Northwest Terascale Workshop
Parton Showers and Event Structure at the LHC
Studying the Underlying Event at CDF
Rick Field
University of Florida
Outline of Talk
 Study “jets” in the “underlying event”
University of Oregon February 24, 2009
(i.e. 3 & 4 jet production).
Outgoing Parton
 Show 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
PT(hard)
Initial-State Radiation
Proton
AntiProton
Underlying Event
Outgoing Parton
Underlying Event
Final-State
Radiation
R. Field, C. Group, & D. Kar
 Study <pT> versus <Nchg> in “min-bias”
collisions and Z-boson production.
 Show some extrapolations to the LHC.
Oregon Terascale Workshop
February 24, 2009
CMS at the LHC
CDF Run 2
Rick Field – Florida/CDF/CMS
Page 1
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!
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 2
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.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 3
“Towards”, “Away”, “Transverse”
Look at the charged
particle density, the
charged PTsum density
and the ETsum density in
all 3 regions!
 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 || < 1
Calorimeter towers ET > 0.1 GeV || < 1
“Toward-Side” Jet
2
Away Region
Z-Boson
Direction
Jet #1 Direction


Transverse
Region
“Toward”
“Toward”
“Transverse”
“Transverse”
“Away”
“Transverse”
“Transverse”

Leading
Jet
Toward Region
“Away”
Transverse
Region
“Away-Side” Jet
Away Region
0
-1

+1
 Look at correlations in the azimuthal angle relative to the leading charged particle jet (|| <
1) or the leading calorimeter jet (|| < 2).
 Define || < 60o as “Toward”, 60o < || < 120o as “Transverse ”, and || > 120o as “Away”.
o
Each of the three regions have area  = 2×120 = 4/3.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 4
Event Topologies
 “Leading Jet” events correspond to the leading
calorimeter jet (MidPoint R = 0.7) in the region || < 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” (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” (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 || < 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 24, 2009
Rick Field – Florida/CDF/CMS
Jet #1 Direction

“Leading Jet”
“Toward”
“Transverse”
“Transverse”
subset
“Away”
Jet #1 Direction

“Inc2J Back-to-Back”
“Toward”
subset
“Transverse”
“Transverse”
“Away”
“Exc2J Back-to-Back”
Jet #2 Direction
ChgJet #1 Direction

“Charged Jet”
“Toward”
“Transverse”
“Transverse”
“Away”
Z-Boson Direction

“Toward”
Z-Boson
“Transverse”
“Transverse”
“Away”
Page 5
“transMAX” & “transMIN”
Jet #1 Direction
Z-Boson
Direction
Jet #1 Direction

Area = 4/6
“transMIN” very sensitive to
the “beam-beam remnants”!
“Toward-Side” Jet

“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 - 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.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 6
Observables at the
Particle and Detector Level
“Leading Jet”
Jet #1 Direction
Observable
Particle Level
Detector Level
dNchg/dd
Number of charged particles
per unit -
(pT > 0.5 GeV/c, || < 1)
Number of “good” charged tracks
per unit -
(pT > 0.5 GeV/c, || < 1)
dPTsum/dd
Scalar pT sum of charged particles
per unit -
(pT > 0.5 GeV/c, || < 1)
Scalar pT sum of “good” charged tracks per
unit -
(pT > 0.5 GeV/c, || < 1)
<pT>
Average pT of charged particles
(pT > 0.5 GeV/c, || < 1)
Average pT of “good” charged tracks
(pT > 0.5 GeV/c, || < 1)
PTmax
Maximum pT charged particle
(pT > 0.5 GeV/c, || < 1)
Require Nchg ≥ 1
Maximum pT “good” charged tracks
(pT > 0.5 GeV/c, || < 1)
Require Nchg ≥ 1
dETsum/dd
Scalar ET sum of all particles
per unit -
(all pT, || < 1)
Scalar ET sum of all calorimeter towers
per unit -
(ET > 0.1 GeV, || < 1)
PTsum/ETsum
Scalar pT sum of charged particles
(pT > 0.5 GeV/c, || < 1)
divided by the scalar ET sum of
all particles (all pT, || < 1)
Scalar pT sum of “good” charged tracks
(pT > 0.5 GeV/c, || < 1)
divided by the scalar ET sum of
calorimeter towers (ET > 0.1 GeV, || < 1)

“Toward”
“Transverse”
“Transverse”
“Away”
Jet #1 Direction

“Toward”
“Transverse”
“Transverse”
“Away”
Jet #2 Direction
“Back-to-Back”
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 7
“Transverse” PTmax versus ET(jet#1)
Jet #1 Direction
“Leading Jet”

“TransMIN”
Highest“TransMAX”
pT particle
in the
“transverse” region!
“Back-to-Back”
“Away”
Jet #1 Direction

“Toward”
“TransMAX”
PTmaxT
PTmaxT
“TransMIN”
“Away”
"Transverse" PTmax (GeV/c)
Jet #1 Direction
“Toward”
PTmaxT
"Transverse" Charged PTmax
3.0
CDF Run 2 Preliminary
1.96 TeV

2.5
data uncorrected
Leading Jet
2.0
“Toward”
1.5
“TransMAX”
1.0
“TransMIN”
0.5“Away”
Min-Bias
Back-to-Back
Charged Particles (||<1.0, PT>0.5 GeV/c)
0.0
0
50
100
150
200
250
ET(jet#1) (GeV)
Jet #2 Direction
Min-Bias
 Use the leading jet to define the “transverse” region and look at the maximum pT
charged particle in the “transverse” region, PTmaxT.
 Shows the average PTmaxT, in the “transverse” region (pT > 0.5 GeV/c, || < 1) versus
ET(jet#1) for “Leading Jet” and “Back-to-Back” events compared with the average
maximum pT particle, PTmax, in “min-bias” collisions (pT > 0.5 GeV/c, || < 1).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 8
Back-to-Back “Associated”
Charged Particle Densities
Maximum pT particle in
the “transverse” region!
PTmaxT
Direction
“Associated” densities do
not include PTmaxT!
Jet #1 Direction


