Northwest Terascale Workshop
Parton Showers and Event Structure at the LHC
Review of the QCD Monte-Carlo Tunes
Rick Field
University of Florida
Outline of Talk
¨ Review some of what we have learned
University of Oregon February 23, 2009
about “min-bias” and the “underlying
event” in Run 1 at CDF.
Outgoing Parton
PT(hard)
Initial-State Radiation
¨ Review the various PYTHIA “underlying
Proton
AntiProton
Underlying Event
Underlying Event
event” QCD Monte-Carlo Model tunes.
¨ Show some things I do not understand
Outgoing Parton
Final-State
Radiation
about the CDF data.
¨ Show some extrapolations to the LHC.
CDF Run 2
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
CMS at the LHC
Page 1
QCD Monte-Carlo Models:
High Transverse Momentum Jets
Hard Scattering
Initial-State Radiation
Hard Scattering
Initial-State Radiation
Outgoing Parton
PT(hard)
Outgoing Parton
PT(hard)
Proton
“Hard Scattering” Component
AntiProton
Underlying Event
Final-State Radiation
Outgoing Parton
Underlying Event
Proton
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).
¨ Of course the outgoing colored partons fragment into hadron “jet” and inevitably “underlying event”
observables receive contributions from initial and final-state radiation.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 2
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
Underlying Event
Final-State Radiation
Outgoing Parton
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!
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 3
QCD Monte-Carlo Models:
Lepton-Pair Production
Lepton-Pair Production
Anti-Lepton
Initial-State Radiation
Lepton-Pair Production
Initial-State Radiation
“Jet”
Proton
Anti-Lepton
“Hard Scattering” Component
AntiProton
Lepton
Underlying Event
Underlying Event
Proton
Lepton
Underlying Event
AntiProton
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.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 4
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 Lepton-Pair
PT Z-Boson Production
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
Underlying Event
AntiProton
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.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 5
Proton-AntiProton Collisions
at the Tevatron
Elastic Scattering
Single Diffraction
Double Diffraction
M
M2
M1
σtot = σEL + σSD +σDD +σHC
1.8 TeV: 78mb
= 18mb
+ 9mb
+ (4-7)mb + (47-44)mb
Hard Core
The “hard core” component
contains both “hard” and
“soft” collisions.
“Hard” Hard Core (hard scattering)
Outgoing Parton
“Soft” Hard Core (no hard scattering)
Proton
PT(hard)
Proton
AntiProton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 6
Proton-AntiProton Collisions
at the Tevatron
Elastic Scattering
The CDF “Min-Bias” trigger
picks up most of the “hard
core” cross-section plus a
Double
Diffraction
small
amount of single &
double diffraction.
M2
M1
Single Diffraction
M
σtot = σEL + σSD +σDD +σHC
1.8 TeV: 78mb
= 18mb
+ 9mb
+ (4-7)mb + (47-44)mb
CDF “Min-Bias” trigger
1 charged particle in forward BBC
AND
1 charged particle in backward BBC
Hard Core
The “hard core” component
contains both “hard” and
“soft” collisions.
“Hard” Hard Core (hard scattering)
Outgoing Parton
“Soft” Hard Core (no hard scattering)
Proton
AntiProton
Beam-Beam Counters
3.2 < |η| < 5.9
PT(hard)
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 7
Particle Densities
2π
ΔηΔφ = 4π = 12.6
φ
31 charged
charged particles
particle
Charged Particles
pT > 0.5 GeV/c |η| < 1
CDF Run 2 “Min-Bias”
CDF Run 2 “Min-Bias”
Observable
Average
Average Density
per unit η-φ
Nchg
Number of Charged Particles
(pT > 0.5 GeV/c, |η| < 1)
3.17 +/- 0.31
0.252 +/- 0.025
PTsum
(GeV/c)
Scalar pT sum of Charged Particles
(pT > 0.5 GeV/c, |η| < 1)
2.97 +/- 0.23
0.236 +/- 0.018
chg/dηdφ = 1/4π
3/4π = 0.08
0.24
dNchg
13 GeV/c PTsum
0
-1
η
+1
Divide by 4π
dPTsum/dηdφ = 1/4π
3/4π GeV/c = 0.08
0.24 GeV/c
¨Study the charged particles (pT > 0.5 GeV/c, |η| < 1) and form the charged
particle density, dNchg/dηdφ, and the charged scalar pT sum density,
dPTsum/dηdφ.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 8
CDF Run 1 “Min-Bias” Data
Charged Particle Density
I will talk about “min-bias” and “pile-up” tomorrow!
Charged Particle Density: dN/dηdφ
Charged Particle Pseudo-Rapidity Distribution: dN/dη
1.0
7
CDF Published
CDF Published
6
0.8
dN/dηdφ
dN/dη
5
4
3
0.6
0.4
2
0.2
CDF Min-Bias 630 GeV
CDF Min-Bias 1.8 TeV
1
CDF Min-Bias 1.8 TeV
all PT
CDF Min-Bias 630 GeV
all PT
0.0
0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-1
0
1
2
3
4
Pseudo-Rapidity η
Pseudo-Rapidity η
<dNchg/dη> = 4.2
-2
<dNchg/dηdφ> = 0.67
¨ Shows CDF “Min-Bias” data on the number of charged particles per unit pseudo-rapidity
at 630 and 1,800 GeV. There are about 4.2 charged particles per unit η in “Min-Bias”
collisions at 1.8 TeV (|η| < 1, all pT).
ΔηxΔφ = 1
¨ Convert to charged particle density, dNchg/dηdφ, by dividing by 2π.
Δφ = 1
There are about 0.67 charged particles per unit η-φ in “Min-Bias”
0.67
collisions at 1.8 TeV (|η| < 1, all pT).
Δη = 1
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 9
CDF Run 1 “Min-Bias” Data
Charged Particle Density
I will talk about “min-bias” and “pile-up” tomorrow!
Charged Particle Density: dN/dηdφ
Charged Particle Pseudo-Rapidity Distribution: dN/dη
1.0
7
CDF Published
CDF Published
6
0.8
dN/dηdφ
dN/dη
5
4
3
0.6
0.4
2
0.2
CDF Min-Bias 630 GeV
CDF Min-Bias 1.8 TeV
1
CDF Min-Bias 1.8 TeV
all PT
CDF Min-Bias 630 GeV
all PT
0.0
0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-1
0
1
2
3
4
Pseudo-Rapidity η
Pseudo-Rapidity η
<dNchg/dη> = 4.2
-2
<dNchg/dηdφ> = 0.67
¨ Shows CDF “Min-Bias” data on the number of charged particles per unit pseudo-rapidity
at 630 and 1,800 GeV. There are about 4.2 charged particles per unit η in “Min-Bias”
collisions at 1.8 TeV (|η| < 1, all pT).
ΔηxΔφ = 1
¨ Convert to charged particle density, dNchg/dηdφ, by dividing by 2π.
Δφ = 1
There are about 0.67 charged particles per unit η-φ in “Min-Bias”
0.25
0.67
collisions at 1.8 TeV (|η| < 1, all pT).
¨ There are about 0.25 charged particles per unit η-φ in “Min-Bias”
Δη = 1
collisions at 1.96 TeV (|η| < 1, pT > 0.5 GeV/c).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 10
CDF Run 1: Evolution of Charged Jets
“Underlying Event”
Charged Particle Δφ Correlations
PT > 0.5 GeV/c |η| < 1
Charged Jet #1
Direction
“Transverse” region
very sensitive to the
“underlying event”!
2π
CDF Run 1 Analysis
“Toward-Side” Jet
Δφ
“Toward”
Away Region
Charged Jet #1
Direction
Δφ
“Toward”
“Transverse”
Look at the charged
particle density in the
“transverse” region!
Transverse
Region
Leading
Jet
φ
“Transverse”
Toward Region
“Transverse”
“Transverse”
Transverse
Region
“Away”
“Away”
“Away-Side” Jet
Away Region
0
-1
η
+1
¨ Look at charged particle correlations in the azimuthal angle Δφ relative to the leading charged
particle jet.
¨ Define |Δφ| < 60o as “Toward”, 60o < |Δφ| < 120o as “Transverse”, and |Δφ| > 120o as “Away”.
¨ All three regions have the same size in η-φ space, ΔηxΔφ = 2x120o = 4π/3.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 11
Run 1 Charged Particle Density
“Transverse” pT Distribution
"Transverse" Charged Particle Density: dN/dηdφ
Charged Particle Jet #1
Direction
Δφ
"Transverse" Charged Density
1.00
CDF Min-Bias
CDF Run 1
CDF JET20
data uncorrected
0.75
“Toward”
0.50
“Transverse”
0.25
“Transverse”
1.8 TeV |η|<1.0 PT>0.5 GeV/c
“Away”
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
¨ Compares the average “transverse” charge particle density with the average “Min-Bias”
charge particle density (|η|<1, pT>0.5 GeV). Shows how the “transverse” charge particle
density and the Min-Bias charge particle density is distributed in pT.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 12
Run 1 Charged Particle Density
“Transverse” pT Distribution
"Transverse" Charged Particle Density: dN/dηdφ
Charged Particle Density
1.0E+00
CDF Min-Bias
CDF Run 1
CDF JET20
data uncorrected
0.50
Factor of 2!
