PYTHIA Tune A versus Run 2 Datarfield/cdf/CDF_Joint_6-27-03.pdf · 6/27/2003 · PYTHIA 6.206 Set A Tuned PYTHIA 6.206 Run 1 Tune A! Compares the average ﬁtransverseﬂ charge

CDF Joint Physics Group June 27, 2003

Rick Field Page 1

PYTHIA Tune A versusPYTHIA Tune A versusRun 2 DataRun 2 Data

! Compare PYTHIA Tune A with Run 2 data on the �underlying event�.

Outline of Talk

! Compare PYTHIA Tune A with the properties of the �calorimeter jets� as measured in Run 2.

! Use PYTHIA Tune A to correct the Run 2 data from measured to �true�.

Proton AntiProton

�Hard� Scattering

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying Event Underlying Event Initial-State Radiation

Final-State Radiation

! Compare PYTHIA Tune A before and after CDFSIM.

Calorimeter Jet Construct �correction factors�!

JetClu R = 0.7


Rick Field Page 2

�Underlying Event��Underlying Event�as defined by �Charged particle Jets�as defined by �Charged particle Jets�

Charged Jet #1Direction

∆φ∆φ∆φ∆φ

�Transverse� �Transverse�

�Toward�

�Away�

�Toward-Side� Jet

�Away-Side� Jet

! Look at charged particle correlations in the azimuthal angle ∆φ ∆φ ∆φ ∆φ relative to the leading charged particle jet.

! Define |∆φ∆φ∆φ∆φ| < 60o as �Toward�, 60o < |∆φ∆φ∆φ∆φ| < 120o as �Transverse�, and |∆φ∆φ∆φ∆φ| > 120o as �Away�.

! All three regions have the same size in ηηηη-φφφφ space, ∆η∆η∆η∆ηx∆φ∆φ∆φ∆φ= 2x120o = 4ππππ/3.

Charged Jet #1Direction


�Toward�


�Away�

Charged Particle ∆φ∆φ∆φ∆φCorrelations PT > 0.5 GeV/c |ηηηη| < 1

Toward-side �jet�(always)

Away-side �jet�(sometimes)

Perpendicular to the plane of the 2-to-2 hard scattering

�Transverse� region is very sensitive to the �underlying event�!

-1 +1

φφφφ

2ππππ

0 ηηηη

Leading ChgJet

Toward Region

Transverse Region

Transverse Region

Away Region

Away Region

Look at the charged particle density in the �transverse� region!


Rick Field Page 3

Charged Particle Density

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CDF Run 1data uncorrectedtheory corrected

1.8 TeV |ηηηη |<1 PT>0.5 GeV/c

CDF Min-Bias

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


PYTHIA 6.206 Set A

CTEQ5L

"Transverse" Charged Particle Density: dN/dηηηηdφφφφ

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PYTHIA 6.206 Set A

Tuned PYTHIA 6.206Tuned PYTHIA 6.206Run 1 Tune ARun 1 Tune A

! Compares the average �transverse� charge particle density (|ηηηη|<1, PT>0.5 GeV) versus PT(charged jet#1) and the PT distribution of the �transverse� and �Min-Bias� densities with the QCD Monte-Carlo predictions of a tuned version of PYTHIA 6.206 (PT(hard) > 0, CTEQ5L, Set A).

Charged Particle Density: dN/dηηηηdφφφφ

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Pythia 6.206 Set ACDF Min-Bias 1.8 TeV 1.8 TeV all PT

CDF Published

Describes �Min-Bias� collisions!

�Min-Bias�

Describes the rise from �Min-Bias� to �underlying event�!


Rick Field Page 4

Charged Particle Density

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CDF Min-Bias



PYTHIA 6.206 Set A

CTEQ5L


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PYTHIA 6.206 Set A

Tuned PYTHIA 6.206Tuned PYTHIA 6.206Run 1 Tune ARun 1 Tune A

! Compares the average �transverse� charge particle density (|ηηηη|<1, PT>0.5 GeV) versus PT(charged jet#1) and the PT distribution of the �transverse� and �Min-Bias� densities with the QCD Monte-Carlo predictions of a tuned version of PYTHIA 6.206 (PT(hard) > 0, CTEQ5L, Set A).

