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
CDF Joint Physics Group June 27, 2003
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
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�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!
CDF Joint Physics Group June 27, 2003
Rick Field Page 3
Charged Particle Density
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
ed D
ensi
ty d
N/d
η ηηηdφ φφφd
PT (1
/GeV
/c)
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
"Transverse"PT(chgjet#1) > 30 GeV/c
PYTHIA 6.206 Set A
CTEQ5L
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV/c
CDF Run 1data uncorrectedtheory corrected
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
0.0
0.2
0.4
0.6
0.8
1.0
-4 -3 -2 -1 0 1 2 3 4
Pseudo-Rapidity ηηηη
dN/d
η ηηηdφ φφφ
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�!
CDF Joint Physics Group June 27, 2003
Rick Field Page 4
Charged Particle Density
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
ed D
ensi
ty d
N/d
η ηηηdφ φφφd
PT (1
/GeV
/c)
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
"Transverse"PT(chgjet#1) > 30 GeV/c
PYTHIA 6.206 Set A
CTEQ5L
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV/c
CDF Run 1data uncorrectedtheory corrected
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�!
CDF Joint Physics Group June 27, 2003
Rick Field Page 5
Charged Particle Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
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�
CDF Joint Physics Group June 27, 2003
Rick Field Page 6
Charged Particle Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Run 1 Min-BiasCDF Run 1 JET20
CDF Run 1 Datadata uncorrected
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Run 1 Min-BiasCDF Run 1 JET20
|ηηηη|<1.0 PT>0.5 GeV
CDF Preliminarydata uncorrected
�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.
! 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.
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Run 2
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty CDF Run 1 PublishedCDF Run 2 Preliminary
|ηηηη|<1.0 PT>0.5 GeV/c
CDF Preliminarydata uncorrected
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Run 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A
|ηηηη|<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).
�Transverse� region as defined by the leading �charged particle jet�
Excellent agreement between Run 1 and 2!
CDF Joint Physics Group June 27, 2003
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
0.00
0.25
0.50
0.75
1.00
1.25
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
) CDF JET20CDF Min-Bias
CDF Run 1 Datadata uncorrected
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV
Charged Particle Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
�Transverse� region as defined by the leading �charged particle jet�
CDF Joint Physics Group June 27, 2003
Rick Field Page 8
�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
0.00
0.25
0.50
0.75
1.00
1.25
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
) CDF JET20CDF Min-Bias
CDF Run 1 Datadata uncorrected
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV
! 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.
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
)
CDF JET20CDF Min-Bias
CDF Preliminarydata uncorrected
|ηηηη|<1.0 PT>0.5 GeV
Charged Particle Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
)
CDF Run 2
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
/c)
CDF Run 1 PublishedCDF Run 2 Preliminary
CDF Preliminarydata uncorrected
|ηηηη|<1.0 PT>0.5 GeV/c
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
1.25
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)"T
rans
vers
e" P
Tsum
Den
sity
(GeV
/c)
CDF Run 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A
CDF Preliminarydata uncorrectedtheory corrected
|ηηηη|<1.0 PT>0.5 GeV/c
! 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!
�Transverse� region as defined by the leading �charged particle jet�
Excellent agreement between Run 1 and 2!
CDF Joint Physics Group June 27, 2003
Rick Field Page 9
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Transverse� �Transverse�
�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�!
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�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!