0.25
1.8 TeV |η|<1.0 PT>0.5 GeV/c
0.00
0
5
10
15
20
25
30
35
40
45
PT(charged jet#1) (GeV/c)
PT(charged jet#1) > 30 GeV/c
“Transverse” <dNchg/dηdφ> = 0.56
“Min-Bias”
CDF Run 1 Min-Bias data
<dNchg/dηdφ> = 0.25
CDF Run 1
"Transverse"
PT(chgjet#1) > 5 GeV/c
0.75
50
Charged Density dN/dηdφdPT (1/GeV/c)
"Transverse" Charged Density
1.00
data uncorrected
1.0E-01
"Transverse"
PT(chgjet#1) > 30 GeV/c
1.0E-02
1.0E-03
1.0E-04
Min-Bias
1.0E-05
1.8 TeV |η|<1 PT>0.5 GeV/c
1.0E-06
0
2
4
6
8
10
12
14
PT(charged) (GeV/c)
¨ Compares the average “transverse” charge particle density with the average “Min-Bias”
charge particle density (|η|<1, pT>0.5 GeV). Shows how the “transverse” charge particle
density and the Min-Bias charge particle density is distributed in pT.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 13
ISAJET 7.32
“Transverse” Density
ISAJET uses a naïve leading-log
parton shower-model which does
not agree with the data!
Charged Jet #1
Direction
1.00
Δφ
“Transverse”
“Transverse”
“Away”
CDF Run 1Data
"Transverse" Charged Density
“Toward”
ISAJET
"Transverse" Charged Particle Density: dN/dηdφ
Isajet
data uncorrected
theory corrected
0.75
"Hard"
0.50
0.25
“Hard”
Component
"Remnants"
1.8 TeV |η|<1.0 PT>0.5 GeV
Beam-Beam
Remnants
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
¨ Plot shows average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus PT(charged jet#1)
compared to the QCD hard scattering predictions of ISAJET 7.32 (default parameters with
PT(hard)>3 GeV/c) .
¨ The predictions of ISAJET are divided into two categories: charged particles that arise from the
break-up of the beam and target (beam-beam remnants); and charged particles that arise from the
outgoing jet plus initial and final-state radiation (hard scattering component).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 14
HERWIG 6.4
“Transverse” Density
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
1.00
CDF Run 1Data
"Transverse" Charged Density
Charged Jet #1
Direction
HERWIG uses a modified leadinglog parton shower-model which
does agrees better with the data!
"Transverse" Charged Particle Density: dN/dηdφ
Total
"Hard"
data uncorrected
theory corrected
0.75
0.50
0.25
"Remnants"
Beam-Beam
Remnants
HERWIG
Herwig 6.4 CTEQ5L
PT(hard) > 3 GeV/c
1.8 TeV |η|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
PT(charged jet#1) (GeV/c)
35
40
45
50
“Hard”
Component
¨ Plot shows average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus PT(charged
jet#1) compared to the QCD hard scattering predictions of HERWIG 5.9 (default parameters with
PT(hard)>3 GeV/c).
¨ The predictions of HERWIG are divided into two categories: charged particles that arise from the
break-up of the beam and target (beam-beam remnants); and charged particles that arise from the
outgoing jet plus initial and final-state radiation (hard scattering component).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 15
HERWIG 6.4
“Transverse” PT Distribution
HERWIG has the too steep of a pT
dependence of the “beam-beam remnant”
"Transverse" Chargedcomponent
Particle Density:
dN/dηdφ
of the
“underlying event”!
"Transverse" Charged Particle Density
CDF Data
"Hard"
Total
data uncorrected
theory corrected
0.75
1.0E+00
Herwig 6.4 CTEQ5L
PT(hard) > 3 GeV/c
CDF Data
PT(chgjet#1) > 5 GeV/c
0.50
0.25
"Remnants"
1.8 TeV |η|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
35
40
45
PT(charged jet#1) (GeV/c)
Herwig PT(chgjet#1) > 30 GeV/c
“Transverse” <dNchg/dηdφ> = 0.51
50
Charged Density dN/dηdφdPT (1/GeV/c)
"Transverse" Charged Density
1.00
data uncorrected
theory corrected
1.0E-01
1.8 TeV |η|<1 PT>0.5 GeV/c
1.0E-02
1.0E-03
1.0E-04
1.0E-05
PT(chgjet#1) > 30 GeV/c
Herwig 6.4 CTEQ5L
Herwig PT(chgjet#1) > 5 GeV/c
<dNchg/dηdφ> = 0.40
1.0E-06
0
2
4
6
8
10
12
14
PT(charged) (GeV/c)
¨ Compares the average “transverse” charge particle density (|η|<1, pT>0.5 GeV) versus
PT(charged jet#1) and the pT distribution of the “transverse” density, dNchg/dηdφdPT with the
QCD hard scattering predictions of HERWIG 6.4 (default parameters with PT(hard)>3
GeV/c. Shows how the “transverse” charge particle density is distributed in pT.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 16
MPI: Multiple Parton
Interactions
“Hard”
Collision
Multiple
Parton
Interaction
outgoing parton
“Hard” Component
“Semi-Hard” MPI
“Soft” Component
AntiProton
Proton
initial-state radiation
outgoing parton
initial-state radiation
final-state radiation
outgoing jet
or
+
final-state radiation
¨ PYTHIA models the “soft” component of the underlying event
with color string fragmentation, but in addition includes a
contribution arising from multiple parton interactions (MPI) in
which one interaction is hard and the other is “semi-hard”.
Beam-Beam Remnants
color string
color string
¨ The probability that a hard scattering events also contains a semi-hard multiple parton
interaction can be varied but adjusting the cut-off for the MPI.
¨ One can also adjust whether the probability of a MPI depends on the PT of the hard
scattering, PT(hard) (constant cross section or varying with impact parameter).
¨ One can adjust the color connections and flavor of the MPI (singlet or nearest neighbor,
q-qbar or glue-glue).
¨ Also, one can adjust how the probability of a MPI depends on PT(hard) (single or double
Gaussian matter distribution).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 17
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.
Core
Hard
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)ε with
ε = 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
ε = 0.25 (Set A))
4
PT0 (GeV/c)
PARP(85)
Take E0 = 1.8 TeV
3
2
ε = 0.16 (default)
1
100
1,000
10,000
100,000
CM Energy W (GeV)
Reference point
at 1.8 TeV
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 18
PYTHIA 6.206 Defaults
MPI constant
probability
scattering
PYTHIA default parameters
6.115
6.125
6.158
6.206
MSTP(81)
1
1
1
1
MSTP(82)
1
1
1
1
PARP(81)
1.4
1.9
1.9
1.9
PARP(82)
1.55
2.1
2.1
1.9
PARP(89)
1,000
1,000
1,000
PARP(90)
0.16
0.16
0.16
4.0
1.0
1.0
PARP(67)
4.0
1.00
"Transverse" Charged Density
Parameter
"Transverse" Charged Particle Density: dN/dηdφ
CDF Data
Pythia 6.206 (default)
MSTP(82)=1
PARP(81) = 1.9 GeV/c
data uncorrected
theory corrected
0.75
0.50
0.25
1.8 TeV |η|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
CTEQ3L
CTEQ4L
CTEQ5L
CDF Min-Bias
CDF JET20
¨ Plot shows the “Transverse” charged particle density versus PT(chgjet#1) compared to the
QCD hard scattering predictions of PYTHIA 6.206 (PT(hard) > 0) using the default
parameters for multiple parton interactions and CTEQ3L, CTEQ4L, and CTEQ5L.
Note Change
PARP(67) = 4.0 (< 6.138)
PARP(67) = 1.0 (> 6.138)
Oregon Terascale Workshop
February 23, 2009
Default parameters give
very poor description of
the “underlying event”!
Rick Field – Florida/CDF/CMS
Page 19
Run 1 PYTHIA Tune A
PYTHIA 6.206 CTEQ5L
CDF Default!
"Transverse" Charged Particle Density: dN/dηdφ
Parameter
Tune B
Tune A
MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
1.9 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
1.0
0.9
PARP(86)
1.0
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(67)
1.0
4.0
New PYTHIA default
(less initial-state radiation)
Oregon Terascale Workshop
February 23, 2009
"Transverse" Charged Density
1.00
CDF Preliminary
PYTHIA 6.206 (Set A)
PARP(67)=4
data uncorrected
theory corrected
0.75
Run 1 Analysis
0.50
0.25
CTEQ5L
PYTHIA 6.206 (Set B)
PARP(67)=1
1.8 TeV |η|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
¨ Plot shows the “transverse” charged particle density
versus PT(chgjet#1) compared to the QCD hard
scattering predictions of two tuned versions of PYTHIA
6.206 (CTEQ5L, Set B (PARP(67)=1) and Set A
(PARP(67)=4)).