Set A Min-Bias<dNchg/dηηηηdφφφφ> = 0.24

Describes �Min-Bias� collisions! Describes the �underlying event�!

Set A PT(charged jet#1) > 30 GeV/c�Transverse� <dNchg/dηηηηdφφφφ> = 0.60

Describes the rise from �Min-Bias� to �underlying event�!


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Charged Particle Jet #1 Direction


�Toward�


�Away�


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CDF Run 1 Min-BiasCDF Run 1 JET20

CDF Run 1 Datadata uncorrected

1.8 TeV |ηηηη|<1.0 PT>0.5 GeV

�Transverse� �Transverse� Charged Particle DensityCharged Particle Density

! Shows the data on the average �transverse� charge particle density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse momentum of the leading charged particle jet from Run 1.

�Transverse� region as defined by the leading �charged particle jet�


Rick Field Page 6



�Toward�


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|ηηηη|<1.0 PT>0.5 GeV

CDF Preliminarydata uncorrected


! Shows the data on the average �transverse� charge particle density (|ηηηη|<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 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A


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).


Excellent agreement between Run 1 and 2!


Rick Field Page 7

�Transverse� �Transverse� Charged Charged PTsumPTsum DensityDensity

! Shows the data on the average �transverse� charged PTsum density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse momentum of the leading charged particle jet from Run 1.

"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ

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�Toward�


�Away�



Rick Field Page 8


! Shows the data on the average �transverse� charged PTsum density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse momentum of the leading charged particle jet from Run 1.


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CDF Run 1 PublishedCDF Run 2 Preliminary




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CDF Run 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A



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

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




Rick Field Page 9

JetClu Jet #1 Direction



�Toward�

�Away�

�Toward-Side� Jet

�Away-Side� Jet

�Underlying Event��Underlying Event�as defined by �Calorimeter Jets�as defined by �Calorimeter Jets�

! Look at charged particle correlations in the azimuthal angle ∆φ ∆φ ∆φ ∆φ relative to the leading JetClu jet.

! Define |∆φ∆φ∆φ∆φ| < 60o as �Toward�, 60o < |∆φ∆φ∆φ∆φ| < 120o as �Transverse�, and |∆φ∆φ∆φ∆φ| > 120o as �Away�.

! All three regions have the same size in ηηηη-φφφφ space, ∆η∆η∆η∆ηx∆φ∆φ∆φ∆φ= 2x120o = 4ππππ/3.

Charged Particle ∆φ∆φ∆φ∆φCorrelations PT > 0.5 GeV/c |ηηηη| < 1

Away-side �jet�(sometimes)

Perpendicular to the plane of the 2-to-2 hard scattering

�Transverse� region is very sensitive to the �underlying event�!



�Toward�


�Away�

-1 +1

φφφφ

2ππππ

0 ηηηη

Leading Jet

Toward Region

Transverse Region

Transverse Region

Away Region

Away Region

Look at the charged particle density in the �transverse� region!


Rick Field Page 10


! Shows the data on the average �transverse� charge particle density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.



�Toward�


�Away�

, compared with PYTHIA Tune A after CDFSIM.


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

JetClu (R = 0.7, |ηηηη(jet#1)| < 2)


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PYTHIA Tune ACDF Run 2 Preliminary




�Transverse� region as defined by the leading

�calorimeter jet�


Rick Field Page 11





�Toward�


�Away�

! Compares the �transverse� region of the leading �charged particle jet�, chgjet#1, with the �transverse� region of the leading �calorimeter jet� (JetClu R = 0.7), jet#1.

JetClu Jet #1 or ChgJet#1

Direction ∆φ∆φ∆φ∆φ

�Toward�


�Away�



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data uncorrected


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JetClu Jet#1 (R = 0.7,|ηηηη(jet)|<2)


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JetClu Jet#1 (R = 0.7, |ηηηη(jet)|<2)

PYTHIA Tune A 1.96 TeV


Rick Field Page 12


! Shows the data on the average �transverse� charged PTsum density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.



