Oregon Terascale Workshop February 23, 2009 Rick Field – Florida/CDF/CMS Page 1 Northwest Northwest Terascale Terascale Workshop Workshop Parton Showers and Event Structure at the LHC Parton Showers and Event Structure at the LHC Proton AntiProton PT(hard) Outgoing Parton Outgoing Parton Underlying Event Underlying Event Initial-State Radiation Final-State Radiation Rick Field University of Florida CMS at the LHC CDF Run 2 Outline of Talk ¨ Review some of what we have learned about “min-bias” and the “underlying event” in Run 1 at CDF. ¨ Review the various PYTHIA “underlying event” QCD Monte-Carlo Model tunes. ¨ Show some extrapolations to the LHC. ¨ Show some things I do not understand about the CDF data. University of Oregon February 23, 2009 Review of the QCD Monte-Carlo Tunes
58
Embed
Review of the QCD Monte-Carlo Tunes Rick Field University ...rfield/cdf/Oregon1_RickField_2-23-09.pdf · Rick Field University of Florida CMS at the LHC CDF Run 2 Outline of Talk
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 1
Northwest Northwest TerascaleTerascale WorkshopWorkshopParton Showers and Event Structure at the LHCParton Showers and Event Structure at the LHC
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
Rick FieldUniversity of Florida
CMS at the LHCCDF Run 2
Outline of TalkReview some of what we have learned about “min-bias” and the “underlying event” in Run 1 at CDF.
Review the various PYTHIA “underlying event” QCD Monte-Carlo Model tunes.
Show some extrapolations to the LHC.
Show some things I do not understand about the CDF data.
Start with the perturbative 2-to-2 (or sometimes 2-to-3) parton-parton scattering and add initial and final-state gluon radiation (in the leading log approximation or modified leading log approximation).
Hard Scattering
PT(hard)
Outgoing Parton
Outgoing Parton
Initial-State Radiation
Final-State Radiation
Hard Scattering
PT(hard)
Outgoing Parton
Outgoing Parton
Initial-State Radiation
Final-State Radiation
Proton AntiProton
Underlying Event Underlying Event
Proton AntiProton
Underlying Event Underlying Event
“Hard Scattering” Component
“Underlying Event”
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.
Start with the perturbative 2-to-2 (or sometimes 2-to-3) parton-parton scattering and add initial and final-state gluon radiation (in the leading log approximation or modified leading log approximation).
Hard Scattering
PT(hard)
Outgoing Parton
Outgoing Parton
Initial-State Radiation
Final-State Radiation
Hard Scattering
PT(hard)
Outgoing Parton
Outgoing Parton
Initial-State Radiation
Final-State Radiation
Proton AntiProton
Underlying Event Underlying Event
Proton AntiProton
Underlying Event Underlying Event
“Hard Scattering” Component
“Jet”
“Jet”
“Underlying Event”
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.
“Jet”
The “underlying event” is an unavoidable background to most collider observables and having good understand of it leads to
more precise collider measurements!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 4
QCD MonteQCD Monte--Carlo Models:Carlo Models:LeptonLepton--Pair ProductionPair Production
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).
Proton AntiProton
Underlying Event Underlying Event
Proton AntiProton
Underlying Event Underlying Event
Lepton-Pair Production
Lepton
Anti-Lepton
Initial-State Radiation
Lepton-Pair Production
Lepton
Anti-Lepton
Initial-State Radiation
“Underlying Event”
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.
“Jet” “Hard Scattering” Component
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 5
QCD MonteQCD Monte--Carlo Models:Carlo Models:LeptonLepton--Pair ProductionPair Production
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).
Proton AntiProton
Underlying Event Underlying Event
Proton AntiProton
Underlying Event Underlying Event
Lepton-Pair Production
Lepton
Anti-Lepton
Initial-State Radiation
Lepton-Pair Production
Lepton
Anti-Lepton
Initial-State Radiation
“Underlying Event”
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.
“Jet”
Proton AntiProton
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation Final-State Radiation
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation
Final-State Radiation
“Hard Scattering” Component
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 6
ProtonProton--AntiProtonAntiProton CollisionsCollisionsat the at the TevatronTevatron
The CDF “Min-Bias” trigger picks up most of the “hard core” cross-section plus a small amount of single &
double diffraction.
The “hard core” component contains both “hard” and
“soft” collisions.
