a
My Thesis Advisor
The Energy
Dependence of the UnderlyingCraig
Event
Group
Dave Jackson
Rick Field
University of Florida
Me
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Outline
 Review: The CDF Tevatron “underlying event” tunes
Outgoing Parton
Outgoing Parton
Underlying Event
Final-State
Radiation
(Tune A, B, D, AW, DW, D6, DWT, D6T).
 How Universal are the QCD MC Model Tunes?
• Do we need a separate tune for each center-of-mass
•
energy? 900 GeV, 1.96 TeV, 7 TeV, etc.
Do we need a separate tune for each hard QCD
subprocess? Jet Production, Drell-Yan Production, etc.
 A close look at two PYTHIA tunes:
• PYTHIA 6.2 Tune DW
(CDF UE tune).
Craig’s
Thesis Advisor
• PYTHIA 6.4 Tune Z1 (CMS UE tune).
 New CDF UE Data: The Tevatron Energy Scan (300
CDF Run 2
300 GeV, 900 GeV, 1.96 TeV
CMS
GeV, 900 GeV, 1.96 TeV)
900 GeV, 7 TeV & 8 TeV
University of Virginia
April 10, 2012
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!
University of Virginia
April 10, 2012
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.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 3
MPI, Pile-Up, and Overlap
MPI: Multiple Parton Interactions
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Underlying Event
Outgoing Parton
Pile-Up
 MPI: Additional 2-to-2 parton-parton
scatterings within a single hadron-hadron
collision.
Final-State
Radiation
Proton
Pile-Up
Proton
Proton
Proton
Primary
Interaction Region Dz
 Pile-Up: More than one hadron-hadron collision in the beam
crossing.
Overlap
University of Virginia
April 10, 2012
 Overlap: An experimental timing issue where a hadron-hadron
collision from the next beam crossing gets included in the hadronhadron collision from the current beam crossing because the next
crossing happened before the event could be read out.
Rick Field – Florida/CDF/CMS
Page 4
Traditional Approach
CDF Run 1 Analysis Charged Particle Df Correlations
Leading Calorimeter Jet or
Charged Jet #1
Leading Charged Particle Jet or
PT > PTmin |h| < hcut
Direction
Leading Charged Particle or
2
“Transverse” region
very sensitive to the
“underlying event”!
Away RegionZ-Boson
“Toward-Side” Jet
Df
“Toward”
“Transverse”
“Transverse”
“Away”
Leading Object
Direction
Df
“Toward”
“Transverse”
“Transverse”
Transverse
Region
f
Leading
Object
Toward Region
Transverse
Region
“Away”
Away Region
0
-hcut
“Away-Side” Jet
h
+hcut
 Look at charged particle correlations in the azimuthal angle Df relative to a leading object (i.e.
CaloJet#1, ChgJet#1, PTmax, Z-boson). For CDF PTmin = 0.5 GeV/c hcut = 1.
 Define |Df| < 60o as “Toward”, 60o < |Df| < 120o as “Transverse”, and |Df| > 120o as

“Away”.
o
All three regions have the same area in h-f space, Dh×Df = 2hcut×120 = 2hcut×2/3. Construct
densities by dividing by the area in h-f space.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 5
PYTHIA 6.206 Defaults
MPI constant
probability
scattering
PYTHIA default parameters
6.115
6.125
6.158
6.206
MSTP(81)
1
1
1
1
MSTP(82)
1
1
1
1
PARP(81)
1.4
1.9
1.9
1.9
PARP(82)
1.55
2.1
2.1
1.9
PARP(89)
1,000
1,000
1,000
PARP(90)
0.16
0.16
0.16
4.0
1.0
1.0
PARP(67)
4.0
1.00
"Transverse" Charged Density
Parameter
"Transverse" Charged Particle Density: dN/dhdf
CDF Data
Pythia 6.206 (default)
MSTP(82)=1
PARP(81) = 1.9 GeV/c
data uncorrected
theory corrected
0.75
0.50
0.25
1.8 TeV |h|<1.0 PT>0.5 GeV
0.00
0
5
10
15
20
25
30
35
40
45
50
PT(charged jet#1) (GeV/c)
CTEQ3L
CTEQ4L
CTEQ5L
CDF Min-Bias
CDF JET20
 Plot shows the “Transverse” charged particle density versus PT(chgjet#1) compared to
the QCD hard scattering predictions of PYTHIA 6.206 (PT(hard) > 0) using the default
parameters for multiple parton interactions and CTEQ3L, CTEQ4L, and CTEQ5L.
Note Change
PARP(67) = 4.0 (< 6.138)
PARP(67) = 1.0 (> 6.138)
University of Virginia
April 10, 2012
Default parameters give
very poor description of
the “underlying event”!
Rick Field – Florida/CDF/CMS
Page 6
Tuning PYTHIA 6.2:
Multiple Parton Interaction Parameters
Parameter
Default
PARP(83)
0.5
Double-Gaussian: Fraction of total hadronic
matter within PARP(84)
PARP(84)
0.2
Double-Gaussian: Fraction of the overall hadron
radius containing the fraction PARP(83) of the
total hadronic matter.
Determines the energy
Probability
that of
thethe
MPI
produces two gluons
dependence
MPI!
with color connections to the “nearest neighbors.
0.33
PARP(86)
0.66
PARP(89)
PARP(82)
PARP(90)
PARP(67)
1 TeV
1.9
GeV/c
0.16
1.0
University of Virginia
April 10, 2012
Multiple Parton Interaction
Color String
Color String
Multiple PartonDetermine
Interactionby comparing
Probability thatAffects
the MPI
theproduces
amount two
of gluons
either as described
by PARP(85)
or as a closed
initial-state
radiation!
gluon loop. The remaining fraction consists of
quark-antiquark pairs.
with 630 GeV data!
Color String
Hard-Scattering Cut-Off PT0
Determines the reference energy E0.
The cut-off PT0 that regulates the 2-to-2
scattering divergence 1/PT4→1/(PT2+PT02)2
Determines the energy dependence of the cut-off
PT0 as follows PT0(Ecm) = PT0(Ecm/E0)e with
e = PARP(90)
A scale factor that determines the maximum
parton virtuality for space-like showers. The
larger the value of PARP(67) the more initialstate radiation.
Rick Field – Florida/CDF/CMS
5
PYTHIA 6.206
e = 0.25 (Set A))
4
PT0 (GeV/c)
PARP(85)
Description
Take E0 = 1.8 TeV
3
2
e = 0.16 (default)
1
100
1,000
10,000
100,000
CM Energy W (GeV)
Reference point
at 1.8 TeV
Page 7
“Transverse” Charged Densities
Energy Dependence
"Transverse" Charged PTsum Density: dPTsum/dhdf
"Min Transverse" PTsum Density: dPTsum/dhdf
0.60
0.3
Charged PTsum Density (GeV)
Charged PTsum Density (GeV)
e = 0.25
HERWIG 6.4
0.40
e = 0.16
e=0
0.20
630 GeV |h|<1.0 PT>0.4 GeV
0.2
0.1
CTEQ5L
630 GeV |h|<1.0 PT>0.4 GeV
0.0
0.00
0
5
10
15
20
25
30
35
40
45
50
0
5
10
Lowering PT0 at 630 GeV (i.e.
increasing e) increases UE activity
charged
PT density
resulting insum
less energy dependence.
(|h|<1, PT>0.4 GeV) versus PT(charged jet#1) at
630 GeV predicted by HERWIG 6.4 (PT(hard) > 3
GeV/c, CTEQ5L) and a tuned version of PYTHIA
6.206 (PT(hard) > 0, CTEQ5L, Set A, e = 0, e =
0.16 (default) and e = 0.25 (preferred)).