“Toward”
“TransMAX”
PTmaxT

“TransMIN”
PTmaxT
Direction
Jet#1
Region
Jet#2
Region
Jet#1
Region
Jet#2
Region
“Away”
Jet #2 Direction
 Use the leading jet in “back-to-back” events to define the “transverse” region and look at
the maximum pT charged particle in the “transverse” region, PTmaxT.
 Look at the  dependence of the “associated” charged particle and PTsum densities,
dNchg/dd and dPTsum/dd for charged particles (pT > 0.5 GeV/c, || < 1, not including
PTmaxT) relative to PTmaxT.
 Rotate so that PTmaxT is at the center of the plot (i.e. 180o).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 9
Back-to-Back “Associated”
Charged Particle Densities
“Associated” densities do
not include PTmaxT!
PTmaxT
Direction
Associated Particle Density

Jet#2
Region
Charged Particles
(||<1.0, PT>0.5 GeV/c)
CDF Preliminary
Jet #3
Jet #2
Associated Particle Density: dN/dd
10.0
Jet #1
Jet#1
Region
data uncorrected
Back-to-Back
30 < ET(jet#1) < 70 GeV
PTmaxT not included
1.0
Jet#2
Region
PTmaxT > 2.0 GeV/c
PTmaxT > 1.0 GeV/c
Jet #4??
"Jet#1"
Region
PTmaxT
PTmaxT > 0.5 GeV/c
0.1
0
30
60
90
Log Scale!
120
150
180
210
240
270
300
330
360
 (degrees)
 Look at the  dependence of the “associated” charged particle density, dNchg/dd for
charged particles (pT > 0.5 GeV/c, || < 1, not including PTmaxT) relative to PTmaxT
(rotated to 180o) for PTmaxT > 0.5 GeV/c, PTmaxT > 1.0 GeV/c and PTmaxT > 2.0
GeV/c, for “back-to-back” events with 30 < ET(jet#1) < 70 GeV.
 Shows “jet structure” in the “transverse” region (i.e. the “birth” of the 3rd & 4th jet).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 10
“Back-to-Back” vs “Min-Bias”
“Associated” Charge Density
“Back-to-Back”
“Associated” Density
“Birth” of jet#3 in the
“transverse” region!
PTmaxT
Direction
Associated Particle Density: dN/dd

“Min-Bias”
“Associated” Density
Associated Particle Density
Jet#2
Region
10.0
Jet#1
Region
PTmax Direction

PTmaxT > 2.0 GeV/c
PTmax > 2.0 GeV/c
Charged Particles
Particles
Charged
(||<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
(||<1.0,
3030< <ET(jet#1)
ET(jet#1)< <7070GeV
GeV
1.0
Min-Bias x 1.65
PTmaxT
PTmaxT
PTmax
PTmax
Min-Bias
PTmaxT,
PTmaxT,PTmax
PTmaxnot
notincluded
included
CDFPreliminary
Preliminary
CDF
data
uncorrected
data
uncorrected
0.1
Correlations in 
0
30
60
90
120
150
180
210
240
270
300
330
360
 (degrees)
Log Scale!
“Birth” of jet#1 in
 Shows the  dependence of the “associated” charged particle density, “min-bias”
dNchg/dd
for pT
collisions!
> 0.5 GeV/c, || < 1 (not including PTmaxT) relative to PTmaxT (rotated to 180o) for
PTmaxT > 2.0 GeV/c, for “back-to-back” events with 30 < ET(jet#1) < 70 GeV.
 Shows the data on the  dependence of the “associated” charged particle density,
dNchg/dd, pT > 0.5 GeV/c, || < 1 (not including PTmax) relative to PTmax (rotated to
180o) for “min-bias” events with PTmax > 2.0 GeV/c.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 11
Back-to-Back “Associated”
Charged Particle Densities
“Back-to-Back”
charge density
Charged Particle Density: dN/dd
Jet #1 Direction

2
CDF Preliminary
346
350
354
358
6
10
14
18
342
22
338
26
334
data uncorrected
“Toward”
30 < ET(jet#1) < 70 GeV
Back-to-Back
30
330
34
326
38
322
42
318
46
314
“Transverse”
“Transverse”
50
310
54
Jet#1
306
58
302
62
298
“Away”
66
294
70
290
“Back-to-Back”
“associated” density
74
286
78
"Transverse"
Region
282
Jet #2 Direction
278
274
82
PTmaxT
270
86
"Transverse"
Region
90
94
266

Jet#1
Region
98
262
102
0.5
258
106
254
110
250
PTmaxT
Direction
114
1.0
246
118
242
122
238
Jet#2
Region
126
234
130
1.5
230
134
226
138
222
142
2.0
218
Polar Plot
Charged Particles
(||<1.0, PT>0.5 GeV/c)
214
154
206
158
202
162
198
194
190
186
Associated Density
PTmaxT not included
146
150
210
178
174
170
166
182
 Shows the  dependence of the “associated” charged particle density, dNchg/dd, pT > 0.5
GeV/c, || < 1 (not including PTmaxT) relative to PTmaxT (rotated to 180o) and the charged
particle density, dNchg/dd, pT > 0.5 GeV/c, || < 1 relative to jet#1 (rotated to 270o) for
“back-to-back events” with 30 < ET(jet#1) < 70 GeV.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 12
Back-to-Back “Associated”
Charged Particle Densities
“Back-to-Back”
charge density
Charged Particle Density: dN/dd
Jet #1 Direction

2
CDF Preliminary
346
350
354
358
6
10
14
18
342
22
338
26
334
data uncorrected
“Toward”
30 < ET(jet#1) < 70 GeV
Back-to-Back
30
330
34
326
38
322
42
318
46
314
“Transverse”
“Transverse”
50
310
54
Jet#1
306
58
302
“Away”
62
298
66
294
70
290
“Back-to-Back”
“associated” density
74
286
Jet #2 Direction
78
"Transverse"
Region
282
278
82
PTmaxT
270
86
"Transverse"
Region
274
90
94
266