Beam-Beam Counters3.2 < |η| < 5.9
CDF “Min-Bias” trigger1 charged particle in forward BBC
AND1 charged particle in backward BBC
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 8
-1 +1
φ
2π
0 η
1 charged particle
dNchg/dηdφ = 1/4π = 0.08
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.
Charged ParticlespT > 0.5 GeV/c |η| < 1
ΔηΔφ = 4π = 12.6
1 GeV/c PTsum
dPTsum/dηdφ = 1/4π GeV/c = 0.08 GeV/c
dNchg/dηdφ = 3/4π = 0.24
3 charged particles
dPTsum/dηdφ = 3/4π GeV/c = 0.24 GeV/c
3 GeV/c PTsum
0.236 +/- 0.0182.97 +/- 0.23Scalar pT sum of Charged Particles(pT > 0.5 GeV/c, |η| < 1)
Average Densityper unit η-φAverageCDF Run 2 “Min-Bias”
Observable
Divide by 4π
CDF Run 2 “Min-Bias”
Particle DensitiesParticle Densities
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 9
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).
Convert to charged particle density, dNchg/dηdφ, by dividing by 2π. There are about 0.67 charged particles per unit η-φ in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).
Δη = 1
Δφ = 1
ΔηxΔφ = 1
0.67
CDF Run 1 CDF Run 1 ““MinMin--BiasBias”” DataDataCharged Particle DensityCharged Particle Density
I will talk about “min-bias” and “pile-up” tomorrow!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 10
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).
Convert to charged particle density, dNchg/dηdφ, by dividing by 2π. There are about 0.67 charged particles per unit η-φ in “Min-Bias”collisions at 1.8 TeV (|η| < 1, all pT).
Δη = 1
Δφ = 1
ΔηxΔφ = 1
0.67
There are about 0.25 charged particles per unit η-φ in “Min-Bias”collisions at 1.96 TeV (|η| < 1, pT > 0.5 GeV/c).
0.25
CDF Run 1 CDF Run 1 ““MinMin--BiasBias”” DataDataCharged Particle DensityCharged Particle Density
I will talk about “min-bias” and “pile-up” tomorrow!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 11
Charged Jet #1Direction
Δφ
“Transverse” “Transverse”
“Toward”
“Away”
“Toward-Side” Jet
“Away-Side” Jet
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.
Look at the charged particle density in the “transverse” region!“Transverse” region
very sensitive to the “underlying event”!
CDF Run 1 Analysis
CDF Run 1: Evolution of Charged JetsCDF Run 1: Evolution of Charged Jets““Underlying EventUnderlying Event””
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 12
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.
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.
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).
ISAJET uses a naïve leading-log parton shower-model which does
not agree with the data!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 15
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).
Beam-BeamRemnants
HERWIG
Charged Jet #1Direction
Δφ
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" Charged Particle Density: dN/dηdφ
0.00
0.25
0.50
0.75
1.00
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Run 1Datadata uncorrectedtheory corrected
1.8 TeV |η|<1.0 PT>0.5 GeV
Herwig 6.4 CTEQ5LPT(hard) > 3 GeV/c
Total "Hard"
"Remnants"
“Hard”Component
HERWIG uses a modified leading-log parton shower-model which does agrees better with the data!
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.
HERWIG has the too steep of a pTdependence of the “beam-beam remnant”
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”.
Proton AntiProton
Multiple Parton Interaction
initial-state radiation
final-state radiation outgoing parton
outgoing parton
color string
color string
The probability that a hard scattering events also contains a semi-hard multiple partoninteraction 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).
A scale factor that determines the maximum parton virtuality for space-like showers. The larger the value of PARP(67) the more initial-state radiation.
1.0PARP(67)
Determines the energy dependence of the cut-offPT0 as follows PT0(Ecm) = PT0(Ecm/E0)ε with ε = PARP(90)
0.16PARP(90)
Double-Gaussian: Fraction of the overall hadronradius containing the fraction PARP(83) of the total hadronic matter.
0.2PARP(84)
Determines the reference energy E0.1 TeVPARP(89)
Probability that the MPI produces two gluons either as described by PARP(85) or as a closed gluon loop. The remaining fraction consists of quark-antiquark pairs.
0.66PARP(86)
Probability that the MPI produces two gluons with color connections to the “nearest neighbors.
