1st Workshop on Energy Scaling
in Hadron-Hadron Collisions
From Min-Bias to the Underlying Event
Fermilab 2009
Rick Field
University of Florida
Outline of Talk
 The CDF 630 GeV “underlying event”
Outgoing Parton
data. Determining PARP(90).
 Tuning the QCD Monte-Carlo
PT(hard)
Initial-State Radiation
Proton
AntiProton
model generators and some Minbias comparisions.
Underlying Event
 Studying the “associated” charged particle
Outgoing Parton
Underlying Event
Final-State
Radiation
densities in “min-bias” collisions.
 The latest “underlying event” studies at CDF
for “leading Jet” and Z-boson events. Data
corrected to the particle level.
CDF-QCD Data for Theory
CDF Run 2
CMS at the LHC
R. Field, C. Group, & D. Kar
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 1
Tuning PYTHIA:
Multiple Parton Interaction Parameters
Parameter
Default
Description
PARP(83)
0.5
Double-Gaussian: Fraction of total hadronic
matter within PARP(84)
PARP(84)
0.2
Double-Gaussian: Fraction of the overall hadron
radius containing the fraction PARP(83) of the
total hadronic matter.
Multiple Parton Interaction
Color String
Color String
PARP(86)
PARP(89)
PARP(90)
PARP(67)
0.33
0.66
1 TeV
0.16
1.0
Probability that the MPI produces two gluons
with color connections to the “nearest neighbors.
Multiple PartonDetermine
Interactionby comparing
with 630 GeV data!
Probability that the MPI produces two gluons
either as described by PARP(85) or as a closed
gluon
loop.
remaining
fraction consists of
Affects
the The
amount
of
quark-antiquark
pairs.
initial-state radiation!
Color String
Hard-Scattering Cut-Off PT0
5
Determines the reference energy E0.
Determines the energy dependence of the cut-off
PT0 as follows PT0(Ecm) = PT0(Ecm/E0)e with
e = PARP(90)
A scale factor that determines the maximum
parton virtuality for space-like showers. The
larger the value of PARP(67) the more initialstate radiation.
PYTHIA 6.206
e = 0.25 (Set A))
4
PT0 (GeV/c)
PARP(85)
Take E0 = 1.8 TeV
3
2
e = 0.16 (default)
1
100
1,000
10,000
100,000
CM Energy W (GeV)
Reference point
at 1.8 TeV
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 2
“Transverse” Cones
vs “Transverse” Regions
“Cone Analysis”
2
2
Transverse
Cone:
(0.7)2=0.49
Away Region
Transverse
Region

(Tano, Kovacs, Huston, Bhatti)
Cone 1

Leading
Jet
Leading
Jet
Toward Region
Transverse
Region:
2/3=0.67
Transverse
Region
Cone 2
Away Region
0
0
-1
h
+1
-1
h
+1
 Sum the PT of charged particles in two cones of radius
0.7 at the same h as the leading jet but with |DF| = 90o.
 Plot the cone with the maximum and minimum PTsum
versus the ET of the leading (calorimeter) jet.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 3
Energy Dependence
of the “Underlying Event”
“Cone Analysis”
(Tano, Kovacs, Huston, Bhatti)
630 GeV
1,800 GeV
PYTHIA 6.115
PT0 = 1.4 GeV
PYTHIA 6.115
PT0 = 2.0 GeV
 Sum the PT of charged particles (pT > 0.4 GeV/c) in two cones of radius 0.7 at the same h as the leading
jet but with |DF| = 90o. Plot the cone with the maximum and minimum PTsum versus the ET of the
leading (calorimeter) jet.
 Note that PYTHIA 6.115 is tuned at 630 GeV with PT0 = 1.4 GeV and at 1,800 GeV with PT0 = 2.0 GeV.
This implies that e = PARP(90) should be around 0.30 instead of the 0.16 (default).
 For the MIN cone 0.25 GeV/c in radius R = 0.7 implies a PTsum density of dPTsum/dhd = 0.16 GeV/c
and 1.4 GeV/c in the MAX cone implies dPTsum/dhd = 0.91 GeV/c (average PTsum density of 0.54
GeV/c per unit h-).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 4
“Transverse” Charged Densities
Energy Dependence
"Transverse" Charged PTsum Density: dPTsum/dhd
"Min Transverse" PTsum Density: dPTsum/dhd
0.60
0.3
Charged PTsum Density (GeV)
Charged PTsum Density (GeV)
e = 0.25
HERWIG 6.4
0.40
e = 0.16
e=0
0.20
HERWIG 6.4
e = 0.25
0.2
Increasing e produces less energy
dependence for the
UE resulting
in
e = 0.16
e=0
less UE activity at the LHC!
CTEQ5L
Pythia 6.206 (Set A)
Pythia 6.206 (Set A)
630 GeV |h|<1.0 PT>0.4 GeV
0.1
CTEQ5L
630 GeV |h|<1.0 PT>0.4 GeV
0.0
0.00
0
5
10
15
20
25
30
35
40
45
50
0
5
10
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
PT(charged jet#1) (GeV/c)
Lowering PT0 at 630 GeV (i.e.
increasing e) increases UE activity
charged
PTsum density
resulting in
less energy dependence.
(|h|<1, PT>0.4 GeV) versus PT(charged jet#1) at 630
GeV predicted by HERWIG 6.4 (PT(hard) > 3
GeV/c, CTEQ5L) and a tuned version of PYTHIA
6.206 (PT(hard) > 0, CTEQ5L, Set A, e = 0, e = 0.16
(default) and e = 0.25 (preferred)).
 Also shown are the PTsum densities (0.16 GeV/c and
0.54 GeV/c) determined from the Tano cone
analysis at 630 GeV
Hard-Scattering Cut-Off PT0
5
PYTHIA 6.206
e = 0.25 (Set A))
4
PT0 (GeV/c)
 Shows the “transverse”
15
3
2
e = 0.16 (default)
1
Rick Field Fermilab MC Workshop
Reference point
October 4, 2002!