�Toward�


�Away�



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! Shows the data on the average �transverse� charged PTsum density (|ηηηη|<1, PT>0.5 GeV) as a function of the transverse energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.



�Toward�


�Away�

! Compares the �transverse� region of the leading �charged particle jet�, chgjet#1, with the �transverse� region of the leading �calorimeter jet� (JetClu R = 0.7), jet#1.

JetClu Jet #1 or ChgJet#1

Direction ∆φ∆φ∆φ∆φ

�Toward�


�Away�



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Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) ChgJet#1 R = 0.7




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�Toward�


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�Toward�


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! Shows the generated prediction of PYTHIA Tune A before CDFSIM.



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PY Tune A GeneratedPY Tune A CorrectedCDF Run 2 Preliminary




CDFSIM/Generated: "Transverse" dN/dηηηηdφφφφ

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! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.

Small correction (about 10%) independent of ET(jet#1)!


Rick Field Page 16

The Leading The Leading �Charged Particle� Jet�Charged Particle� Jet

! Shows the data on the average number of charged particles within the leading �charged particle jet� (|ηηηη|<1, PT>0.5 GeV, R = 0.7) as a function of the transverse momentum of the leading�charged particle jet� from Run 1.

Nchg(chgjet#1) versus PT(chgjet#1)

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The Leading The Leading �Charged Particle� Jet�Charged Particle� Jet

! Shows the data on the average number of charged particles within the leading �charged particle jet� (|ηηηη|<1, PT>0.5 GeV, R = 0.7) as a function of the transverse momentum of the leading�charged particle jet� from Run 1.


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PYTHIA produces too many charged particles in the leading

�charged particle jet�!


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The Leading The Leading �Calorimeter� Jet�Calorimeter� Jet

! Shows the Run 2 data on the average number of charged particles (|ηηηη|<1, PT>0.5 GeV, R = 0.7) within the leading �calorimeter jet� (JetClu R = 0.7, |ηηηη(jet)|< 0.7) as a function of the transverse energy of the leading �calorimeter jet�.

Nchg(jet#1) versus ET(jet#1)

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PYTHIA produces too many charged particles in the

leading �calorimeter jet�!


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The Leading The Leading �Calorimeter� Jet�Calorimeter� Jet

! Shows the Run 2 data on the average number of charged particles (|ηηηη|<1, PT>0.5 GeV, R = 0.7) within the leading �calorimeter jet� (JetClu R = 0.7, |ηηηη(jet)|< 0.7) as a function of the transverse energy of the leading �calorimeter jet�.

! Compares the number of charged particles within the leading �charged particle jet�, chgjet#1, with the number of charged particles within the leading �calorimeter jet�(JetClu R = 0.7), jet#1.


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The Leading �Calorimeter� JetThe Leading �Calorimeter� JetCharged Particle MultiplicityCharged Particle Multiplicity

! Shows the Run 2 data on the average number of charged particles (|ηηηη|<1, PT>0.5 GeV, R = 0.7) within the leading �calorimeter jet� (JetClu R = 0.7, |ηηηη(jet)|< 0.7) as a function of ET(jet#1) compared with PYTHIA Tune A after CDFSIM.

Calorimeter Jet


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Calorimeter Jet CDFSIM/Generated: Leading Jet Nchg

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

CD

FSIM

/Gen

erat

ed

PYTHIA Tune A 1.96 TeV JetClu R = 0.7 |ηηηη(jet)| < 0.7



Correction becomes large for ET(jet#1) > 100 GeV and

depends on ET(jet#1)!


0

2

4

6

8

10

12

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)A

vera

ve N

chg





0

2

4

6

8

10

12

14

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)A

vera

ve N

chg

PY Tune A GeneratedPY Tune A + CDFSIMCDF Run 2 Uncorrected Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)

JetClu R = 0.7 |ηηηη(jet)| < 0.7



Rick Field Page 22




Calorimeter Jet CDFSIM/Generated: Leading Jet Nchg

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

CD

FSIM

/Gen

erat

ed

PYTHIA Tune A 1.96 TeV JetClu R = 0.7 |ηηηη(jet)| < 0.7



Correction becomes large for ET(jet#1) > 100 GeV and

depends on ET(jet#1)!