0.33PARP(85)
Double-Gaussian: Fraction of total hadronicmatter within PARP(84)
0.5PARP(83)
DescriptionDefault Parameter
Hard Core
Multiple Parton Interaction
Color String
Color String
Multiple Parton Interaction
Color String
Hard-Scattering Cut-Off PT0
1
2
3
4
5
100 1,000 10,000 100,000CM Energy W (GeV)
PT0
(GeV
/c)
PYTHIA 6.206
ε = 0.16 (default)
ε = 0.25 (Set A))
Take E0 = 1.8 TeV
Reference pointat 1.8 TeV
Determine by comparingwith 630 GeV data!
Affects the amount ofinitial-state radiation!
Tuning PYTHIA:Tuning PYTHIA:Multiple Parton Interaction ParametersMultiple Parton Interaction Parameters
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 19
"Transverse" Charged Particle Density: dN/dηdφ
0.00
0.25
0.50
0.75
1.00
0 5 10 15 20 25 30 35 40 45 50
PT(charged jet#1) (GeV/c)"T
rans
vers
e" C
harg
ed D
ensi
ty
CTEQ3L CTEQ4L CTEQ5L CDF Min-Bias CDF JET20
1.8 TeV |η|<1.0 PT>0.5 GeV
Pythia 6.206 (default)MSTP(82)=1
PARP(81) = 1.9 GeV/c
CDF Datadata uncorrectedtheory corrected
Default parameters give very poor description of the “underlying event”!
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 defaultparameters for multiple parton interactions and CTEQ3L, CTEQ4L, and CTEQ5L.
Old PYTHIA default(more initial-state radiation)New PYTHIA default
(less initial-state radiation)
0.50.5PARP(83)
0.40.4PARP(84)
0.250.25PARP(90)
0.951.0PARP(86)
1.8 TeV1.8 TeVPARP(89)
4.0
0.9
2.0 GeV
4
1
Tune A
1.0PARP(67)
1.0PARP(85)
1.9 GeVPARP(82)
4MSTP(82)
1MSTP(81)
Tune BParameter
Old PYTHIA default(more initial-state radiation)New PYTHIA default
(less initial-state radiation)
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)).
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).
Run 1 Run 1 vsvs Run 2: Run 2: ““TransverseTransverse””Charged Particle DensityCharged Particle Density“Transverse” region as defined by the leading “charged particle jet”
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.
CDF Run 1 PublishedCDF Run 2 PreliminaryPYTHIA Tune A
|η|<1.0 PT>0.5 GeV/c
CDF Preliminarydata uncorrectedtheory corrected
PYTHIA Tune A was tuned to fit the “underlying event” in Run I!
Shows the prediction of PYTHIA Tune A at 1.96 TeV after detector simulation (i.e. after CDFSIM).
Run 1 Run 1 vsvs Run 2: Run 2: ““TransverseTransverse””Charged Particle DensityCharged Particle Density“Transverse” region as defined by the leading “charged particle jet”
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.
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Δφ Correlations relative to the leading jetCharged particles pT > 0.5 GeV/c |η| < 1Calorimeter towers ET > 0.1 GeV |η| < 1“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!
Z-Boson Direction
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 24
Event TopologiesEvent Topologies“Leading Jet” events correspond to the leading calorimeter jet (MidPoint R = 0.7) in the region |η| < 2 with no other conditions.
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
“Leading Jet”
“Leading ChgJet” events correspond to the leading charged particle jet (R = 0.7) in the region |η| < 1 with no other conditions.
ChgJet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #2 Direction
“Charged Jet”
“Inc2J Back-to-Back”
“Exc2J Back-to-Back”
“Inclusive 2-Jet 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 (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 “back-to-back” (Δφ12 > 150o) with almost equal transverse energies (PT(jet#2)/PT(jet#1) > 0.8) and PT(jet#3) < 15 GeV/c.
subset
subset
Z-Boson Direction
Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Z-Boson“Z-Boson” events are Drell-Yan events with 70 < M(lepton-pair) < 110 GeVwith no other conditions.
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 25
Charged Particle Density Charged Particle Density ΔφΔφ DependenceDependence
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.
Charged Particle Density: dN/dηdφ
0.1
1.0
10.0
0 30 60 90 120 150 180 210 240 270 300 330 360
Δφ (degrees)C
harg
ed P
artic
le D
ensi
ty
CDF Preliminarydata uncorrected
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
30 < ET(jet#1) < 70 GeV
"Transverse" Region
Jet#1
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #1 Direction
Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #2 Direction
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.