Also shown are the PTsum densities (0.16 GeV/c
and 0.54 GeV/c) determined from the Tano,
Kovacs, Huston, and Bhatti “transverse” cone
analysis at 630 GeV.
20
25
30
40
45
50
Hard-Scattering Cut-Off PT0
PYTHIA 6.206
e = 0.25 (Set A))
3
2
e = 0.16 (default)
1
100
1,000
Rick Field Fermilab MC Workshop
Reference point
E = 1.8 TeV
October 4, 2002!
University of Virginia
April 10, 2012
35
5
4
PT0 (GeV/c)
 Shows the “transverse”
15
PT(charged jet#1) (GeV/c)
PT(charged jet#1) (GeV/c)

HERWIG 6.4
e = 0.25
Increasing e produces less energy
dependence for the
UE resulting
in
e = 0.16
e=0
less UE activity at the LHC!
CTEQ5L
Pythia 6.206 (Set A)
Pythia 6.206 (Set A)
Rick Field – Florida/CDF/CMS
10,000
100,000
CM Energy W (GeV)
0
Page 8
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
s = 1.0
Parameter
Tune A
Tune A25
Tune A50
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
0.9
0.9
ISR Parameter
0.95
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(67)
4.0
4.0
4.0
MSTP(91)
1
1
1
PARP(91)
1.0
2.5
5.0
PARP(93)
5.0
15.0
25.0
Intrensic KT
University of Virginia
April 10, 2012
CDF Run 1 Data
PYTHIA Tune A
PYTHIA Tune A25
PYTHIA Tune A50
s = 2.5
0.08
CDF Run 1
published
1.8 TeV
s = 5.0
Normalized to 1
0.04
0.00
0
PARP(86)
Z-Boson Transverse Momentum
0.12
PT Distribution 1/N dN/dPT
UE Parameters
2
4
6
8
10
12
14
16
18
20
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution
(<pT(Z)> ≈ 11.5 GeV/c) compared with PYTHIA
Tune A (<pT(Z)> = 9.7 GeV/c), Tune A25
(<pT(Z)> = 10.1 GeV/c), and
Tune A50
(<pT(Z)> = 11.2 GeV/c).
Vary the intrensic KT!
Rick Field – Florida/CDF/CMS
Page 9
CDF Run 1 PT(Z)
Parameter
Tune A
Tune AW
UE Parameters MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
2.0 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
0.9
0.9
PARP(86)
0.95
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.0
1.25
PARP(64)
1.0
0.2
PARP(67)
4.0
4.0
MSTP(91)
1
1
PARP(91)
1.0
2.1
PARP(93)
5.0
15.0
ISR Parameters
Z-Boson Transverse Momentum
0.12
PT Distribution 1/N dN/dPT
PYTHIA 6.2 CTEQ5L
Tune used by the
CDF-EWK group!
CDF Run 1 Data
PYTHIA Tune A
PYTHIA Tune AW
CDF Run 1
published
0.08
1.8 TeV
Normalized to 1
0.04
0.00
0
2
4
6
8
10
12
14
16
18
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution (<pT(Z)>
≈ 11.5 GeV/c) compared with PYTHIA Tune A
(<pT(Z)> = 9.7 GeV/c), and PYTHIA Tune AW
(<pT(Z)> = 11.7 GeV/c).
Effective Q cut-off, below which space-like showers are not evolved.
Intrensic KT
The Q2 = kT2 in as for space-like showers is scaled by PARP(64)!
University of Virginia
April 10, 2012
20
Rick Field – Florida/CDF/CMS
Page 10
Jet-Jet Correlations (DØ)
Jet#1-Jet#2 Df Distribution
Df Jet#1-Jet#2
 MidPoint Cone Algorithm (R = 0.7, fmerge = 0.5)
 L = 150 pb-1 (Phys. Rev. Lett. 94 221801 (2005))
 Data/NLO agreement good. Data/HERWIG
agreement good.
 Data/PYTHIA agreement good provided PARP(67)
= 1.0→4.0 (i.e. like Tune A, best fit 2.5).
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 11
CDF Run 1 PT(Z)
PYTHIA 6.2 CTEQ5L
Tune DW
Tune AW
UE Parameters MSTP(81)
1
1
MSTP(82)
4
4
PARP(82)
1.9 GeV
2.0 GeV
PARP(83)
0.5
0.5
PARP(84)
0.4
0.4
PARP(85)
1.0
0.9
PARP(86)
1.0
0.95
PARP(89)
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
PARP(62)
1.25
1.25
PARP(64)
0.2
0.2
PARP(67)
2.5
4.0
MSTP(91)
1
1
PARP(91)
2.1
2.1
PARP(93)
15.0
15.0
ISR Parameters
Intrensic KT
PT Distribution 1/N dN/dPT
Parameter
Z-Boson Transverse Momentum
0.12
CDF Run 1 Data
PYTHIA Tune DW
HERWIG
CDF Run 1
published
0.08
1.8 TeV
Normalized to 1
0.04
0.00
0
2
4
6
8
10
12
14
16
18
20
Z-Boson PT (GeV/c)
 Shows the Run 1 Z-boson pT distribution (<pT(Z)>
≈ 11.5 GeV/c) compared with PYTHIA Tune DW,
and HERWIG.
Tune DW uses D0’s perfered value of PARP(67)!
Tune DW has a lower value of PARP(67) and slightly more MPI!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 12
All use LO as
with L = 192 MeV!
UE Parameters
ISR Parameter
PYTHIA 6.2 Tunes
Parameter
Tune AW
Tune DW
Tune D6
PDF
CTEQ5L
CTEQ5L
CTEQ6L
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
1.9 GeV
1.8 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
1.0
1.0
PARP(86)
0.95
1.0
1.0
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(62)
1.25
1.25
1.25
PARP(64)
0.2
0.2
0.2
PARP(67)
4.0
2.5
2.5
MSTP(91)
1
1
1
PARP(91)
2.1
2.1
2.1
PARP(93)
15.0
15.0
15.0
Uses CTEQ6L
Tune A energy dependence!
Intrinsic KT
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 13
All use LO as
with L = 192 MeV!
UE Parameters
PYTHIA 6.2 Tunes
Parameter
Tune DWT
Tune D6T
ATLAS
PDF
CTEQ5L
CTEQ6L
CTEQ5L
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
1.9409 GeV
1.8387 GeV
1.8 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
Tune
AW
Tune A
ISR Parameter
0.4
Tune
B
1.0
1.0
0.33
PARP(86)
1.0
1.0
0.66
PARP(89)
1.96 TeV
1.96 TeV
1.0 TeV
PARP(90)
0.16
0.16
0.16
PARP(62)
1.25
1.25
1.0
PARP(64)
0.2
0.2
1.0
PARP(67)
2.5
2.5
1.0
MSTP(91)
1
1
1
PARP(93)
Tune 2.1
DW
15.0
2.1
15.0
ATLAS energy dependence!