E = 1.8 TeV
100
1,000
10,000
100,000
CM Energy W (GeV)
0
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 5
All use LO as
with L = 192 MeV!
PYTHIA 6.2 Tunes
UE Parameters
ISR Parameter
Parameter
Tune AW
Tune DW
Tune D6
PDF
CTEQ5L
CTEQ5L
CTEQ6L
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
1.9 GeV
1.8 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
1.0
1.0
PARP(86)
0.95
1.0
1.0
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(62)
1.25
1.25
1.25
PARP(64)
0.2
0.2
0.2
PARP(67)
4.0
2.5
2.5
MSTP(91)
1
1
1
PARP(91)
2.1
2.1
2.1
PARP(93)
15.0
15.0
15.0
Uses CTEQ6L
Tune A energy dependence!
Intrinsic KT
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 6
All use LO as
with L = 192 MeV!
PYTHIA 6.2 Tunes
UE Parameters
Tune A
ISR Parameter
Parameter
Tune DWT
Tune D6T
ATLAS
PDF
CTEQ5L
CTEQ6L
CTEQ5L
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
1.9409 GeV
1.8387 GeV
1.8 GeV
PARP(83)
0.5
0.5
0.5
ATLAS energy dependence!
PARP(84)
0.4
0.4
Tune
B 0.5
Tune
AW
Tune BW
These are 1.0
“old” PYTHIA
6.2
PARP(85)
1.0
0.33 tunes!
are new 6.420
tunes
PARP(86)There 1.0
1.0
0.66 by
PARP(89)
1.96 TeV
TeV
1.0 TeV
Peter Skands
(Tune1.96S320,
update
of S0)
PARP(90)
0.16
0.16 N324,0.16
Peter Skands
(Tune
N0CR)
PARP(62)
1.25
1.25
1.0
Hendrik Hoeth (Tune P329, “Professor”)
PARP(64)
0.2
0.2
1.0
PARP(67)
2.5
2.5
1.0
MSTP(91)
1
1
1
PARP(91)
Tune D
PARP(93)
Tune 2.1
DW
15.0
2.1
15.0
5.0
Tune D6T
Intrinsic KT
Fermilab Energy Scaling Workshop
April 28, 2009
1.0
Tune D6
Rick Field – Florida/CDF/CMS
Page 7
Charged Particle Density: dN/dh
Charged Particle Density: dN/dh
Charged Particle Density: dN/dh
5.0
2.0
PY Tune A
generator level
4.0
3.0
2.0
PY64 Tune S320
PY64 Tune P329
1.0
Min-Bias
1.96 TeV
Charged Particles (all PT)
PY64 Tune P329
RDF Preliminary
Charged Particle Density
Charged Particle Density
RDF Preliminary
generator level
1.5
PY Tune A
1.0
PY64 Tune S320
0.5
Min-Bias
1.96 TeV
Charged Particles (PT>0.5 GeV/c)
0.0
0.0
-8
-6
-4
-2
0
2
4
6
8
-8
-6
PseudoRapidity h
-4
-2
0
2
4
6
8
PseudoRapidity h
Charged particle (all pT) pseudo-rapidity Charged particle (pT>0.5 GeV/c) pseudodistribution, dNchg/dhd, at 1.96 TeV for
inelastic non-diffractive collisions from
PYTHIA Tune A, Tune S320, and Tune
P324.
Fermilab Energy Scaling Workshop
April 28, 2009
rapidity distribution, dNchg/dhd, at 1.96
TeV for inelastic non-diffractive collisions
from PYTHIA Tune A, Tune S320, and
Tune P324.
Rick Field – Florida/CDF/CMS
Page 8
CDF Run 2 Min-Bias “Associated”
Charged Particle Density
“Associated” densities do
not include PTmax!
Highest pT
charged particle!
Charged Particle Density: dN/dhd
PTmax Direction
PTmax Direction
0.5
D
Correlations in 
Charged Particle Density
CDF Preliminary
Associated Density
PTmax not included
data uncorrected
0.4
D
Charge Density
0.3
0.2
0.1
Min-Bias
Correlations
in 
Charged Particles
(|h|<1.0, PT>0.5 GeV/c)
PTmax
0.0
0
30
60
90
120
150
180
210
240
270
300
330
360
D (degrees)
 Use the maximum pT charged particle in the event, PTmax, to define a direction and look
It is more probable
to find
a particle
at the the “associated”
density, dN
chg/dhd,
in “min-bias” collisions (pT > 0.5 GeV/c, |h| <
accompanying
PTmax
than
it
is
to
1).
find a particle in the central region!
 Shows the data
on the D dependence of the “associated” charged particle density,
dNchg/dhd, for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative
to PTmax (rotated to 180o) for “min-bias” events. Also shown is the average charged
particle density, dNchg/dhd, for “min-bias” events.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 9
CDF Run 2 Min-Bias “Associated”
Charged Particle Density Rapid rise in the particle
density in the “transverse”
region as PTmax increases!
Associated Particle Density: dN/dhd
PTmaxDirection
Direction
PTmax
D
“Toward”
“Transverse”
“Transverse”
Correlations in 
“Away”
Associated Particle Density
Jet #1
D
PTmax > 2.0 GeV/c
1.0
PTmax > 2.0 GeV/c
PTmax > 1.0 GeV/c
0.8
Charged Particles
(|h|<1.0, PT>0.5 GeV/c)
CDF Preliminary
data uncorrected
PTmax > 0.5 GeV/c
Transverse
Region
0.6
Transverse
Region
0.4
0.2
Jet #2
PTmax
PTmax not included
Min-Bias
0.0
0
30
60
90
120
150
180
210
240
270
300
330
360
D (degrees)
Ave Min-Bias
0.25 per unit h-
PTmax > 0.5 GeV/c
 Shows the data on the D dependence of the “associated” charged particle density,
dNchg/dhd, for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative
to PTmax (rotated to 180o) for “min-bias” events with PTmax > 0.5, 1.0, and 2.0 GeV/c.