Charged Particle Density: dN/dηdφ
0.1
1.0
10.0
0 30 60 90 120 150 180 210 240 270 300 330 360
Δφ (degrees)C
harg
ed P
artic
le D
ensi
ty
Back-to-BackLeading JetMin-Bias
CDF Preliminarydata uncorrected
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
30 < ET(jet#1) < 70 GeV
"Transverse" Region
Jet#1
Refer to this as a “Leading Jet” event
Refer to this as a “Back-to-Back” event
Subset
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 26
Charged Particle Density Charged Particle Density ΔφΔφ DependenceDependence
Jet #1 DirectionΔφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #1 Direction
Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #2 Direction
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.
“Leading Jet”
“Back-to-Back”
Charged Particle Density: dN/dηdφ272
276 280 284 288292
296300
304308
312
316
320
324
328
332
336
340
344
348
352
356
360
4
8
12
16
20
24
28
32
36
40
44
48
5256
6064
6872
7680848892
96100104108112
116120
124128
132
136
140
144
148
152
156
160
164
168
172
176
180
184
188
192
196
200
204
208
212
216
220
224
228
232236
240244
248252
256 260 264 268
CDF Preliminarydata uncorrected
30 < ET(jet#1) < 70 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Transverse" Region
"Transverse" Region
Jet#1
Back-to-BackLeading Jet
0.5
1.0
1.5
2.0
Polar Plot
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 27
““transMAXtransMAX”” & & ““transMINtransMIN””
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”.
Jet #1 Direction Δφ
“Toward”
“TransMAX” “TransMIN”
“Away”
Jet #1 Direction
Δφ
“TransMAX” “TransMIN”
“Toward”
“Away”
“Toward-Side” Jet
“Away-Side” Jet
Jet #3
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).
Area = 4π/6
“transMIN” very sensitive to the “beam-beam remnants”!
The overall “transverse” density is the average of the “transMAX” and “transMIN”densities.
Z-Boson Direction
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 28
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #1 Direction
Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Jet #2 Direction
“Back-to-Back”
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)
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)
PTsum/ETsum
Scalar ET sum of all calorimeter towers per unit η-φ
Let Ntrig40 equal the number of events with at least one jet with PT > 40 geV and |η| < 1.0 (this is the “offline” trigger).
Let N3Jexc20 equal the number of events with exactly three jets with PT > 20 GeV/cand |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.
The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune AW (PARP(67)=4), Tune DW (PARP(67)=2.5), Tune BW (PARP(67)=1).
PARP(67) affects the initial-state radiation which contributes primarily to the region R(j2,j3) > 1.0.
Normalized to N3JexcFr
Proton AntiProton
Initial-State Radiation
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
“Jet 1”
“Jet 2”
“Jet 3”
R > 1.0
The data have more 3 jet events with small R(j2,j3)!?
Let Ntrig40 equal the number of events with at least one jet with PT > 40 geV and |η| < 1.0 (this is the “offline” trigger).
Let N3Jexc20 equal the number of events with exactly three jets with PT > 20 GeV/cand |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.
The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune DW (PARP(67)=2.5) and HERWIG (without MPI).
Final-State radiation contributes to the region R(j2,j3) < 1.0.
Normalized to N3JexcFr
“Jet 1”
“Jet 2” If you ignore the normalization and normalize all the distributions to one then the data prefer Tune BW, but I believe this is misleading.R < 1.0
Let Ntrig40 equal the number of events with at least one jet with PT > 40 geV and |η| < 1.0 (this is the “offline” trigger).
Let N3Jexc20 equal the number of events with exactly three jets with PT > 20 GeV/cand |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.
The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune DW (PARP(67)=2.5) and HERWIG (without MPI).
Final-State radiation contributes to the region R(j2,j3) < 1.0.
Normalized to N3JexcFr
“Jet 1”
“Jet 2” If you ignore the normalization and normalize all the distributions to one then the data prefer Tune BW, but I believe this is misleading.R < 1.0
Let Ntrig40 equal the number of events with at least one jet with PT > 40 geV and |η| < 1.0 (this is the “offline” trigger).
Let N3Jexc20 equal the number of events with exactly three jets with PT > 20 GeV/cand |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.
The CDF data on dN/dR(j2,j3) at 1.96 TeV compared with PYTHIA Tune DW (PARP(67)=2.5) and HERWIG (without MPI).