Tune BW
1.0
Tune D6
5.0
Tune D6T
Intrinsic KT
University of Virginia
April 10, 2012
0.5
PARP(85)
PARP(91)
Tune D
0.4
Rick Field – Florida/CDF/CMS
Page 14
“Transverse” Charged Density
PTmax Direction
"Transverse" Charged Particle Density: dN/dhdf
Df
1.6
“Transverse”
“Transverse”
“Away”
ChgJet#1 Direction
Df
“Toward”
“Transverse”
“Transverse”
“Away”
"Transverse" Charged Density
“Toward”
RDF Preliminary
7 TeV
py Tune DW generator level
1.2
PTmax
0.8
ChgJet#1
DY(muon-pair)
70 < M(pair) < 110 GeV
0.4
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
Muon-Pair Direction
Df
0
5
10
15
20
25
30
35
40
45
50
PT(chgjet#1) or PTmax or PT(pair) (GeV/c)
“Toward”
“Transverse”
“Transverse”
“Away”
 Shows the charged particle density in the “transverse” region for charged particles (pT > 0.5
GeV/c, |h| < 1) at 7 TeV as defined by PTmax, PT(chgjet#1), and PT(muon-pair) from PYTHIA
Tune DW at the particle level (i.e. generator level). Charged particle jets are constructed using
the Anti-KT algorithm with d = 0.5.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 15
Min-Bias “Associated”
Charged Particle Density
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
RDF Preliminary
14 TeV
Min-Bias
"Transverse" Charged Density
"Transverse" Charged Density
1.2
py Tune DW generator level
10 TeV
7 TeV
0.8
1.96 TeV
0.9 TeV
0.4
0.2 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
RDF Preliminary
LHC14
py Tune DW generator level
0.8
LHC10
LHC7
Tevatron
900 GeV
0.4
PTmax = 5.25 GeV/c
RHIC
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
0
25
2
Df
“Toward”
RHIC
“Transverse”
“Transverse”
“Away”
6
8
10
12
14
Center-of-Mass Energy (TeV)
PTmax (GeV/c)
PTmax Direction
4
0.2 TeV → 1.96 TeV
(UE increase ~2.7 times)
Tevatron
PTmax Direction
Df
“Toward”
“Transverse”
PTmax Direction
1.96 TeV → 14 TeV
(UE increase ~1.9 times)
LHC
“Transverse”
“Away”
Df
“Toward”
“Transverse”
“Transverse”
“Away”
 Shows the “associated” charged particle density in the “transverse” region as a function of
PTmax for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) for “min-bias” events
at 0.2 TeV, 0.9 TeV, 1.96 TeV, 7 TeV, 10 TeV, 14 TeV predicted by PYTHIA Tune DW at the particle
Linear scale!
level (i.e. generator level).
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 16
Min-Bias “Associated”
Charged Particle Density
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
RDF Preliminary
14 TeV
Min-Bias
"Transverse" Charged Density
"Transverse" Charged Density
1.2
py Tune DW generator level
10 TeV
7 TeV
0.8
1.96 TeV
0.9 TeV
0.4
0.2 TeV
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
RDF Preliminary
py Tune DW generator level
LHC14
LHC10
LHC7
0.8
Tevatron
0.4
900 GeV
RHIC
PTmax = 5.25 GeV/c
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0.1
Df
“Toward”
LHC7
“Transverse”
100.0
PTmax Direction
7 TeV → 14 TeV
(UE increase ~20%)
Df
“Toward”
LHC14
“Transverse”
“Away”
10.0
Center-of-Mass Energy (TeV)
PTmax (GeV/c)
PTmax Direction
1.0
Linear on a log plot!
“Transverse”
“Transverse”
“Away”
 Shows the “associated” charged particle density in the “transverse” region as a function of
PTmax for charged particles (pT > 0.5 GeV/c, |h| < 1, not including PTmax) for “min-bias” events
at 0.2 TeV, 0.9 TeV, 1.96 TeV, 7 TeV, 10 TeV, 14 TeV predicted by PYTHIA Tune DW at the particle
Log scale!
level (i.e. generator level).
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 17
Conclusions November 2009
 We are making good progress in understanding and modeling the
“underlying event”. RHIC data at 200 GeV are very important!
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
 The new Pythia pT ordered tunes (py64 S320 and py64 P329)
are very similar to Tune A, Tune AW, and Tune DW. At present
the new tunes do not fit the data better than Tune AW and Tune
DW. However, the new tune are theoretically preferred!
AntiProton
Underlying Event
Underlying Event
Outgoing Parton
Final-State
Radiation
Hard-Scattering Cut-Off PT0
PYTHIA 6.206
e = 0.25 (Set A))
4
PT0 (GeV/c)
 It is clear now that the default value PARP(90) = 0.16 is
not correct and the value should be closer to the Tune A
value of 0.25.
 The new and old PYTHIA tunes are beginning to
converge and I believe we are finally in a position to make
some legitimate predictions at the LHC!
5
3
2
e = 0.16 (default)
1
 All tunes with the default value PARP(90) = 0.16 are
wrong and are overestimating the activity of min-bias and
the underlying event at the LHC! This includes all my
“T” tunes and the (old) ATLAS tunes!
 Need to measure “Min-Bias” and the “underlying
event” at the LHC as soon as possible to see if there is
new QCD physics to be learned!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
100
1,000
10,000
100,000
CM Energy W (GeV)
UE&MB@CMS
Page 18
“Transverse” Charged Particle Density
PT(chgjet#1) Direction
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Density
0.8
Df
RDF Preliminary
Fake Data
pyDW generator level
ChgJet#1
“Toward”
0.6
PTmax
“Transverse”
“Transverse”
0.4
Leading Charged
Particle Jet, chgjet#1.
“Away”
0.2
900 GeV
Prediction!
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
PTmax Direction
0.0
0
2
4
6
8
10
12
14
16
PTmax or PT(chgjet#1) (GeV/c)
“Toward”
 Fake data (from MC) at 900 GeV on the
“transverse” charged particle density,
dN/dhdf, as defined by the leading
charged particle (PTmax) and the leading
charged particle jet (chgjet#1) for charged
particles with pT > 0.5 GeV/c and |h| < 2.
The fake data (from PYTHIA Tune DW)
are generated at the particle level (i.e.
generator level) assuming 0.5 M min-bias
events at 900 GeV (361,595 events in the
plot).
University of Virginia
April 10, 2012
Df
18
Rick Field – Florida/CDF/CMS
“Transverse”
“Transverse”
Leading Charged
Particle, PTmax.
“Away”
Rick Field
MB&UE@CMS Workshop
CERN, November 6, 2009
Page 19
“Transverse” Charge Density
"Transverse" Charged Particle Density: dN/dhdf
Rick Field
MB&UE@CMS Workshop
CERN, November 6, 2009
"Transverse" Charged Density
1.2
RDF Preliminary
py Tune DW generator level
7 TeV
0.8
factor of 2!
900 GeV
0.4
Prediction!
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
4
10
0.0
0
2
6
8
12
14
16
18
20
PTmax (GeV/c)
PTmax Direction
Df
LHC
900 GeV
“Toward”
“Transverse”
PTmax Direction
900 GeV → 7 TeV
(UE increase ~ factor of 2)
“Transverse”
“Away”
~0.4 → ~0.8
Df
“Toward”
LHC
7 TeV
“Transverse”
“Transverse”
“Away”
 Shows the charged particle density in the “transverse” region for charged particles (pT > 0.5
GeV/c, |h| < 2) at 900 GeV and 7 TeV as defined by PTmax from PYTHIA Tune DW and at the
particle level (i.e. generator level).
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 20
“Transverse” Charged Particle Density
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
RDF Preliminary
Fake Data
pyDW generator level
"Transverse" Charged Density
"Transverse" Charged Density
0.8
ChgJet#1
0.6
PTmax
0.4
0.2
900 GeV
Monte-Carlo!
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.8
CMS Preliminary
ChgJet#1
data uncorrected
pyDW + SIM
0.6
PTmax
0.4
0.2
900 GeV
Real Data!