 Shows “jet structure” in “min-bias” collisions (i.e. the “birth” of the leading two jets!).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 10
CDF Run 2 Min-Bias “Associated”
Charged Particle Density
PY Tune A
PTmax > 2.0 GeV/c
PTmax Direction
Direction
PTmax
D
“Toward”
“Transverse”
“Transverse”
Correlations in 
“Away”
PTmax > 2.0 GeV/c
Associated Particle Density
D
Associated Particle Density: dN/dhd
1.0
CDF Preliminary
PY Tune A
0.8
data uncorrected
theory + CDFSIM
PTmax > 0.5 GeV/c
PY Tune A
Transverse
Region
0.6
PY Tune A 1.96 TeV
Transverse
Region
0.4
0.2
PTmax
PTmax not included
(|h|<1.0, PT>0.5 GeV/c)
0.0
0
30
60
90
120
PTmax > 0.5 GeV/c
150
180
210
240
270
300
330
360
D (degrees)
 Shows the data on the D dependence of the “associated” charged particle density,
dNchg/dhd, for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative
to PTmax (rotated to 180o) for “min-bias” events with PTmax > 0.5 GeV/c and PTmax >
2.0 GeV/c compared with PYTHIA Tune A (after CDFSIM).
 PYTHIA Tune A predicts a larger correlation than is seen in the “min-bias” data (i.e.
Tune A “min-bias” is a bit too “jetty”).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 11
Min-Bias “Associated”
Charged Particle Density
PTmax Direction
Associated Charged
Charged
Particle
Density:
dN/dhd
Associated
"Transverse"
ChargedParticle
ParticleDensity:
Density:dN/dhd
dN/dhd
D
Associated Charged Particle Density: dN/dhd
10.0
Charged Particle Density
py Tune A generator level
“Toward” Region
PTmax > 2.0 GeV/c
PTmax > 5.0 GeV/c
1.0
PTmax > 10.0 GeV/c
“Transverse”
“Transverse”
0.1
Min-Bias
1.96 TeV
PTmax > 0.5 GeV/c
PTmax > 1.0 GeV/c
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
Density
"Transverse"
Charged
Density
Charged Particle
1.6
2.5
1.2
RDF Preliminary
RDF Preliminary
RDF Preliminary
py Tune A generator level
py Tune A generator level
1.0
2.0
1.2
0.8
1.5
Min-Bias
Min-Bias
Min-Bias
14 TeV
1.96 TeV
“Toward”
14 TeV
"Toward"
"Away"
"Toward"
“Transverse”
~ factor of "Away"
2!
“Transverse”
0.8
0.6
1.0
0.4
0.4
0.5
0.2
1.96 TeV
"Transverse"
"Transverse"
“Away”
Charged
ChargedParticles
Particles(|h|<1.0,
(|h|<1.0,PT>0.5
PT>0.5 GeV/c)
GeV/c)
Charged
Particles
(|h|<1.0,
PT>0.5
GeV/c)
0.0
0.0
0
30
60
90
120
150
180
210
240
270
300
330
360
00
2
D (degrees)
54
6
8
10
10
12
15
14
16
20
18
PTmax (GeV/c)
(GeV/c)
PTmax
 Shows the D dependence of the “associated” charged particle density, dNchg/dhd, for charged
particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180o) for
“min-bias” events at 1.96 TeV with PTmax > 0.5, 1.0, 2.0, 5.0, and 10.0 GeV/c from PYTHIA
Tune A (generator level).
PTmax Direction
D
“Toward”
“Transverse”
“Transverse”
“Away”
 Shows the “associated” charged particle density in the “toward”, “away” and
“transverse” regions as a function of PTmax for charged particles (pT > 0.5
GeV/c, |h| < 1, not including PTmax) for “min-bias” events at 1.96 TeV from
PYTHIA Tune A (generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 12
25
20
25
Min-Bias “Associated”
Charged Particle Density
Associated Charged Particle Density: dN/dhd
Associated
Associated Charged
Charged Particle
Particle Density:
Density: dN/dhd
dN/dhd
0.60
PY64 Tune P329
PY64 Tune N324
RDF
Preliminary
RDF
Preliminary
generator
level
generator
level
0.15
0.40
0.10
PY64 Tune S320
0.20
0.05
PY64
Tune
PY
Tune
A S320
Min-Bias
Min-Bias
1.96
1.96 TeV
TeV
PTmax
> 0.5
GeV/c
PTmax
> 2.0
GeV/c
Charged
Particles
(PT>0.5
GeV/c)
Charged
Particles
(PT>0.5
GeV/c)
Associated Charged Density
Associated Charged
Charged Density
Density
Associated
0.20
0.60
RDF Preliminary
PY Tune A
generator level
PY64 Tune P329
0.40
0.20
PY64 Tune S320
Min-Bias
1.96 TeV
PTmax > 2.0 GeV/c
Charged Particles (PT>0.5 GeV/c)
0.00
0.00
0.00
00
30
30
60
60
90
90
120
120 150
150 180
180 210
210 240
240 270
270 300
300 330
330 360
360
0
30
60
90
120
150
180
210
240
270
300
330
360
D (degrees)
D
D (degrees)
(degrees)
 Shows the D dependence of the “associated” charged particle density, dNchg/dhd, for charged
particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180o) for
“min-bias” events at 1.96 TeV with PTmax > 0.5 GeV/c for PYTHIA Tune A, Tune S320, Tune
P320 (generator level).