Final-State radiation contributes to the region R(j2,j3) < 1.0.
Normalized to N3JexcFr
“Jet 1”
“Jet 2” If you ignore the normalization and normalize all the distributions to one then the data prefer Tune BW, but I believe this is misleading.R < 1.0
Exclusive 3-Jet Production: R(j2,j3)
0.00
0.20
0.40
0.60
0.80
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
R(j2,j3)
dN/d
R(j2
,j3)
CDF Datahw05pyDWpyBW
CDF Run 2 Preliminarydata uncorrected
generator level theory
Normalized to 1
I do not understand the excess number of events
with R(j2,j3) < 1.0.Perhaps this is related to the
“soft energy” problem??I will show you a lot more on Thursday!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 38
PYTHIA 6.2 TunesPYTHIA 6.2 Tunes
15.0
2.1
1
4.0
0.2
1.25
0.25
1.8 TeV
0.95
0.9
0.4
0.5
2.0 GeV
4
1
CTEQ5L
Tune AW
15.0
2.1
1
2.5
0.2
1.25
0.25
1.8 TeV
1.0
1.0
0.4
0.5
1.8 GeV
4
1
CTEQ6L
Tune D6
CTEQ5LPDF
1.25PARP(62)
0.2PARP(64)
15.0PARP(93)
2.1PARP(91)
1MSTP(91)
0.5PARP(83)
0.4PARP(84)
0.25PARP(90)
1.0PARP(86)
1.8 TeVPARP(89)
2.5
1.0
1.9 GeV
4
1
Tune DW
PARP(67)
PARP(85)
PARP(82)
MSTP(82)
MSTP(81)
Parameter
Intrinsic KT
ISR Parameter
UE Parameters
Uses CTEQ6L
All use LO αswith Λ = 192 MeV!
Tune A energy dependence!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 39
PYTHIA 6.2 TunesPYTHIA 6.2 Tunes
15.0
2.1
1
2.5
0.2
1.25
0.16
1.96 TeV
1.0
1.0
0.4
0.5
1.8387 GeV
4
1
CTEQ6L
Tune D6T
5.0
1.0
1
1.0
1.0
1.0
0.16
1.0 TeV
0.66
0.33
0.5
0.5
1.8 GeV
4
1
CTEQ5L
ATLAS
CTEQ5LPDF
1.25PARP(62)
0.2PARP(64)
15.0PARP(93)
2.1PARP(91)
1MSTP(91)
0.5PARP(83)
0.4PARP(84)
0.16PARP(90)
1.0PARP(86)
1.96 TeVPARP(89)
2.5
1.0
1.9409 GeV
4
1
Tune DWT
PARP(67)
PARP(85)
PARP(82)
MSTP(82)
MSTP(81)
Parameter
Intrinsic KT
ISR Parameter
UE Parameters
All use LO αswith Λ = 192 MeV!
ATLAS energy dependence!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 40
PYTHIA 6.2 TunesPYTHIA 6.2 Tunes
15.0
2.1
1
2.5
0.2
1.25
0.16
1.96 TeV
1.0
1.0
0.4
0.5
1.8387 GeV
4
1
CTEQ6L
Tune D6T
5.0
1.0
1
1.0
1.0
1.0
0.16
1.0 TeV
0.66
0.33
0.5
0.5
1.8 GeV
4
1
CTEQ5L
ATLAS
CTEQ5LPDF
1.25PARP(62)
0.2PARP(64)
15.0PARP(93)
2.1PARP(91)
1MSTP(91)
0.5PARP(83)
0.4PARP(84)
0.16PARP(90)
1.0PARP(86)
1.96 TeVPARP(89)
2.5
1.0
1.9409 GeV
4
1
Tune DWT
PARP(67)
PARP(85)
PARP(82)
MSTP(82)
MSTP(81)
Parameter
Intrinsic KT
ISR Parameter
UE Parameters
All use LO αswith Λ = 192 MeV!
ATLAS energy dependence!