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
2
4
6
8
10
12
14
16
18
0
2
6
8
10
12
14
16
18
PTmax or PT(chgjet#1) (GeV/c)
PTmax or PT(chgjet#1) (GeV/c)
 Fake data (from MC) at 900 GeV on the
“transverse” charged particle density,
dN/dhdf, as defined by the leading
charged particle (PTmax) and the leading
charged particle jet (chgjet#1) for charged
particles with pT > 0.5 GeV/c and |h| < 2.
The fake data (from PYTHIA Tune DW)
are generated at the particle level (i.e.
generator level) assuming 0.5 M min-bias
events at 900 GeV (361,595 events in the
plot).
University of Virginia
April 10, 2012
4
 CMS preliminary data at 900 GeV on the
“transverse” charged particle density,
dN/dhdf, as defined by the leading charged
particle (PTmax) and the leading charged
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2. The data
are uncorrected and compared with
PYTHIA Tune DW after detector simulation
(216,215 events in the plot).
Rick Field – Florida/CDF/CMS
Page 21
“Transverse” Charged PTsum Density
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged PTsum Density: dPT/dhdf
0.8
0.8
ChgJet#1
Fake Data
pyDW generator level
0.6
PTsum Density (GeV/c)
PTsum Density (GeV/c)
RDF Preliminary
PTmax
0.4
0.2
900 GeV
Monte-Carlo!
CMS Preliminary
data uncorrected
pyDW + SIM
0.6
ChgJet#1
PTmax
0.4
0.2
900 GeV
Real Data!
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
2
4
6
8
10
12
14
16
18
0
2
4
6
8
10
12
14
16
18
PTmax or PT(chgjet#1) (GeV/c)
PTmax or PT(chgjet#1) (GeV/c)
 Fake data (from MC) at 900 GeV on the
 CMS preliminary data at 900 GeV on the
“transverse” charged PTsum density,
“transverse” charged PTsum density,
dPT/dhdf, as defined by the leading charged
dPT/dhdf, as defined by the leading charged
particle (PTmax) and the leading charged
particle (PTmax) and the leading charged
particle jet (chgjet#1) for charged particles
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2. The fake
with pT > 0.5 GeV/c and |h| < 2. The data
data (from PYTHIA Tune DW) are
are uncorrected and compared with
generated at the particle level (i.e. generator
PYTHIA Tune DW after detector simulation
level) assuming 0.5 M min-bias events at 900
(216,215 events in the plot).
GeV (361,595 events in the plot).
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 22
PYTHIA Tune DW
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
3.0
1.2
CMS Preliminary
7 TeV
data uncorrected
pyDW + SIM
Ratio: 7 TeV/900 GeV
Charged Particle Density
CMS Preliminary
0.8
Ratio
CMS
900 GeV
0.4
data uncorrected
pyDW + SIM
2.0
CMS
1.0
7 TeV / 900 GeV
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
30
35
40
45
50
0
2
4
6
8
10
12
14
16
18
PT(chgjet#1) (GeV/c)
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7 TeV  Ratio of CMS preliminary data at 900 GeV and
7 TeV on the “transverse” charged particle
on the “transverse” charged particle density,
density, dN/dhdf, as defined by the leading
dN/dhdf, as defined by the leading charged
charged particle jet (chgjet#1) for charged
particle jet (chgjet#1) for charged particles
particles with pT > 0.5 GeV/c and |h| < 2. The
with pT > 0.5 GeV/c and |h| < 2. The data are
data are uncorrected and compared with
uncorrected and compared with PYTHIA
PYTHIA Tune DW after detector simulation.
Tune DW after detector simulation.
PT(chgjet#1) Direction
PT(chgjet#1) Direction
Df
Df
“Toward”
“Transverse”
“Toward”
“Transverse”
“Transverse”
“Away”
University of Virginia
April 10, 2012
“Transverse”
“Away”
Rick Field – Florida/CDF/CMS
Page 23
PYTHIA Tune DW
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
Charged Particle Density
CMS Preliminary
"Transverse" Charged Density
1.2
7 TeV
data uncorrected
pyDW + SIM
0.8
CMS
900 GeV
0.4
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
1.2
RDF Preliminary
7 TeV
ATLAS corrected data
Tune DW generator level
0.8
ATLAS
900 GeV
0.4
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
30
35
40
45
0
50
2
4
6
8
10
12
14
16
18
20
PTmax (GeV/c)
PT(chgjet#1) GeV/c
Charged Particle Density
 CMS preliminary data at 900 GeV and 7 TeV  ATLAS preliminary data at 900 GeV and 7
"Transverse" Charged Particle Density: dN/dhdf
TeV on the “transverse” charged particle
on the “transverse” charged
particle density,
1.2
Preliminary
density,
dN/dhdf, as defined by the leading
dN/dhdf, as defined by theRDF
leading
charged
CDF 1.96 TeV
data corrected
charged
(PTmax) for charged particles
pyDW generatorparticles
level
particle jet (chgjet#1) for charged
Leading particle
Jet
with pT > 0.5 GeV/c and |h| < 2.5. The data are
with pT > 0.5 GeV/c and0.8|h| < 2. The data are
corrected and compared with PYTHIA Tune
uncorrected and compared with PYTHIA
DW at the generator level.
Tune DW after detector simulation.
PT(chgjet#1) Direction
0.4
PTmax Direction
Df
“Toward”
“Transverse”
Df
Charged Particles (PT>0.5 GeV/c, |h| < 1.0)
0.0
“Transverse”
“Transverse”
0
“Away”
University of Virginia
April 10, 2012
“Toward”
50
100
150
200
250
PT(jet#1) GeV/c
Rick Field – Florida/CDF/CMS
300
350
“Transverse”
400
“Away”
Page 24
PYTHIA Tune DW
"Transverse" Charged PTsum Density: dPT/dhdf
1.5
CMS Preliminary
RDF Preliminary
7 TeV
data uncorrected
pyDW + SIM
1.2
PTsum Density (GeV/c)
Charged PTsum Density (GeV/c)
"Transverse" Charged PTsum Density: dPT/dhdf
1.6
CMS
0.8
900 GeV
0.4
7 TeV
ATLAS corrected data
Tune DW generator level
1.0
ATLAS
900 GeV
0.5
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
30
35
40
45
0
50
2
4
6
8
10
12
14
16
18
PTmax (GeV/c)
PT(chgjet#1) (GeV/c)
PTsum Density (GeV/c)
 Density:
ATLASdPT/dhdf
preliminary data at 900 GeV and
 CMS preliminary data at 900
GeV andCharged
7
"Transverse"
PTsum
7 TeV on the “transverse” charged PTsum
TeV on the “transverse”1.6charged PTsum
RDF Preliminary
density, dPT/dhdf, as defined by the
density, dPT/dhdf, as defined
by the leading
data corrected
level
leading charged particle (PTmax) for
1.2 pyDW generator
charged particle jet (chgjet#1)
for charged
charged particles with pT > 0.5 GeV/c and
particles with pT > 0.5 GeV/c and |h| < 2.
|h| < 2.5. The data are corrected and
The data are uncorrected
0.8 and compared
CDF 1.96 TeV
compared
with PYTHIA Tune DW after detector
Leading Jet with PYTHIA Tune DW at the
PT(chgjet#1) Direction
generator level. PTmax DirectionDf
simulation.
