TeV4LHC Workshop
Talk #1
Rick Field
University of Florida
Drell-Yan Production
Lepton
Multiple Parton Interactions
Outgoing Parton
PT(hard)
Proton
AntiProton
Underlying Event
Proton
Underlying Event
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Anti-Lepton
TeV4LHC - Fermilab
October 20, 2005
CDF Run 2
Rick Field - Florida/CDF
Outgoing Parton
Page 1
CDF Run 2
Monte Carlo Tunes
Lepton-Pair
Drell-Yan Production
Outline of Talk
PT(pair)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
 PT(Z-boson): Tuning to fit the
PT(Z) distribution.
Outgoing Parton
Drell-Yan Production
 Drell-Yan: Tuning to fit the
Lepton
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
 Jet Production: Tuning to fit the
“underlying event” is high PT jet
production.
Anti-Lepton
“Hard” Scattering
“underlying event” in
Drell-Yan production.
CDF Run 2 Tunes
PYTHIA Tune A
PYTHIA Tune A25
PYTHIA Tune A50
PYTHIA Tune AW
PYTHIA Tune Q
PYTHIA Tune QW
JIMMY Default
JIMMY 325
Outgoing Parton
PT(hard)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
 Energy: Tuning to fit the energy in the
“underlying event”.
Final-State
Radiation
Outgoing Parton
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 2
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Parameter
Tune A
Tune
A25
Tune
A50
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
0.9
0.9
PARP(86)
0.95
0.95
0.95
s = 1.0
Z-Boson Transverse Momentum
0.12
PT Distribution 1/N dN/dPT
UE Parameters
CDF Run 1 Data
PYTHIA Tune A
PYTHIA Tune A25
PYTHIA Tune A50
s = 2.5
0.08
CDF Run 1
published
1.8 TeV
s = 5.0
Normalized to 1
0.04
0.00
0
2
4
6
8
10
12
14
16
18
20
Z-Boson PT (GeV/c)
ISR Parameter
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(67)
4.0
4.0
4.0
MSTP(91)
1
1
1
PARP(91)
1.0
2.5
5.0
PARP(93)
5.0
15.0
25.0
 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).
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 3
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Parameter
MSTP(81)
Tune A
1
Tune
A25
Tune
A50
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
0.9
0.9
Z-Boson Transverse Momentum
1.0E+00
PT Distribution 1/N dN/dPT
UE Parameters
High pT shape agrees!
CDF Run 1 Data
PYTHIA Tune A
PYTHIA Tune A25
PYTHIA Tune A50
1.0E-01
CDF Run 1
published
1.0E-02
1.8 TeV
Normalized to 1
1.0E-03
1.0E-04
1.0E-05
ISR Parameter
PARP(86)
0.95
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(67)
4.0
4.0
4.0
MSTP(91)
1
1
1
PARP(91)
1.0
2.5
5.0
PARP(93)
5.0
15.0
25.0
0
10
20
30
40
50
60
70
80
90
100
Z-Boson PT (GeV/c)
 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).
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 4
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Parameter
Tune A
Tune AW
Z-Boson Transverse Momentum
UE Parameters
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
1.0
2.1
PARP(93)
5.0
15.0
PT Distribution 1/N dN/dPT
MSTP(81)
0.12
CDF Run 1 Data
PYTHIA Tune AW
0.08
CDF Run 1
published
s = 2.1
1.8 TeV
Normalized to 1
0.04
0.00
ISR Parameters
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
0
2
4
6
8
10
12
14
16
18
20
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution
(<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA
Tune AW (<pT(Z)> = 11.7 GeV/c).
Effective Q cut-off, below which space-like showers are not evolved.
The Q2 = kT2 in as for space-like showers is scaled by PARP(64)!
Rick Field - Florida/CDF
Page 5
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Parameter
Tune A
Tune AW
Z-Boson Transverse Momentum
UE Parameters
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
1.0
2.1
PARP(93)
5.0
15.0
PT Distribution 1/N dN/dPT
MSTP(81)
1.0E+00
CDF Run 1 Data
PYTHIA Tune AW
1.0E-01
CDF Run 1
published
1.8 TeV
1.0E-02
Normalized to 1
1.0E-03
1.0E-04
1.0E-05
ISR Parameters
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
0
10
20
30
40
50
60
70
80
90
100
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution
(<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA
Tune AW (<pT(Z)> = 11.7 GeV/c).