! Shows �corrected� Run 2 data compared with PYTHIA Tune A (uncorrected).


0

2

4

6

8

10

12

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)A

vera

ve N

chg





0

2

4

6

8

10

12

14

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)A

vera

ve N

chg

PY Tune A GeneratedPY Tune A + CDFSIMCDF Run 2 Uncorrected Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)




0

2

4

6

8

10

12

14

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)A

vera

ve N

chg



CDF Preliminarydata corrected

theory uncorrected


Multiply data by the �unfolding function�(i.e. Generated/CDFSIM) determined from PYTHIA Tune A to get �corrected� data.


Rick Field Page 23

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetCharged PCharged PTT DistributionDistribution

! Shows the transverse momentum distribution of charged particles (|ηηηη|<1) within the leading �charged particle jet� compared with PYTHIA Tune A. The plot shows dNchg/dz with z = PT/PT(chgjet#1) for the range 30 < PT(chgjet#1) < 70 GeV/c.

! Shows the transverse momentum distribution of charged particles (|ηηηη|<1) within the leading �calorimeter jet�(JetClu, R = 0.7, |ηηηη(jet)| < 0.7) compared with PYTHIA Tune A. The plot shows dNchg/dz with z = PT/ET(jet#1) for the range 30 < ET(jet#1) < 70 GeV.

Leading Charged Particle Jet

0.1

1.0

10.0

100.0

0.0 0.2 0.4 0.6 0.8 1.0

z = PT/PT(chgjet#1)

F(z)

= d

N/d

z


R = 0.7 30 < PT(chgjet#1) < 70 GeV



Leading Calorimeter Jet

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

0.0 0.2 0.4 0.6 0.8 1.0 1.2

z = PT/ET(Jet#1)

F(z)

= d

N/d

z


JetClu R = 0.7 30 < ET(jet#1) < 70 GeV




Rick Field Page 24

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetCharged PCharged PTT DistributionDistribution

! Shows the transverse momentum distribution of charged particles (|ηηηη|<1) within the leading �charged particle jet� compared with PYTHIA Tune A. The plot shows dNchg/dz with z = PT/PT(chgjet#1) for the range 30 < PT(chgjet#1) < 70 GeV/c.

! Shows the transverse momentum distribution of charged particles (|ηηηη|<1) within the leading �calorimeter jet�(JetClu, R = 0.7, |ηηηη(jet)| < 0.7) compared with PYTHIA Tune A. The plot shows dNchg/dz with z = PT/ET(jet#1) for the range 30 < ET(jet#1) < 70 GeV.

PYTHIA produces too many �soft� charged particles within

the leading �jet�!

Leading Charged Particle Jet

0.1

1.0

10.0

100.0

0.0 0.2 0.4 0.6 0.8 1.0

z = PT/PT(chgjet#1)

F(z)

= d

N/d

z


R = 0.7 30 < PT(chgjet#1) < 70 GeV



Leading Calorimeter Jet

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

0.0 0.2 0.4 0.6 0.8 1.0 1.2

z = PT/ET(Jet#1)

F(z)

= d

N/d

z





PYTHIA produces too many �soft� charged particles within

the leading �jet�!


Rick Field Page 25

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetChargedCharged PTPTsumsum & & PTPTmaxmax FractionFraction

! Shows average charged PTsumfraction, PTsum/ET(jet#1), and the average charged PTmax fraction, PTmax/ET(jet#1), within the leading �calorimeter jet� (JetClu, R = 0.7, |ηηηη(jet)| < 0.7) compared with PYTHIA Tune A.

! Shows distribution of the charged PTsumfraction, z = PTsum/ET(jet#1), and the distribution of charged PTmax fraction, z = PTmax/ET(jet#1), within the leading �calorimeter jet� (JetClu, R = 0.7, |ηηηη(jet)| < 0.7) for the range 95 < ET(jet#1) < 130 GeVcompared with PYTHIA Tune A.