Jet#1
Region
98
262
102
0.5
258
106
254
PTmaxT
Direction
110
250
114
1.0
246
118
242
122
238
Jet#2
Region
126
1.5
234
230
130
134
226
138
222
Polar Plot
Associated Density
PTmaxT > 2 GeV/c
(not included)
142
2.0
218
Charged Particles
(||<1.0, PT>0.5 GeV/c)
214
146
150
210
154
206
158
202
162
198
194
190
186
178
174
170
166
182
 Shows the  dependence of the “associated” charged particle density, dNchg/dd, pT > 0.5
GeV/c, || < 1, PTmaxT > 2.0 GeV/c (not including PTmaxT) relative to PTmaxT (rotated to
180o) and the charged particle density, dNchg/dd, pT > 0.5 GeV/c, || < 1, relative to jet#1
(rotated to 270o) for “back-to-back events” with 30 < ET(jet#1) < 70 GeV.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 13
Jet Topologies
QCDThree
Four
Jet
QCD
Jet Topology
Topology Charged Particle Density: dN/dd
QCD
2-to-4
Scattering
Multiple
Parton
Interactions
2
CDF
Preliminary
Final-State
Jet #1
data uncorrected
Radiation
Outgoing Parton
346
6
10
14
30 < ET(jet#1) < 70 GeV
Outgoing Parton
Outgoing PartonBack-to-Back
18
30
330
34
326
38
322
42
318
46
Jet #1
PT(hard)
50
54
Jet#1
306
58
PT(hard)
302
298
Proton
Proton
358
26
334
310
Jet #3
354
22
338
314
Jet#1
Region
350
342
62
66
294
Jet #4
PTmaxT
Direction
70
290
74
286
78
Jet #4
AntiProton
AntiProton
"Transverse"
Jet #3
Region
282
278
82
274
Jet#2
Region
Underlying Event
Underlying Event
PTmaxT
270
86
"Transverse"
Region
90
94
266
98
Underlying Event
262
Jet #2
102
0.5
258
Underlying Event
106
254
110
Jet #2
250
114
1.0
246
118
242
238
126
1.5
234
230
130
134
226
138
222
Final-State
Radiation
Outgoing Parton
Charged Particles
(||<1.0, PT>0.5 GeV/c)
Associated Density
PTmaxT > 2 GeV/c
(not included)
142
2.0
218
Polar Plot
Initial-State
Radiation
122
214
146
150
210
154
206
158
202
162
198
194
190
186
178
174
170
166
182
Parton
Outgoing
Parton
 Shows the  dependence
of the
“associated” charged particle Outgoing
density, dN
chg/dd, pT > 0.5
GeV/c, || < 1, PTmaxT > 2.0 GeV/c (not including PTmaxT) relative to PTmaxT (rotated to
180o) and the charged particle density, dNchg/dd, pT > 0.5 GeV/c, || < 1, relative to jet#1
(rotated to 270o) for “back-to-back events” with 30 < ET(jet#1) < 70 GeV.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 14
“Associated” PTsum Density
PYTHIA Tune A vs HERWIG
HERWIG (without multiple parton
interactions) does not produce
enough “associated” PTsum in the
direction of PTmaxT!
Associated PTsum Density: dPT/dd
PTmaxT > 0.5 GeV/cAssociated PTsum Density: dPT/dd
10.0
Associated PTsum Density (GeV/c)
Associated PTsum Density (GeV/c)
10.0
Charged Particles
(||<1.0, PT>0.5 GeV/c)
PTmaxT not included
1.0
PTmaxT > 0.5 GeV/c
Back-to-Back
30 < ET(jet#1) < 70 GeV
PY Tune A
CDF Preliminary
PTmaxT
data uncorrected
theory + CDFSIM
"Jet#1"
Region
0.1
Charged Particles
(||<1.0, PT>0.5 GeV/c)
PTmaxT not included
1.0
PTmaxT > 0.5 GeV/c
HERWIG
CDF Preliminary
30
60
90
120
150
180
210
240
270
300
330
360
0
30
60
90
120
 (degrees)
"Jet#1"
Region
2
CDF Preliminary
And HERWIG (without multiple
parton interactions) does not 2
Charged Particles
Back-to-Back
produce
enough PTsum in the
(||<1.0, PT>0.5 GeV/c) 30 < ET(jet#1) < 70 GeV
direction
opposite of PTmaxT!1
PTmaxT not included
PYTHIA Tune A
Data - Theory (GeV/c)
data uncorrected
theory + CDFSIM
150
180
210
240
270
300
330
360
 (degrees)
Data - Theory: Associated PTsum Density dPT/dd
Data - Theory: Associated PTsum Density dPT/dd
Data - Theory (GeV/c)
PTmaxT
data uncorrected
theory + CDFSIM
0.1
0
1
Back-to-Back
30 < ET(jet#1) < 70 GeV
0
-1
PTmaxT
CDF Preliminary
data uncorrected
theory + CDFSIM
Charged Particles
(||<1.0, PT>0.5 GeV/c)
Back-to-Back
30 < ET(jet#1) < 70 GeV
PTmaxT not included
0
-1
PTmaxT
HERWIG
"Jet#1"
Region
"Jet#1"
Region
-2
-2
0
30
60
90
120
150
180
210
240
270
300
330
360
0
30
60
Oregon Terascale Workshop
February 24, 2009
90
120
150
180
210
240
270
300
330
360
 (degrees)
 (degrees)
Rick Field – Florida/CDF/CMS
Page 15
“Associated” PTsum Density
For PTmaxT > 2.0 GeV both
PYTHIA and HERWIG produce
PYTHIA Tune A vs HERWIG
slightly too much “associated” PTsum
in the direction of PTmaxT!
PTmaxT > 2 GeV/c Associated PTsum Density: dPT/dd
Associated PTsum Density: dPT/dd
10.0
Charged Particles
(||<1.0, PT>0.5 GeV/c)
PTmaxT not included
Associated PTsum Density (GeV/c)
Associated PTsum Density (GeV/c)
10.0
1.0
PTmaxT > 2.0 GeV/c
Back-to-Back
30 < ET(jet#1) < 70 GeV
PY Tune A
CDF Preliminary
PTmaxT
data uncorrected
theory + CDFSIM
"Jet#1"
Region
0.1
Charged Particles
(||<1.0, PT>0.5 GeV/c)
PTmaxT not included
1.0
PTmaxT > 2.0 GeV/c
CDF Preliminary
PTmaxT
data uncorrected
theory + CDFSIM
"Jet#1"
Region
0.1
0
30
60
90
120
150
180
210
240
270
300
330
360
0
30
60
90
120
 (degrees)
CDF Preliminary
240
270
300
330
360
Data - Theory
PTmaxT
0
Charged Particles
(||<1.0, PT>0.5 GeV/c)
"Jet#1"
Region
PTmaxT > 2.0 GeV/c (not included)
Back-to-Back
30 < ET(jet#1) < 70 GeV
HERWIG
data uncorrected
theory + CDFSIM
-1
Charged Particles
(||<1.0, PT>0.5 GeV/c)
210
Data - Theory: Associated Particle Density dN/dd
1
0.0
-1.0
180
2
PYTHIA Tune A
theory + CDFSIM
1.0
150
 (degrees)
But HERWIG (without multiple
Data - Theory: Associated
Particleinteractions)
Density dN/dd
parton
produces
too few particles
in the
Back-to-Back
CDF Preliminary
direction
opposite
of
PTmaxT!
30
<
ET(jet#1)
<
70 GeV
data uncorrected
2.0
Data - Theory
Back-to-Back
30 < ET(jet#1) < 70 GeV
HERWIG
PTmaxT
"Jet#1"
Region
PTmaxT > 2.0 GeV/c (not included)
-2.0
-2
0
30
60
90
120
150
180
210
240
270
300
330
360
0
30
60
 (degrees)
Oregon Terascale Workshop
February 24, 2009
90
120
150
180
210
240
270
300
330
360
 (degrees)
Rick Field – Florida/CDF/CMS
Page 16
Jet Multiplicity
Max pT in the
“transverse” region!
Jet Multiplicity
50%
Jet #1 Direction