Rick Field - Florida/CDF
Page 6
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Parameter
Tune A25
Tune AW
UE Parameters
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PT Distribution 1/N dN/dPT
MSTP(81)
s = 2.5
0.12
Z-Boson Transverse Momentum
CDF Run 1 Data
PYTHIA Tune A25
PYTHIA Tune AW
0.08
CDF Run 1
published
s = 2.1
1.8 TeV
Normalized to 1
0.04
0.00
ISR Parameters
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
2.5
2.1
5.0
15.0
PARP(93)
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
0
2
4
6
8
10
12
14
16
18
20
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution
(<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA
Tune AW (<pT(Z)> = 11.7 GeV/c) and PYTHIA
Tune A25 (<pT(Z)> = 10.1 GeV/c).
Rick Field - Florida/CDF
Page 7
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
UE Parameters
ISR Parameters
Tune A25
Tune AW
MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
2.5
2.1
PARP(93)
5.0
15.0
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
Z-Boson Transverse Momentum
1.0E+00
PT Distribution 1/N dN/dPT
Parameter
PYTHIA Tune A25
PYTHIA Tune AW
1.0E-01
RDF Preliminary
generator level
1.8 TeV
1.0E-02
Normalized to 1
1.0E-03
1.0E-04
1.0E-05
0
10
20
30
40
50
60
70
80
90
100
Z-Boson PT (GeV/c)
 Compares PYTHIA Tune AW with PYTHIA
Tune A25 (both normalized to one).
Rick Field - Florida/CDF
Page 8
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
UE Parameters
ISR Parameters
Tune A25
Tune AW
MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
2.5
2.1
PARP(93)
5.0
15.0
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
Z-Boson Transverse Momentum
1.0E+00
PT Distribution 1/N dN/dPT
Parameter
PYTHIA Tune A25
PYTHIA Tune AW
1.0E-01
RDF Preliminary
generator level
1.8 TeV
1.0E-02
Arbitrary Normalization
1.0E-03
1.0E-04
1.0E-05
0
10
20
30
40
50
60
70
80
90
100
Z-Boson PT (GeV/c)
 Compares PYTHIA Tune AW with PYTHIA
Tune A25 (normalized to agree at high PT(Z)).
Rick Field - Florida/CDF
Page 9
Run 2 Drell-Yan
Drell-Yan Production
Lepton
Proton
<PT(pair)> versus M(pair)
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Anti-Lepton
Lepton-Pair Transverse Momentum
Lepton-Pair Transverse Momentum
20
20
RDF Preliminary
RDF Preliminary
PY Tune AW
15
Average Pair PT
Average Pair PT
PY Tune AW
generator level
generator level
10
PY Tune A
15
10
PY Tune A5
5
5
Z-boson
region
Z-boson
region
Drell-Yan
1.96 TeV
Drell-Yan
1.96 TeV
0
0
0
50
100
150
200
250
0
50
100
150
200
250
Lepton-Pair Invariant Mass (GeV)
Lepton-Pair Invariant Mass (GeV)
 Shows the lepton-pair average PT versus the  Shows the lepton-pair average PT versus the
lepton-pair invariant mass at 1.96 TeV for
lepton-pair invariant mass at 1.96 TeV for
PYTHIA Tune AW and PYTHIA Tune A5.
PYTHIA Tune AW and PYTHIA Tune A.
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 10
Run 2 Drell-Yan
Drell-Yan Production
Lepton
<Densities> versus M(pair)
The “Underlying Event”
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Anti-Lepton
Charged Particle Density: dN/dhdf
Charged PTsum Density: dPT/dhdf
1.0
1.6
Charged PTsum Density (GeV/c)
Charged Particle Density
RDF Preliminary
generator level
PY Tune AW
0.8
0.6
0.4
PY Tune A
Drell-Yan
1.96 TeV
0.2
Z-boson
region
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
RDF Preliminary
generator level
1.2
PY Tune AW
0.8
PY Tune A
0.4
Drell-Yan
1.96 TeV
Z-boson
region
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
50
100
150
200
250
0
Lepton-Pair Invariant Mass (GeV)
50
100
150
200
250
Lepton-Pair Invariant Mass (GeV)
 Shows the charged particle density versus the  Shows the charged PTsum density versus the
lepton-pair invariant mass at 1.96 TeV for
lepton-pair invariant mass at 1.96 TeV for
PYTHIA Tune AW and PYTHIA Tune A.