Charged Fraction within the Leading Jet

0

2

4

6

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

z = PTmax/ET(jet#1) or PTsum/ET(jet#1)

(1/N

) dN/

dz





PTmax/ET(jet#1)

PTsum/ET(jet#1)

PTsum/ET(Jet#1) and PTmax/ET(jet#1)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

Aver

age

Frac

tion





PTsum(chg)/ET(jet#1)

PTmax(chg)/ET(jet#1)


Rick Field Page 26

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetChargedCharged PTPTsumsum & & PTPTmaxmax FractionFraction

! Shows average charged PTsumfraction, PTsum/ET(jet#1), and the average charged PTmax fraction, PTmax/ET(jet#1), within the leading �calorimeter jet� (JetClu, R = 0.7, |ηηηη(jet)| < 0.7) compared with PYTHIA Tune A.

! Shows distribution of the charged PTsumfraction, z = PTsum/ET(jet#1), and the distribution of charged PTmax fraction, z = PTmax/ET(jet#1), within the leading �calorimeter jet� (JetClu, R = 0.7, |ηηηη(jet)| < 0.7) for the range 95 < ET(jet#1) < 130 GeVcompared with PYTHIA Tune A.

Charged Fraction within the Leading Jet

0

2

4

6

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

z = PTmax/ET(jet#1) or PTsum/ET(jet#1)

(1/N

) dN/

dz





PTmax/ET(jet#1)

PTsum/ET(jet#1)

PYTHIA does okay on the charged PTmax fraction!PYTHIA does okay on the charged PTmax fraction!

But PYTHIA does not do well on the charged PTsum fraction!

But PYTHIA does not do as well on the charged PTsum fraction!

PTsum/ET(Jet#1) and PTmax/ET(jet#1)

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

Aver

age

Frac

tion





PTsum(chg)/ET(jet#1)

PTmax(chg)/ET(jet#1)


Rick Field Page 27

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetCharged Charged PTPTsumsum FractionFraction

! Shows average charged PTsum fraction, PTsum/ET(jet#1), within the leading �calorimeter jet� (JetClu, R = 0.7, |ηηηη(jet)| < 0.7) compared with PYTHIA Tune A after CDFSIM.

Calorimeter Jet

Leading Jet: Charged PTsum/ET(Jet#1)

0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)






Rick Field Page 28



Calorimeter Jet


CDFSIM/Generated: Leading Jet PTsum Fraction

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

CD

FSIM

/Gen

erat

ed

PYTHIA Tune A 1.96 TeVCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)



Very large correction that depends on ET(jet#1)!


0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)





Leading Jet: Charged PTsum/ET(jet#1)

0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)

PY Tune A GeneratedPY Tune A + CDFSIMCDF Run 2 Uncorrected

JetClu R = 0.7 |ηηηη(jet)| < 0.7CDF Preliminarydata uncorrected



Rick Field Page 29



Calorimeter Jet


CDFSIM/Generated: Leading Jet PTsum Fraction

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

CD

FSIM

/Gen

erat

ed

PYTHIA Tune A 1.96 TeVCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)



Very large correction that depends on ET(jet#1)!

! Shows �corrected� Run 2 data compared with PYTHIA Tune A (uncorrected).


0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)






0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)

PY Tune A GeneratedPY Tune A + CDFSIMCDF Run 2 Uncorrected

JetClu R = 0.7 |ηηηη(jet)| < 0.7CDF Preliminarydata uncorrected



0.2

0.3

0.4

0.5

0.6

0.7

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)C

harg

ed P

Tsum

/ET(

jet#

1)

JetClu R = 0.7 |ηηηη(jet)| < 0.7CDF Preliminarydata corrected

theory uncorrectedCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)


Multiply data by the �unfolding function�(i.e. Generated/CDFSIM) determined from PYTHIA Tune A to get �corrected� data.


Rick Field Page 30

ProtonProton--AntiProtonAntiProtonCollisionsCollisions

! Draw an R = 0.7 cone around the leading calorimeter jet (JetClu, R = 0.7).

Proton AntiProton

Proton AntiProton

Jet Direction

R

ETjet

Proton AntiProton

Jet Direction

R

ETjet

PT

KT

Charged Particle

! Look at charged particles within R = 0.7 of the leading calorimeter jet.