CDF Joint Physics Group June 27, 2003
Rick Field Page 10
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
�Transverse� region as defined by the leading
�calorimeter jet�
CDF Joint Physics Group June 27, 2003
Rick Field Page 11
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�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�
�Transverse� �Transverse�
�Away�
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
PT(chgjet#1) or ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity CDF Preliminary
data uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
ChgJet#1 R = 0.7
JetClu Jet#1 (R = 0.7,|ηηηη(jet)|<2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
PT(chgjet#1) or ET(jet#1) (GeV)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
ChgJet#1 R = 0.7
JetClu Jet#1 (R = 0.7, |ηηηη(jet)|<2)
PYTHIA Tune A 1.96 TeV
CDF Joint Physics Group June 27, 2003
Rick Field Page 12
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
)
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
)
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
�Transverse� region as defined by the leading
�calorimeter jet�
CDF Joint Physics Group June 27, 2003
Rick Field Page 13
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�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�
�Transverse� �Transverse�
�Away�
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
)
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
)
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
PT(chgjet#1) or ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
)
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) ChgJet#1 R = 0.7
JetClu Jet#1 (R = 0.7,|ηηηη(jet)|<2)
"Transverse" Charged PTsum Density: dPTsum/dηηηηdφφφφ
0.0
0.5
1.0
1.5
0 25 50 75 100 125 150 175 200 225 250
PT(chgjet#1) or ET(jet#1) (GeV)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
) CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) ChgJet#1 R = 0.7
JetClu Jet#1 (R = 0.7,|ηηηη(jet)|<2)
PYTHIA Tune A 1.96 TeV
CDF Joint Physics Group June 27, 2003
Rick Field Page 14
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)"T
rans
vers
e" C
harg
ed D
ensi
ty
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
�Transverse� region as defined by the leading
�calorimeter jet�
CDF Joint Physics Group June 27, 2003
Rick Field Page 15
�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 energy of the leading JetClu jet (R = 0.7, |ηηηη(jet)| < 2) from Run 2.
JetClu Jet #1 Direction
∆φ∆φ∆φ∆φ
�Toward�
�Transverse� �Transverse�
�Away�
! Shows the generated prediction of PYTHIA Tune A before CDFSIM.
, compared with PYTHIA Tune A after CDFSIM.
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)"T
rans
vers
e" C
harg
ed D
ensi
ty
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)"T
rans
vers
e" C
harg
ed D
ensi
ty
PYTHIA Tune ACDF Run 2 Preliminary
CDF Preliminarydata uncorrectedtheory corrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
"Transverse" Charged Particle Density: dN/dηηηηdφφφφ
0.00
0.25
0.50
0.75
1.00
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)"T
rans
vers
e" C
harg
ed D
ensi
ty
PY Tune A GeneratedPY Tune A CorrectedCDF Run 2 Preliminary
CDF Preliminarydata uncorrected
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
CDFSIM/Generated: "Transverse" dN/dηηηηdφφφφ
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
JetClu (R = 0.7, |ηηηη(jet#1)| < 2)
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) PYTHIA Tune A 1.96 TeV
! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.
Small correction (about 10%) independent of ET(jet#1)!
CDF Joint Physics Group June 27, 2003
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)
0
2
4
6
8
10
12
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 1 Min-BiasCDF Run 1 JET20
CDF Run 1 Datadata uncorrected
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV R = 0.7
CDF Joint Physics Group June 27, 2003
Rick Field Page 17
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)
0
2
4
6
8
10
12
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 1 Min-BiasCDF Run 1 JET20
CDF Run 1 Datadata uncorrected
1.8 TeV |ηηηη|<1.0 PT>0.5 GeV R = 0.7
Nchg(chgjet#1) versus PT(chgjet#1)
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 1 Min-BiasCDF Run 1 JET20
CDF Preliminarydata uncorrected
|ηηηη|<1.0 PT>0.5 GeV R = 0.7
! 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.
Nchg(chgjet#1) versus PT(chgjet#1)
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 2
Nchg(chgjet#1) versus PT(chgjet#1)
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 1 Min-BiasCDF Run 1 JET20CDF Run 2
CDF Preliminarydata uncorrected
|ηηηη|<1.0 PT>0.5 GeV/c R = 0.7
Nchg(chgjet#1) versus PT(chgjet#1)
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
PT(charged jet#1) (GeV/c)
Ave
rave
Nch
g
CDF Run 1 Min-BiasCDF Run 1 JET20CDF Run 2PY Tune A
|ηηηη|<1.0 PT>0.5 GeV/c R = 0.7
CDF Preliminarydata uncorrectedtheory corrected
Excellent agreement between Run 1 and 2!