 Shows the D dependence of the “associated” charged particle density, dNchg/dhd, for charged
particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) relative to PTmax (rotated to 180o) for
“min-bias” events at 1.96 TeV with PTmax > 2.0 GeV/c for PYTHIA Tune A, Tune S320, Tune
P320 (generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 13
Min-Bias “Associated”
Charged Particle Density
Associated Charged Particle Density: dN/dhd
"Toward"
Associated
ChargedDensity:
Density:dN/dhd
dN/dhd
Associated
Charged Particle
1.6
1.6
1.6
Charged Particle Density
py Tune A generator level
Charged Particle
Density
Associated
Charged
Density
Min-Bias
1.96 TeV
RDF Preliminary
1.2
"Toward"
"Away"
0.8
"Transverse"
0.4
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
RDF
Preliminary
RDF
Preliminary
Min-Bias
PY Tune
A
py64 generator
Tune S320level
generator level
1.96 TeV
1.2
1.2
"Toward"
0.8
0.8
"Away"
"Transverse"
Min-Bias
PY64 Tune P329
1.96 TeV
0.4
0.4
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
PY64 Tune S320
0.0
0.0
0.0
0
2
4
6
8
10
12
14
16
18
20
00
22
44
66
88
10
10
14
14
16
16
18
18
20
20
PTmax (GeV/c)
(GeV/c)
PTmax
PTmax (GeV/c)
PTmax Direction
PTmax Direction
D
D
“Toward”
“Transverse”
12
12
“Toward”
“Transverse”
“Transverse”
“Transverse”
“Away”
“Away”
 Shows the “associated” charged particle density in the “toward”, “away” and “transverse” regions
as a function of PTmax for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) for
“min-bias” events at 1.96 TeV from PYTHIA Tune A and Tune S320 at the particle level (i.e.
generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 14
Min-Bias “Associated”
Charged Particle Density
RDF LHC Prediction!
"Transverse" Charged Particle Density: dN/dhd
"Transverse" Charged Particle Density: dN/dhd
1.6
RDF Preliminary
PY64 Tune P329
"Transverse" Charged Density
"Transverse" Charged Density
0.8
generator level
0.6
0.4
PY Tune A
PY64 Tune N324
0.2
PY64 Tune S320
Min-Bias
1.96 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
PY Tune DWT
RDF Preliminary
generator level
1.2
0.8
PY64 Tune P329
PY Tune A
PY Tune DW
PY64 Tune S320
0.4
Min-Bias
14 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0.0
0
2
4
6
8
10
12
14
16
18
20
0
5
10
15
PTmax Direction
PTmax Direction
D
D
“Toward”
“Toward”
“Transverse”
25
PTmax (GeV/c)
PTmax (GeV/c)
“Transverse”
20
Tevatron
LHC
“Transverse”
“Transverse”
“Away”
“Away”
 Shows the “associated” charged particle density in the “transverse” region as a function of PTmax
for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) for “min-bias” events at 1.96
TeV from PYTHIA Tune A, Tune S320, Tune N324, and Tune P329 at the particle level (i.e.
generator level).
 Extrapolations of PYTHIA Tune A, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 15
QCD Monte-Carlo Models:
High Transverse Momentum Jets
Hard Scattering
Initial-State Radiation
Hard Scattering “Jet”
Initial-State Radiation
“Jet”
Outgoing Parton
PT(hard)
Outgoing Parton
PT(hard)
Proton
“Hard Scattering” Component
AntiProton
Final-State Radiation
Outgoing Parton
Underlying Event
Underlying Event
Proton
“Jet”
Final-State Radiation
AntiProton
Underlying Event
Outgoing Parton
Underlying Event
“Underlying Event”
 Start with the perturbative 2-to-2 (or sometimes 2-to-3) parton-parton scattering and add initial and finalstate gluon radiation (in the leading log approximation or modified leading log approximation).
 The “underlying event” consists of the “beam-beam remnants” and from particles arising from soft or
semi-soft multiple parton interactions (MPI).
The “underlying
event” is“jet”
an unavoidable
 Of course the outgoing colored partons fragment
into hadron
and inevitably “underlying event”
background to most collider observables
observables receive contributions from initial
and final-state radiation.
and having good understand of it leads to
more precise collider measurements!
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 16
QCD Monte-Carlo Models:
Lepton-Pair Production
Lepton-Pair
Production
High
PT Z-Boson
Production
Anti-Lepton
Outgoing Parton
Initial-State
Initial-State Radiation
Radiation
High P
T Z-Boson Production
Lepton-Pair
Production
Initial-State
Initial-StateRadiation
Radiation
“Jet”
Proton
Proton
Final-State Radiation
Outgoing
Parton
Anti-Lepton
Final-State Radiation
“Hard Scattering” Component
AntiProton
AntiProton
Underlying Event
Lepton
Z-boson
Underlying Event
Proton
Lepton
Z-boson
AntiProton
Underlying Event
Underlying Event
“Underlying Event”
 Start with the perturbative Drell-Yan muon pair production and add initial-state gluon radiation (in the
leading log approximation or modified leading log approximation).
 The “underlying event” consists of the “beam-beam remnants” and from particles arising from soft or
semi-soft multiple parton interactions (MPI).
 Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event”
observables receive contributions from initial-state radiation.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 17
“Towards”, “Away”, “Transverse”
Look at the charged
particle density, the
charged PTsum density
and the ETsum density in
all 3 regions!
D Correlations relative to the leading jet
Jet #1 Direction
“Transverse” region is
very sensitive to the
“underlying event”!
Charged particles pT > 0.5 GeV/c |h| < 1
Calorimeter towers ET > 0.1 GeV |h| < 1
“Toward-Side” Jet
2
Away Region
Z-Boson
Direction
Jet #1 Direction
D
D
Transverse
Region
“Toward”
“Toward”
“Transverse”
“Transverse”
“Away”
“Transverse”
“Transverse”

Leading
Jet
Toward Region
“Away”
Transverse
Region
“Away-Side” Jet
Away Region
0
-1
h
+1
 Look at correlations in the azimuthal angle Drelative to the leading charged particle jet (|h| <
1) or the leading calorimeter jet (|h| < 2).
 Define |D| < 60o as “Toward”, 60o < |D| < 120o as “Transverse ”, and |D| > 120o as “Away”.
o
Each of the three regions have area DhD = 2×120 = 4/3.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 18
Event Topologies
 “Leading Jet” events correspond to the leading
calorimeter jet (MidPoint R = 0.7) in the region |h| < 2
with no other conditions.