Old PYTHIA default
(more initial-state radiation)
Rick Field – Florida/CDF/CMS
Page 20
Run 1 vs Run 2: “Transverse”
Charged Particle Density
“Transverse” region as
defined by the leading
“charged particle jet”
"Transverse" Charged Particle Density: dN/dηdφ
Charged Particle Jet #1
Direction
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
"Transverse" Charged Density
1.25
CDF Run 1 Min-Bias
CDF Run 1 Data
CDF Run 1 JET20
data uncorrected
1.00
0.75
0.50
0.25
1.8 TeV |η|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
¨ Shows the data on the average “transverse” charge particle density (|η|<1, pT>0.5 GeV) as
a function of the transverse momentum of the leading charged particle jet from Run 1.
¨ Compares the Run 2 data (Min-Bias, JET20, JET50, JET70, JET100) with Run 1. The
errors on the (uncorrected) Run 2 data include both statistical and correlated
systematic uncertainties.
¨ Shows the prediction of PYTHIA Tune A at 1.96 TeV after detector simulation (i.e. after
CDFSIM).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 21
Run 1 vs Run 2: “Transverse”
Charged Particle Density
“Transverse” region as
defined by the leading
“charged particle jet”
Charged Particle Jet #1
Direction
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
"Transverse"
ChargedDensity
Density
"Transverse"Charged
Charged
"Transverse"
Density
"Transverse"
Charged
Density
1.25
1.25
1.25
"Transverse"
"Transverse" Charged
Charged Particle
Particle Density:
Density: dN/dηdφ
dN/dηdφ
"Transverse"
Charged
Particle
Density:
dN/dηdφ
"Transverse"
Charged
Particle
Density:
dN/dηdφ
CDF Run 1 Min-Bias
CDF Run 1 Min-Bias
CDF
Run
11Published
CDF
Run
JET20
CDF
Run
1 Published
CDF
Run
1 JET20
CDF Run 2 Preliminary
CDF Run 2 Preliminary
PYTHIA Tune A
CDF Run 2
CDFPreliminary
Run 1 Data
CDF
CDF
Preliminary
CDF
Preliminary
data
uncorrected
1.00
1.00
1.00
data
uncorrected
data
uncorrected
data
uncorrected
theory corrected
0.75
0.75
0.75
0.50
0.50
0.50
0.25
0.25
0.25
|η|<1.0
PT>0.5
GeV/c
|TeV
PT>0.5
GeV/c
η|<1.0
1.8
|η|<1.0
|η|<1.0
PT>0.5PT>0.5
GeV GeV
0.00
0.00
0.00
0.00
000
0
10
20
10
10 5 20
20
30
30
10
30
40
50
40
4015 50
50
60
70 2580
60
20
60 70
70 80
80
PT(charged
jet#1)
PT(charged jet#1)
90
10035110
120
140 150
90
130
30
40 130
50
90 100
100 110
110 120
120
13045140
140 150
150
(GeV/c)
PT(charged jet#1) (GeV/c)
(GeV/c)
¨ Shows the
Excellent agreement
between
Run
1 and 2!
data
on the
average
“transverse” charge particle density (|η|<1, pT>0.5 GeV) as
a function of the transverse momentum of the leading charged particle jet from Run 1.
¨ Compares the Run 2 data (Min-Bias, JET20, JET50, JET70, JET100) with Run 1. The
errors on the (uncorrected) Run 2 data include both statistical and
correlated
PYTHIA
Tune A was tuned to fit
the
“underlying
event” in Run I!
systematic uncertainties.
¨ Shows the prediction of PYTHIA Tune A at 1.96 TeV after detector simulation (i.e. after
CDFSIM).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 22
“Towards”, “Away”, “Transverse”
Jet #1 Direction
“Transverse” region is
very sensitive to the
“underlying event”!
Look at the charged
particle density, the
charged PTsum density
and the ETsum density in
all 3 regions!
Δφ Correlations relative to the leading jet
Charged particles pT > 0.5 GeV/c |η| < 1
Calorimeter towers ET > 0.1 GeV |η| < 1
“Toward-Side” Jet
2π
Z-Boson
Direction
Jet #1 Direction
Δφ
Away Region
Δφ
Transverse
Region
“Toward”
“Toward”
“Transverse”
“Transverse”
“Away”
“Transverse”
“Transverse”
φ
Leading
Jet
Toward Region
“Away”
Transverse
Region
“Away-Side” Jet
Away Region
0
-1
η
+1
¨ Look at correlations in the azimuthal angle Δφ relative to the leading charged particle jet (|η| <
1) or the leading calorimeter jet (|η| < 2).
¨ Define |Δφ| < 60o as “Toward”, 60o < |Δφ| < 120o as “Transverse ”, and |Δφ| > 120o as “Away”.
Each of the three regions have area ΔηΔφ = 2×120o = 4π/3.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 23
Event Topologies
¨ “Leading Jet” events correspond to the leading
calorimeter jet (MidPoint R = 0.7) in the region |η| < 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” (Δφ12 > 150o) with almost equal transverse
energies (PT(jet#2)/PT(jet#1) > 0.8) with no other
conditions .
¨ “Exclusive 2-Jet Back-to-Back” events are selected to
have at least two jets with Jet#1 and Jet#2 nearly “backto-back” (Δφ12 > 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 |η| < 1 with
no other conditions.
¨ “Z-Boson” events are Drell-Yan events
with 70 < M(lepton-pair) < 110 GeV
with no other conditions.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Jet #1 Direction
Δφ
“Leading Jet”
“Toward”
“Transverse”
“Transverse”
subset
“Away”
Jet #1 Direction
Δφ
“Toward”
“Transverse”
“Inc2J Back-to-Back”
subset
“Transverse”
“Away”
“Exc2J Back-to-Back”
Jet #2 Direction
ChgJet #1 Direction
Δφ
“Toward”
“Transverse”
“Charged Jet”
“Transverse”
“Away”
Z-Boson Direction
Δφ
“Toward”
“Transverse”
“Transverse”
Z-Boson
“Away”
Page 24
Charged Particle Density Δφ Dependence
Refer to this as a
“Leading Jet” event
Jet #1 Direction
Charged
Particle Density:
Density: dN/dηdφ
dN/dηdφ
Charged Particle
Δφ
10.0
10.0
Subset
“Transverse”
“Transverse”
“Away”
Refer to this as a
“Back-to-Back” event
Jet #1 Direction
Δφ
“Toward”
“Transverse”
“Transverse”
Charged Particle
Particle Density
Density
Charged
“Toward”
CDF
CDF Preliminary
Preliminary
30 << ET(jet#1)
ET(jet#1) << 70
70 GeV
GeV
30
Back-to-Back
Leading Jet
data
data uncorrected
uncorrected
Min-Bias
"Transverse"
"Transverse"
Region
Region
1.0
1.0
Jet#1
Jet#1
Charged
Charged Particles
Particles
(|η|<1.0,
(|η|<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
0.1
0.1
00
30
30
60
60
90
120
“Away”
150
180
210
210
240
240
270
270
300
300
330
330
360
360
Δφ (degrees)
Jet #2 Direction
¨ Look at the “transverse” region as defined by the leading jet (JetClu R = 0.7, |η| < 2) or by the
leading two jets (JetClu R = 0.7, |η| < 2). “Back-to-Back” events are selected to have at least two
jets with Jet#1 and Jet#2 nearly “back-to-back” (Δφ12 > 150o) with almost equal transverse
energies (ET(jet#2)/ET(jet#1) > 0.8) and with ET(jet#3) < 15 GeV.