Df 0.4
Charged Particles (PT>0.5 GeV/c, |h| < 1.0)
“Toward”
“Transverse”
University of Virginia
April 10, 2012
0.0
“Transverse”
“Away”
“Toward”
0
50
100
150
200
250
PT(jet#1) GeV/c
Rick Field – Florida/CDF/CMS
300
“Transverse”
350
400
“Transverse”
“Away”
Page 25
20
Charged Particle Density
1.96 TeV
data corrected
pyDW generator level
Charged Particle Density
Average Charged Density
3
Drell-Yan Production
70 < M(pair) < 110 GeV
2
1
Average Charged Density
Large increase in the UE
in going from 1.96 TeV
Charged Particle Density: dN/dhdf
Charged Particle Density: dN/dhdf
"Toward" Charged Particle Density: dN/dhdf
to 7 TeV as predicted by
3
Tune DW! 1.2 RDF Preliminary
CDF RunPYTHIA
2
CMS Preliminary
data corrected
"Away"
pyDW generator level
0.8
Drell-Yan
Production
Charged Particles
(|h|<1.0, PT>0.5
GeV/c)
excluding the lepton-pair
0
10
20
30
40
50
60
0
70
PT(lepton-pair) GeV/c
80
20
90
Initial-State Radiation
“Transverse”
“Transverse”
“Away”
"Toward"
Charged Particles (PT>0.5 GeV/c)
0 60
PT(lepton-pair) GeV/c
Outgoing Parton
T
"Transverse"
1
100
40
High P Z-Boson Production
CDF:DfProton-Antiproton
Collisions at 1.96 GeV
Lepton Cuts: pT > 20 GeV |h| < 1.0
“Toward”
Proton
Mass Cut:
70 < M(lepton-pair) < 110
GeV
AntiProton
Charged Particles: pT > 0.5 GeV/c |h| < 1.0
Z-Boson Direction
"Away"
Drell-Yan Production
60 < M(pair) < 120 GeV
2
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
excluding the lepton-pair
0
0.0
0
CMS
CDF 1.96 TeV
0.4
"Transverse"
"Toward"
7 TeV
data corrected
CMS pyDW
7 TeV
generator level
2080
40
100
60
80
100
PT(lepton-pair) GeV/c
High P Z-Boson Production
CMS: Proton-Proton
Collisions at 7 GeV
Df
Lepton Cuts: pT > 20 GeV |h| < 2.4
“Toward”
Mass Cut:Proton
60 < M(lepton-pair) < 120 Proton
GeV
Charged Particles: pT > 0.5 GeV/c |h| < 2.0
Z-Boson Direction
Outgoing Parton
T
Initial-State Radiation
“Transverse”
“Transverse”
“Away”
Z-boson
Z-boson
 CDF data at 1.96 TeV on the density of charged particles, dN/dhdf, with pT > 0.5 GeV/c and |h| < 1 for
Drell-Yan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared
with PYTHIA Tune DW.
 CMS data at 7 TeV on the density of charged particles, dN/dhdf, with pT > 0.5 GeV/c and |h| < 2 for DrellYan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune DW.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 26
Charged PTsum Density
data corrected
pyDW generator level
data corrected
pyDW generator level
"Toward"
Drell-Yan Production
70 < M(pair) < 110 GeV
1.0
CDF 1.96 TeV
0.5
Charged Particles
(|h|<1.0,
PT>0.5 GeV/c)
Drell-Yan
Production
excluding the lepton-pair
0.1
20
40
60
0
80
20
PT(lepton-pair) GeV/c
Z-Boson Direction
Df
"Transverse"
1.0
"Toward"
CMS
Drell-Yan Production
Charged Particles (PT>0.5 GeV/c)
60 < M(pair) < 120 GeV
High PT Z-Boson Production
0
60
100
40
20
80
40
100
Z-Boson Direction
Outgoing Parton
Df
60
80
100
PT(lepton-pair) GeV/c
PT(lepton-pair) GeV/c
High PT Z-Boson Production
Initial-State Radiation
Outgoing Parton
Initial-State Radiation
“Toward”
“Toward”
Proton
“Transverse”
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
excluding the lepton-pair
0.1
0.0
0
data corrected
pyDW generator level
CMS 7 TeV
"Transverse"
1.0
Charged PTsum Density (GeV/c)
Charged PTsum Density (GeV/c)
10.0
Charged PTsum Density (GeV/c)
Large increase in the UE
inCharged
going from
1.96Density:
TeV dPT/dhdf
Charged PTsum Density: dPT/dhdf
PTsum
"Toward" Charged PTsum Density: dPT/dhdf
to 7 TeV as predicted by
10.0
1.5
CMS Preliminary
CDF Run
2
1.96
TeV DW! "Away"
7 TeV
RDF Preliminary
PYTHIA
Tune
"Away"
Proton
AntiProton
“Transverse”
“Transverse”
“Away”
Proton
“Transverse”
“Away”
Z-boson
Z-boson
 CDF data at 1.96 TeV on the charged PTsum density, dPT/dhdf, with pT > 0.5 GeV/c and |h| < 1 for Drell-
Yan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune DW.
 CMS data at 7 TeV on the charged PTsum density, dPT/dhdf, with pT > 0.5 GeV/c and |h| < 1 for Drell-Yan
production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune DW.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 27
PYTHIA Tune DW
Charged Particle Density: dN/dhdf
"Toward" Charged Particle Density: dN/dhdf
3
1.2
CMS
7 TeV
data corrected
pyDW generator level
"Away"
Drell-Yan Production
60 < M(pair) < 120 GeV
2
Charged Particle Density
Average Charged Density
CMS Preliminary
data corrected
pyDW generator level
CMS 7 TeV
0.8
CDF 1.96 TeV
Overall PYTHIA0.4Tune DW
"Toward"
is in amazingly good agreement
with the
Charged Particles (PT>0.5 GeV/c)
Drell-Yan Production
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
excluding
the
lepton-pair
Tevatron Jet production 0.0
and Drell-Yan data
20
40
60 did a very
80
100 job in
0 predicting
20
60
80
and
good
the40
PT(lepton-pair) GeV/c
PT(lepton-pair) GeV/c
LHC Jet production and Drell-Yan data!
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
(although not perfect)
"Transverse"
1
0
0
100
1.5
1.5
RDF Preliminary
data corrected
pyDW generator level
Charged Particle Density
RDF Preliminary
Charged Particle Density
RDF Preliminary
CMS 7 TeV
1.0
CDF 1.96 TeV
0.5
CMS 900 GeV
CMS 7 TeV
data corrected
pyDW generator level
1.0
CDF 1.96 TeV
0.5
CMS 900 GeV
Charged Particles (PT>0.5 GeV/c)
Charged Particles (PT>0.5 GeV/c)
0.0
0.0
0
20
40
60
80
100
0
100
150
200
250
PT(chgjet#1 or jet#1) GeV/c
PT(chgjet#1 or jet#1) GeV/c
University of Virginia
April 10, 2012
50
Rick Field – Florida/CDF/CMS
Page 28
300
PYTHIA Tune Z1
 All my previous tunes (A, DW, DWT, D6,
D6T, CW, X1, and X2) were PYTHIA 6.4
tunes using the old Q2-ordered parton
showers and the old MPI model (really 6.2
tunes)!
 I believe that it is time to move to PYTHIA
6.4 (pT-ordered parton showers and new
MPI model)!
 Tune Z1: I started with the parameters of
ATLAS Tune AMBT1, but I changed LO* to
CTEQ5L and I varied PARP(82) and PARP(90)
to get a very good fit of the CMS UE data at 900
GeV and 7 TeV.