 “Inclusive 2-Jet Back-to-Back” events are selected to
have at least two jets with Jet#1 and Jet#2 nearly “backto-back” (D12 > 150o) with almost equal transverse
energies (PT(jet#2)/PT(jet#1) > 0.8) with no other
conditions .
 “Exclusive 2-Jet Back-to-Back” events are selected to
have at least two jets with Jet#1 and Jet#2 nearly “backto-back” (D12 > 150o) with almost equal transverse
energies (PT(jet#2)/PT(jet#1) > 0.8) and PT(jet#3) < 15
GeV/c.
 “Leading ChgJet” events correspond to the leading
charged particle jet (R = 0.7) in the region |h| < 1 with
no other conditions.
 “Z-Boson” events are Drell-Yan events
with 70 < M(lepton-pair) < 110 GeV
with no other conditions.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Jet #1 Direction
D
“Leading Jet”
“Toward”
“Transverse”
“Transverse”
subset
“Away”
Jet #1 Direction
D
“Inc2J Back-to-Back”
“Toward”
subset
“Transverse”
“Transverse”
“Away”
“Exc2J Back-to-Back”
Jet #2 Direction
ChgJet #1 Direction
D
“Charged Jet”
“Toward”
“Transverse”
“Transverse”
“Away”
Z-Boson Direction
D
“Toward”
Z-Boson
“Transverse”
“Transverse”
“Away”
Page 19
“transMAX” & “transMIN”
Jet #1 Direction
Z-Boson
Direction
Jet #1 Direction
D
Area = 4/6
“transMIN” very sensitive to
the “beam-beam remnants”!
“Toward-Side” Jet
D
“Toward”
“TransMAX”
“Toward”
“TransMIN”
“TransMAX”
“Away”
“TransMIN”
Jet #3
“Away”
“Away-Side” Jet
 Define the MAX and MIN “transverse” regions (“transMAX” and “transMIN”) on an
event-by-event basis with MAX (MIN) having the largest (smallest) density. Each of the
two “transverse” regions have an area in h- space of 4/6.
 The “transMIN” region is very sensitive to the “beam-beam remnant” and the soft
multiple parton interaction components of the “underlying event”.
 The difference, “transDIF” (“transMAX” minus “transMIN”), is very sensitive to the
“hard scattering” component of the “underlying event” (i.e. hard initial and final-state
radiation).
 The overall “transverse” density is the average of the “transMAX” and “transMIN”
densities.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 20
Observables at the
Particle and Detector Level
“Leading Jet”
Jet #1 Direction
Observable
Particle Level
Detector Level
dNchg/dhd
Number of charged particles
per unit h-
(pT > 0.5 GeV/c, |h| < 1)
Number of “good” charged tracks
per unit h-
(pT > 0.5 GeV/c, |h| < 1)
dPTsum/dhd
Scalar pT sum of charged particles
per unit h-
(pT > 0.5 GeV/c, |h| < 1)
Scalar pT sum of “good” charged tracks per
unit h-
(pT > 0.5 GeV/c, |h| < 1)
<pT>
Average pT of charged particles
(pT > 0.5 GeV/c, |h| < 1)
Average pT of “good” charged tracks
(pT > 0.5 GeV/c, |h| < 1)
PTmax
Maximum pT charged particle
(pT > 0.5 GeV/c, |h| < 1)
Require Nchg ≥ 1
Maximum pT “good” charged tracks
(pT > 0.5 GeV/c, |h| < 1)
Require Nchg ≥ 1
dETsum/dhd
Scalar ET sum of all particles
per unit h-
(all pT, |h| < 1)
Scalar ET sum of all calorimeter towers
per unit h-
(ET > 0.1 GeV, |h| < 1)
PTsum/ETsum
Scalar pT sum of charged particles
(pT > 0.5 GeV/c, |h| < 1)
divided by the scalar ET sum of
all particles (all pT, |h| < 1)
Scalar pT sum of “good” charged tracks
(pT > 0.5 GeV/c, |h| < 1)
divided by the scalar ET sum of
calorimeter towers (ET > 0.1 GeV, |h| < 1)
D
“Toward”
“Transverse”
“Transverse”
“Away”
Jet #1 Direction
D
“Toward”
“Transverse”
“Transverse”
“Away”
Jet #2 Direction
“Back-to-Back”
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 21
Overall Totals (|h| < 1)
ETsum = 775 GeV!
“Leading Jet”
Overall Totals versus PT(jet#1)
ETsum = 330 GeV
1000
CDF Run 2 Preliminary
ETsum (GeV)
data corrected
pyA generator level
Jet #1 Direction
D
PTsum (GeV/c)
Average
100
“Overall”
Nchg
"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
10
PTsum = 190 GeV/c
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
Stable Particles (|h|<1.0, all PT)
1
0
50
Nchg = 30
100
150
200
250
300
350
400
PT(jet#1) (GeV/c)
 Data at 1.96 TeV on the overall number of charged particles (pT > 0.5 GeV/c, |h| < 1) and the overall
scalar pT sum of charged particles (pT > 0.5 GeV/c, |h| < 1) and the overall scalar ET sum of all
particles (|h| < 1) for “leading jet” events as a function of the leading jet pT. The data are corrected to
the particle level (with errors that include both the statistical error and the systematic uncertainty) and
are compared with PYTHIA Tune A at the particle level (i.e. generator level)..