¨ Shows the Δφ dependence of the charged particle density, dNchg/dηdφ, for charged
particles in the range pT > 0.5 GeV/c and |η| < 1 relative to jet#1 (rotated to 270o) for 30
< ET(jet#1) < 70 GeV for “Leading Jet” and “Back-to-Back” events.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 25
Charged Particle Density Δφ Dependence
“Leading Jet”
Jet #1 Direction
Charged Particle Density: dN/dηdφ
Δφ
272
CDF Preliminary
“Toward”
252
256
260
276 280
264 268
284
288
292
296
248
data uncorrected
30 < ET(jet#1) < 70 GeV
300
244
304
240
308
236
312
232
“Transverse”
316
228
“Transverse”
320
224
324
220
Jet#1
216
328
332
212
“Away”
336
208
340
204
344
200
“Back-to-Back”
196
348
192
Jet #1 Direction
352
188
Δφ
"Transverse"
Region
184
180
356
"Transverse"
Region
360
4
176
“Toward”
8
172
12
0.5
168
16
20
164
“Transverse”
“Transverse”
24
160
1.0
156
28
Leading Jet
152
“Away”
Back-to-Back
36
148
1.5
144
140
40
44
136
48
132
Jet #2 Direction
Charged Particles
(|η|<1.0, PT>0.5 GeV/c)
52
2.0
128
Polar Plot
32
124
56
60
120
64
116
68
112
108
104
100
96
88
84
80
76
72
92
¨ Shows the Δφ dependence of the charged particle density, dNchg/dηdφ, for charged
particles in the range pT > 0.5 GeV/c and |η| < 1 relative to jet#1 (rotated to 270o) for 30
< ET(jet#1) < 70 GeV for “Leading Jet” and “Back-to-Back” events.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 26
“transMAX” & “transMIN”
Jet #1 Direction
Z-Boson
Direction
Jet #1 Direction
Δφ
Area = 4π/6
“Toward-Side” Jet
“transMIN” very sensitive to
the “beam-beam remnants”!
Δφ
“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 η-φ space of 4π/6.
¨ The “transMIN” region is very sensitive to the “beam-beam remnant” and the soft
multiple parton interaction components of the “underlying event”.
¨ 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.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 27
Observables at the
Particle and Detector Level
“Leading Jet”
Jet #1 Direction
Observable
Particle Level
Detector Level
dNchg/dηdφ
Number of charged particles
per unit η-φ
(pT > 0.5 GeV/c, |η| < 1)
Number of “good” charged tracks
per unit η-φ
(pT > 0.5 GeV/c, |η| < 1)
dPTsum/dηdφ
Scalar pT sum of charged particles
per unit η-φ
(pT > 0.5 GeV/c, |η| < 1)
Scalar pT sum of “good” charged tracks per
unit η-φ
(pT > 0.5 GeV/c, |η| < 1)
<pT>
Average pT of charged particles
(pT > 0.5 GeV/c, |η| < 1)
Average pT of “good” charged tracks
(pT > 0.5 GeV/c, |η| < 1)
PTmax
Maximum pT charged particle
(pT > 0.5 GeV/c, |η| < 1)
Require Nchg ≥ 1
Maximum pT “good” charged tracks
(pT > 0.5 GeV/c, |η| < 1)
Require Nchg ≥ 1
dETsum/dηdφ
Scalar ET sum of all particles
per unit η-φ
(all pT, |η| < 1)
Scalar ET sum of all calorimeter towers
per unit η-φ
(ET > 0.1 GeV, |η| < 1)
PTsum/ETsum
Scalar pT sum of charged particles
(pT > 0.5 GeV/c, |η| < 1)
divided by the scalar ET sum of
all particles (all pT, |η| < 1)
Scalar pT sum of “good” charged tracks
(pT > 0.5 GeV/c, |η| < 1)
divided by the scalar ET sum of
calorimeter towers (ET > 0.1 GeV, |η| < 1)
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
Jet #1 Direction
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
Jet #2 Direction
“Back-to-Back”
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 28
CDF Run 1 PT(Z)
PYTHIA
6.2 CTEQ5L
UE Parameters Parameter
Tune A
Tune A25
Tune A50
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
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
PT Distribution 1/N dN/dPT
MSTP(81)
σ = 1.0
Z-Boson Transverse Momentum
0.12
CDF Run 1 Data
PYTHIA Tune A
σ = 2.5
PYTHIA Tune A25
PYTHIA Tune A50
0.08
CDF Run 1
published
1.8 TeV
σ = 5.0
Normalized to 1
0.04
0.00
ISR Parameter
0
2
4
6
8
10
12
14
16
18
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).
Vary the intrensic KT!
Intrensic KT
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 29
20
CDF Run 1 PT(Z)
Parameter
Tune A
Tune AW
UE Parameters 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)
1.0
2.1
PARP(93)
5.0
15.0
ISR Parameters
Z-Boson Transverse Momentum
0.12
CDF Run 1 Data
PT Distribution 1/N dN/dPT
PYTHIA 6.2 CTEQ5L
Tune used by the
CDF-EWK group!
CDF Run 1
PYTHIA Tune A
PYTHIA Tune AW
published
0.08
1.8 TeV
Normalized to 1
0.04
0.00
0
2
4
6
8
10
12
14
16
18
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), and PYTHIA Tune AW
(<pT(Z)> = 11.7 GeV/c).
Effective Q cut-off, below which space-like showers are not evolved.
Intrensic KT
The Q2 = kT2 in αs for space-like showers is scaled by PARP(64)!
Oregon Terascale Workshop
February 23, 2009
20
Rick Field – Florida/CDF/CMS
Page 30
Jet-Jet Correlations (DØ)
Jet#1-Jet#2 Δφ Distribution
Δφ Jet#1-Jet#2
¨ MidPoint Cone Algorithm (R = 0.7, fmerge = 0.5)
¨ L = 150 pb-1 (Phys. Rev. Lett. 94 221801 (2005))
¨ Data/NLO agreement good. Data/HERWIG agreement
good.
¨ Data/PYTHIA agreement good provided PARP(67) =
1.0→4.0 (i.e. like Tune A, best fit 2.5).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 31
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Tune DW
Tune AW
UE Parameters MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
1.9 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
1.0
0.9
PARP(86)
1.0
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.25
1.25
PARP(64)
0.2
0.2
PARP(67)
2.5
4.0
MSTP(91)
1
1
PARP(91)
2.1
2.1
PARP(93)
15.0
15.0
ISR Parameters
PT Distribution 1/N dN/dPT
Parameter
Z-Boson Transverse Momentum
0.12
CDF Run 1 Data
PYTHIA Tune DW
HERWIG
CDF Run 1
published
0.08
1.8 TeV
Normalized to 1
0.04
0.00
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 DW,
and HERWIG.
Tune DW uses D0’s perfered value of PARP(67)!
Intrensic KT
Tune DW has a lower value of PARP(67) and slightly more MPI!
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 32
MIT Search Scheme: Vista/Sleuth
Exclusive 3 Jet Final State Challenge
At least 1 Jet (“trigger” jet)
(PT > 40 GeV/c, |η| < 1.0)
CDF Data
Normalized to 1
PYTHIA
Tune A
Exactly 3 jets
(PT > 20 GeV/c, |η| < 2.5)
R(j2,j3)
Order Jets by PT
Jet1 highest PT, etc.
Bruce Knuteson
Khaldoun
Makhoul
Georgios
Choudalakis
Oregon Terascale Workshop
February 23, 2009
Markus
Klute
Conor
Henderson
Rick Field – Florida/CDF/CMS
Ray
Culbertson
Gene
Flanagan
Page 33
3Jexc R(j2,j3) Normalized
The data have more
3 jet events with
small R(j2,j3)!?
¨ Let Ntrig40 equal the number of events
Exclusive 3-Jet Production: R(j2,j3)
with at least one jet with PT > 40 geV and
|η| < 1.0 (this is the “offline” trigger).
0.16
¨ Let N3Jexc20 equal the number of events
0.12
with exactly three jets with PT > 20 GeV/c
and |η| < 2.5 which also have at least one
jet with PT > 40 GeV/c and |η| < 1.0.
¨ Let N3JexcFr = N3Jexc20/Ntrig40. The is
the fraction of the “offline” trigger events
that are exclusive 3-jet events.
Initial-State Radiation
Underlying Event
Outgoing Parton
0.08
Normalized to
N3JexcFr
0.04
0.00
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
¨ PARP(67) affects the initial-state radiation which
contributes primarily to the region R(j2,j3) > 1.0.
“Jet 3”
Initial-State Radiation
“Jet 2”
R > 1.0
Oregon Terascale Workshop
February 23, 2009
5.0
R(j2,j3)
with PYTHIA Tune AW (PARP(67)=4), Tune DW
(PARP(67)=2.5), Tune BW (PARP(67)=1).
AntiProton
Underlying Event
Data R(j2,j3)
pyAW
pyDW
pyBW
data uncorrected
generator level theory
¨ The CDF data on dN/dR(j2,j3) at 1.96 TeV compared
Outgoing Parton
“Jet 1”
Proton
dN/dR(j2,j3)
CDF Run 2 Preliminary
Rick Field – Florida/CDF/CMS
Page 34
3Jexc R(j2,j3) Normalized
¨ Let Ntrig40 equal the number of events
Exclusive
Exclusive 3-Jet
3-Jet Production:
Production: R(j2,j3)
R(j2,j3)
0.16
0.16
with at least one jet with PT > 40 geV and
|η| < 1.0 (this is the “offline” trigger).
¨ Let N3JexcFr = N3Jexc20/Ntrig40. The is
the fraction of the “offline” trigger events
that are exclusive 3-jet events.