“Away”
Jet #2 Direction
HERWIG (without
multiple parton
interactions) does not have equal
amounts of 3 and 4 jet topologies!
Percent of Events
PTmaxT
“TransMIN”
data uncorrected
theory + CDFSIM
PY
HERWIG
Tune A
40%
“Toward”
“TransMAX”
CDF Run 2 Pre-Preliminary
Data
Data
Data
Back-to-Back
30 < ET(jet#1) < 70 GeV
PTmaxT > 2.0 GeV/c
30%
20%
10%
0%
0
1
2
3
Data have about equal amounts
of 3 and 4 jet topologies!
4
5
6
7
8
9
10
Number of Jets
 Shows the data on the number of jets (JetClu, R = 0.7, || < 2, ET(jet) > 3 GeV)
for “back-to-back” events with 30 < ET(jet#1) < 70 GeV and PTmaxT > 2.0
GeV/c.
PYTHIA Tune
after CDFSIM.
Compares the (uncorrected) data with HERWIG
afterACDFSIM.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 17
Overall Totals (|| < 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

PTsum (GeV/c)
Average
100
“Overall”
Nchg
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
10
PTsum = 190 GeV/c
Charged Particles (||<1.0, PT>0.5 GeV/c)
Stable Particles (||<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, || < 1) and the overall
scalar pT sum of charged particles (pT > 0.5 GeV/c, || < 1) and the overall scalar ET sum of all
particles (|| < 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)..
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 18
“Towards”, “Away”, “Transverse”
“Leading Jet”
Jet #1 Direction

“Toward”
“Transverse”
“Transverse”
“Away”
ETsum
Density
(GeV)
Charged
PTsum
Density
(GeV/c)
Average
Charged
Density
Charged
Particle
Density:
dN/dd
Charged
PTsum
Density:
dPT/dd
ETsum
Density:
dET/dd
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 |(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 |(jet#1)|<2
MidPoint R=0.7 |(jet#1)|<2
ChargedStable
Particles
(||<1.0,
PT>0.5
GeV/c)
Charged
Particles
(||<1.0,
PT>0.5
GeV/c)
Particles
(||<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/dd,
p > 0.5 GeV/c
and || < 1 for

pT sum
density, with
dPT/dd,
and“leading
||
T > 0.5 GeV/c

Data at
1.96 TeV
on the
particle scalar
ETscalar
sum density,
dET/dd,
forT|| < 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).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 19
Charged Particle Density
HERWIG + JIMMY
Tune
(PTJIM
= 3.6)
Charged
ParticleParticle
Density:Density:
dN/dd
"Transverse"
Charged
dN/ddCharged Particle Density:"Away"
Charged
Particle
Density:
dN/dd
"Away"
dN/dd
Charged
Particle
Density:
dN/dd
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

High PT Z-Boson Production
CDF
CDFRun
Run22Preliminary
Preliminary
100
200
40
"Leading Jet"
data
datacorrected
corrected
pyA generator
generator
levellevel
theory
pyAW
Charged Particles
Particles (||<1.0,
(||<1.0, PT>0.5
PT>0.5
GeV/c)
HW
Charged
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
33
"Away"
"Toward"
22
JIM
11
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
"Z-Boson""Transverse"
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<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

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/dd, with pT > 0.5 GeV/c and || < 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 24, 2009
Rick Field – Florida/CDF/CMS
Page 20
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 (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<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

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/dd
Charged
PTsum
Density:
dPT/dd
Charged
PTsum
Density:
dPT/dd
"Transverse"
Charged
Density:
dPT/dd
"Away" Charged PTsum Density:"Away"
dPT/dd
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 (||<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 |(jet#1)|<2
Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<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

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/dd, with pT > 0.5 GeV/c and || < 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 24, 2009
Rick Field – Florida/CDF/CMS
Page 21
The “TransMAX/MIN” Regions
"TransDIF"
Charged
Particle
Density:
dN/dd
"TransDIF" Charged
Particle
Density:
dN/dd
Charged
Particle
Density:
dN/dd
"TransMAX/MIN"
Charged
Particle
Density:
dN/dd Charged Particle"TransMAX/MIN"
"TransMAX/MIN"
Charged
Particle
Density:
dN/dd
"TransDIF"
Density:
dN/dd
"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 (||<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

High PT Z-Boson Production
TransMAX
- TransMIN
"Transverse"
Charged Density
Density
Charged Particles
Particles (||<1.0,
(||<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"
0.4
0.3
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
Charged Particles (||<1.0, PT>0.5 GeV/c) Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<1.0, PT>0.5 GeV/c)
0.0
0.0
0
100
0
120 50
160
50 140 100
100
150
180
150
200
200
200
250
250
Jet #1 Direction
Initial-State Radiation
300
300
350
350
400
400
PT(jet#1)
PT(jet#1) (GeV/c)
(GeV/c)
Outgoing Parton