Momentum perpendicular to

the jet axis

Momentum perpendicular to

the beam axis


Rick Field Page 31

The Leading �Calorimeter� JetThe Leading �Calorimeter� JetCharged KCharged KTT DistributionDistribution

! Shows the average momentum perpendicular to the jet axis for charged particles (PT > 0.5 GeV/c, |ηηηη|<1) within the leading �calorimeter jet� (JetClu, R = 0.7) compared with PYTHIA Tune A.

! Shows the distribution of momentum perpendicular to the jet axis for charged particles within the leading �calorimeter jet� compared with PYTHIA Tune A. The plot shows dNchg/dKT for the range 30 < ET(jet#1) < 70 GeV and 95 < ET(jet#1) < 130 GeV.

Jet#1 <KT> versus ET(jet#1)

0.0

0.4

0.8

1.2

1.6

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

Ave

rave

KT

(GeV

/c)

CDF Run 2PY Tune A

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7

CDF Preliminarydata uncorrectedtheory + CDFSIM

Perpendicular to Jet Axis

1.96 TeV

KT Distribution within Jet#1

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

0 2 4 6 8 10 12 14 16 18 20

KT (GeV/c)

dN/d

KT

(1/G

eV/c

)

Perpendicular to Jet Axis


JetClu R = 0.7 0.1 < |DETηηηη| < 0.7

30 < ET(jet1) < 70 GeV

95 < ET(jet1) < 130 GeV

1.96 TeV


Rick Field Page 32

Inclusive Inclusive Jet Cross SectionJet Cross Section

! Shows the uncorrected inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) compared with PYTHIA Tune A (after CDFSIM).

Inclusive Jet Cross Section

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

d σ σσσ/d

ET ( µ µµµ

b/G

eV) CDF Run2 AllJets

PY Tune A


JetClu R = 0.7 0.1 < |DETηηηη | < 0.7

1.96 TeV

Inclusive Jet Cross Section: Data/Theory

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

Rat

io: D

ata/

Theo

ry

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7


PY Tune A + CDFSIM

1.96 TeV

! Shows the ratio of the uncorrected inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) to PYTHIA Tune A (after CDFSIM).

Very similar to Frank Chlebana�s

�corrected� plots!


Rick Field Page 33

Inclusive Inclusive Jet Cross SectionJet Cross Section

! Shows the uncorrected inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) compared with PYTHIA Tune A (after CDFSIM).

Inclusive Jet Cross Section

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

d σ σσσ/d

ET ( µ µµµ

b/G


PY Tune A


JetClu R = 0.7 0.1 < |DETηηηη | < 0.7

1.96 TeV

Inclusive Jet Cross Section: Data/Theory

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

Rat

io: D

ata/

Theo

ry

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7


PY Tune A + CDFSIM

1.96 TeV

! Shows the ratio of the uncorrected inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) to PYTHIA Tune A (after CDFSIM).

Very similar to Frank Chlebana�s

�corrected� plots!

Data and theory are normalized to agree at this one point. This fixes the normalization for all the other plots presented in this talk!


Rick Field Page 34

Inclusive CrossInclusive Cross--SectionSection�Correction Factors��Correction Factors�

! Shows PYTHIA Tune A + CDFSIM inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7) compared with the �true� cross-section where �true� is the PTsum of all hadrons (partons) with PT > 0 in R = 0.7 cone around JetClu.

Inclusive Cross-Section: dσσσσ/dET

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET (GeV)

d σ σσσ/d

ET ( µ µµµ

b/G

eV)

ET(particles in R)

ET(partons in R)

ET(jetclu)


0.1<|DETηηηη|<0.7

R = 0.7

Inclusive X-Sec Ratio: (PTsum in R=0.7)/ET(jetclu)

0.5

1.0

1.5

2.0

2.5

3.0

0 25 50 75 100 125 150 175 200 225 250

ET(jetclu) (GeV)

Cro

ss-S

ectio

n R

atio

PYTHIA Tune A 1.96 teV


Particles

Partons

Measured

�True�

Correction factors!


