ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 1
ICHEP 2012ICHEP 2012Rick Field
University of Florida
Outline of Talk
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Initial-State Radiation
Final-State Radiation
CMS at the LHC
CDF Run 2
CDF PYTHIA 6.2 Tevatron Tune DW predictions.
CMS PYTHIA 6.4 LHC Tune Z1.
300 GeV, 900 GeV, 1.96 TeV
900 GeV, 7 & 8 TeV
New UE data at 300 GeV, 900 GeV, and 1.96 TeV from the Tevatron Energy-Scan.
New comparisons with PYTHIA 6.2 Tune DW and PYTHIA 6.4 Tune Z1.
Much more coming soon!
Energy Dependence of the UE
Melbourne July 4-11, 2012
LPCC MB&UE working group “common plots”.
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 2
QCD Monte-Carlo Models:QCD Monte-Carlo Models:High Transverse Momentum JetsHigh Transverse Momentum Jets
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!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 3
Parameter Default
Description
PARP(83) 0.5 Double-Gaussian: Fraction of total hadronic matter within PARP(84)
PARP(84) 0.2 Double-Gaussian: Fraction of the overall hadron radius containing the fraction PARP(83) of the total hadronic matter.
PARP(85) 0.33 Probability that the MPI produces two gluons with color connections to the “nearest neighbors.
PARP(86) 0.66 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.
PARP(89) 1 TeV Determines the reference energy E0.
PARP(82) 1.9 GeV/c
The cut-off PT0 that regulates the 2-to-2 scattering divergence 1/PT4→1/(PT2+PT0
2)2
PARP(90) 0.16 Determines the energy dependence of the cut-off
PT0 as follows PT0(Ecm) = PT0(Ecm/E0) with = PARP(90)
PARP(67) 1.0 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.
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 10,000 100,000
CM Energy W (GeV)P
T0
(G
eV
/c)
PYTHIA 6.206
= 0.16 (default)
= 0.25 (Set A))
Take E0 = 1.8 TeV
Reference pointat 1.8 TeV
Determine by comparingwith 630 GeV data!
Tuning PYTHIA 6.2:Tuning PYTHIA 6.2:Multiple Parton Interaction ParametersMultiple Parton Interaction Parameters
Determines the energy dependence of the MPI!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 4
Traditional ApproachTraditional Approach
Look at charged particle correlations in the azimuthal angle relative to a leading object (i.e. CaloJet#1, ChgJet#1, PTmax, Z-boson). For CDF PTmin = 0.5 GeV/c cut = 1.
Charged Particle Correlations PT > PTmin || < cut
Leading Object Direction
“Toward”
“Transverse” “Transverse”
“Away”
Define || < 60o as “Toward”, 60o < || < 120o as “Transverse”, and || > 120o as “Away”.
Leading Calorimeter Jet or Leading Charged Particle Jet or
Leading Charged Particle orZ-Boson
-cut +cut
2
0
Leading Object
Toward Region
Transverse Region
Transverse Region
Away Region
Away Region
All three regions have the same area in - space, × = 2cut×120o = 2cut×2/3. Construct densities by dividing by the area in - space.
Charged Jet #1Direction
“Transverse” “Transverse”
“Toward”
“Away”
“Toward-Side” Jet
“Away-Side” Jet
“Transverse” region very sensitive to the “underlying event”!
CDF Run 1 Analysis
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 5
““Transverse” Charged DensityTransverse” Charged Density
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
ChgJet#1 Direction
“Toward”
“Transverse” “Transverse”
“Away”
Shows the charged particle density in the “transverse” region for charged particles (pT > 0.5 GeV/c, || < 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.
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30 35 40 45 50
PT(chgjet#1) or PTmax or PT(pair) (GeV/c)
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sity
7 TeV
Charged Particles (||<1.0, PT>0.5 GeV/c)
RDF Preliminarypy Tune DW generator level
PTmax
ChgJet#1
DY(muon-pair)70 < M(pair) < 110 GeV
Muon-Pair Direction
“Toward”
“Transverse” “Transverse”
“Away”
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 6
Min-Bias “Associated”Min-Bias “Associated”Charged Particle DensityCharged Particle Density
Shows the “associated” charged particle density in the “transverse” region as a function of PTmax for charged particles (pT > 0.5 GeV/c, || < 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 level (i.e. generator level).