Tune A
Tune AW Tune B Tune BW
Tune D
Tune DW Tune D6Tune D6T
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 41
PYTHIA 6.2 TunesPYTHIA 6.2 Tunes
15.0
2.1
1
2.5
0.2
1.25
0.16
1.96 TeV
1.0
1.0
0.4
0.5
1.8387 GeV
4
1
CTEQ6L
Tune D6T
5.0
1.0
1
1.0
1.0
1.0
0.16
1.0 TeV
0.66
0.33
0.5
0.5
1.8 GeV
4
1
CTEQ5L
ATLAS
CTEQ5LPDF
1.25PARP(62)
0.2PARP(64)
15.0PARP(93)
2.1PARP(91)
1MSTP(91)
0.5PARP(83)
0.4PARP(84)
0.16PARP(90)
1.0PARP(86)
1.96 TeVPARP(89)
2.5
1.0
1.9409 GeV
4
1
Tune DWT
PARP(67)
PARP(85)
PARP(82)
MSTP(82)
MSTP(81)
Parameter
Intrinsic KT
ISR Parameter
UE Parameters
All use LO αswith Λ = 192 MeV!
ATLAS energy dependence!
Tune A
Tune AW Tune B Tune BW
Tune D
Tune DW Tune D6Tune D6T
These are “old” PYTHIA 6.2 tunes! There are new 6.4 tunes byArthur Moraes (ATLAS)Hendrik Hoeth (MCnet)Peter Skands (Tune S0)
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 42
PYTHIA 6.2 TunesPYTHIA 6.2 Tunes
5.0
2.0
1
2.74
0.12
2.97
0.17
1.0
0.91
0.82
0.5
0.84
2.1 GeV
4
1
CTEQ5L
Tune H(6.418)
15.0
2.1
1
2.5
0.2
1.25
0.16
1.96 TeV
1.0
1.0
0.4
0.5
1.8387 GeV
4
1
CTEQ6L
Tune D6T
5.0
1.0
1
1.0
1.0
1.0
0.16
1.0 TeV
0.66
0.33
0.5
0.5
1.8 GeV
4
1
CTEQ5L
ATLAS
CTEQ5LPDF
1.25PARP(62)
0.2PARP(64)
15.0PARP(93)
2.1PARP(91)
1MSTP(91)
0.5PARP(83)
0.4PARP(84)
0.16PARP(90)
1.0PARP(86)
1.96 TeVPARP(89)
2.5
1.0
1.9409 GeV
4
1
Tune DWT
PARP(67)
PARP(85)
PARP(82)
MSTP(82)
MSTP(81)
Parameter
Intrinsic KT
ISR Parameter
UE Parameters
All use LO αswith Λ = 192 MeV!
Q2 ordered showers, old MPI!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 43
JIMMY at CDFJIMMY at CDFThe Energy in the “Underlying
Event” in High PT Jet Production
“Transverse” <Densities> vs PT(jet#1)
Jet #1 DirectionΔφ
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" PTsum Density: dPT/dηdφ
0.0
0.4
0.8
1.2
1.6
0 50 100 150 200 250 300 350 400 450 500
PT(particle jet#1) (GeV/c)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
) PY Tune A
HW
1.96 TeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c) CDF Run 2 Preliminary
generator level theory
MidPoint R = 0.7 |η(jet)| < 2
"Leading Jet"
JIMMY Default
JM325
"Transverse" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
4.0
0 100 200 300 400 500
PT(particle jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) 1.96 TeV
All Particles (|η|<1.0)
HW
PY Tune A
MidPoint R = 0.7 |η(jet)| < 2CDF Run 2 Preliminarygenerator level theory
"Leading Jet"
JIMMY Default
JM325JIMMY: MPI
J. M. ButterworthJ. R. Forshaw
M. H. Seymour
JIMMY was tuned to fit the energy density in the “transverse” region for
“leading jet” events!JIMMY
Runs with HERWIG and adds multiple parton interactions!
PT(JIM)= 2.5 GeV/c.
PT(JIM)= 3.25 GeV/c.
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 44
JIMMY at CDFJIMMY at CDFThe Energy in the “Underlying
Event” in High PT Jet Production
“Transverse” <Densities> vs PT(jet#1)
Jet #1 DirectionΔφ
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" PTsum Density: dPT/dηdφ
0.0
0.4
0.8
1.2
1.6
0 50 100 150 200 250 300 350 400 450 500
PT(particle jet#1) (GeV/c)
"Tra
nsve
rse"
PTs
um D
ensi
ty (G
eV/c
) PY Tune A
HW
1.96 TeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c) CDF Run 2 Preliminary
generator level theory
MidPoint R = 0.7 |η(jet)| < 2
"Leading Jet"
JIMMY Default
JM325
"Transverse" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
4.0
0 100 200 300 400 500
PT(particle jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) 1.96 TeV
All Particles (|η|<1.0)
HW
PY Tune A
MidPoint R = 0.7 |η(jet)| < 2CDF Run 2 Preliminarygenerator level theory
"Leading Jet"
JIMMY Default
JM325JIMMY: MPI
J. M. ButterworthJ. R. Forshaw
M. H. Seymour
JIMMY was tuned to fit the energy density in the “transverse” region for
“leading jet” events!JIMMY
Runs with HERWIG and adds multiple parton interactions!