Rick Field Page 35

Inclusive CrossInclusive Cross--SectionSection�Correction Factors��Correction Factors�

! Shows PYTHIA Tune A + CDFSIM inclusive �calorimeter jet� cross-section for (JetClu, R = 0.7) compared with the �true� cross-section where �true� is the PTsum of all hadrons (partons) with PT > 0 in R = 0.7 cone around JetClu.

Inclusive Cross-Section: dσσσσ/dET

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET (GeV)

d σ σσσ/d

ET ( µ µµµ

b/G

eV)

ET(particles in R)

ET(partons in R)

ET(jetclu)



R = 0.7

Inclusive X-Sec Ratio: (PTsum in R=0.7)/ET(jetclu)

0.5

1.0

1.5

2.0

2.5

3.0

0 25 50 75 100 125 150 175 200 225 250

ET(jetclu) (GeV)

Cro

ss-S

ectio

n R

atio

PYTHIA Tune A 1.96 teV


Particles

Partons

Measured

�True�

ETsum(in R)/ET(jet#1) vs ET(jet#1)

0.8

0.9

1.0

1.1

1.2

1.3

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

ETsu

m(in

R)/E

T(je

t)



Particles

Partons

JetClu R = 0.7

�True�


Rick Field Page 36

Jet Cross SectionsJet Cross Sections

! Shows the Run 2 uncorrected inclusive �calorimeter jet� cross-section and the leading �calorimeter jet� cross-section (JetClu, R = 0.7, energy scale factor of 1.042).

! Shows the ratio of the leading jet cross section to the inclusive jet cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) compared with PYTHIA Tune A (after CDFSIM).

Jet Cross Sections

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

d σ σσσ/d

ET ( µ µµµ

b/G


CDF Run2 Jet1


JetClu R = 0.7 0.1 < |DETηηηη | < 0.7

1.96 TeV

Jet Cross-Section Ratio: Jet#1/AllJets

0.5

0.6

0.7

0.8

0.9

1.0

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

Jet#

1/A

llJet

s

CDF Run 2PY Tune A

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7


1.96 TeV

Measures how much cross-section comes

from >1 jet!


Rick Field Page 37


! Shows the uncorrected inclusive jet cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) compared with PYTHIA Tune A (after CDFSIM).

! Shows the ratio of the uncorrected inclusive jet cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) to PYTHIA Tune A (after CDFSIM).

Jet Cross Sections

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

d σ σσσ/d

ET (

µ µµµb/G

eV)


JetClu R = 0.7 0.1 < |DETηηηη | < 0.7

Jet#1

Jet#2Jet#3

1.96 TeV

Jet Cross-Sections: Data/Theory

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

Rat

io: D

ata/

Theo

ry

Jet#1Jet#2Jet#3

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7


PY Tune A + CDFSIM

1.96 TeV


Rick Field Page 38


! Shows the uncorrected inclusive jet cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) compared with PYTHIA Tune A (after CDFSIM).

! Shows the ratio of the uncorrected inclusive jet cross-section for (JetClu, R = 0.7, energy scale factor of 1.042) to PYTHIA Tune A (after CDFSIM).

Jet Cross Sections

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

d σ σσσ/d

ET (

µ µµµb/G

eV)


JetClu R = 0.7 0.1 < |DETηηηη | < 0.7

Jet#1

Jet#2Jet#3

1.96 TeV


0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150 175 200 225 250

ET(jet) (GeV)

Rat

io: D

ata/

Theo

ry

Jet#1Jet#2Jet#3

JetClu R = 0.7 0.1 < |DETηηηη| < 0.7


PY Tune A + CDFSIM

1.96 TeV

PThat/ET(jet#1) vs ET(jet#1)

0.7

0.8

0.9

1.0

1.1

1.2

1.3

0 25 50 75 100 125 150 175 200 225 250

ET(jet#1) (GeV)

PTha

t/ET(

jet#

1)



JetClu R = 0.7

Tansverse momentum of the hard 2-to-2 parton-parton collision!