PYTHIA Tune AW and PYTHIA Tune A.
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 11
High PT Drell-Yan
70 < M(lepton-pair) < 110 GeV
Lepton-Pair
Direction
f
“Toward”
“Transverse”
"Toward" Charged Particle Density: dN/dhdf
1.0
"Toward" Charged Density
The “Underlying Event” in High
PT Lepton-Pair Production
Drell-Yan
1.96 TeV
RDF Preliminary
generator level
0.8
PY Tune AW
0.6
0.4
70 < M(pair) < 110 GeV
PY Tune A
0.2
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
“Transverse”
0.0
0
“Away”
25
50
75
100
125
150
Lepton-Pair PT (GeV/c)
"Toward" PTsum Density: dPT/dhdf
PT(pair)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
"Toward" PTsum Density (GeV/c)
Drell-Yan Production
Lepton-Pair
1.6
Drell-Yan
1.96 TeV
RDF Preliminary
generator level
1.2
PY Tune AW
0.8
70 < M(pair) < 110 GeV
0.4
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
“Toward” <Densities> vs PT(pair)
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
25
50
75
100
125
150
Lepton-Pair PT (GeV/c)
Page 12
High PT Drell-Yan
70 < M(lepton-pair) < 110 GeV
Lepton-Pair
Direction
f
“Toward”
“Transverse”
“Transverse”
"Transverse" Charged Particle Density: dN/dhdf
1.0
"Transverse" Charged Density
The “Underlying Event” in High
PT Lepton-Pair Production
RDF Preliminary
0.8
Drell-Yan
1.96 TeV
PY Tune AW
generator level
0.6
0.4
PY Tune A
70 < M(pair) < 110 GeV
0.2
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
“Away”
25
50
75
100
125
150
Lepton-Pair PT (GeV/c)
"Transverse" PTsum Density: dPT/dhdf
Lepton-Pair
PT(pair)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
"Transverse" PTsum Density (GeV/c)
Drell-Yan Production
1.6
generator level
PY Tune AW
1.2
0.8
0.4
70 < M(pair) < 110 GeV
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
“Transverse” <Densities> vs PT(pair)
TeV4LHC - Fermilab
October 20, 2005
Drell-Yan
1.96 TeV
RDF Preliminary
Rick Field - Florida/CDF
25
50
75
100
125
150
Lepton-Pair PT (GeV/c)
Page 13
High PT Drell-Yan
The “Underlying Event” in High PT Lepton-Pair Production
"Transverse" PTsum Density: dPT/dhdf
1.6
Drell-Yan
1.96 TeV
RDF Preliminary
generator level
1.2
PY Tune AW
0.8
70 < M(pair) < 110 GeV
0.4
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
25
50
75
100
125
150
"Transverse" PTsum Density (GeV/c)
"Toward" PTsum Density (GeV/c)
"Toward" PTsum Density: dPT/dhdf
1.6
generator level
PY Tune AW
1.2
0.8
0.4
70 < M(pair) < 110 GeV
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
25
50
Lepton-Pair PT (GeV/c)
Lepton-Pair
Direction
Drell-Yan
1.96 TeV
RDF Preliminary
75
100
125
150
Lepton-Pair PT (GeV/c)
70 < M(lepton-pair) < 110 GeV
Drell-Yan Production
f
Lepton-Pair
PT(pair)
“Toward”
Proton
“Transverse”
“Transverse”
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
“Away”
Final-State
Radiation
Outgoing Parton
“Toward” <Densities> vs “Transverse” <Densities>
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 14
High PT Drell-Yan
The “Underlying Event” in Lepton-Pair Production
"Toward" PTsum Density: dPT/dhdf
Charged PTsum Density: dPT/dhdf
"Toward" PTsum Density (GeV/c)
Charged PTsum Density (GeV/c)
1.6
RDF Preliminary
generator level
1.2
PY Tune AW
0.8
PY Tune A
0.4
Z-boson
region
Drell-Yan
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
1.6
Drell-Yan
1.96 TeV
RDF Preliminary
generator level
1.2
PY Tune AW
0.8
70 < M(pair) < 110 GeV
0.4
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0.0
0
50
100
150
200
250
0