AntiProton
Underlying Event
Final-State Radiation
“Jet “Jet
2” 3”
R < 1.0
Oregon Terascale Workshop
February 23, 2009
Normalized to
N3JexcFr
0.04
0.04
0.00
0.00
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
3.5
3.5
4.0
4.0
4.5
4.5
5.0
5.0
R(j2,j3)
R(j2,j3)
with PYTHIA Tune DW (PARP(67)=2.5) and
HERWIG (without MPI).
Proton
Outgoing Parton
0.08
0.08
¨ The CDF data on dN/dR(j2,j3) at 1.96 TeV compared
Outgoing Parton
“Jet 1”
Underlying Event
dN/dR(j2,j3)
dN/dR(j2,j3)
with exactly three jets with PT > 20 GeV/c
and |η| < 2.5 which also have at least one
jet with PT > 40 GeV/c and |η| < 1.0.
Data
Data R(j2,j3)
R(j2,j3)
pyDW
pyDW
pyDWnoFSR
hw05
data uncorrected
data uncorrected
generator level theory
generator level theory
0.12
0.12
¨ Let N3Jexc20 equal the number of events
Final-State Radiation
CDF Run
Run 22 Preliminary
Preliminary
CDF
¨ Final-State radiation contributes to the region
R(j2,j3) < 1.0.
¨ If you ignore the normalization and normalize all the
distributions to one then the data prefer Tune BW, but
I believe this is misleading.
Rick Field – Florida/CDF/CMS
Page 35
3Jexc R(j2,j3) Normalized
¨ Let Ntrig40 equal the number of events
Exclusive
Exclusive 3-Jet
3-Jet Production:
Production: R(j2,j3)
R(j2,j3)
0.16
0.80
0.16
with at least one jet with PT > 40 geV and
|η| < 1.0 (this is the “offline” trigger).
¨ Let N3JexcFr = N3Jexc20/Ntrig40. The is
the fraction of the “offline” trigger events
that are exclusive 3-jet events.
AntiProton
Underlying Event
Final-State Radiation
“Jet “Jet
2” 3”
R < 1.0
Oregon Terascale Workshop
February 23, 2009
Normalized to
N3JexcFr
0.04
0.20
0.04
Normalized to 1
0.00
0.00
0.0
0.0
0.5
0.5
1.0
1.0
1.5
1.5
2.0
2.0
2.5
2.5
3.0
3.0
3.5
3.5
4.0
4.0
4.5
4.5
5.0
5.0
R(j2,j3)
R(j2,j3)
with PYTHIA Tune DW (PARP(67)=2.5) and
HERWIG (without MPI).
Proton
Outgoing Parton
0.08
0.40
0.08
¨ The CDF data on dN/dR(j2,j3) at 1.96 TeV compared
Outgoing Parton
“Jet 1”
Underlying Event
dN/dR(j2,j3)
dN/dR(j2,j3)
dN/dR(j2,j3)
with exactly three jets with PT > 20 GeV/c
and |η| < 2.5 which also have at least one
jet with PT > 40 GeV/c and |η| < 1.0.
CDF Data
Data
Data R(j2,j3)
R(j2,j3)
hw05
pyDW
pyDW
pyDW
pyDWnoFSR
hw05
pyBW
data
data uncorrected
uncorrected
data uncorrected
generator
generator level
level theory
theory
generator level theory
0.12
0.60
0.12
¨ Let N3Jexc20 equal the number of events
Final-State Radiation
CDF Run
Run 22 Preliminary
Preliminary
CDF
¨ Final-State radiation contributes to the region
R(j2,j3) < 1.0.
¨ If you ignore the normalization and normalize all the
distributions to one then the data prefer Tune BW, but
I believe this is misleading.
Rick Field – Florida/CDF/CMS
Page 36
3Jexc R(j2,j3) Normalized
¨ Let Ntrig40 equal the number of events
Exclusive
Exclusive 3-Jet
3-Jet Production:
Production: R(j2,j3)
R(j2,j3)
0.16
0.80
0.16
with at least one jet with PT > 40 geV and
|η| < 1.0 (this is the “offline” trigger).
0.12
0.60
0.12
with exactly three jets with PT > 20 GeV/c
0.08
0.40
0.08
and |η| < 2.5 which also have at least one
I do not understand
the
0.04
jet with PT > 40 GeV/c and |η| < 1.0.
0.20
0.04
excess number of events
Normalized to 1
¨ Let N3JexcFr = N3Jexc20/Ntrig40. The
is R(j2,j3)
with
<
1.0.
0.00
0.00
0.5
1.0
1.5
the fraction of the “offline” trigger
events
0.0related
0.5
1.0
1.5
Perhaps this is0.0
to the
that are exclusive 3-jet events.
“soft energy” problem??
Final-State Radiation
CDF Data
Data
Data R(j2,j3)
R(j2,j3)
hw05
pyDW
pyDW
pyDW
pyDWnoFSR
hw05
pyBW
data
data uncorrected
uncorrected
data uncorrected
generator
generator level
level theory
theory
generator level theory
dN/dR(j2,j3)
dN/dR(j2,j3)
dN/dR(j2,j3)
¨ Let N3Jexc20 equal the number of events
CDF Run
Run 22 Preliminary
Preliminary
CDF
Normalized to
N3JexcFr
2.0
2.0
2.5
2.5
3.0
3.0
3.5
3.5
4.0
4.0
4.5
4.5
5.0
5.0
R(j2,j3)
R(j2,j3)
I will¨
show
youCDF
a lot more
The
data on dN/dR(j2,j3) at 1.96 TeV compared
on Thursday!
with PYTHIA Tune DW (PARP(67)=2.5) and
Outgoing Parton
“Jet 1”
HERWIG (without MPI).
Proton
AntiProton
Underlying Event
Underlying Event
Outgoing Parton
Final-State Radiation
“Jet “Jet
2” 3”
R < 1.0
Oregon Terascale Workshop
February 23, 2009
¨ Final-State radiation contributes to the region
R(j2,j3) < 1.0.
¨ If you ignore the normalization and normalize all the
distributions to one then the data prefer Tune BW, but
I believe this is misleading.
Rick Field – Florida/CDF/CMS
Page 37
All use LO αs
with Λ = 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
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 38
All use LO αs
with Λ = 192 MeV!
PYTHIA 6.2 Tunes
UE Parameters
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
PARP(84)
0.4
0.4
0.5
PARP(85)
1.0
1.0
0.33
PARP(86)
1.0
1.0
0.66
PARP(89)
1.96 TeV
1.96 TeV
1.0 TeV
PARP(90)
0.16
0.16
0.16
PARP(62)
1.25
1.25
1.0
PARP(64)
0.2
0.2
1.0
PARP(67)
2.5
2.5
1.0
MSTP(91)
1
1
1
PARP(91)
2.1
2.1
1.0
PARP(93)
15.0
15.0
5.0
ATLAS energy dependence!
Intrinsic KT
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 39
All use LO αs
with Λ = 192 MeV!
PYTHIA 6.2 Tunes
UE Parameters
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
PARP(84)
Tune
AW
Tune A
ISR Parameter
0.4
0.4
Tune
B
PARP(85)
1.0
1.0
0.33
PARP(86)
1.0
1.0
0.66
PARP(89)
1.96 TeV
1.96 TeV
1.0 TeV
PARP(90)
0.16
0.16
0.16
PARP(62)
1.25
1.25
1.0
PARP(64)
0.2
0.2
1.0
PARP(67)
2.5
2.5
1.0
MSTP(91)
1
1
1
PARP(91)
PARP(93)
Tune 2.1
DW
15.0
2.1
15.0
ATLAS energy dependence!
Tune BW
1.0
Tune
D6
5.0
Tune D
Tune D6T
Intrinsic KT
Oregon Terascale Workshop
February 23, 2009
0.5
Rick Field – Florida/CDF/CMS
Page 40
All use LO αs
with Λ = 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
energy dependence!
PARP(84)
0.4
0.4
Tune
B
These
PYTHIA
6.20.5tunes!ATLASTune
Tune
AWare “old”
BW
PARP(85)
1.0
1.0
0.33
There are new 6.4 tunes by
PARP(86)
1.0
1.0
0.66
Arthur
Moraes
(ATLAS)
PARP(89)
1.96 TeV
1.96 TeV
1.0 TeV
Hendrik
Hoeth
(MCnet)
PARP(90)
0.16
0.16
0.16
(Tune S0)
PARP(62) Peter
1.25Skands1.25
1.0
PARP(64)
0.2
0.2
1.0
PARP(67)
2.5
2.5
1.0
MSTP(91)
1
1
1
PARP(91)
PARP(93)
Tune 2.1
DW
15.0
2.1
15.0
Tune D
Tune D6T
Intrinsic KT
Oregon Terascale Workshop
February 23, 2009
1.0
Tune
D6
5.0
Rick Field – Florida/CDF/CMS
Page 41
All use LO αs
with Λ = 192 MeV!
