tune AW and HERWIG (without MPI).

The “Underlying Event”


0.0

0.2

0.4

0.6

0.8

1.0

0 50 100 150 200 250 300 350 400 450 500


"Tra

nsve

rse"

Cha

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Den

sity

RDF Preliminarygenerator level

Charged Particles (|η|<1.0, PT>0.5 GeV/c) "Leading Jet"

PY Tune AW

1.96 TeV

HERWIG


0.0

0.5

1.0

1.5

2.0

0 250 500 750 1000 1250 1500 1750 2000 2250 2500


"Tra

nsve

rse"

Cha

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Den

sity


Charged Particles (|η|<1.0, PT>0.5 GeV/c) "Leading Jet"

PY Tune AW

CDF

LHC

HERWIG

Charged particle density versus PT(jet#1)

“Underlying event” much more active at the LHC!

Proton AntiProton

High PT Jet Production

PT(hard)

Outgoing Parton

Outgoing Parton






DrellDrell--Yan Production (Run 2 Yan Production (Run 2 vsvs LHC)LHC)

Average Lepton-Pair transverse momentum at the Tevatron and the LHC for PYTHIA Tune DW and HERWIG (without MPI).

Shape of the Lepton-Pair pT distribution at the Z-boson mass at the Tevatron and the LHC for PYTHIA Tune DW and HERWIG (without MPI).

Proton AntiProton

Drell-Yan Production Lepton

Underlying Event Underlying Event Initial-State Radiation

Anti-Lepton

Lepton-Pair Transverse Momentum

Shapes of the pT(μ+μ-) distribution at the Z-boson mass.

<pT(μ+μ-)> is much larger at the LHC!

Lepton-Pair Transverse Momentum

0

20

40

60

80

0 100 200 300 400 500 600 700 800 900 1000

Lepton-Pair Invariant Mass (GeV)

Ave

rage

Pai

r PT

Drell-Yangenerator level LHC

Tevatron Run 2

PY Tune DW (solid)HERWIG (dashed)

Drell-Yan PT(μ+μ-) Distribution

0.00

0.02

0.04

0.06

0.08

0.10

0 5 10 15 20 25 30 35 40

PT(μ+μ-) (GeV/c)

1/N

dN

/dPT

(1/G

eV)

Drell-Yangenerator level

PY Tune DW (solid)HERWIG (dashed)

70 < M(μ-pair) < 110 GeV|η(μ-pair)| < 6

Normalized to 1LHC

Tevatron Run2

Z



The The ““Underlying EventUnderlying Event”” ininDrellDrell--Yan ProductionYan Production

Charged particle density versus the lepton-pair invariant mass at 1.96 TeV for PYTHIA Tune AW and HERWIG (without MPI).

Charged particle density versus the lepton-pair invariant mass at 14 TeV for PYTHIA Tune AWand HERWIG (without MPI).

The “Underlying Event”

Proton AntiProton

Drell-Yan Production Lepton

Underlying Event Underlying Event Initial-State Radiation

Anti-Lepton


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0 50 100 150 200 250


Cha

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Par

ticle

Den

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Drell-Yan1.96 TeV

PY Tune AW

HERWIG

Charged Particles (|η|<1.0, PT>0.5 GeV/c)(excluding lepton-pair )


0.0

0.5

1.0

1.5

0 50 100 150 200 250


Cha

rged

Par

ticle

Den

sity


Drell-Yan Charged Particles (|η|<1.0, PT>0.5 GeV/c)(excluding lepton-pair )

PY Tune AW

HERWIG

LHC

CDF

Charged particle density versus M(pair)

“Underlying event” much more active at the LHC!

HERWIG (without MPI) is much less active than

PY Tune AW (with MPI)!

Z

Z



SummarySummaryWe are making good progress in modeling “min-bias”collisions! I will talk more about this tomorrow.

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton




We are making good progress in understanding and modeling the “underlying event” high transverse momentum jet production and in Drell-Yan production. I will talk much more about this tomorrow.

Proton AntiProton

Drell-Yan Production

Anti-Lepton

Lepton


Proton AntiProton

“Minumum Bias” Collisions

There are still some things we do not fully understand!

** Soft Underlying Event Energy **

** R(J2,J3) **

** Jet Mass **

AND we really do not know how to extrapolate to the LHC!

I will talk much more about this on Thursday!

Review of the QCD Monte-Carlo Tunes Rick Field University...

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Transcript of Review of the QCD Monte-Carlo Tunes Rick Field University...