Post on 28-Dec-2015
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 1
Outline of Talk
CMS at the LHCCDF Run 2
300 GeV, 900 GeV, 1.96 TeV900 GeV, 7 & 8 TeV
HEP SeminarHEP Seminar
CDF data from the Tevatron Energy Scan.
The “transMAX”, “transMIN”, “transAVE” and “transDIF” UE observables.
The overall event topology for events with at least 1 charged particle.
Summary & Conclusions.
Mapping out the energy dependence: Tevatron to the LHC!
Comparisions with PYTHIA 6.4 Tune Z1 & Z2* and PYTHIA 8 Tune 4C*.
Rick FieldUniversity of Florida
Proton AntiProton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Initial-State Radiation
Final-State Radiation
Tevatron Energy Scan: Findings & Surprises
HEP Seminar - Baylor Waco, January 21, 2014
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!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 3
Proton-Proton CollisionsProton-Proton Collisions Elastic Scattering Single Diffraction
M
tot = ELSD DD HC
Double Diffraction
M1 M2
Proton Proton
“Soft” Hard Core (no hard scattering)
Proton Proton
PT(hard)
Outgoing Parton
Outgoing Parton
Underlying Event Underlying Event
Initial-State Radiation
Final-State Radiation
“Hard” Hard Core (hard scattering)
Hard Core The “hard core” component
contains both “hard” and “soft” collisions.
“Inelastic Non-Diffractive Component”
NDtot = ELIN
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 4
The Inelastic Non-Diffractive The Inelastic Non-Diffractive Cross-SectionCross-Section
Proton Proton
Proton Proton +
Proton Proton
Proton Proton
+
Proton Proton +
+ …
“Semi-hard” parton-parton collision(pT < ≈2 GeV/c)
Occasionally one of the parton-parton collisions is hard(pT > ≈2 GeV/c)
Majority of “min-bias” events!
Multiple-parton interactions (MPI)!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 5
The “Underlying Event”The “Underlying Event”
Proton Proton
Select inelastic non-diffractive events that contain a hard scattering
Proton Proton
Proton Proton +
Proton Proton
+ + …
“Semi-hard” parton-parton collision(pT < ≈2 GeV/c)
Hard parton-parton collisions is hard(pT > ≈2 GeV/c) The “underlying-event” (UE)!
Multiple-parton interactions (MPI)!
Given that you have one hard scattering it is more probable to have MPI! Hence, the UE has more activity than “min-bias”.
1/(pT)4→ 1/(pT2+pT0
2)2
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 6
Model of Model of NDND
Proton Proton
Proton Proton +
Proton Proton
Proton Proton
+
Proton Proton +
+ …
“Semi-hard” parton-parton collision(pT < ≈2 GeV/c)
Allow leading hard scattering to go to zero pT with same cut-off as the MPI!
Model of the inelastic non-diffractive cross section!
Multiple-parton interactions (MPI)!
Proton Proton
1/(pT)4→ 1/(pT2+pT0
2)2
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 7
UE TunesUE Tunes
Proton Proton
Proton Proton +
Proton Proton
Proton Proton
+
Proton Proton +
+ …
“Underlying Event”
“Min-Bias” (ND)
Fit the “underlying event” in a hard
scattering process.
Predict MB (ND)!
1/(pT)4→ 1/(pT2+pT0
2)2
Allow primary hard-scattering to go to pT = 0 with same cut-off!
Single Diffraction
M
Double Diffraction
M1 M2
“Min-Bias” (add single & double diffraction)
Predict MB (IN)!
All of Rick’s tunes (except X2):A, AW, AWT,DW, DWT,
D6, D6T, CW, X1, and Tune Z1,are UE tunes!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 8
MB TunesMB Tunes
Proton Proton +
Proton Proton
Proton Proton
+
Proton Proton +
+ …
“Underlying Event”
“Min-Bias” (ND)
Predict the “underlying event” in a hard
scattering process!
Fit MB (ND).
Proton Proton
Most of Peter Skand’s tunes:S320 Perugia 0, S325 Perugia X,
S326 Perugia 6are MB tunes!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 9
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!
Affects the amount ofinitial-state radiation!
Tuning PYTHIA 6.2:Tuning PYTHIA 6.2:Multiple Parton Interaction ParametersMultiple Parton Interaction Parameters
Determines the energy dependence of the MPI!Remember the energy dependence
of the “underlying event”activity depends on both the = PARP(90) and the PDF!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 10
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
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 11
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
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 12
Jet ObservablesJet Observables“Toward” Charged Particle Density: Number of charged particles (pT
> 0.5 GeV/c, || < 0.8) in the “toward” region (not including PTmax) as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
“Toward” Charged PTsum Density: Scalar pT sum of the charged particles (pT > 0.5 GeV/c, || < 0.8) in the “toward” region (not including PTmax) as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
“Away” Charged Particle Density: Number of charged particles (pT > 0.5 GeV/c, || < 0.8) in the “away” region as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
“Away” Charged PTsum Density: Scalar pT sum of the charged particles (pT > 0.5 GeV/c, || < 0.8) in the “away” region as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
cut = 0.8
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 13
UE ObservablesUE Observables“Transverse” Charged Particle Density: Number of charged particles
(pT > 0.5 GeV/c, || < cut) in the “transverse” region as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
“Transverse” Charged PTsum Density: Scalar pT sum of the charged particles (pT > 0.5 GeV/c, || < cut) in the “transverse” region as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/3, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
“Transverse” Charged Particle Average PT: Event-by-event <pT> = PTsum/Nchg for charged particles (pT > 0.5 GeV/c, || < cut) in the “transverse” region as defined by the leading charged particle, PTmax, averaged over all events with at least one particle in the “transverse” region with pT > 0.5 GeV/c, || < cut.