 The ATLAS Tune AMBT1 was designed to fit
the inelastic data for Nchg ≥ 6 and to fit the
PTmax UE data with PTmax > 10 GeV/c. Tune
AMBT1 is primarily a min-bias tune, while
Tune Z1 is a UE tune!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
PARP(90)
PARP(82)
Color
Connections
Diffraction
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Underlying Event
Final-State
Radiation
UE&MB@CMS
Page 29
PYTHIA Tune Z1
Tune Z1
(R. Field CMS)
Tune AMBT1
(ATLAS)
CTEQ5L
LO*
PARP(82) – MPI Cut-off
1.932
2.292
PARP(89) – Reference energy, E0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.25
PARP(77) – CR Suppression
1.016
1.016
PARP(78) – CR Strength
0.538
0.538
0.1
0.1
PARP(83) – Matter fraction in core
0.356
0.356
PARP(84) – Core of matter overlap
0.651
0.651
PARP(62) – ISR Cut-off
1.025
1.025
PARP(93) – primordial kT-max
10.0
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
21
MSTP(82) – Double gaussion matter distribution
4
4
MSTP(91) – Gaussian primordial kT
1
1
MSTP(95) – strategy for color reconnection
6
6
Parameter
Parton Distribution Function
Parameters not
shown are the
PYTHIA 6.4 defaults!
PARP(80) – Probability colored parton from BBR
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 30
CMS UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
2.0
CMS Preliminary
CMS Preliminary
data corrected
Tune Z1 generator level
7 TeV
PTsum Density (GeV/c)
Charged Particle Density
1.6
1.2
0.8
900 GeV
CMS
0.4
Tune Z1
data corrected
Tune Z1 generator level
1.6
7 TeV
1.2
CMS
0.8
900 GeV
Tune Z1
0.4
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
10
PT(chgjet#1) GeV/c
University of Virginia
April 10, 2012
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle jet (chgjet#1) for charged
particles with pT > 0.5 GeV/c and |h| < 2.0.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
CMS corrected
data!
20
 CMS preliminary data at 900 GeV and 7
TeV on the “transverse” charged PTsum
density, dPT/dhdf, as defined by the leading
charged particle jet (chgjet#1) for charged
particles with pT > 0.5 GeV/c and |h| < 2.0.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
Very nice agreement!
Rick Field – Florida/CDF/CMS
CMS corrected
data!
Page 31
ATLAS UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.5
RDF Preliminary
RDF Preliminary
7 TeV
ATLAS corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
"Transverse" Charged Density
1.2
0.8
ATLAS
900 GeV
0.4
Tune Z1
7 TeV
ATLAS corrected data
Tune Z1 generator level
1.0
ATLAS
900 GeV
0.5
Tune Z1
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0
5
10
15
20
25
PTmax (GeV/c)
PTmax (GeV/c)
 ATLAS published data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 2.5.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
 ATLAS published data at 900 GeV and 7
TeV on the “transverse” charged PTsum
density, dPT/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 2.5.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
ATLAS publication – arXiv:1012.0791
December 3, 2010
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 32
CMS-ATLAS UE Data
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.6
RDF Preliminary
RDF Preliminary
CMS: Chgjet#1
data corrected
Tune Z1 generator level
Charged Particle Density
Charged Particle Density
1.6
1.2
0.8
CMS (red)
ATLAS (blue)
ATLAS: PTmax
0.4
Tune Z1
data corrected
Tune Z1 generator level
1.2
0.8
CMS (red)
ATLAS (blue)
Tune Z1
0.4
Charged Particles (PT > 0.5 GeV/c)
7 TeV
Charged Particles (PT > 0.5 GeV/c)
7 TeV
0.0
0.0
0
5
10
15
20
25
30
0
10
20
30
40
50
60
70
80
90
100
PTmax or PT(chgjet#1) (GeV/c)
PTmax or PT(chgjet#1) (GeV/c)
 CMS preliminary data at 7 TeV on the “transverse” charged particle density, dN/dhdf, as
defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c
and |h| < 2.0 together with the ATLAS published data at 7 TeV on the “transverse” charged
particle density, dN/dhdf, as defined by the leading charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 2.5 The data are corrected and compared with PYTHIA
Tune Z1 at the generator level.
Amazing agreement!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 33
Jet Radius Dependence
The UE activity is higher
for large jet radius!
"Transverse" Charged Particle Density: dN/dhdf
Charged Particle Density
1.5
d = 1.0
RDF Preliminary
pyZ1 generator level
1.0
d = 0.5
7 TeV
d = 0.2
0.5
Chgjet#1 (|h|<1.5)
Tune Z1
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
0.0
0
10
20
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
 The charged particle density in the “transverse” region as defined by the leading charged
particle jet from PYTHIA Tune Z1. The charged particles are in the region pT > 0.5 GeV/c and
|h| < 2.5. Charged particle jets are constructed using the Anti-KT algorithm with d = 0.2, 0.5,
and 1.0 from charged particles in the region pT > 0.5 GeV/c and |h| < 2.5, however, the leading
charged particle jet is required to have |h(chgjet#1)| < 1.5.
It seems that large jet radius “biases” the UE
to be more active!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 34
ALICE UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.5
RDF Preliminary
RDF Preliminary
7 TeV
ALICE corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
"Transverse" Charged Density
1.2
0.8
900 GeV
0.4
ALICE
Tune Z1
7 TeV
ALICE corrected data
Tune Z1 generator level
1.0
900 GeV
0.5
ALICE
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0
5
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
University of Virginia
April 10, 2012
15
20
25
PTmax (GeV/c)
PTmax (GeV/c)
I read the points off
with a ruler!
10
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged PTsum
density, dPT/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
ALICE UE Data: Talk by S. Vallero
MPI@LHC 2010 Glasgow, Scotland
November 30, 2010
Rick Field – Florida/CDF/CMS
Page 35
PYTHIA Tune Z1
Tune Z1 describes the
energy dependence
Charged Particle Density: dN/dhdf
Charged Particle Density: dN/dhdf
"Toward" Charged Particle Density: dN/dhdf
fairly well!
3
1.2
Drell-Yan Production
70 < M(pair) < 110 GeV
2
1
CMS Preliminary
RDF Preliminary
1.96 TeV
data corrected
pyZ1 generator level
Charged Particle Density
Average Charged Density
CDF Run 2
Average Charged Density
3
data corrected
"Away"
pyZ1 generator level
0.8
Charged Particles
(|h|<1.0, Production
PT>0.5 GeV/c)
Drell-Yan
excluding the lepton-pair
0
10
20
30
40
50
60
0
70
80
20
PT(lepton-pair) GeV/c
Z-Boson Direction
Df
High PT Z-Boson Production
90
"Transverse"
1
"Toward"
0
100
40
0 60
2080
40
100
Z-Boson Direction
Df
High PT Z-Boson Production
Initial-State Radiation
80
100
Outgoing Parton
Initial-State Radiation
“Toward”
“Toward”
Proton
“Transverse”
60
PT(lepton-pair) GeV/c
PT(lepton-pair) GeV/c
Outgoing Parton
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
excluding the lepton-pair
Charged Particles (PT>0.5 GeV/c)
0.0
0
"Away"
Drell-Yan Production
60 < M(pair) < 120 GeV
2
CDF 1.96 TeV
0.4
"Transverse"
"Toward"
CMS
7 TeV
data corrected
pyZ1
generator level
CMS 7
TeV
Proton
AntiProton
“Transverse”
“Transverse”
“Away”
Proton
“Transverse”
“Away”
Z-boson
Z-boson
 CDF data at 1.96 TeV on the density of charged particles, dN/dhdf, with pT > 0.5 GeV/c and |h| < 1 for
Drell-Yan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared
with PYTHIA Tune Z1.