PT(JIM)= 2.5 GeV/c.
PT(JIM)= 3.25 GeV/c.
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
The Drell-Yan JIMMY TunePTJIM = 3.6 GeV/c,JMRAD(73) = 1.8JMRAD(91) = 1.8
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 45
Z-Boson Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle DensityCharged Particle Density
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).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyA generator level
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Away"
"Toward"
"Transverse"
Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyAW generator level"Away"
"Transverse"
"Toward"
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
Proton AntiProton
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 46
Z-Boson Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle DensityCharged Particle Density
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).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyA generator level
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Away"
"Toward"
"Transverse"
Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyAW generator level"Away"
"Transverse"
"Toward"
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
Proton AntiProton
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
"Transverse" Charged Particle Density: dN/dηdφ
0.0
0.3
0.6
0.9
1.2
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
"Away" Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Aw
ay"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 47
Z-Boson Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle DensityCharged Particle Density
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).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyA generator level
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Away"
"Toward"
"Transverse"
Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyAW generator level"Away"
"Transverse"
"Toward"
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
Proton AntiProton
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
"Transverse" Charged Particle Density: dN/dηdφ
0.0
0.3
0.6
0.9
1.2
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
"Away" Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Aw
ay"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
"Away" Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
"Aw
ay"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
JIM
HW
pyAW
HERWIG + JIMMYTune (PTJIM = 3.6)
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 48
Z-Boson Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle DensityCharged Particle Density
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).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyA generator level
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Away"
"Toward"
"Transverse"
Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
Ave
rage
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
pyAW generator level"Away"
"Transverse"
"Toward"
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
Proton AntiProton
High PT Z-Boson Production
Z-boson
Outgoing Parton
Initial-State Radiation
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
"Transverse" Charged Particle Density: dN/dηdφ
0.0
0.3
0.6
0.9
1.2
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Tra
nsve
rse"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
"Away" Charged Particle Density: dN/dηdφ
0
1
2
3
4
0 20 40 60 80 100 120 140 160 180 200
PT(jet#1) or PT(Z-Boson) (GeV/c)
"Aw
ay"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
Charged Particles (|η|<1.0, PT>0.5 GeV/c)
"Leading Jet"
"Z-Boson"
"Away" Charged Particle Density: dN/dηdφ
0
1
2
3
0 20 40 60 80 100
PT(Z-Boson) (GeV/c)
"Aw
ay"
Cha
rged
Den
sity
CDF Run 2 Preliminarydata corrected
generator level theory
"Drell-Yan Production"70 < M(pair) < 110 GeV
Charged Particles (|η|<1.0, PT>0.5 GeV/c)excluding the lepton-pair
JIM
HW
pyAW
HERWIG + JIMMYTune (PTJIM = 3.6)
H. Hoeth, MPI@LHC08
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 49
“Leading Jet”
The The ““TransverseTransverse”” RegionRegion
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Shows the Data - Theory for the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
4.0
5.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 50
“Leading Jet”
The The ““TransMAXTransMAX/MIN/MIN”” RegionsRegions
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMAX” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMIN” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for “transDIF” = “transMAX”-”transMIN. 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 and HERWIG (without MPI) at the particle level (i.e. generator level).
Jet #1 Direction Δφ
“Toward”
“TransMAX” “TransMIN”
“Away”
"TransMAX" ETsum Density: dET/dηdφ
0.0
2.0
4.0
6.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsM
AX"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"TransMIN" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
MIN
" ET
sum
Den
sity
(GeV
)
CDF Run 2 Preliminarydata corrected
generator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"TransMAX/MIN" ETsum Density: dET/dηdφ
0.0
2.0
4.0
6.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"transMAX"
"transMIN"
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 51
“Leading Jet”
The The ““TransverseTransverse”” RegionRegion
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Shows the Data - Theory for the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
4.0
5.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"Transverse" ETsum Density: dET/dηdφ
-0.4
0.0
0.4
0.8
1.2
1.6
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
Dat
a - T
heor
y (G
eV)
CDF Run 2 Preliminarydata corrected
generator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
HWPY Tune A
0.4 density corresponds to 1.67 GeV in the
“transverse” region!