Rick Field Page 39

Leading �Charged Particle Jet� Leading �Charged Particle Jet� Cross SectionCross Section

! Shows the uncorrected leading �charged particle jet� cross-section for (PT > 0.5 GeV/c, |ηηηη|<1) compared with PYTHIA Tune A (after CDFSIM).

! Shows the ratio of the uncorrected leading �charged particle jet� cross-section for (PT > 0.5GeV/c, |ηηηη|<1) to PYTHIA Tune A (after CDFSIM).

Leading ChgJet Cross Section

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

0 25 50 75 100 125 150


d σ σσσ/d

PT ( µ µµµ

b/G

eV) PY Tune A

CDF Run2


1.96 TeV |ηηηη|<1.0 PT>0.5 GeV R = 0.7

Leading ChgJet Cross Section: Data/Theory

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150

PT(charged jet#1) (GeV)

Rat

io: D

ata/

Theo

ry

PT > 0.5 GeV/c |ηηηη| < 0.7 R = 0.7


PY Tune A + CDFSIM

1.96 TeV


Rick Field Page 40

Leading �Charged Particle Jet� Leading �Charged Particle Jet� Cross SectionCross Section

! Shows the uncorrected leading �charged particle jet� cross-section for (PT > 0.5 GeV/c, |ηηηη|<1) compared with PYTHIA Tune A (after CDFSIM).

! Shows the ratio of the uncorrected leading �charged particle jet� cross-section for (PT > 0.5GeV/c, |ηηηη|<1) to PYTHIA Tune A (after CDFSIM).

Leading ChgJet Cross Section

1.0E-06

1.0E-05

1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

0 25 50 75 100 125 150


d σ σσσ/d

PT ( µ µµµ

b/G

eV) PY Tune A

CDF Run2


1.96 TeV |ηηηη|<1.0 PT>0.5 GeV R = 0.7

Leading ChgJet Cross Section: Data/Theory

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150

PT(charged jet#1) (GeV)

Rat

io: D

ata/

Theo

ry

PT > 0.5 GeV/c |ηηηη| < 0.7 R = 0.7


PY Tune A + CDFSIM

1.96 TeV


0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

0 25 50 75 100 125 150 175 200 225 250


Rat

io: D

ata/

Theo

ry

Charged Particle Jet#1Calorimeter Jet#1


PY Tune A + CDFSIM

Compares data/theory for the leading charged particle jet and the

leading calorimeter jet!


Rick Field Page 41

Summary & ConclusionsSummary & Conclusions

PYTHIA Tune A

! PYTHIA Tune A does a good job of describing the �underlying event� in the Run 2 data as defined by �charged particle jets� and as defined by �calorimeter jets�. HERWIG Run 2 comparisons will be coming soon!

! PYTHIA Tune A does a fairly good job (although not perfect) describing the properties of the �calorimeter jets� in Run 2 (in the central region!).

! I am hoping we can use the QCD Monte-Carlo models (PYTHIA & HERWIG) to correct the data from measured to �true� by constructing �correction factors� for every observable of interest.

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying Event Underlying Event

Initial-State Radiation



Rick Field Page 42

Summary & ConclusionsSummary & Conclusions

PYTHIA Tune A

! PYTHIA Tune A does a good job of describing the �underlying event� in the Run 2 data as defined by �charged particle jets� and as defined by �calorimeter jets�. HERWIG Run 2 comparisons will be coming soon!

! PYTHIA Tune A does a fairly good job (although not perfect) describing the properties of the �calorimeter jets� in Run 2 (in the central region!).

! I am hoping we can use the QCD Monte-Carlo models (PYTHIA & HERWIG) to correct the data from measured to �true� by constructing �correction factors� for every observable of interest.

Proton AntiProton

PT(hard)

Outgoing Parton

Outgoing Parton

Underlying Event Underlying Event

Initial-State Radiation


This is a different method from the �jet energy corrections� used in Run 1!

Documents

PYTHIA Tune A versus Run 2 Datarfield/cdf/CDF_Joint_6-27-03.pdf · 6/27/2003 · PYTHIA 6.206 Set A Tuned PYTHIA 6.206 Run 1 Tune A! Compares the average ﬁtransverseﬂ charge