 CMS data at 7 TeV on the density of charged particles, dN/dhdf, with pT > 0.5 GeV/c and |h| < 2 for DrellYan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune Z1.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 36
PYTHIA Tune Z1
Charged PTsum Density: dPT/dhdf
Charged PTsum Density: dPT/dhdf
"Toward" Charged PTsum Density: dPT/dhdf
10.0
1.5
1.96 TeV
data corrected
pyZ1 generator level
"Away"
RDF
Preliminary
data corrected
pyZ1 generator level
"Toward"
Drell-Yan Production
70 < M(pair) < 110 GeV
1.0
CDF 1.96 TeV
0.5
Charged Particles
(|h|<1.0,
PT>0.5 GeV/c)
Drell-Yan
Production
excluding the lepton-pair
0.1
20
40
60
0
80
20
PT(lepton-pair) GeV/c
Z-Boson Direction
Df
7 TeV
"Transverse"
1.0
"Toward"
Drell-Yan Production
Charged Particles (PT>0.5 GeV/c)
60 < M(pair) < 120 GeV
High PT Z-Boson Production
100
40
0
60
20
80
CMS
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
excluding the lepton-pair
40
100
Z-Boson Direction
Outgoing Parton
Df
60
80
100
PT(lepton-pair) GeV/c
PT(lepton-pair) GeV/c
High PT Z-Boson Production
Initial-State Radiation
Outgoing Parton
Initial-State Radiation
“Toward”
“Toward”
Proton
“Transverse”
"Away"
data corrected
pyZ1 generator level
0.1
0.0
0
CMS Preliminary
CMS 7 TeV
"Transverse"
1.0
Charged PTsum Density (GeV/c)
CDF Run 2
Charged PTsum Density (GeV/c)
Charged PTsum Density (GeV/c)
10.0
Proton
AntiProton
“Transverse”
“Transverse”
“Away”
Proton
“Transverse”
“Away”
Z-boson
Z-boson
 CDF data at 1.96 TeV on the charged PTsum density, dPT/dhdf, with pT > 0.5 GeV/c and |h| < 1 for Drell-
Yan production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune Z1.
 CMS data at 7 TeV on the charged PTsum density, dPT/dhdf, with pT > 0.5 GeV/c and |h| < 2 for Drell-Yan
production as a function of PT(Z) for the “toward”, “away”, and “transverse” regions compared with
PYTHIA Tune Z1.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 37
PYTHIA Tune Z1
"Transverse"Charged
ChargedParticle
ParticleDensity:
Density:dN/dhdf
dN/dhdf
"Transverse"
1.2
"Transverse" Charged Particle Density: dN/dhdf
1.5
CMSPreliminary
Preliminary
RDF
RDF Preliminary
data
corrected
data
corrected
Tune generator
Z1 generator
level
pyZ1
level
CMS 7 TeV7 TeV
Charged Particle Density
Charged
Charged Particle
Particle Density
Density
1.6
1.5
1.0
CDF 1.96 TeV
0.8
900 GeV
0.5
0.4
CMS 900 GeV
Tune Z1
data corrected
pyZ1 generator level
CMS 7 TeV
1.0
CDF 1.96 TeV
0.5
CMS 900 GeV
Tune Z1
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (PT>0.5 GeV/c)
0.0
0.0
Charged Particles (PT>0.5 GeV/c)
0.0
00
10
20
20
30
40
40
50
60
60
70
80
80
90
100
100
0
50
PT(chgjet#1)
GeV/c
PT(chgjet#1
or jet#1)
GeV/c
100
150
200
250
300
PT(chgjet#1 or jet#1) GeV/c
 CMS data at 900 GeV on the “transverse”
 CDF data at 1.96 TeV on the “transverse”
charged particle density, dN/dhdf, as
charged particle density, dN/dhdf, as
defined by the leading charged particle jet
defined by the leading calorimeter jet (jet#1)
(chgjet#1) for charged particles with pT >
for charged particles with pT > 0.5 GeV/c
0.5 GeV/c and |h| < 2.0. The data are
and |h| < 1.0. The data are corrected and
corrected and compared with PYTHIA Tune
compared with PYTHIA Tune Z1 at the
Z1 at the generator level.
generator level.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 38
PYTHIA Tune Z1
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged PTsum Density: dPT/dhdf
2.0
2.0
RDF Preliminary
datacorrected
corrected
data
Tune
generator
level
pyZ1 Z1
generator
level
1.6
7 TeV
CMS
7 TeV
1.2
PTsum Density (GeV/c)
PTsum Density (GeV/c)
CMSPreliminary
Preliminary
RDF
CDF 1.96 TeV
0.8
900 GeV
CMS 900 GeV
Tune Z1
0.4
CMS 7 TeV
data corrected
pyZ1 generator level
1.6
CDF 1.96 TeV
1.2
0.8
Tune Z1
CMS 900 GeV
0.4
Charged Particles (PT>0.5 GeV/c)
Charged Particles (PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
100
150
200
250
300
PT(chgjet#1 or jet#1) GeV/c
PT(chgjet#1
or jet#1)
GeV/c
PT(chgjet#1)
GeV/c
 CMS data at 900 GeV and 7 TeV on the
“transverse” charged PTsum density,
dPT/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
are corrected and compared with PYTHIA
Tune Z1 at the generator level.
University of Virginia
April 10, 2012
50
 CDF data at 1.96 TeV on the “transverse”
charged PTsum density, dPT/dhdf, as
defined by the leading calorimeter jet (jet#1)
for charged particles with pT > 0.5 GeV/c
and |h| < 1.0. The data are corrected and
compared with PYTHIA Tune Z1 at the
generator level.
Rick Field – Florida/CDF/CMS
Page 39
PYTHIA Tune Z1
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
1.5
RDF Preliminary
data corrected
pyZ1 generator level
Charged Particle Density
Charged Particle Density
RDF Preliminary
CMS 7 TeV
1.0
CDF 1.96 TeV
0.5
CMS 900 GeV
Tune Z1
0.8
CDF 1.96 TeV
0.4
Tune Z1
0.0
0
20
40
60
80
100
0
20
PT(chgjet#1 or jet#1) GeV/c
3.0
7 TeV
1.2
0.8
Drell-Yan Production
0.4
80
100
RDF Preliminary
Chgjet Production
Charged Particle Density
data corrected
pyZ1 generator level
60
"Away" Charged Particle Density: dN/dhdf
1.6
CMS Preliminary
40
PT(lepton-pair) GeV/c
"Transverse" Charged Particle Density: dN/dhdf
Charged Particle Density
Charged Particles (PT>0.5 GeV/c)
Drell-Yan Production
Charged Particles (PT>0.5 GeV/c)
0.0
CMS 7 TeV
data corrected
pyZ1 generator level
Tune Z1
data corrected
pyZ1 generator level
CDF 1.96 TeV
2.0
CMS 7 TeV
1.0
Tune Z1
Drell-Yan Production
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
40
60
80
100
PT(lepton-pair) GeV/c
PT(chgjet#1) or PT(lepton-pair) GeV/c
University of Virginia
April 10, 2012
20
Rick Field – Florida/CDF/CMS
Page 40
PYTHIA Tune Z1
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged PTsum Density: dPT/dhdf
2.0
Charged PTsum Density (GeV/c)
2.0
PTsum Density (GeV/c)
RDF Preliminary
data corrected
pyZ1 generator level
1.6
CMS 7 TeV
1.2
CDF 1.96 TeV
0.8
CMS 900 GeV
0.4
Tune Z1
Charged PTsum Density (GeV/c)
2.0
1.5
CMS 7 TeV
1.0
CDF 1.96 TeV
0.5
Charged Particles (PT>0.5 GeV/c)
10.0
CMS Preliminary
7 TeV
data corrected
pyZ1 generator level
Charged PTsum Density (GeV/c)
0
Tune Z1
data corrected
pyZ1 generator level
Drell-Yan Production
Overall amazingly good agreement
0.0
with
0
10
20
30
40
50
60
70
80
10
20
30
40
50
60
70
80the90LHC
100 and Tevatron
PT(chgjet#1 or jet#1) GeV/c
Jet production and Drell-Yan! PT(lepton-pair) GeV/c
not perfect yet)
"Away" Charged PTsum Density: dPT/dhdf
"Transverse" Charged PTsum Density:(although
dPT/dhdf
Charged Particles (PT>0.5 GeV/c)
0.0
RDF Preliminary
Chgjet Production
1.5
1.0
Tune Z1
0.5
Drell-Yan Production
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
90
100
RDF Preliminary
data corrected
pyZ1 generator level
8.0
CDF 1.96 TeV
Drell-Yan Production
6.0
CMS 7 TeV
4.0
Tune Z1
2.0
Charged Particles (PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
10
30
40
50
60
70
80
90
PT(lepton-pair) GeV/c
PT(chgjet#1) or PT(lepton-pair) GeV/c
University of Virginia
April 10, 2012
20
Rick Field – Florida/CDF/CMS
Page 41
100
MB&UE Working Group
MB & UE Common Plots
CMS
ATLAS
 The LPCC MB&UE Working Group has suggested
several MB&UE “Common Plots” the all the LHC
groups can produce and compare with each other.