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
RHIC Tevatron
0.2 TeV → 1.96 TeV (UE increase ~2.7 times)
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
LHC
1.96 TeV → 14 TeV (UE increase ~1.9 times)
Linear scale!
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25
PTmax (GeV/c)
"Tra
ns
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Ch
arg
ed D
en
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
RDF Preliminarypy Tune DW generator level
Min-Bias 14 TeV
1.96 TeV
0.2 TeV
7 TeV
0.9 TeV
10 TeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 2 4 6 8 10 12 14
Center-of-Mass Energy (TeV)
"Tra
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Ch
arg
ed D
ensi
ty RDF Preliminarypy Tune DW generator level
Charged Particles (||<1.0, PT>0.5 GeV/c)
PTmax = 5.25 GeV/c
RHIC
Tevatron900 GeV
LHC7
LHC14
LHC10
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 7
Min-Bias “Associated”Min-Bias “Associated”Charged Particle DensityCharged Particle Density
Shows the “associated” charged particle density in the “transverse” region as a function of PTmax for charged particles (pT > 0.5 GeV/c, || < 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 level (i.e. generator level).
Log scale!
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25
PTmax (GeV/c)
"Tra
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Ch
arg
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en
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
RDF Preliminarypy Tune DW generator level
Min-Bias 14 TeV
1.96 TeV
0.2 TeV
7 TeV
0.9 TeV
10 TeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0.1 1.0 10.0 100.0
Center-of-Mass Energy (TeV)
"Tra
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Ch
arg
ed D
ensi
ty RDF Preliminarypy Tune DW generator level
Charged Particles (||<1.0, PT>0.5 GeV/c)
PTmax = 5.25 GeV/c
RHIC
Tevatron
900 GeV
LHC7
LHC14LHC10
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
LHC7 LHC14
7 TeV → 14 TeV (UE increase ~20%)
Linear on a log plot!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 8
PYTHIA Tune DWPYTHIA Tune DW
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 2 4 6 8 10 12 14 16 18 20
PTmax (GeV/c)
"Tra
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erse
" C
har
ged
Den
sity RDF Preliminary
ATLAS corrected dataTune DW generator level
900 GeV
7 TeV
Charged Particles (||<2.5, PT>0.5 GeV/c)
ATLAS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 2.5. The data are corrected and compared with PYTHIA Tune DW at the generator level.
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c and || < 2. The data are uncorrected and compared with PYTHIA Tune DW after detector simulation.
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25 30 35 40 45 50
PT(chgjet#1) GeV/c
Ch
arg
ed P
arti
cle
Den
sity
900 GeV
CMS Preliminarydata uncorrected
pyDW + SIM
Charged Particles (||<2.0, PT>0.5 GeV/c)
7 TeV
CMS ATLAS
PT(chgjet#1) Direction
“Toward”
“Transverse” “Transverse”
“Away”
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 50 100 150 200 250 300 350 400
PT(jet#1) GeV/c
Ch
arg
ed P
arti
cle
Den
sity
CDF 1.96 TeVLeading Jet
RDF Preliminarydata corrected
pyDW generator level
Charged Particles (PT>0.5 GeV/c, || < 1.0)
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 9
PYTHIA Tune DWPYTHIA Tune DW
Ratio of CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c and || < 2. The data are uncorrected and compared with PYTHIA Tune DW after detector simulation.
"Transverse" Charged Particle Density: dN/dd
0.0
1.0
2.0
3.0
0 2 4 6 8 10 12 14 16 18
PT(chgjet#1) (GeV/c)
Rat
io:
7 T
eV/9
00 G
eV
CMS Preliminarydata uncorrected
pyDW + SIM
Charged Particles (||<2.0, PT>0.5 GeV/c) 7 TeV / 900 GeV
CMS
PT(chgjet#1) Direction
“Toward”
“Transverse” “Transverse”
“Away”
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c and || < 2. The data are uncorrected and compared with PYTHIA Tune DW after detector simulation.