Overall PTsum Density vs M(pair)
Drell-Yan Production
25
50
75
100
125
150
Lepton-Pair PT (GeV/c)
Lepton-Pair Invariant Mass (GeV)
“Toward” PTsum Density vs PT(pair)
Lepton-Pair
Direction
Lepton
f
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
“Toward”
“Transverse”
“Transverse”
“Away”
Anti-Lepton
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 15
High PT Jets
Jet #1 Direction
f
“Toward”
“Transverse”
“Transverse”
"Transverse" Charged Particle Density: dN/dhdf
1.0
"Transverse" Charged Density
The “Underlying Event” in High
PT Jet Production
PY Tune AW
RDF Preliminary
generator level
0.8
0.6
PY Tune A
0.4
"Leading Jet"
CTEQ5L
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.2
0.0
“Away”
0
50
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
"Transverse" PTsum Density: dPT/dhdf
1.6
Outgoing Parton
PT(hard)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
PY Tune AW
RDF Preliminary
generator level
1.2
PY Tune A
0.8
CTEQ5L
0.4
"Leading Jet"
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
“Transverse” <Densities> vs PT(jet#1)
TeV4LHC - Fermilab
October 20, 2005
"Transverse" PTsum Density (GeV/c)
“Hard” Scattering
0
50
Rick Field - Florida/CDF
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
Page 16
Drell-Yan vs Jets
The “Underlying Event” in High PT Lepton-Pair and Jet Production
"Transverse" PTsum Density: dPT/dhdf
1.6
Drell-Yan
1.96 TeV
RDF Preliminary
generator level
PY Tune AW
1.2
0.8
0.4
70 < M(pair) < 110 GeV
PY Tune A
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
"Transverse" PTsum Density (GeV/c)
"Transverse" PTsum Density (GeV/c)
"Transverse" PTsum Density: dPT/dhdf
1.6
PY Tune AW
RDF Preliminary
generator level
1.2
PY Tune A
0.8
CTEQ5L
0.4
"Leading Jet"
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0.0
0
25
50
75
100
125
150
0
50
100
150
200
250
“Transverse” <Densities> vs PT(pair)
400
450
500
Jet #1 Direction
f
f
“Toward”
“Toward”
“Transverse”
“Transverse”
“Transverse”
“Away”
“Away”
TeV4LHC - Fermilab
October 20, 2005
350
“Transverse” <Densities> vs PT(jet#1)
Lepton-Pair
Direction
“Transverse”
300
PT(particle jet#1) (GeV/c)
Lepton-Pair PT (GeV/c)
Rick Field - Florida/CDF
Page 17
CTEQ6.1 Tune
I used LHAPDF! See the
next talk by Craig Group!
PYTHIA 6.2 CTEQ6.1
Parameter
Tune Q
Tune QW
"Transverse" Charged Particle Density: dN/dhdf
UE Parameters
MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
1.2 GeV
1.2 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
"Transverse" Charged Density
1.0
PY Tune Q
CTEQ61
RDF Preliminary
generator level
0.8
0.6
PY Tune A
CTEQ5L
PY Tune A
CTEQ61
0.4
"Leading Jet"
0.2
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
PARP(85)
0.9
0.9
0
50
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
PARP(62)
0.25
1.0
0.25
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
"Transverse" PTsum Density: dPT/dhdf
1.6
"Transverse" PTsum Density (GeV/c)
ISR Parameters
PARP(86)
PY Tune Q
CTEQ61
RDF Preliminary
generator level
1.2
PY Tune A
CTEQ5L
0.8
PY Tune A
CTEQ61
0.4
"Leading Jet"
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
PARP(91)
1.0
2.1
0
50
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
PARP(93)
Intrensic KT
TeV4LHC - Fermilab
October 20, 2005
5.0
15.0
Rick Field - Florida/CDF
Page 18
JIMMY at CDF
The Energy in the “Underlying
Event” in High PT Jet Production
Jet #1 Direction
JIMMY: MPI
J. M. Butterworth
J. R. Forshaw
M. H. Seymour
f
PT(JIM)= 2.5 GeV/c.