PYTHIA produces too many charged particles in the leading
�charged particle jet�!
CDF Joint Physics Group June 27, 2003
Rick Field Page 18
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)
0
2
4
6
8
10
12
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) (GeV)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrected
Nchg(jet#1) versus 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)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
PYTHIA produces too many charged particles in the
leading �calorimeter jet�!
CDF Joint Physics Group June 27, 2003
Rick Field Page 19
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.
Nchg(jet#1) versus 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)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrected
Nchg(jet#1) versus 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)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Nchg(jet#1) and Nchg(charged jet#1)
0
2
4
6
8
10
12
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) or PT(charged jet#1) (GeV)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrected
Nchg(jet#1)
Nchg(chgjet#1)
Nchg(jet#1) and Nchg(charged jet#1)
0
2
4
6
8
10
12
0 25 50 75 100 125 150 175 200 225 250
ET(jet#1) or PT(charged jet#1) (GeV)
Ave
rave
Nch
gCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Nchg(jet#1)
Nchg(chgjet#1)
CDF Joint Physics Group June 27, 2003
Rick Field Page 20
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
Nchg(jet#1) versus 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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
CDF Joint Physics Group June 27, 2003
Rick Field Page 21
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.
! Shows the generated prediction of PYTHIA Tune A before CDFSIM.
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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.
Correction becomes large for ET(jet#1) > 100 GeV and
depends on ET(jet#1)!
Nchg(jet#1) versus 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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Nchg(jet#1) versus ET(jet#1)
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
CDF Preliminarydata uncorrected
CDF Joint Physics Group June 27, 2003
Rick Field Page 22
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.
! Shows the generated prediction of PYTHIA Tune A before CDFSIM.
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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.
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).
Nchg(jet#1) versus 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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c) JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Nchg(jet#1) versus ET(jet#1)
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
CDF Preliminarydata uncorrected
Nchg(jet#1) versus ET(jet#1)
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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata corrected
theory uncorrected
PYTHIA Tune A 1.96 TeV
Multiply data by the �unfolding function�(i.e. Generated/CDFSIM) determined from PYTHIA Tune A to get �corrected� data.
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory corrected
R = 0.7 30 < PT(chgjet#1) < 70 GeV
|ηηηη|<1.0 PT>0.5 GeV/c
PYTHIA Tune A 1.96 TeV
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
CDF Preliminarydata uncorrectedtheory corrected
JetClu R = 0.7 30 < ET(jet#1) < 70 GeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PYTHIA Tune A 1.96 TeV
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory corrected
R = 0.7 30 < PT(chgjet#1) < 70 GeV
|ηηηη|<1.0 PT>0.5 GeV/c
PYTHIA Tune A 1.96 TeV
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
CDF Preliminarydata uncorrectedtheory corrected
JetClu R = 0.7 30 < ET(jet#1) < 70 GeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PYTHIA Tune A 1.96 TeV
PYTHIA produces too many �soft� charged particles within
the leading �jet�!
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory corrected
JetClu R = 0.7 95 < ET(jet#1) < 130 GeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PYTHIA Tune A 1.96 TeV
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
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PTsum(chg)/ET(jet#1)
PTmax(chg)/ET(jet#1)
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory corrected
JetClu R = 0.7 95 < ET(jet#1) < 130 GeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PYTHIA Tune A 1.96 TeV
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
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PTsum(chg)/ET(jet#1)
PTmax(chg)/ET(jet#1)
CDF Joint Physics Group June 27, 2003
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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
CDF Joint Physics Group June 27, 2003
Rick Field Page 28
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
! Shows the generated prediction of PYTHIA Tune A before CDFSIM.
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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.
Very large correction that depends on 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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
CDF Joint Physics Group June 27, 2003
Rick Field Page 29
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
! Shows the generated prediction of PYTHIA Tune A before CDFSIM.
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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
! Shows the ratio CDFSIM/Generated for PYTHIA Tune A.
Very large correction that depends on ET(jet#1)!