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25 30 35 40 45 50
PT(chgjet#1) GeV/c
Ch
arg
ed P
arti
cle
Den
sity
900 GeV
CMS Preliminarydata uncorrected
pyDW + SIM
Charged Particles (||<2.0, PT>0.5 GeV/c)
7 TeV
CMS
PT(chgjet#1) Direction
“Toward”
“Transverse” “Transverse”
“Away”
Ratio
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 10
PYTHIA Tune Z1PYTHIA Tune Z1
Proton Proton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Initial-State Radiation
Final-State Radiation
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.
UE&MB@CMSUE&MB@CMS
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)!
PARP(90)
Color
Connections
PARP(82)
Diffraction
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!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 11
PYTHIA Tune Z1PYTHIA Tune Z1Parameter
Tune Z1
(R. Field CMS)Tune AMBT1
(ATLAS)
Parton Distribution Function 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
PARP(80) – Probability colored parton from BBR 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
Parameters not shown are the PYTHIA 6.4
defaults!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 12
CMS UE DataCMS UE Data
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged PTsum density, dPT/dd, as defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c and || < 2.0. The data are corrected and compared with PYTHIA Tune Z1 at the generator level.
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c and || < 2.0. The data are corrected and compared with PYTHIA Tune Z1 at the generator level.
CMS
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
1.6
0 10 20 30 40 50 60 70 80 90 100
PT(chgjet#1) GeV/c
Ch
arg
ed
Par
ticl
e D
en
sity
CMS Preliminarydata corrected
Tune Z1 generator level
900 GeV
7 TeV
Charged Particles (||<2.0, PT>0.5 GeV/c)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.4
0.8
1.2
1.6
2.0
0 10 20 30 40 50 60 70 80 90 100
PT(chgjet#1) GeV/c
PT
sum
Den
sity
(G
eV/c
)
Charged Particles (||<2.0, PT>0.5 GeV/c)
CMS Preliminarydata corrected
Tune Z1 generator level
900 GeV
7 TeV
Tune Z1
Very nice agreement!CMS corrected
data!CMS corrected
data!
CMSTune Z1
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 13
ATLAS UE DataATLAS UE Data
ATLAS published data at 900 GeV and 7 TeV on the “transverse” charged PTsum density, dPT/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 2.5. The data are corrected and compared with PYTHIA Tune Z1 at the generrator level.
ATLAS published data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 2.5. The data are corrected and compared with PYTHIA Tune Z1 at the generator level.
ATLASATLAS
Tune Z1Tune Z1
ATLAS publication – arXiv:1012.0791December 3, 2010
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25
PTmax (GeV/c)
"Tra
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ers
e" C
ha
rge
d D
ensi
ty
Charged Particles (||<2.5, PT>0.5 GeV/c)
RDF Preliminary ATLAS corrected dataTune Z1 generator level
900 GeV
7 TeV
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25
PTmax (GeV/c)
PT
sum
De
nsi
ty (
Ge
V/c
)
Charged Particles (||<2.5, PT>0.5 GeV/c)
RDF PreliminaryATLAS corrected data
Tune Z1 generator level
900 GeV
7 TeV
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 14
MB&UE Working Group
CMS
ATLAS
MB & UE Common Plots
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.
Proton Proton
“Minimum Bias” Collisions
Proton Proton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Initial-State Radiation
Final-State Radiation
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 15
ALICE-ATLAS UEALICE-ATLAS UE"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25
PTmax (GeV/c)
"Tra
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erse
" C
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ged
Den
sity RDF Preliminary
Tune Z1 generator level
7 TeV Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
ALICE (red)ATLAS (blue)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
RDF PreliminaryTune Z1 generator level
7 TeV
ALICE (red)ATLAS (blue)
Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
"Transverse" Charged Particle Density: dN/dd
0.0
0.2
0.4
0.6
0.8
0 2 4 6 8 10
PTmax (GeV/c)
"Tra
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Den
sity RDF Preliminary
Tune Z1 generator level
ALICE (red)ATLAS (blue)
900 GeVCharged Particles (|| < 0.8, PT > 0.5 GeV/c)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.2
0.4
0.6
0.8
0 2 4 6 8 10
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
RDF PreliminaryTune Z1 generator level
ALICE (red)ATLAS (blue)
900 GeVCharged Particles (|| < 0.8, PT > 0.5 GeV/c)
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 16
New CMS UE DataNew CMS UE Data
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged PTsum density, dPT/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected and compared with PYTHIA Tune Z1 at the generator level.