PT(hard)
Initial-State Radiation
“Toward”
Proton
“TransMAX”
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
PY Tune A
PY Tune A
0.8
0.6
PT(jet#1) or PT(Z-Boson) (GeV/c)
Outgoing Parton
"transMAX"
data corrected
generatorlevel
leveltheory
theory
generator
AntiProton
“Toward”
Proton
AntiProton
Underlying Event
“TransMIN”
“TransMAX”
“Away”
“TransMIN”
“Away”
Outgoing Parton
Z-boson
Underlying Event
Final-State
Radiation

particle
density,
dN/dd,
withwith
pT > p0.5
GeV/c and || < 1 for “Z-Boson” and
Data
Dataat
at1.96
1.96TeV
TeVon
onthe
thecharged
density of
charged
particles,
dN/dd,
T > 0.5 GeV/c and || < 1 for “leading
“Leading
Jet”
as aof
function
of PTjet
(Z)por
the leading jet pT for the
“transMIN” regions.
jet” events
as aevents
function
the leading
as“transMAX”,
a function of Pand
T and for Z-Boson events
T(Z) for “TransDIF” =
The
data are corrected
to the particle
level (with
errors
includeto
both
statistical
the that
systematic
“transMAX”
minus “transMIN”
regions.
The data
arethat
corrected
thethe
particle
levelerror
(withand
errors
include
uncertainty)
and
are
compared
with
PYTHIA
Tune
AW
and
Tune
A,
respectively,
at
the
particle
level
(i.e.
both the statistical error and the systematic uncertainty) and are compared with PYTHIA Tune A and HERWIG
generator
level).at the particle level (i.e. generator level).
(without MPI)
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 22
The “TransMAX/MIN” Regions
3.0
3.0
3.0
Charged Particles
(||<1.0,
GeV/c)
CDF
RunPT>0.5
2 Preliminary
excluding the lepton-pair
data corrected
CDFRun
Run22Preliminary
Preliminary
CDF
datacorrected
corrected
data
generatorlevel
leveltheory
theory
generator
generator level theory
pyAW
2.0
2.0
"Drell-Yan Production"
"transMAX"
70 <"Drell-Yan
M(pair) < Production"
110 GeV
70 < M(pair) < 110 GeV
1.0
1.0
HW
20
20
1.0 HW
0.0
60
60 0
40
40

High PT Z-Boson Production
data
corrected
data
corrected
"Leading
Jet"
generator
level
theory
generator
level
theory
80 40
20 80
10080
60 100
PY Tune A
PY Tune A
"Leading Jet"
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
MidPoint R=0.7 |(jet#1)|<2
HW
"transMIN"
HW
Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<1.0, PT>0.5 GeV/c)
0.0
0.0
1000 0 120 5050140
100
160
100
PT(jet#1) or PT(Z-Boson) (GeV/c)
Outgoing Parton
150
180
150
200
200
200
250
250
Jet #1 Direction
Initial-State Radiation
300
300
350
350
400
400
PT(jet#1)(GeV/c)
(GeV/c)
PT(jet#1)
Outgoing Parton

PT(hard)
Initial-State Radiation
“Toward”
Proton
“TransMAX”
"transMAX"
1.0
1.0
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
Z-Boson Direction
CDF
CDFRun
Run2 2Preliminary
Preliminary
2.0
2.0
"Z-Boson"
"transMIN"
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.0
0.0
00
2.0
pyAW
"Transverse" PTsum Density (GeV/c)
TransMAX - TransMIN Density (GeV/c)
3.0
3.0
"TransDIF" PTsum Density (GeV/c)
"Transverse"
PTsum Density
TransMAX
- TransMIN
Density (GeV/c)
(GeV/c)
"TransMAX/MIN"
PTsum Density
"TransMAX/MIN"
Charged
"TransDIF"
Charged
PTsum PTsum
Density:Density
dPT/dd
"TransDIF"
ChargedCharged
PTsum Density:
dPT/dd
"TransDIF" Charged PTsum Density:
dPT/dd
AntiProton
“Toward”
Proton
AntiProton
Underlying Event
“TransMIN”
“TransMAX”
“Away”
“TransMIN”
“Away”
Outgoing Parton
Z-boson
Underlying Event
Final-State
Radiation

 Data
Data at
at 1.96
1.96 TeV
TeV on
on the
the charged
charged scalar
scalar PTsum
PTsum density,
density, dPT/dd,
dPT/dd, with
with ppTT >> 0.5
0.5 GeV/c
GeV/c and
and ||
|| << 11 for
for “Z-Boson”
“leading
and
eventsofasthe
a function
of PpT(Z)
or the leading jet pT for
“transMAX”,
jet” “Leading
events as aJet”
function
leading jet
as athe
function
of PT(Z)and
for “transMIN”
“TransDIF” =
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)
PYTHIAand
Tune
and Tune
A, respectively,
at A
the
particle
level
both the statistical
errorand
andare
thecompared
systematicwith
uncertainty)
areAW
compared
with
PYTHIA Tune
and
HERWIG
(i.e.
generator
(without
MPI)level).
at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 23
Charged Particle <pT>
H. Hoeth, MPI@LHC08
"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
PY Tune A
1.5
1.0
"Leading Jet"
MidPoint R=0.7 |(jet#1)|<2
HW
data corrected
generator level theory
"Drell-Yan Production"
70 < M(pair) < 110 GeV
pyDW
pyAW
1.2
0.8
ATLAS
JIM
HW
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (||<1.0, PT>0.5 GeV/c)
0.4
0.5
0
50
100
150
200
250
300
350
400
0
20
40
60
PT(jet#1) (GeV/c)
Jet #1 Direction
100
Z-BosonDirection