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 22
“Towards”, “Away”, “Transverse”
“Leading Jet”
Jet #1 Direction
D
“Toward”
“Transverse”
“Transverse”
“Away”
ETsum
Density
(GeV)
Charged
PTsum
Density
(GeV/c)
Average
Charged
Density
Charged
Particle
Density:
dN/dhd
Charged
PTsum
Density:
dPT/dhd
ETsum
Density:
dET/dhd
5
100.0
100.0
CDFCDF
RunRun
2 Preliminary
2 Preliminary
4
data corrected
data"Toward"
corrected
pyA generator level
pyA generator level
10.0
3
"Toward"
"Away"
"Away"
Factor of ~13
"Toward"
"Transverse"
Factor of ~16
"Away"
"Transverse" "Leading Jet"
Factor of MidPoint
~4.5 R=0.7 |h(jet#1)|<2
2
1.0
1.0
1
0 0.1
0.1
0 0
0
"Transverse"
CDF Run 2 Preliminary
data corrected
pyA generator level
50 50
50
100100
100
150
150
150
"Leading Jet"
"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
MidPoint R=0.7 |h(jet#1)|<2
ChargedStable
Particles
(|h|<1.0,
PT>0.5
GeV/c)
Charged
Particles
(|h|<1.0,
PT>0.5
GeV/c)
Particles
(|h|<1.0,
all
PT)
200
200
200
250
250
250
300
300
300
350
350
350
400
400
400
PT(jet#1)
PT(jet#1)(GeV/c)
(GeV/c)
PT(jet#1)
(GeV/c)
 Data
Data at
at 1.96
1.96 TeV
TeV on
on the
the charged
density ofparticle
charged
particles,
dN/dhd,
p > 0.5 GeV/c
and |h| < 1 for

pT sum
density, with
dPT/dhd,
and“leading
|h|
T > 0.5 GeV/c

Data at
1.96 TeV
on the
particle scalar
ETscalar
sum density,
dET/dhd,
forT|h| < with
1 for p“leading
jet” events
as<a1
jet” events as a function of the leading jet p for the “toward”, “away”, and “transverse” regions. The
for “leading
jet”
eventsjet
as pa function
of the Tleading
jet pand
the “toward”,
“away”,The
anddata
“transverse”
T for“transverse”
function
of the
leading
“toward”,
“away”,
regions.
are corrected
T for the
data
are
corrected
to
the
particle
level
(with
errors
that
include
both
the
statistical
error
and
the systematic
regions.
The
data
are
corrected
to
the
particle
level
(with
errors
that
include
both
the
statistical
errorand
andare
to the particle level (with errors that include both the statistical error and the systematic uncertainty)
uncertainty)
and
are
compared
with
PYTHIA
Tune
A
at
the
particle
level
(i.e.
generator
level).
the systematic
and A
are
with
PYTHIA
Tune Alevel).
at the particle level (i.e. generator
compared
withuncertainty)
PYTHIA Tune
at compared
the particle
level
(i.e. generator
level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 23
Charged Particle Density
HERWIG + JIMMY
Tune
(PTJIM
= 3.6)
Charged
ParticleParticle
Density:Density:
dN/dhd
"Transverse"
Charged
dN/dhdCharged Particle Density:"Away"
Charged
Particle
Density:
dN/dhd
"Away"
dN/dhd
Charged
Particle
Density:
dN/dhd
3
CDF Run 2 Preliminary
data corrected
data corrected
generator level theory
pyAW generator level
0.9
2
"Drell-Yan Production"
70 < M(pair) < 110 GeV
0.6
1
"Toward"
0
0.0
00
20
20
40
60
"Leading
Jet"
"Away" data corrected
generator level theory
2
"Drell-Yan Production"
70 < M(pair) < 110 GeV
40
80
Charged Particles
Particles (|h|<1.0,
(|h|<1.0, PT>0.5
PT>0.5
GeV/c)
HW
Charged
GeV/c)
excluding the lepton-pair
100
0
60
120
0
80
160
20
140
180
PT(Z-Boson)
(GeV/c)(GeV/c)
PT(jet#1)
or PT(Z-Boson)
Z-Boson Direction
D
High PT Z-Boson Production
CDF
CDFRun
Run22Preliminary
Preliminary
100
200
40
"Leading Jet"
data
datacorrected
corrected
pyA generator
generator
levellevel
theory
pyAW
1
"Transverse"
"Z-Boson"
0.3
44
Average
Density
"Away" Charged
Charged Density
CDFRun
Run22Preliminary
Preliminary
CDF
"Away" Charged Density
"Transverse"
ChargedDensity
Density
Average Charged
3
1.2
33
"Away"
"Toward"
22
JIM
11
"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
"Z-Boson""Transverse"
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
00
00
60
20
20
40
40
60
60
80
80
80
100
100
100
120
120
140
140
Jet #1 Direction
“Transverse”
PT(hard)
“Toward”
AntiProton
“Transverse”
“Transverse”
200
200
Outgoing Parton
D
Initial-State Radiation
“Toward”
Proton
180
180
PT(jet#1)
or PT(Z-Boson)
PT(jet#1)
(GeV/c) (GeV/c)
PT(Z-Boson) (GeV/c)
Outgoing Parton
160
160
“Transverse”
Initial-State Radiation
Proton
AntiProton
Underlying Event
Underlying Event
“Away”
“Away”
Outgoing Parton
Z-boson
Final-State
Radiation
 Data at 1.96 TeV on the density of charged particles, dN/dhd, with pT > 0.5 GeV/c and |h| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 24
Charged PTsum Density
12
CDFRun
Run2 2Preliminary
Preliminary
CDF
"Away"
data
corrected
data
corrected
pyAW generator level
generator level theory
1.5
CDF Run 2 Preliminary
data corrected
"Leading Jet"
generator level theory
8
"Transverse"
1.0
1.0
0.5
"Drell-Yan Production"
70 < M(pair) < 110 GeV
"Z-Boson"
0.1
0.0
00
"Drell-Yan Production"
70 < M(pair) < 110 GeV
4 "Toward"
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0
20
40
20
40
80
60
100
60
0
120
80
20
160
140
180
PT(Z-Boson)
(GeV/c)
PT(jet#1)
or PT(Z-Boson)
(GeV/c)
Z-Boson Direction
D
High PT Z-Boson Production
100
40
200
Charged
Density(GeV/c)
(GeV/c)