! Shows �corrected� Run 2 data compared with PYTHIA Tune A (uncorrected).
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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A 1.96 TeV
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
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
Charged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
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)
JetClu R = 0.7 |ηηηη(jet)| < 0.7CDF Preliminarydata corrected
theory uncorrectedCharged Particles (|ηηηη|<1.0, PT>0.5 GeV/c)
PYTHIA Tune A 1.96 TeV
Multiply data by the �unfolding function�(i.e. Generated/CDFSIM) determined from PYTHIA Tune A to get �corrected� data.
CDF Joint Physics Group June 27, 2003
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
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory + CDFSIM
JetClu R = 0.7 0.1 < |DETηηηη| < 0.7
30 < ET(jet1) < 70 GeV
95 < ET(jet1) < 130 GeV
1.96 TeV
CDF Joint Physics Group June 27, 2003
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
CDF Preliminarydata uncorrectedtheory + CDFSIM
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
CDF Preliminarydata uncorrected
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!
CDF Joint Physics Group June 27, 2003
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
eV) CDF Run2 AllJets
PY Tune A
CDF Preliminarydata uncorrectedtheory + CDFSIM
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
CDF Preliminarydata uncorrected
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!
CDF Joint Physics Group June 27, 2003
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)
PYTHIA Tune A 1.96 TeV
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
0.1<|DETηηηη|<0.7
Particles
Partons
Measured
�True�
Correction factors!
CDF Joint Physics Group June 27, 2003
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)
PYTHIA Tune A 1.96 TeV
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
0.1<|DETηηηη|<0.7
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)
PYTHIA Tune A 1.96 TeV
0.1<|DETηηηη|<0.7
Particles
Partons
JetClu R = 0.7
�True�
CDF Joint Physics Group June 27, 2003
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
eV) CDF Run2 AllJets
CDF Run2 Jet1
CDF Preliminarydata uncorrected
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
CDF Preliminarydata uncorrectedtheory + CDFSIM
1.96 TeV
Measures how much cross-section comes
from >1 jet!
CDF Joint Physics Group June 27, 2003
Rick Field Page 37
Jet Cross SectionsJet Cross Sections
! 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)
CDF Preliminarydata uncorrectedtheory + CDFSIM
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
CDF Preliminarydata uncorrected
PY Tune A + CDFSIM
1.96 TeV
CDF Joint Physics Group June 27, 2003
Rick Field Page 38
Jet Cross SectionsJet Cross Sections
! 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)
CDF Preliminarydata uncorrectedtheory + CDFSIM
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
CDF Preliminarydata uncorrected
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)
PYTHIA Tune A 1.96 TeV
0.1<|DETηηηη|<0.7
JetClu R = 0.7
Tansverse momentum of the hard 2-to-2 parton-parton collision!
CDF Joint Physics Group June 27, 2003
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
PT(charged jet#1) (GeV/c)
d σ σσσ/d
PT ( µ µµµ
b/G
eV) PY Tune A
CDF Run2
CDF Preliminarydata uncorrectedtheory corrected
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
CDF Preliminarydata uncorrected
PY Tune A + CDFSIM
1.96 TeV
CDF Joint Physics Group June 27, 2003
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
PT(charged jet#1) (GeV/c)
d σ σσσ/d
PT ( µ µµµ
b/G
eV) PY Tune A
CDF Run2
CDF Preliminarydata uncorrectedtheory corrected
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
CDF Preliminarydata uncorrected
PY Tune A + CDFSIM
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#1) or PT(charged jet#1) (GeV)
Rat
io: D
ata/
Theo
ry
Charged Particle Jet#1Calorimeter Jet#1
CDF Preliminarydata uncorrected
PY Tune A + CDFSIM
Compares data/theory for the leading charged particle jet and the
leading calorimeter jet!
CDF Joint Physics Group June 27, 2003
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
Final-State Radiation
CDF Joint Physics Group June 27, 2003
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
Final-State Radiation
This is a different method from the �jet energy corrections� used in Run 1!