CMS preliminary data at 900 GeV and 7 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected and compared with PYTHIA Tune Z1 at the generator level.
Very nice agreement!CMS corrected
data!CMS corrected
data!
"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
"Tra
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erse
" C
har
ged
Den
sity CMS Preliminary
corrected dataTune Z1 generator level
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
7 TeV
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.5
1.0
1.5
2.0
0 5 10 15 20 25 30
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
CMS Preliminary corrected data
Tune Z1 generator level
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
7 TeV
CMSTune Z1
CMSTune Z1
"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
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Den
sity RDF Preliminary
Tune Z1
Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
7 TeV
8 TeV
Less than 4% change!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 17
UE Common PlotsUE Common Plots"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
"Tra
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Den
sity RDF Preliminary
corrected data
7 TeV
Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.4
0.8
1.2
1.6
0 5 10 15 20 25 30
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
RDF Preliminarycorrected data
7 TeV
Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
"Transverse" Charged Particle Density: dN/dd
0.0
0.2
0.4
0.6
0.8
0 2 4 6 8 10 12 14
PTmax (GeV/c)
"Tra
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sity RDF Preliminary
corrected data
900 GeVCharged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.2
0.4
0.6
0.8
0 2 4 6 8 10 12 14
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
RDF Preliminarycorrected data
900 GeVCharged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 18
Tevatron Energy ScanTevatron Energy Scan
Just before the shutdown of the Tevatron CDF has collected more than 10M “min-bias” events at several center-of-mass energies!
Proton
AntiProton
1 mile CDF
Proton AntiProton 1.96 TeV300 GeV
300 GeV 12.1M MB Events
900 GeV 54.3M MB Events
900 GeV
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 19
New CDF UE DataNew CDF UE Data"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
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Den
sity CDF Preliminary
Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0.
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
900 GeV37,075,521 Events
300 GeV7,233,840 Events
1.96 TeV25,371,145 Events
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 20
Energy DependenceEnergy Dependence"Transverse" Charged Particle Density: dN/dd
1.0
2.0
3.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
CDF Preliminary Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 300 GeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0.
Ratio of the CDF data at 300 GeV and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0. Shows 1.96 TeV divided by 300 GeV.
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 21
Energy DependenceEnergy Dependence"Transverse" Charged Particle Density: dN/dd
1.0
1.5
2.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
CDF Preliminary Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
900 GeV divided by 300 GeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0.
Ratio of the CDF data at 300 GeV and 900 GeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0. Shows 900 GeV divided by 300 GeV.
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 22
Energy DependenceEnergy Dependence"Transverse" Charged Particle Density: dN/dd
1.0
1.2
1.4
1.6
0 5 10 15 20 25
PTmax (GeV/c)
Rat
io
CDF Preliminary Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 900 GeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0.
Ratio of the CDF data at 900 GeV and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0. Shows 1.96 TeV divided by 900 GeV.
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 23
Energy DependenceEnergy Dependence"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
"Transverse" Charged Particle Density: dN/dd
0.25
0.35
0.45
0.55
0.65
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary Corrected Data
Charged Particles (||<1.0, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0.
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0 for 5.0 < PTmax < 6.0 GeV/c.