"Away" PTsum
PTsum Density
10.0
2.0
"Away" PTsum Density (GeV/c)
"Transverse"
PTsumDensity
Density(GeV/c)
(GeV/c)
Charged PTsum
Charged
PTsumPTsum
Density:
dPT/dhd
Charged
PTsum
Density:
dPT/dhd
Charged
PTsum
Density:
dPT/dhd
"Transverse"
Charged
Density:
dPT/dhd
"Away" Charged PTsum Density:"Away"
dPT/dhd
HW
20
100.0
CDF
2 Preliminary
CDF
RunRun
2 Preliminary
15 pyAW
corrected
data data
corrected
pyA generator
level
generator
level theory
"Leading Jet"
"Toward"
10.0
"Away"
"Z-Boson"
10
"Transverse"
JIM
1.0
5
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
00.1
0 060 20 20
404080 6060
"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
8080100100
100
120
120
140
140
Jet #1 Direction
“Transverse”
PT(hard)
“Toward”
AntiProton
“Transverse”
“Transverse”
200
Outgoing Parton
D
Initial-State Radiation
“Toward”
Proton
180
180
PT(jet#1) PT(jet#1)
or PT(Z-Boson)
(GeV/c)(GeV/c)
PT(Z-Boson) (GeV/c)
Outgoing Parton
160
160
“Transverse”
Initial-State Radiation
Proton
AntiProton
Underlying Event
Underlying Event
“Away”
“Away”
Outgoing Parton
Z-boson
Final-State
Radiation
 Data at 1.96 TeV on the charged scalar PTsum density, dPT/dhd, with pT > 0.5 GeV/c and |h| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 25
The “TransMAX/MIN” Regions
"TransDIF"
Charged
Particle
Density:
dN/dhd
"TransDIF" Charged
Particle
Density:
dN/dhd
Charged
Particle
Density:
dN/dhd
"TransMAX/MIN"
Charged
Particle
Density:
dN/dhd Charged Particle"TransMAX/MIN"
"TransMAX/MIN"
Charged
Particle
Density:
dN/dhd
"TransDIF"
Density:
dN/dhd
"Drell-Yan
Production"
"Drell-Yan
Production"
"Drell-Yan
Production"
70
M(pair)
110
GeV
70
M(pair)
110
GeV
70
<<<
M(pair)
<<<
110
GeV
"transMAX"
"transMAX"
0.6
0.8
0.8
ATLAS
0.9
0.6
pyDW
JIM
HW
"transMIN"
"transMIN"
0.3
0.4
0.4
ATLAS
HW
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.0
0.0
00
20
20
"Z-Boson"
0.3
0.0
60
60 0
40
40
80 40
20 80
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
Z-Boson Direction
D
High PT Z-Boson Production
TransMAX
- TransMIN
"Transverse"
Charged Density
Density
Charged Particles
Particles (|h|<1.0,
(|h|<1.0,
PT>0.5
GeV/c)
Charged
PT>0.5
GeV/c)
CDF Run
2 Preliminary
excluding the
the lepton-pair
lepton-pair
excluding
data
corrected
pyAW
pyDW
pyAW
JIM
generator level theory
datacorrected
corrected
data
corrected
data
generatorlevel
leveltheory
theory
generator
level
theory
generator
0.9
1.2
1.2
1.6
1.2
1.2
CDFRun
Run222Preliminary
Preliminary
CDF
Run
Preliminary
CDF
"TransDIF" Charged Density
TransMAX - TransMIN
"Transverse"
Charged
"Transverse"
Charged Density
Density
1.2
1.6
1.6
100 80
60100
CDF Run
Run 22 Preliminary
Preliminary
CDF
"Leading
Jet"
data corrected
1.2
0.9
HW
HW
"transMIN"
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generator
level).at the particle level (i.e. generator level).
(without MPI)
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 26
The “TransMAX/MIN” Regions
3.0
3.0
3.0
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Run22Preliminary
Preliminary
CDF
datacorrected
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M(pair) < Production"
110 GeV
70 < M(pair) < 110 GeV
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1.0
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20
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corrected
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corrected
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level
theory
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20 80
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PY Tune A
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"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
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HW
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Charged Particles (|h|<1.0, PT>0.5 GeV/c)
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150
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300
300
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excluding the lepton-pair
0.0
0.0
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2.0
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TransMAX - TransMIN Density (GeV/c)
3.0
3.0
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(GeV/c)
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Data at
at 1.96
1.96 TeV
TeV on
on the
the charged
charged scalar
scalar PTsum
PTsum density,
density, dPT/dhd,
dPT/dhd, with
with ppTT >> 0.5
0.5 GeV/c
GeV/c and
and |h|
|h| << 11 for
for “Z-Boson”
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and
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a function
of PpT(Z)
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events as aJet”
function
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as athe
function
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for “transMIN”
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T and for Z-Boson events
regions.