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 52
“Leading Jet”
The The ““TransMAXTransMAX/MIN/MIN”” RegionsRegions
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMAX” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for the “transMIN” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Data at 1.96 TeV on the scalar ET sum density, dET/dηdφ, with |η| < 1 for “leading jet” events as a function of the leading jet pT for “transDIF” = “transMAX”-”transMIN. 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 and HERWIG (without MPI) at the particle level (i.e. generator level).
Jet #1 Direction Δφ
“Toward”
“TransMAX” “TransMIN”
“Away”
"TransMAX" ETsum Density: dET/dηdφ
0.0
2.0
4.0
6.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsM
AX"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"TransMIN" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
MIN
" ET
sum
Den
sity
(GeV
)
CDF Run 2 Preliminarydata corrected
generator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"TransMAX/MIN" ETsum Density: dET/dηdφ
0.0
2.0
4.0
6.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
nsve
rse"
ETs
um D
ensi
ty (G
eV) CDF Run 2 Preliminary
data correctedgenerator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
Stable Particles (|η|<1.0, all PT)
PY Tune A
HW
"transMAX"
"transMIN"
"TransDIF" ETsum Density: dET/dηdφ
0.0
1.0
2.0
3.0
4.0
5.0
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
Tran
sMA
X - T
rans
MIN
(GeV
)
CDF Run 2 Preliminarydata corrected
generator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
PY Tune A
HWStable Particles (|η|<1.0, all PT)
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 53
“Leading Jet”
The Leading Jet MassThe Leading Jet Mass
Data at 1.96 TeV on the leading jet invariant mass for “leading jet” events as a function of the leading jet pTfor the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Shows the Data - Theory for the leading jet invariant mass for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Leading Jet Invariant Mass
0
10
20
30
40
50
60
70
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
Jet M
ass
(GeV
)
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
CDF Run 2 Preliminarydata corrected
generator level theory
PY Tune A
HW
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 54
“Leading Jet”
The Leading Jet MassThe Leading Jet Mass
Data at 1.96 TeV on the leading jet invariant mass for “leading jet” events as a function of the leading jet pTfor the “transverse” 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 A and HERWIG (without MPI) at the particle level (i.e. generator level).
Shows the Data - Theory for the leading jet invariant mass for “leading jet” events as a function of the leading jet pT for the “transverse” region for PYTHIA Tune A and HERWIG (without MPI).
Jet #1 Direction Δφ
“Toward”
“Transverse” “Transverse”
“Away”
Leading Jet Invariant Mass
0
10
20
30
40
50
60
70
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
Jet M
ass
(GeV
)
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
CDF Run 2 Preliminarydata corrected
generator level theory
PY Tune A
HW
Leading Jet Invariant Mass
-4.0
0.0
4.0
8.0
12.0
0 50 100 150 200 250 300 350 400
PT(jet#1 uncorrected) (GeV/c)
Dat
a - T
heor
y (G
eV)
CDF Run 2 Preliminarydata corrected
generator level theory
"Leading Jet"MidPoint R=0.7 |η(jet#1)|<2
HW PY Tune A
Off by ~2 GeV
Oregon Terascale Workshop February 23, 2009
Rick Field – Florida/CDF/CMS Page 55
The The ““Underlying EventUnderlying Event”” ininHigh PHigh PTT Jet Production (LHC)Jet Production (LHC)
Charged particle density in the “Transverse”region versus PT(jet#1) at 1.96 TeV for PY Tune AW and HERWIG (without MPI).
Charged particle density in the “Transverse”region versus PT(jet#1) at 14 TeV for PY Tune AW and HERWIG (without MPI).
SummarySummaryWe are making good progress in modeling “min-bias”collisions! I will talk more about this tomorrow.
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying EventUnderlying Event
Initial-State Radiation
Final-State Radiation
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.
Proton AntiProton
Drell-Yan Production
Anti-Lepton
Lepton
Underlying EventUnderlying Event
Proton AntiProton
“Minumum Bias” Collisions
There are still some things we do not fully understand!
** Soft Underlying Event Energy **
** R(J2,J3) **
** Jet Mass **
AND we really do not know how to extrapolate to the LHC!