“Toward”
“Transverse”
80
PT(Z-Boson) (GeV/c)
“Toward”
“Transverse”
“Transverse”
“Away”
“Transverse”
“Away”
 Data at 1.96 TeV on the charged particle average pT, with pT > 0.5 GeV/c and || < 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)
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 24
Z-Boson: “Towards”, Transverse”,
& “TransMIN” Charge Density
H. Hoeth, MPI@LHC08
Charged
Particle
Density:
dN/dd
Charged
Particle
Density:
dN/dd
"TransMIN"
Charged
Particle
Density:
dN/dd
"Toward"
Charged
Particle
Density:
dN/dd
"TransMIN" Charged Particle Density:
dN/dd
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 (||<1.0,
(||<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)
Initial-State Radiation
0.9
0.6
0.8
Charged
Density
"TransMIN"
Charged
Density
CDF Run 2 Preliminary
CDF Run
2 Preliminary
data corrected
"TransMIN" Charged Density
Charged
Density
"Toward"
Charged
Density
0.9
0.9
Initial-State Radiation
CDF Run 2 Preliminary
data corrected
Proton
generator
level theory
pyAW
generator
level
0.6
0.4
"Leading Jet"
"Drell-Yan Production"
"Drell-Yan Production"
70 < M(pair) < 110 GeV
70 < M(pair) < 110 GeV
AntiProtonpyDW
ATLAS
JIM
"Toward"
0.3
0.2
Z-boson
Z-boson
"transMIN"
Charged
Charged Particles
Particles (||<1.0,
(||<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
pyAW
HW
excluding
excluding the
the lepton-pair
lepton-pair
Charged Particles (||<1.0, PT>0.5 GeV/c)
0.0
80 40
20 80
100 80
60 100
1000
120
20
140
PT(jet#1) or PT(Z-Boson) (GeV/c)
160
40
180
60
200
100
PT(Z-Boson) (GeV/c)
Z-Boson Direction
Z-BosonDirection


“Toward”
“Toward”
“Transverse”
80
“TransMAX”
“Transverse”
“TransMIN”
“Away”
“Away”
 Data at 1.96 TeV on the density of charged particles, dN/dd, with pT > 0.5 GeV/c and || < 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).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 25
Z-Boson: “Towards”, Transverse”,
& “TransMIN” Charge Density
H. Hoeth, MPI@LHC08
1.8
1.2
data
datacorrected
corrected
pyAW
generator
level
generator
level theory
pyDW
1.2
0.8
"Transverse
0.6
0.4
"Toward"
pyAW
HW
20
20
dataATLAS
corrected
generator level theory
0.4
JIM
0.2
Charged
ChargedParticles
Particles(||<1.0,
(||<1.0,PT>0.5
PT>0.5GeV/c)
GeV/c)
excluding
excludingthe
thelepton-pair
lepton-pair"Z-Boson"
0.0
0.0
00
0.6
Run 2 Preliminary
0.0
60
60 0
40
40
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
"TransMIN" PTsum Density (GeV/c)
"Drell-Yan
CDF
"Drell-YanProduction"
Production"
70
70<<M(pair)
M(pair)<<110
110GeV
GeV
Charged PTsum Density (GeV/c)
0.8
CDF
CDF Run
Run 22 Preliminary
Preliminary
"TransMIN" PTsum Density (GeV/c)
Charged PTsum
"Toward"
PTsumDensity
Density(GeV/c)
(GeV/c)
Charged
PTsum
Density:
dPT/dd
Charged
PTsum
Density:
dPT/dd
"Toward"
Charged
PTsum
Density:
dPT/dd
"TransMIN" Charged PTsum Density:
dPT/dd
"TransMIN"
Charged
PTsum
Density:
dPT/dd
High
PT Z-Boson
Production
Outgoing Parton
1.2
0.8
Initial-State Radiation
Initial-State Radiation
"Drell-Yan Production"
CDF
CDF Run
Run 22 Preliminary
Preliminary
"Drell-Yan Production"
70 < M(pair) < 110 GeV
70 < M(pair) < 110 GeV
AntiProtonpyDW
data
datacorrected
corrected
0.6
0.8
Proton
"Leading
Jet"
pyAW
generator
level
generator
level theory
JIM
ATLAS "Toward"
0.4
0.4
Z-boson
Z-boson
0.2
"transMIN"
Charged Particles
pyAW (||<1.0,
HWPT>0.5 GeV/c)
Charged Particles (||<1.0, PT>0.5 GeV/c)
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
excluding the lepton-pair
0.0
0.0
80 40
20 80
100 80
60 100
10000
120
20
20 160
140
PT(jet#1) or PT(Z-Boson) (GeV/c)
40
40
180
80
80
100
100
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
Z-Boson Direction
Z-BosonDirection


“Toward”
“Toward”
“Transverse”
60
60
200
“TransMAX”
“Transverse”
“TransMIN”
“Away”
“Away”
 Data at 1.96 TeV on the charged scalar PTsum density, dPT/dd, with pT > 0.5 GeV/c and || < 1 for
“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).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 26
Z-Boson: “Towards” Region
"Toward" Charged Particle Density: dN/dd
"Toward" Charged Particle Density: dN/dd
CDF Run 2 Preliminary
CDF Run 2 Preliminary
generator level theory
data corrected
generator level theory
1.5
0.6
1.0
2.0
0.9
"Drell-Yan Production"
pyDWT LHC14
70 < M(pair) pyDW
< 110 GeV
ATLAS
JIM
HW Tevatron
pyDWT Tevatron
HW LHC14
DWT
0.3
pyAW
0.5
"Drell-Yan Production"
70 < M(pair) < 110 GeV
HW
Charged
ChargedParticles
Particles(||<1.0,
(||<1.0,PT>0.5
PT>0.5GeV/c)
GeV/c)
excluding
excludingthe
thelepton-pair
lepton-pair
0.0
0.0
00
2520
50
40
75
60
100
80125
"Toward"Charged
ChargedDensity
Density
"Toward"
"Toward" Charged Density
0.9
2.0
CDF Run 2 Preliminary
CDF Run
2 Preliminary
data corrected
pyDWT
datagenerator
correctedlevel
HW generator level
1.5
LHC14
1.0
Tevatron
LHC10
0.3
0.5
LHC10
Tevatron
Charged
Charged Particles
Particles (||<1.0,
(||<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
excluding
excluding the
the lepton-pair
lepton-pair
0.0
0.0
100
150
00
25 20
50
75
40
60 100
80125
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
Z-BosonDirection
Z-BosonDirection


“Transverse”
"Drell-Yan
Production"
70 < M(pair)
< 110 GeV
70 < M(pair) < 110 GeV
0.6
PT(Z-Boson)
PT(Z-Boson) (GeV/c)
(GeV/c)
“Toward”
"Drell-Yan Production"
LHC14
HW without MPI
“Toward”
“Transverse”
“Transverse”
“Transverse”
“Away”
“Away”
 Data at 1.96 TeV on the density of charged particles, dN/dd, with pT > 0.5 GeV/c and || < 1 for “ZBoson” 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).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 27
150
100
Z-Boson: “Towards” Region
"Toward" Average PT Charged
"Toward" Average PT Charged
1.6
1.6
data corrected
generator level theory
CDF Run 2 Preliminary
"Drell-Yan Production"
70 < M(pair) < 110 GeV
pyDW
"Toward" <PT> (GeV/c)
"Toward" <PT> (GeV/c)
CDF Run 2 Preliminary
pyAW
1.2
0.8
ATLAS
JIM
HW
"Drell-Yan Production"
70 < M(pair) < 110 GeV
1.2
DWT
0.8
HW LHC14
HW Tevatron
pyDWT Tevatron
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.4
pyDWT LHC14
data corrected
generator level theory
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.4
0
20
40
60
80
100
0
20
PT(Z-Boson) (GeV/c)
40
60
Z-BosonDirection