PYTHIA 6.2 Tunes
UE Parameters
ISR Parameter
Parameter
Tune H(6.418)
Tune DWT
Tune D6T
ATLAS
PDF
CTEQ5L
CTEQ5L
CTEQ6L
CTEQ5L
MSTP(81)
1
1
1
1
MSTP(82)
4
4
4
4
PARP(82)
2.1 GeV
1.9409 GeV
1.8387 GeV
1.8 GeV
PARP(83)
0.84
0.5
0.5
0.5
PARP(84)
0.5
0.4
0.4
0.5
PARP(85)
0.82
1.0
1.0
0.33
PARP(86)
0.91
1.0
1.0
0.66
PARP(89)
1.0
1.96 TeV
1.96 TeV
1.0 TeV
PARP(90)
0.17
0.16
0.16
0.16
PARP(62)
2.97
1.25
1.25
1.0
PARP(64)
0.12
0.2
0.2
1.0
PARP(67)
2.74
2.5
2.5
1.0
MSTP(91)
1
1
1
1
PARP(91)
2.0
2.1
2.1
1.0
PARP(93)
5.0
15.0
15.0
5.0
Q2 ordered showers, old MPI!
Intrinsic KT
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 42
JIMMY at CDF
PT(JIM)= 2.5 GeV/c.
The Energy in the “Underlying
Event” in High PT Jet Production
JIMMY: MPI
J. M. Butterworth
J. R. Forshaw
M. H. Seymour
Jet #1 Direction
Δφ
“Toward”
“Transverse”
PT(JIM)= 3.25 GeV/c.
“Transverse”
"Transverse" ETsum Density: dET/dηdφ
4.0
"Transverse" ETsum Density (GeV)
JIMMY
Runs with HERWIG and adds
multiple parton interactions!
JIMMY was tuned to fit
the energy density in the
“transverse” region for
“leading jet” events!
JIMMY Default
1.96 TeV
HW
3.0
2.0
PY Tune A
JM325
"Leading Jet"
1.0
CDF Run 2 Preliminary
MidPoint R = 0.7 |η(jet)| < 2
generator level theory
All Particles (|η|<1.0)
0.0
0
100
“Away”
Initial-State Radiation
AntiProton
Outgoing Parton
Underlying Event
Final-State
Radiation
"Transverse" PTsum Density (GeV/c)
1.6
PT(hard)
Underlying Event
300
400
500
"Transverse" PTsum Density: dPT/dηdφ
Outgoing Parton
Proton
200
PT(particle jet#1) (GeV/c)
JIMMY Default
1.96 TeV
1.2
JM325
PY Tune A
0.8
"Leading Jet"
HW
0.4
MidPoint R = 0.7 |η(jet)| < 2
CDF Run 2 Preliminary
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
0.0
“Transverse” <Densities> vs PT(jet#1)
Oregon Terascale Workshop
February 23, 2009
0
50
Rick Field – Florida/CDF/CMS
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
Page 43
JIMMY at CDF
PT(JIM)= 2.5 GeV/c.
The Energy in the “Underlying
Event” in High PT Jet Production
JIMMY: MPI
J. M. Butterworth
J. R. Forshaw
M. H. Seymour
Jet #1 Direction
Δφ
“Toward”
“Transverse”
PT(JIM)= 3.25 GeV/c.
“Transverse”
"Transverse" ETsum Density: dET/dηdφ
4.0
"Transverse" ETsum Density (GeV)
JIMMY
Runs with HERWIG and adds
multiple parton interactions!
JIMMY was tuned to fit
the energy density in the
“transverse” region for
“leading jet” events!
JIMMY Default
1.96 TeV
HW
3.0
2.0
PY Tune A
JM325
"Leading Jet"
1.0
CDF Run 2 Preliminary
MidPoint R = 0.7 |η(jet)| < 2
generator level theory
All Particles (|η|<1.0)
The Drell-Yan JIMMY Tune
PTJIM = 3.6 GeV/c,
PT(particle jet#1) (GeV/c)
JMRAD(73) = 1.8
"Transverse" PTsum Density: dPT/dηdφ
JMRAD(91) = 1.8
0.0
0
“Away”
Outgoing Parton
1.6
Initial-State Radiation
Proton
AntiProton
Underlying Event
Outgoing Parton
Underlying Event
Final-State
Radiation
"Transverse" PTsum Density (GeV/c)
PT(hard)
100
200
300
400
500
JIMMY Default
1.96 TeV
1.2
JM325
PY Tune A
0.8
"Leading Jet"
HW
0.4
MidPoint R = 0.7 |η(jet)| < 2
CDF Run 2 Preliminary
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
0.0
“Transverse” <Densities> vs PT(jet#1)
Oregon Terascale Workshop
February 23, 2009
0
50
Rick Field – Florida/CDF/CMS
100
150
200
250
300
350
400
450
500
PT(particle jet#1) (GeV/c)
Page 44
Charged Particle Density
Charged Particle Density: dN/dηdφ
Charged Particle Density: dN/dηdφ
4
CDF Run 2 Preliminary
CDF Run 2 Preliminary
data corrected
pyAW generator level
2
"Away"
"Drell-Yan Production"
70 < M(pair) < 110 GeV
1
"Transverse"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
"Toward"
0
0
20
40
60
80
100
Average Charged Density
Average Charged Density
3
data corrected
pyA generator level
3
"Toward"
2
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
1
"Transverse"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
0
0
20
40
Δφ
High PT Z-Boson Production
60
80
100
120
140
Outgoing Parton
Jet #1 Direction
“Transverse”
“Toward”
AntiProton
“Transverse”
“Transverse”
180
200
Outgoing Parton
Δφ
PT(hard)
Initial-State Radiation
“Toward”
Proton
160
PT(jet#1) (GeV/c)
PT(Z-Boson) (GeV/c)
Z-Boson Direction
"Away"
“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/dηdφ, with pT > 0.5 GeV/c and |η| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 45
Charged Particle Density
Charged
ParticleParticle
Density:Density:
dN/dηdφdN/dηdφ
"Transverse"
Charged
Charged
Particle
Density:
dN/dηdφ
"Away"
Charged
Particle
Density:
dN/dηdφ
44
CDFRun
Run22Preliminary
Preliminary
CDF
data corrected
data corrected
generator level theory
pyAW generator level
0.9
2
"Leading
Jet"
"Away"
"Drell-Yan Production"
70 < M(pair) < 110 GeV
0.6
1
"Transverse"
"Z-Boson"
0.3
Charged Particles
Particles (|η|<1.0,
PT>0.5 GeV/c)
GeV/c)
Charged
(|η|<1.0, PT>0.5
excluding the lepton-pair
"Toward"
0
0.0
00
20
20
40
60
40
80
100
60
120
80
160
140
180
100
200
Average
Density
"Away" Charged
Charged Density
"Transverse"
ChargedDensity
Density
Average Charged
3
1.2
CDF
CDFRun
Run22Preliminary
Preliminary
33
Δφ
High PT Z-Boson Production
"Away"
"Toward"
22
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
11
"Z-Boson""Transverse"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
00
00
20
20
40
40
60
60
80
80
100
100
120
120
140
140
Outgoing Parton
Jet #1 Direction
“Transverse”
“Toward”
AntiProton
“Transverse”
“Transverse”
180
180
200
200
Outgoing Parton
Δφ
PT(hard)
Initial-State Radiation
“Toward”
Proton
160
160
PT(jet#1)
or PT(Z-Boson)
PT(jet#1)
(GeV/c) (GeV/c)
PT(Z-Boson)
(GeV/c)(GeV/c)
PT(jet#1)
or PT(Z-Boson)
Z-Boson Direction
"Leading Jet"
data
datacorrected
corrected
pyA generator
generator
levellevel
theory
“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/dηdφ, with pT > 0.5 GeV/c and |η| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 46
Charged Particle Density
HERWIG + JIMMY
Tune
(PTJIM
= 3.6)
Charged
ParticleParticle
Density:Density:
dN/dηdφ
"Transverse"
Charged
dN/dηdφCharged Particle Density:"Away"
Charged
Particle
Density:
dN/dηdφ
"Away"
dN/dηdφ
Charged
Particle
Density:
dN/dηdφ
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
20
20
40
60
generator level theory
2
40
80
100
0
60
120
0
"Drell-Yan Production"
70 < M(pair) < 110 GeV
80
160
20
140
180
PT(Z-Boson)
(GeV/c)(GeV/c)
PT(jet#1)
or PT(Z-Boson)
Z-Boson Direction
Δφ
High PT Z-Boson Production
CDF
CDFRun
Run22Preliminary
Preliminary
100
200
40
33
"Away"
"Toward"
22
JIM
11
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
"Z-Boson""Transverse"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
Charged Particles (|η|<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
“Toward”
Proton
“Transverse”
AntiProton
“Transverse”
“Transverse”
180
180
200
200
Outgoing Parton
Δφ
PT(hard)
Initial-State Radiation
“Toward”
160
160
PT(jet#1)
or PT(Z-Boson)
PT(jet#1)
(GeV/c) (GeV/c)
PT(Z-Boson) (GeV/c)
Outgoing Parton
"Leading Jet"
data
datacorrected
corrected
pyA generator
generator
levellevel
theory
pyAW
Charged Particles
Particles (|η|<1.0,
PT>0.5
GeV/c)
HW
Charged
(|η|<1.0, PT>0.5
GeV/c)
excluding the lepton-pair
"Toward"
0
0.0
00
"Leading
Jet"
"Away" data corrected
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
“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/dηdφ, with pT > 0.5 GeV/c and |η| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 47
Charged Particle Density
HERWIG + JIMMY
Tune
(PTJIM
= 3.6)
Charged