The
data
are
corrected
to
the
particle
level
(with
errors
that
include
both
the
statistical
error
and
the
“transMAX” minus “transMIN” regions. The data are corrected to the particle level (with errors that
include
systematic
uncertainty)
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at the particle level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 27
Charged Particle <pT>
"Toward" Average PT Charged
"Transverse" Average PT
1.6
CDF Run 2 Preliminary
CDF Run 2 Preliminary
data corrected
generator level theory
"Toward" <PT> (GeV/c)
"Transverse" Average PT (GeV/c)
2.0
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1.5
1.0
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MidPoint R=0.7 |h(jet#1)|<2
HW
data corrected
generator level theory
"Drell-Yan Production"
70 < M(pair) < 110 GeV
pyDW
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1.2
0.8
ATLAS
JIM
HW
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.4
0.5
0
50
100
150
200
250
300
350
400
0
20
40
60
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100
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“Transverse”
“Away”
 Data at 1.96 TeV on the charged particle average pT, with pT > 0.5 GeV/c and |h| < 1 for the “toward”
region for “Z-Boson” and the “transverse” region for “Leading Jet” events as a function of the
leading jet pT or PT(Z). The data are corrected to the particle level (with errors that include both the
statistical error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A,
respectively, at the particle level (i.e. generator level). The Z-Boson data are also compared with
PYTHIA Tune DW, the ATLAS tune, and HERWIG (without MPI)
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 28
Z-Boson: “Towards”, Transverse”,
& “TransMIN” Charge Density
Charged
Particle
Density:
dN/dhd
Charged
Particle
Density:
dN/dhd
"TransMIN"
Charged
Particle
Density:
dN/dhd
"Toward"
Charged
Particle
Density:
dN/dhd
"TransMIN" Charged Particle Density:
dN/dhd
High
PT Z-Boson
Production
Outgoing Parton
datagenerator
correctedlevel
pyAW
generator level theory
"Toward"
0.3
0.3
"Drell-Yan Production"
Production"
"Drell-Yan
70 << M(pair)
M(pair) <
70
< 110
110 GeV
GeV
HW
20
20
0.6
pyDW
data corrected
generator level theory
0.4
0.2
pyAW
Charged
Charged Particles
Particles (|h|<1.0,
(|h|<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
"Z-Boson"
excluding
excluding the
the lepton-pair
lepton-pair
0.0
0.0
00
CDF Run 2 Preliminary
"Transverse
ATLAS
JIM
0.6
0.6
0.0
60
60 0
40
40
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
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0.9
0.6
0.8
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Density
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Density
CDF Run 2 Preliminary
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2 Preliminary
data corrected
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0.9
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data corrected
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level theory
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level
0.6
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70 < M(pair) < 110 GeV
70 < M(pair) < 110 GeV
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20 80
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 Data at 1.96 TeV on the density of charged particles, dN/dhd, with pT > 0.5 GeV/c and |h| < 1 for “ZBoson” events as a function of PT(Z) for the “toward” and “transverse” regions. The data are
corrected to the particle level (with errors that include both the statistical error and the systematic
uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle
level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 29
Z-Boson: “Towards”, Transverse”,
& “TransMIN” Charge Density
1.8
1.2
data
datacorrected
corrected
pyAW
generator
level
generator
level theory
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HWPT>0.5 GeV/c)
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excluding the lepton-pair
excluding the lepton-pair
0.0
0.0
80 40
20 80
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“Z-Boson” events as a function of PT(Z) for the “toward” and “transverse” regions. The data are
corrected to the particle level (with errors that include both the statistical error and the systematic
uncertainty) and are compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle
level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 30
Z-Boson: “Towards” Region
"Toward" Charged Particle Density: dN/dhd
"Toward" Charged Particle Density: dN/dhd
CDF Run 2 Preliminary
CDF Run 2 Preliminary
generator level theory
data corrected
generator level theory
1.5
0.6
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"Drell-Yan Production"
pyDWT LHC14
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< 110 GeV
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level (with errors that include both the statistical error and the systematic uncertainty) and are
compared with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator
level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 31
150
100
Z-Boson: “Towards” Region
"Toward" Average PT Charged
"Toward" Average PT Charged
1.6
1.6
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excluding the lepton-pair
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data corrected
generator level theory
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excluding the lepton-pair
0.4
0
20
40
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80
100
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almost no change!
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events as a function of PT(Z) for the “toward” region. The data are corrected to the particle level
(with errors that include both the statistical error and the systematic uncertainty) and are compared
with PYTHIA Tune AW and HERWIG (without MPI) at the particle level (i.e. generator level).
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 32
Z-Boson: “Towards” Region
RDF LHC
Prediction!
"Toward" Charged Particle Density:
dN/dhd
"Toward" Charged Particle Density: dN/dhd
1.6
RDF Preliminary
PY Tune AW
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generator level
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Drell-Yan
1.96 TeV
"Toward" Charged Density
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0.8
0.6
0.4
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70 < M(pair) < 110 GeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
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0.8
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0.4
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14 TeV
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25
50
75
100
125
150
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Boson” events as a function of PT(Z) for the “toward” region from PYTHIA Tune AW, Tune DW, Tune
S320, and Tune P329 at the particle level (i.e. generator level).
 Extrapolations of PYTHIA Tune AW, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
Page 33
150
Z-Boson: “Towards” Region
RDF LHC Prediction!
"Toward" Charged PTsum Density: dN/dhd
"Toward" Charged PTsum Density: dN/dhd
2.0
1.0
generator level
0.8
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0.4
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0.2
Drell-Yan
1.96 TeV
RDF Preliminary
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"Toward" PTsum Density
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RDF Preliminary
PY64 Tune S320
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
PY Tune DWT
generator level
1.6
1.2
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0.8
PY64 Tune P329
0.4
70 < M(pair) < 110 GeV
PY64 Tune S320
Drell-Yan
14 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
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0
25
50
75
100
125
150
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50
75
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“Transverse”
125
Lepton-Pair PT (GeV/c)
Lepton-Pair PT (GeV/c)
“Transverse”
100
Tevatron
LHC
“Transverse”
“Transverse”
“Away”
“Away”
 Data at 1.96 TeV on the charged PTsum density, dPT/dhd, with pT > 0.5 GeV/c and |h| < 1 for “Z-Boson”
events as a function of PT(Z) for the “toward” region from PYTHIA Tune AW, Tune DW, Tune S320, and
Tune P329 at the particle level (i.e. generator level).
 Extrapolations of PYTHIA Tune AW, Tune DW, Tune DWT, Tune S320, and Tune P329 to the LHC.
Fermilab Energy Scaling Workshop
April 28, 2009
Rick Field – Florida/CDF/CMS
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1st Workshop on Energy Scaling
in Hadron-Hadron Collisions
 Rick Field Talk 3 Wednesday at 9:00am
From CDF to CMS
Peter’s favorite observable:
<pT> versus Nchg
Fermilab Energy Scaling Workshop
April 28, 2009
Summary & Conclusions & Predictions!
Rick Field – Florida/CDF/CMS
Page 35