“Transverse”
“Transverse”
100
PT(Z-Boson) (GeV/c)
Z-BosonDirection
“Toward”
80
HW (without MPI)
almost no change!
“Toward”
“Transverse”
“Transverse”
“Away”
“Away”
 Data at 1.96 TeV on the average pT of charged particles with pT > 0.5 GeV/c and || < 1 for “Z-Boson”
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).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 28
Min-Bias Correlations
Average PT versus Nchg
Average PT (GeV/c)
1.4
CDF Run 2 Preliminary
pyDW
data corrected
generator level theory
“Minumum Bias” Collisions
1.2
Min-Bias
1.96 TeV
pyA
Proton
1.0
AntiProton
ATLAS
0.8
Charged Particles (||<1.0, PT>0.4 GeV/c)
0.6
0
10
20
30
40
50
Number of Charged Particles
 Data at 1.96 TeV on the average pT of charged particles versus the number of charged particles (pT >
0.4 GeV/c, || < 1) for “min-bias” collisions at CDF Run 2. The data are corrected to the particle level
and are compared with PYTHIA Tune A at the particle level (i.e. generator level).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 29
Min-Bias: Average PT versus Nchg
 Beam-beam remnants (i.e. soft hard core) produces
Average PT versus Nchg
Average PT (GeV/c)
1.4
CDF Run 2 Preliminary
Min-Bias
1.96 TeV
data corrected
generator level theory
1.2
low multiplicity and small <pT> with <pT>
independent of the multiplicity.
 Hard scattering (with no MPI) produces large
pyA
multiplicity and large <pT>.
pyAnoMPI
1.0
 Hard scattering (with MPI) produces large
0.8
multiplicity and medium <pT>.
ATLAS
Charged Particles (||<1.0, PT>0.4 GeV/c)
0.6
0
5
10
15
20
25
30
35
40
This observable is sensitive
to the MPI tuning!
Number of Charged Particles
“Hard” Hard Core (hard scattering)
Outgoing Parton
“Soft” Hard Core (no hard scattering)
PT(hard)
CDF “Min-Bias”
=
Proton
+
AntiProton
Proton
AntiProton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Multiple-Parton Interactions
+
Proton
AntiProton
Underlying Event
Outgoing Parton
Oregon Terascale Workshop
February 24, 2009
Outgoing Parton
PT(hard)
Initial-State
Radiation
The CDF “min-bias” trigger
picks up most of the “hard
core” component!
Outgoing Parton
Underlying Event
Final-State
Radiation
Rick Field – Florida/CDF/CMS
Page 30
Average PT versus Nchg
Average PT
PT versus
versus Nchg
Nchg
Average
Average PT versus Nchg
2.5
2.5
CDF Run 2 Preliminary
data corrected
generator level theory
1.2
CDFRun
Run22Preliminary
Preliminary
CDF
Min-Bias
1.96 TeV
Average
Average PT
PT (GeV/c)
(GeV/c)
Average PT (GeV/c)
1.4
pyA
pyAnoMPI
1.0
0.8
ATLAS
data corrected
generator
level theory
generator level theory
2.0
2.0
HW
HW
pyAW
pyAW
"Drell-YanProduction"
Production"
"Drell-Yan
70<<M(pair)
M(pair)<<110
110GeV
GeV
70
1.5
1.5
JIM
JIM
1.0
1.0
ATLAS
ATLAS
Charged Particles (||<1.0, PT>0.4 GeV/c)
0.6
ChargedParticles
Particles(||<1.0,
(||<1.0,PT>0.5
PT>0.5GeV/c)
GeV/c)
Charged
excludingthe
thelepton-pair
lepton-pair
excluding
0.5
0.5
0
5
10
15
20
25
30
35
40
00
55
10
10
Number of Charged Particles
15
15
20
20
25
25
30
30
Numberof
ofCharged
ChargedParticles
Particles
Number
Drell-Yan Production
Lepton
“Minumum Bias” Collisions
Proton
AntiProton
Proton
AntiProton
Underlying Event
Underlying Event
Anti-Lepton
 Data at 1.96 TeV on the average pT of charged particles versus the number of charged particles (pT > 0.4 GeV/c, || <
1) for “min-bias” collisions at CDF Run 2. The data are corrected to the particle leveland are compared with PYTHIA
Tune A, Tune DW, and the ATLAS tune at the particle level (i.e. generator level).
 Particle level predictions for the average pT of charged particles versus the number of charged particles (pT > 0.5
GeV/c, || < 1, excluding the lepton-pair) for for Drell-Yan production (70 < M(pair) < 110 GeV) at CDF Run 2.
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 31
35
35
Average PT versus Nchg
 Z-boson production (with low pT(Z) and no MPI)
No MPI!
Average PT versus Nchg
produces low multiplicity and small <pT>.
2.5
Average PT (GeV/c)
CDF Run 2 Preliminary
data corrected
generator level theory
2.0
HW
 High pT Z-boson production produces large
pyAW
multiplicity and high <pT>.
"Drell-Yan Production"
70 < M(pair) < 110 GeV
 Z-boson production (with MPI) produces large
1.5
multiplicity and medium <pT>.
JIM
1.0
ATLAS
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.5
0
5
10
15
20
25
30
35
Number of Charged Particles
Drell-Yan Production (no MPI)
High PT Z-Boson Production
Lepton
Initial-State Radiation
Outgoing Parton
Final-State Radiation
Drell-Yan
=
Proton
AntiProton
Underlying Event
Underlying Event
Anti-Lepton
+
+
Drell-Yan Production (with MPI)
Proton
Proton
Lepton
AntiProton
Z-boson
AntiProton
Underlying Event
Underlying Event
Anti-Lepton
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 32
Average PT(Z) versus Nchg
No MPI!
Average PT versus Nchg
PT(Z-Boson)
PT(Z-Boson) versus
versus Nchg
Nchg
80
80
2.5
data corrected
generator level theory
2.0
CDF
CDF Run
Run 22 Preliminary