ParticleParticle
Density:Density:
dN/dηdφ
"Transverse"
Charged
dN/dηdφCharged Particle Density:"Away"
Charged
Particle
Density:
dN/dηdφ
"Away"
dN/dηdφ
Charged
Particle
Density:
dN/dηdφ
H. Hoeth, MPI@LHC08
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
20
20
40
60
generator level theory
2
40
80
100
0
60
120
0
"Drell-Yan Production"
70 < M(pair) < 110 GeV
80
160
20
140
180
PT(Z-Boson)
(GeV/c)(GeV/c)
PT(jet#1)
or PT(Z-Boson)
Z-Boson Direction
Δφ
High PT Z-Boson Production
CDF
CDFRun
Run22Preliminary
Preliminary
100
200
40
33
"Away"
"Toward"
22
JIM
11
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
"Z-Boson""Transverse"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
Charged Particles (|η|<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
“Toward”
Proton
“Transverse”
AntiProton
“Transverse”
“Transverse”
180
180
200
200
Outgoing Parton
Δφ
PT(hard)
Initial-State Radiation
“Toward”
160
160
PT(jet#1)
or PT(Z-Boson)
PT(jet#1)
(GeV/c) (GeV/c)
PT(Z-Boson) (GeV/c)
Outgoing Parton
"Leading Jet"
data
datacorrected
corrected
pyA generator
generator
levellevel
theory
pyAW
Charged Particles
Particles (|η|<1.0,
PT>0.5
GeV/c)
HW
Charged
(|η|<1.0, PT>0.5
GeV/c)
excluding the lepton-pair
"Toward"
0
0.0
00
"Leading
Jet"
"Away" data corrected
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
“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/dηdφ, with pT > 0.5 GeV/c and |η| < 1 for “Z-Boson”
and “Leading Jet” events as a function of the leading jet pT or PT(Z) for the “toward”, “away”, and
“transverse” regions. The data are corrected to the particle level (with errors that include both the statistical
error and the systematic uncertainty) and are compared with PYTHIA Tune AW and Tune A, respectively, at the
particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 48
The “Transverse” Region
“Leading Jet”
"Transverse" ETsum Density: dET/dηdφ
Jet #1 Direction
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
"Transverse" ETsum Density (GeV)
5.0
CDF Run 2 Preliminary
data corrected
generator level theory
4.0
3.0
2.0
PY Tune A
1.0
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
HW
Stable Particles (|η|<1.0, all PT)
0.0
0
50
100
150
200
250
300
350
400
PT(jet#1) (GeV/c)
¨
1.96
TeV- Theory
on the scalar
ETscalar
sum density,
with |η| <with
1 for
jet” events
a function
¨ Data
Showsatthe
Data
for the
ET sum dET/dηdφ,
density, dET/dηdφ,
|η|“leading
< 1 for “leading
jet”asevents
as a
of
the leading
pT forjet
thep“transverse”
region. The data are corrected to the particle level (with errors that
function
of thejet
leading
T for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and
HERWIG (without MPI) at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 49
The “TransMAX/MIN” Regions
“Leading Jet”
Jet #1 Direction
Δφ
“Toward”
“TransMAX”
“TransMIN”
“Away”
"TransMAX"ETsum
ETsum
Density
(GeV)
"Transverse"
"TransveMIN"
ETsumDensity
Density(GeV)
(GeV)
"TransMAX"
"TransMIN" ETsum
Density:
dET/dηdφ
"TransMAX/MIN"
ETsum
Density:
dET/dηdφ
6.0
3.0
6.0
CDF
"Leading Jet"
CDF Run
Run 22 Preliminary
Preliminary
CDF Run 2 Preliminary
data corrected
MidPoint R=0.7 |η(jet#1)|<2
data corrected
"transMAX"
generator level theory
generator level
theory
Stable
Particles (|η|<1.0, all PT)
data corrected
generator level theory
4.0
2.0
4.0
HW
PY
PYTune
TuneAA
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
"Leading Jet"
"transMIN"
MidPoint R=0.7 |η(jet#1)|<2
PY Tune A
Stable Particles (|η|<1.0, all PT)
Stable Particles (|η|<1.0, all PT)
HW
2.0
1.0
2.0
HW
0.0
0.0
0.0
00
0
50
50
50
100
100
100
150
150
150
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 scalar
scalar E
ETTT sum
sum density,
density, dET/dηdφ,
dET/dηdφ, with
with |η|
|η| <
< 11 for
for “leading
“leading jet”
jet” events
events as
as aa function
function of
of
of
leading
“transMAX”
region.
corrected
to the
particle
(with
errors
the
leading
jet
ppT pfor
thethe
“transMIN”
region.
TheThe
datadata
are are
corrected
to the
particle
levellevel
(with
errors
thatthat
T for
thethe
leading
jetjet
T for “transDIF” = “transMAX”-”transMIN. The data are corrected to the particle level (with
include
both
the statistical
and the
systematic
) and are compared
PYTHIA
A and
errors that
include
both theerror
statistical
error
and the uncertainty
systematic uncertainty
) and are with
compared
withTune
PYTHIA
level).
HERWIG
MPI)
at the particle
(i.e. generator
generator level).
Tune A and(without
HERWIG
(without
MPI) at level
the particle
level (i.e.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 50
The “Transverse” Region
“Leading Jet”
Jet #1 Direction
Δφ
“Toward”
“Transverse”
“Transverse”
“Away”
Data - Theory
(GeV) (GeV)
"Transverse"
ETsum Density
5.0
1.6
0.4Density:
density corresponds
"Transverse" ETsum
dET/dηdφ to
1.67 GeV in the
CDF CDF
Run Run
2 Preliminary
2 Preliminary “transverse”
"Leading
Jet"
region!
data corrected
data corrected
generator
level theory
generator
level theory
4.0
1.2
MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
HW
3.0
0.8
PY Tune A
2.0
0.4
PY Tune A
1.0
0.0
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
HW
Stable Particles (|η|<1.0, all PT)
0.0
-0.4
00
50
50
100
100
150
150
200
250
300
350
400
PT(jet#1) (GeV/c)
¨
1.96
TeV- Theory
on the scalar
ETscalar
sum density,
with |η| <with
1 for
jet” events
a function
¨ Data
Showsatthe
Data
for the
ET sum dET/dηdφ,
density, dET/dηdφ,
|η|“leading
< 1 for “leading
jet”asevents
as a
of
the leading
pT forjet
thep“transverse”
region. The data are corrected to the particle level (with errors that
function
of thejet
leading
T for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
include both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and
HERWIG (without MPI) at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 51
The “TransMAX/MIN” Regions
“Leading Jet”
Jet #1 Direction
Δφ
“Toward”
“TransMAX”
“TransMIN”
“Away”
"TransMAX"
Density
(GeV)
"Transverse"
Density
(GeV)
TransMAX ETsum
-ETsum
TransMIN
(GeV)
"TransveMIN"
ETsum
Density
(GeV)
"TransMAX"
"TransMIN"
ETsum
Density:
dET/dηdφ
"TransMAX/MIN"
ETsum
Density:
dET/dηdφ
"TransDIF" ETsum
Density:
dET/dηdφ
6.0
3.0
6.0
5.0
CDF
"Leading Jet"
CDF Run
Run 22 Preliminary
Preliminary
CDF
Run
4.0
4.0
2.0
4.0
3.0
PY Tune A
2.0
2.0
1.0
2.0
HW
data corrected
generator level theory
HW
PY
PYTune
TuneAA
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
"Leading Jet"
"transMIN"
Jet"
MidPoint "Leading
R=0.7 |η(jet#1)|<2
MidPoint
R=0.7 |η(jet#1)|<2
PY Tune
A
Stable Particles (|η|<1.0, all PT)
Stable
Particles
(|η|<1.0,
all PT)
Stable
Particles
(|η|<1.0,
all PT)
HW
1.0
HW
0.0
0.0
0.0
0.0
CDF Run 2 Preliminary
data
MidPoint R=0.7 |η(jet#1)|<2
datacorrected
corrected
data
corrected
"transMAX"
generator
theory
generatorlevel
level
generator
level
theory
Stable
Particles (|η|<1.0, all PT)
00
0
50
50
50
100
100
100
150
150
150
200
200
200
250
250
250
250
300
300
300
300
350
350
350
350
400
400
400
400
PT(jet#1)
PT(jet#1) (GeV/c)
(GeV/c)
(GeV/c)
PT(jet#1)
(GeV/c)
¨
¨ Data
Data at
at 1.96
1.96 TeV
TeV on
on the
the scalar
scalar E
ETTT sum
sum density,
density, dET/dηdφ,
dET/dηdφ, with
with |η|
|η| <
< 11 for
for “leading
“leading jet”
jet” events
events as
as aa function
function of
of
of
leading
“transMAX”
region.
corrected
to the
particle
(with
errors
the
leading
jet
ppT pfor
thethe
“transMIN”
region.