“Toward”
“Transverse”
“Transverse”
“Away”
2.0
PY Tune A
JM325
"Leading Jet"
1.0
CDF Run 2 Preliminary
MidPoint R = 0.7 |h(jet)| < 2
generator level theory
All Particles (|h|<1.0)
0
100
200
300
400
500
PT(particle jet#1) (GeV/c)
"Transverse" PTsum Density: dPT/dhdf
Outgoing Parton
AntiProton
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
“Transverse” <Densities> vs PT(jet#1)
"Transverse" PTsum Density (GeV/c)
1.6
PT(hard)
TeV4LHC - Fermilab
October 20, 2005
HW
3.0
0.0
“Hard” Scattering
Underlying Event
JIMMY Default
1.96 TeV
PT(JIM)= 3.25 GeV/c.
Proton
JIMMY was tuned to fit
the energy density in the
“transverse” region for
“leading jet” events!
"Transverse" ETsum Density: dET/dhdf
4.0
"Transverse" ETsum Density (GeV)
JIMMY
Runs with HERWIG and adds
multiple parton interactions!
JIMMY Default
1.96 TeV
1.2
JM325
PY Tune A
0.8
"Leading Jet"
HW
0.4
MidPoint R = 0.7 |h(jet)| < 2
CDF Run 2 Preliminary
generator level theory
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
50
Rick Field - Florida/CDF
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
Page 19
JIMMY at CDF
Jet #1 Direction
f
“Toward”
“Transverse”
“Transverse”
"Transverse" Charged Particle Density: dN/dhdf
1.2
"Transverse" Charged Density
The “Underlying Event” in High
PT Jet Production
“Away”
JIMMY Default
JM325
"Leading Jet"
1.96 TeV
0.8
PY Tune A
HW
0.4
MidPoint R = 0.7 |h(jet)| < 2
CDF Run 2 Preliminary
generator level theory
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
50
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
"Transverse" PTsum Density: dPT/dhdf
Outgoing Parton
1.6
PT(hard)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
“Transverse” <Densities> vs PT(jet#1)
TeV4LHC - Fermilab
October 20, 2005
"Transverse" PTsum Density (GeV/c)
“Hard” Scattering
JIMMY Default
1.96 TeV
1.2
JM325
PY Tune A
0.8
"Leading Jet"
HW
0.4
MidPoint R = 0.7 |h(jet)| < 2
CDF Run 2 Preliminary
generator level theory
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
50
Rick Field - Florida/CDF
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
Page 20
Summary
 PYTHIA Tune AW correctly describes the Z-boson PT
distribution and also fits the “underlying event” as well
as Tune A does! I do not see anything wrong with it,
except that it may only work at the Tevatron. You can
not trust the energy dependence!
Good way to study the
“underlying event”!
Drell-Yan Production
Proton
AntiProton
Underlying Event
 JIMMY 325 (PTJIM = 3.25 GeV/c) fits the energy in the
“underlying event” but does so by producing too many
particles (i.e. it is too soft). See my talk tomorrow!
Underlying Event
Initial-State
Radiation
 PYTHIA Tune Q works as well as Tune A but uses
CTEQ6.1! At the Tevatron use Tune QW!
 Default JIMMY (PTJIM = 2.5 GeV/c) does not fit the
CDF “underlying event” data! Default JIMMY’s
“underlying event” is much too active!
Lepton
Anti-Lepton
“Hard” Scattering
Outgoing Parton
PT(hard)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
 We are making good progress in understanding and modeling the “underlying event”.
However, we do not yet have a perfect fit to all the features of the “underlying event”.
PYTHIA Tune A does not produce enough energy in the “underlying event”! See my
talk tomorrow!
TeV4LHC - Fermilab
October 20, 2005
Rick Field - Florida/CDF
Page 21