Preliminary
HW
Average PT(Z) (GeV/c)
Average PT (GeV/c)
CDF Run 2 Preliminary
pyAW
"Drell-Yan Production"
70 < M(pair) < 110 GeV
1.5
JIM
1.0
ATLAS
generator
level theory
data corrected
generator level theory
60
60
pyAW
pyAW
HW
HW
"Drell-Yan
"Drell-Yan Production"
Production"
70
70 << M(pair)
M(pair) << 110
110 GeV
GeV
40
40
JIM
JIM
20
20
Charged Particles (||<1.0, PT>0.5 GeV/c)
excluding the lepton-pair
ATLAS
ATLAS
Charged
Charged Particles
Particles (||<1.0,
(||<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
excluding
excluding the
the lepton-pair
lepton-pair
00
0.5
0
5
10
15
20
25
30
35
00
55
Outgoing Parton
Lepton
Initial-State Radiation
Proton
Proton
AntiProton
Underlying Event
Underlying Event
15
15
20
20
25
25
30
30
35
35
40
40
Number
Number of
of Charged
Charged Particles
Particles
Number of Charged Particles
High PDrell-Yan
Production
T Z-BosonProduction
10
10
 Predictions for the average PT(Z-Boson) versus
the number of charged particles (pT > 0.5
GeV/c, || < 1, excluding the lepton-pair) for for
Drell-Yan production (70 < M(pair) < 110 GeV)
at CDF Run 2.
Anti-Lepton
Z-boson
 Data on the average pT of charged particles versus the number of charged particles (pT > 0.5 GeV/c, || < 1,
excluding the lepton-pair) for for Drell-Yan production (70 < M(pair) < 110 GeV) at CDF Run 2. The data are
corrected to the particle level and are compared with various Monte-Carlo tunes at the particle level (i.e.
generator level).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 33
Average PT versus Nchg
PT(Z) < 10 GeV/c
Average
Charged
PT
versus
Nchg
Average
Average Charged
Charged PT
PT versus
versus Nchg
Nchg
CDF
Run
Preliminary
CDF
CDF Run
Run 22
2 Preliminary
Preliminary
data corrected
generator
level
generator
level theory
theory
generator level theory
1.2
1.2
1.2
pyAW
pyAW
pyAW
1.0
1.0
1.0
HW
HW
HW
0.8
0.8
0.8
"Drell-Yan
Production"
"Drell-Yan
"Drell-Yan Production"
Production"
70
M(pair)
110
GeV
70
70 <<
< M(pair)
M(pair) <<
< 110
110 GeV
GeV
PT(Z)
10
GeV/c
PT(Z)
PT(Z) <<
< 10
10 GeV/c
GeV/c
CDF Run 2 Preliminary
JIM
JIM
Average PT (GeV/c)
Average
PT
(GeV/c)
AveragePT
PT(GeV/c)
(GeV/c)
Average
1.4
1.4
1.4
Average PT versus Nchg
1.4
ATLAS
ATLAS
Drell-Yan PT > 0.5 GeV PT(Z) < 10 GeV/c
data corrected
generator level theory
1.2
pyAW
No MPI!
1.0
Min-Bias PT > 0.4 GeV/c
0.8
Charged
Particles
(||<1.0,
PT>0.5
GeV/c)
Charged
Charged Particles
Particles (||<1.0,
(||<1.0, PT>0.5
PT>0.5 GeV/c)
GeV/c)
excluding
the
lepton-pair
excluding
excluding the
the lepton-pair
lepton-pair
Charged Particles (||<1.0)
pyA
0.6
0.6
0.6
0.6
00
0
55
5
10
10
10
15
15
15
20
20
20
25
25
25
30
30
30
35
35
35
0
Number
of
Charged
Particles
Number
Number of
of Charged
Charged Particles
Particles
Drell-Yan Production
Proton
20
30
40
Number of Charged Particles
Lepton
AntiProton
Underlying Event
10
Underlying Event
Remarkably similar behavior!
Perhaps indicating that MPIProton
playing an important role in
both processes.
“Minumum Bias” Collisions
AntiProton
Anti-Lepton
 Predictions
for thepTaverage
pT ofparticles
chargedversus
particles
theofnumber
charged(p
particles
(pT > 0.5
Data the average
of charged
theversus
number
chargedofparticles
||GeV/c,
< 1, ||
T > 0.5 GeV/c,
<
1, excluding
the lepton-pair)
forDrell-Yan
for Drell-Yan
production
< M(pair)
110 GeV,
PT(pair)
10 GeV/c)
at
excluding
the lepton-pair)
for for
production
(70 <(70
M(pair)
< 110< GeV,
PT(pair)
< 10<GeV/c)
at CDF
CDF
Run
Run 2.
The2.data are corrected to the particle level and are compared with various Monte-Carlo tunes at the
particle level (i.e. generator level).
Oregon Terascale Workshop
February 24, 2009
Rick Field – Florida/CDF/CMS
Page 34
Summary
 It is important to produce a lot of plots (corrected to the particle level) so that the theorists
can tune and improve the QCD Monte-Carlo models. If they improve the “transverse”
region they might miss-up the “toward” region etc.. We need to show the whole story!
 We are making good progress in understanding and
modeling the “underlying event”. However, we do not
yet have a perfect fit to all the features of the CDF
CDF Run 2 publication
“underlying
event” data!
should be out soon!
 There are over 128 plots to get “blessed” and then
published. So far we have only looked at average
quantities. We plan to also produce distributions and
flow plots
 I will construct a “CDF-QCD Data for Theory”
WEBsite with the “blessed” plots together with
tables of the data points and errors so that people
can have access to the results .
PT(hard)
Initial-State Radiation
Proton
AntiProton
Underlying Event
Outgoing Parton
Underlying Event
Final-State
Radiation
CDF-QCD Data for Theory
 Need to measure “Min-Bias” and the “underlying
event” at the LHC as soon as possible and tune the
Monte-Carlo modles and compare with CDF!
Oregon Terascale Workshop
February 24, 2009
Outgoing Parton
Rick Field – Florida/CDF/CMS
UE&MB@CMS
Page 35