Outgoing Parton
“Minimum Bias” Collisions
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
University of Virginia
April 10, 2012
Proton
Proton
Underlying Event
Final-State
Radiation
Rick Field – Florida/CDF/CMS
Page 42
CMS Common Plots
Observable
900 GeV
7 TeV
MB1: dNchg/dh Nchg ≥ 1
|h| < 0.8 pT > 0.5 Gev/c & 1.0 GeV/c
Done
QCD-10-024
Done
QCD-10-024
MB2: dNchg/dpT Nchg ≥ 1 |h| < 0.8
Stalled
Stalled
MB3: Multiplicity Distribution
|h| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/c
Stalled
Stalled
MB4: <pT> versus Nchg
|h| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/c
In progress
(Antwerp)
In progress
(Antwerp)
UE1: Transverse Nchg & PTsum as
defined by the leading charged
particle, PTmax
|h| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/c
In progress
(M. Zakaria)
In progress
(M. Zakaria)
Direct charged particles (including leptons) corrected to
the particle level with no corrections for SD or DD.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 43
ATLAS UE Data
"Transverse" Charged Particle Density: dN/dhdf
1.5
RDF Preliminary
7 TeV
RDF Preliminary
ATLAS corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
"Transverse" Charged Density
1.2
"Transverse" Charged PTsum Density: dPT/dhdf
0.8
900 GeV
0.4
ATLAS
Tune Z1
7 TeV
ATLAS corrected data
Tune Z1 generator level
1.0
900 GeV
0.5
ATLAS
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
Charged Particles (|h| < 0.8, PT > 0.5 GeV/c)
0.0
0
5
10
15
20
25
0
5
PTmax (GeV/c)
10
15
20
25
PTmax (GeV/c)
 ATLAS preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
 ATLAS preliminary data at 900 GeV and 7
TeV on the “transverse” charged PTsum
density, dPT/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
ATLAS-CONF-2011-009
February 21, 2011
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 44
ALICE-ATLAS UE
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
RDF Preliminary
"Transverse" Charged Density
"Transverse" Charged Density
1.2
7 TeV
ALICE corrected data
Tune Z1 generator level
0.8
900 GeV
0.4
ALICE
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
RDF Preliminary
7 TeV
ATLAS corrected data
Tune Z1 generator level
0.8
900 GeV
0.4
ATLAS
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0
10
15
20
25
PTmax (GeV/c)
PTmax (GeV/c)
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
University of Virginia
April 10, 2012
5
 ATLAS preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
Rick Field – Florida/CDF/CMS
Page 45
ALICE-ATLAS UE
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged PTsum Density: dPT/dhdf
1.5
1.5
RDF Preliminary
7 TeV
ALICE corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
PTsum Density (GeV/c)
RDF Preliminary
1.0
900 GeV
0.5
ALICE
Tune Z1
1.0
900 GeV
0.5
ATLAS
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
7 TeV
ATLAS corrected data
Tune Z1 generator level
Charged Particles (|h| < 0.8, PT > 0.5 GeV/c)
0.0
0
5
10
15
20
25
0
PTmax (GeV/c)
10
15
20
25
PTmax (GeV/c)
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
University of Virginia
April 10, 2012
5
 ATLAS preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
Rick Field – Florida/CDF/CMS
Page 46
Tevatron Energy Scan
Proton
CDF
1 mile
AntiProton
Proton
900GeV
GeV
300
1.96
TeV
AntiProton
 Just before the shutdown of the Tevatron CDF
has collected more than 10M “min-bias” events
at several center-of-mass energies!
300 GeV 12.1M MB Events
900 GeV 54.3M MB Events
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 47
New CDF Energies
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged
Charged Density
"Transverse"
1.2
7 TeV ATLAS
ATLAS
RDF Preliminary
Tune Z1 generator level
0.8
1.96 TeV CDF
900 GeV ATLAS 900 GeV CDF
0.4
300 GeV CDF
Tune Z1
Charged
Charged Particles
Particles (|h|<0.8,
(|h|<0.8, PT>0.5
PT>0.5 GeV/c)
GeV/c)
0.0
0
5
10
15
20
25
25
30
30
35
35
PTmax (GeV/c)
 ATLAS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading charged particle (PTmax) for charged particles
with pT > 0.5 GeV/c and |h| < 0.8. The data are corrected and compared with PYTHIA
Tune Z1 at the generator level.
 Predictions for CDF on the “transverse” charged particle density, dN/dhdf, as
defined by the leading charged particle (PTmax) for charged particles with pT > 0.5
GeV/c and |h| < 0.8 from PYTHIA Tune Z1 at the generator level.
 Very very preliminary CDF data at 900 GeV and 1.96 TeV on the “transverse” charged
particle density, dN/dhdf, as defined by the leading charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 1.0.
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 48
My CDF UE Plan
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
AntiProton
Underlying Event
Final-State
Radiation
 Produce the CDF PTmax UE “common plots” at
900 GeV to compare with ALICE-ATLAS-CMS.
Must correct the data to the particle level!
"Transverse" Charged Particle Density: dN/dhdf
0.8
"Transverse" Charged Density
Outgoing Parton
Underlying Event
RDF Preliminary
Tune Z1 generator level
0.6
ALICE (red)
ATLAS (blue)
0.4
0.2
900 GeV
Charged Particles (|h| < 0.8, PT > 0.5 GeV/c)
0.0
0
2
4
6
8
10
PTmax (GeV/c)
(300 GeV, 900 GeV, 1.96 TeV) at CDF.
Must correct the data to the particle level!
"Transverse" Charged Density
 Study the energy dependence of the PTmax UE
"Transverse" Charged Particle Density: dN/dhdf
1.2
7 TeV ATLAS
RDF Preliminary
Tune Z1 generator level
0.8
1.96 TeV CDF
900 GeV ATLAS
900 GeV CDF
0.4
300 GeV CDF
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
0
5
10
15
20
25
30
PTmax (GeV/c)
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 49
35
My CDF MB Plan
 Produce the CDF MB “common plots” at 900 GeV to
compare with ALICE-ATLAS-CMS.
I would be very happy if someone would help
with the MB. It comes along with the UE
analysis without much extra work!
 Study the energy dependence of MB (300 GeV, 900
GeV, 1.96 TeV) at CDF.
I would be very happy if someone would help
with the MB. It comes along with the UE
analysis without much extra work!
University of Virginia
April 10, 2012
Rick Field – Florida/CDF/CMS
Page 50