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 24
PYTHIA 6.2 Tune DWPYTHIA 6.2 Tune DW"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected DataTune DW Generator Level
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
PYTHIA Tune DW
"Transverse" Charged Particle Density: dN/dd
1.0
2.0
3.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 300 GeV
CDF Preliminary Corrected Data
Tune DW Generator Level
Tune DW
"Transverse" Charged Particle Density: dN/dd
1.0
1.5
2.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
Charged Particles (||<1.0, PT>0.5 GeV/c)
900 GeV divided by 300 GeV
CDF Preliminary Corrected Data
Tune DW Generator Level
Tune DW
"Transverse" Charged Particle Density: dN/dd
1.0
1.2
1.4
1.6
0 5 10 15 20 25
PTmax (GeV/c)
Rat
io
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 900 GeV
CDF Preliminary Corrected Data
Tune DW Generator Level
Tune DW
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 25
PYTHIA 6.4 Tune Z1PYTHIA 6.4 Tune Z1"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity CDF Preliminary
Corrected DataTune Z1 Generator Level
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
PYTHIA Tune Z1
"Transverse" Charged Particle Density: dN/dd
0.25
0.35
0.45
0.55
0.65
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
nsv
erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CDF Preliminary Corrected Data
Tune Z1 Generator Level
PYTHIA Tune Z1
"Transverse" Charged Particle Density: dN/dd
1.0
2.0
3.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
CDF Preliminary Corrected Data
Tune Z1 Generator Level
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 300 GeV
Tune Z1
"Transverse" Charged Particle Density: dN/dd
1.0
1.5
2.0
0 2 4 6 8 10 12 14
PTmax (GeV/c)
Rat
io
Charged Particles (||<1.0, PT>0.5 GeV/c)
900 GeV divided by 300 GeV
CDF Preliminary Corrected Data
Tune Z1 Generator Level
Tune Z1
"Transverse" Charged Particle Density: dN/dd
1.0
1.2
1.4
1.6
0 5 10 15 20 25
PTmax (GeV/c)
Rat
io
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV divided by 900 GeV
CDF Preliminary Corrected Data
Tune Z1 Generator Level
Tune Z1
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity
RDF Preliminary Corrected Data
Charged Particles (PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
PYTHIA Tune Z1
7 TeV
CDF
CDFCDF
ALICE
ATLAS CMS
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 26
PTmax versus Leading JetPTmax versus Leading Jet"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
1.2
0 50 100 150 200 250 300 350 400
PT(jet#1) (GeV/c)
"Tra
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erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
1.96 TeV
CDF PublishedCorrected Data
PYTHIA Tune Z1
Published CDF Run 2 data at 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading calorimeter jet (jet#1) for charged particles with pT > 0.5 GeV/c and || < 1.0 compared with PYTHIA Tune Z1.
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
1.2
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
CDF PreliminaryCorrected Data
Tune Z1 generator level
1.96 TeV
PYTHIA Tune Z1
New CDF data 1.96 TeV on the “transverse” charged particle density, dN/dd, as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 1.0 compared with PYTHIA Tune Z1.
Yikes!???
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
1.2
0 50 100 150 200 250 300 350 400
PTmax or PT(jet#1) (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
Leading JetPTmax1.96 TeV
CDF PreliminaryCorrected Data
PYTHIA Tune Z1
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
1.2
0 10 20 30 40 50 60 70 80 90 100
PTmax or PT(jet#1) (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c)
Leading Jet
PTmax
1.96 TeV
CDF PreliminaryCorrected Data
PYTHIA Tune Z1
"Transverse" Charged Particle Density: dN/dd
0.0
0.3
0.6
0.9
1.2
0 5 10 15 20 25 30 35 40
PTmax or PT(jet#1) (GeV/c)
"Tra
nsv
erse
" C
har
ged
Den
sity
Charged Particles (||<1.0, PT>0.5 GeV/c) Leading Jet
PTmax
1.96 TeV
CDF PreliminaryCorrected Data
PYTHIA Tune Z1
OkayNo inconsistency
But need to understand!
ICHEP 2012 Melbourne, July 5, 2012
Rick Field – Florida/CDF/CMS Page 27
More Coming Soon!More Coming Soon!CDF - Many More UE Observables: Nchg density, PTsum
density, average pT, “toward”, “away”, “transverse”, “transMAX”, “transMIN”, distributions, etc..
CDF - Two Ranges: Must do (pT > 0.5 GeV/c, || < 0.8) as well as (pT > 0.5 GeV, || < 1).
CDF - Min-Bias: Many MB observables: Multiplicity, dN/d, pT distribution, <pT> versus Nchg, etc.
Soon we will have MB & UE data at300 GeV, 900 GeV, 1.96 TeV, 7 TeV, and 8 TeV!
We can study the energy dependence more precisely than ever before!
What we are learning shouldallow for more precise
predictions at the future LHC energy of 13 TeV!