TheThe
datadata
are are
corrected
to the
particle
levellevel
(with
errors
thatthat
T for
thethe
leading
jetjet
T for “transDIF” = “transMAX”-”transMIN. The data are corrected to the particle level (with
include
both
the statistical
and the
systematic
) and are compared
PYTHIA
A and
errors that
include
both theerror
statistical
error
and the uncertainty
systematic uncertainty
) and are with
compared
withTune
PYTHIA
level).
HERWIG
MPI)
at the particle
(i.e. generator
generator level).
Tune A and(without
HERWIG
(without
MPI) at level
the particle
level (i.e.
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 52
The Leading Jet Mass
“Leading Jet”
Leading Jet Invariant Mass
70
“Toward”
“Transverse”
“Transverse”
“Away”
Jet Mass (GeV)
Jet #1 Direction
Δφ
CDF Run 2 Preliminary
data corrected
generator level theory
60
50
40
PY Tune A
30
20
10
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
HW
0
0
50
100
150
200
250
300
350
400
PT(jet#1) (GeV/c)
¨
1.96
TeV- on
the leading
invariant
mass formass
“leading
jet” events
a function
of the leading
pT
¨ Data
Showsatthe
Data
Theory
for thejet
leading
jet invariant
for “leading
jet”asevents
as a function
of thejet
leading
for
“transverse” region. The data are corrected to the particle level (with errors that include both the
jet pthe
T for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and HERWIG
(without MPI) at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 53
The Leading Jet Mass
“Leading Jet”
Leading Jet Invariant
Off by ~2Mass
GeV
12.0
70
“Toward”
“Transverse”
“Transverse”
“Away”
Data
Theory
(GeV)
Jet-Mass
(GeV)
Jet #1 Direction
Δφ
CDF
CDFRun
Run22Preliminary
Preliminary
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
data
datacorrected
corrected
generator
generatorlevel
leveltheory
theory
60
8.0
50
HW
PY Tune A
40
4.0
30
PY Tune A
20
0.0
10
"Leading Jet"
MidPoint R=0.7 |η(jet#1)|<2
HW
-4.0
0
00
5050
100
100
150
150
200
200
250
250
300
300
350
400
PT(jet#1
uncorrected)
PT(jet#1)
(GeV/c)(GeV/c)
¨
1.96
TeV- on
the leading
invariant
mass formass
“leading
jet” events
a function
of the leading
pT
¨ Data
Showsatthe
Data
Theory
for thejet
leading
jet invariant
for “leading
jet”asevents
as a function
of thejet
leading
for
“transverse” region. The data are corrected to the particle level (with errors that include both the
jet pthe
T for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and HERWIG
(without MPI) at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 54
The “Underlying Event” in
High PT Jet Production (LHC)
High PT Jet Production
Outgoing Parton
PT(hard)
Initial-State
Radiation
The “Underlying Event” Proton
Underlying Event
Underlying Event
“Underlying event” much
more active at the LHC!
Final-State
Radiation
Outgoing Parton
"Transverse" Charged Particle Density: dN/dηdφ
"Transverse" Charged Particle Density: dN/dηdφ
1.0
2.0
RDF Preliminary
LHC
RDF Preliminary
generator level
0.8
0.6
PY Tune AW
HERWIG
0.4
1.96 TeV
0.2
"Leading Jet"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
0.0
"Transverse" Charged Density
"Transverse" Charged Density
Charged particle density
versus PT(jet#1)
AntiProton
generator level
1.5
PY Tune AW
HERWIG
1.0
CDF
0.5
"Leading Jet"
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
0.0
0
50
100
150
200
250
300
350
400
450
500
0
250
500
PT(particle jet#1) (GeV/c)
750
1000
1250
1500
1750
2000
2250
2500
PT(particle jet#1) (GeV/c)
¨ Charged particle density in the “Transverse” ¨ Charged particle density in the “Transverse”
region versus PT(jet#1) at 1.96 TeV for PY
region versus PT(jet#1) at 14 TeV for PY Tune
Tune AW and HERWIG (without MPI).
AW and HERWIG (without MPI).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 55
Drell-Yan Production (Run 2 vs LHC)
Drell-Yan Production
Proton
<pT(μ+μ-)> is much
larger at the LHC!
Lepton-Pair Transverse
Momentum
Lepton
AntiProton
Underlying Event
Underlying Event
Shapes of the pT(μ+μ-)
distribution at the Z-boson mass.
Initial-State
Radiation
Anti-Lepton
Lepton-Pair Transverse Momentum
Drell-Yan PT(μ+μ-) Distribution
80
0.10
Drell-Yan
Drell-Yan
LHC
60
1/N dN/dPT (1/GeV)
Average Pair PT
generator level
40
Tevatron Run 2
20
0
0.08
PY Tune DW (solid)
HERWIG (dashed)
0.06
70 < M(μ-pair) < 110 GeV
|η(μ-pair)| < 6
0.04
0.02
PY Tune DW (solid)
HERWIG (dashed)
Z
generator level
Tevatron Run2
LHC
Normalized to 1
0.00
0
100
200
300
400
500
600
700
800
900
1000
0
5
Lepton-Pair Invariant Mass (GeV)
10
15
20
25
30
35
40
PT(μ+μ-) (GeV/c)
¨ Average Lepton-Pair transverse momentum ¨ Shape of the Lepton-Pair pT distribution at the
Z-boson mass at the Tevatron and the LHC for
at the Tevatron and the LHC for PYTHIA
PYTHIA Tune DW and HERWIG (without MPI).
Tune DW and HERWIG (without MPI).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 56
The “Underlying Event” in
Drell-Yan Production
Drell-Yan Production
The “Underlying Event”
Lepton
Proton
HERWIG (without MPI)
is much less active than
PY Tune AW (with MPI)!
Underlying Event
Charged particle density
versus M(pair)
AntiProton
Underlying Event
“Underlying event” much
more active at the LHC!
Initial-State
Radiation
Anti-Lepton
Charged Particle Density: dN/dηdφ
Charged Particle Density: dN/dηdφ
1.5
1.0
RDF Preliminary
generator level
PY Tune AW
0.8
0.6
0.4
HERWIG
0.2
Drell-Yan
1.96 TeV
Z
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
(excluding lepton-pair )
Charged Particle Density
Charged Particle Density
RDF Preliminary
generator level
Z
LHC
1.0
PY Tune AW
CDF
0.5
Drell-Yan
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
(excluding lepton-pair )
HERWIG
0.0
0.0
0
50
100
150
200
250
0
50
100
150
200
250
Lepton-Pair Invariant Mass (GeV)
Lepton-Pair Invariant Mass (GeV)
¨ Charged particle density versus the lepton- ¨ Charged particle density versus the lepton-pair
pair invariant mass at 1.96 TeV for PYTHIA invariant mass at 14 TeV for PYTHIA Tune AW
and HERWIG (without MPI).
Tune AW and HERWIG (without MPI).
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 57
Summary
¨ We are making good progress in modeling “min-bias”
collisions! I will talk more about this tomorrow.
¨ We are making good progress in understanding and
modeling the “underlying event” high transverse
momentum jet production and in Drell-Yan production.
I will talk much more about this tomorrow.
“Minumum Bias” Collisions
Proton
AntiProton
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
AntiProton
Underlying Event
¨ There are still some things we do not fully understand!
Outgoing Parton
** Soft Underlying Event Energy **
Underlying Event
Final-State
Radiation
** Jet Mass **
Drell-Yan Production
** R(J2,J3) **
Proton
Lepton
AntiProton
Underlying Event
Underlying Event
I will talk much more
about this on Thursday!
Anti-Lepton
¨AND we really do not know how to
extrapolate to the LHC!
Oregon Terascale Workshop
February 23, 2009
Rick Field – Florida/CDF/CMS
Page 58