Zero “Transverse” Charged Particles: If there are no charged particles in the “transverse” region then Nchg and PTsum are zero and one includes these zeros in the average over all events with at least one particle with pT > 0.5 GeV/c, || < cut. However, if there are no charged particles in the “transverse” region then the event is not used in constructing the “transverse” average pT.
cut = 0.8
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 14
ObservablesObservables
Overall “Associated” Charged Particle Density: Number of charged particles (pT > 0.5 GeV/c, || < 0.8, not including PTmax) as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
PTmax Direction
“Toward”
“Transverse” “Transverse”
“Away”
Overall “Associated” Charged PTsum Density: Scalar pT sum of the charged particles (pT > 0.5 GeV/c, || < 0.8, not including PTmax) as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
Note: The overall “associated” density is equal to the average of the “Towards”, “Away”, and “Transverse” densities.
Overall “Associated” Density = (“Towards” Density + “Away” Density + “Transverse” Density)/3
cut = 0.8
Total Number of Charged Particles: Number of charged particles (pT > 0.5 GeV/c, || < 0.8, including PTmax) as defined by the leading charged particle, PTmax, with at least one particle with pT > 0.5 GeV/c, || < cut.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 15
UE ObservablesUE Observables“transMAX” and “transMIN” Charged Particle Density: Number of
charged particles (pT > 0.5 GeV/c, || < 0.8) in the the maximum (minimum) of the two “transverse” regions as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/6, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
PTmax Direction
“Toward”
“TransMAX” “TransMIN”
“Away”
“transMAX” and “transMIN” Charged PTsum Density: Scalar pT sum of charged particles (pT > 0.5 GeV/c, || < 0.8) in the the maximum (minimum) of the two “transverse” regions as defined by the leading charged particle, PTmax, divided by the area in - space, 2cut×2/6, averaged over all events with at least one particle with pT > 0.5 GeV/c, || < cut.
Note: The overall “transverse” density is equal to the average of the “transMAX” and “TransMIN” densities. The “TransDIF” Density is the “transMAX” Density minus the “transMIN” Density
“Transverse” Density = “transAVE” Density = (“transMAX” Density + “transMIN” Density)/2
“TransDIF” Density = “transMAX” Density - “transMIN” Density
cut = 0.8Overall “Transverse” = “transMAX” + “transMIN”
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 16
““transMIN” & “transDIF”transMIN” & “transDIF”The “toward” region contains the leading “jet”, while the “away”
region, on the average, contains the “away-side” “jet”. The “transverse” region is perpendicular to the plane of the hard 2-to-2 scattering and is very sensitive to the “underlying event”. For events with large initial or final-state radiation the “transMAX” region defined contains the third jet while both the “transMAX” and “transMIN” regions receive contributions from the MPI and beam-beam remnants. Thus, the “transMIN” region is very sensitive to the multiple parton interactions (MPI) and beam-beam remnants (BBR), while the “transMAX” minus the “transMIN” (i.e. “transDIF”) is very sensitive to initial-state radiation (ISR) and final-state radiation (FSR).
“TransDIF” density more sensitive to ISR & FSR.
PTmax Direction
“TransMAX” “TransMIN”
“Toward”
“Away”
“Toward-Side” Jet
“Away-Side” Jet
Jet #3
“TransMIN” density more sensitive to MPI & BBR.
0 ≤ “TransDIF” ≤ 2×”TransAVE”
“TransDIF” = “TransAVE” if “TransMIX” = 3×”TransMIN”
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 17
PTmax UE DataPTmax UE DataCDF PTmax UE Analysis: “Towards”, “Away”, “transMAX”,
“transMIN”, “transAVE”, and “transDIF” charged particle and PTsum densities (pT > 0.5 GeV/c, || < 0.8) in proton-antiproton collisions at 300 GeV, 900 GeV, and 1.96 TeV (R. Field analysis).
PTmax Direction
“Toward”
“TransMAX” “TransMIN”
“Away”
CMS PTmax UE Analysis: “Towards”, “Away”, “transMAX”, “transMIN”, “transAVE”, and “transDIF” charged particle and PTsum densities (pT > 0.5 GeV/c, || < 0.8) in proton-proton collisions at 900 GeV and 7 TeV (Mohammed Zakaria Ph.D. Thesis, CMS PAS FSQ-12-020).
CMS UE Tunes: PYTHIA 6.4 Tune Z1 (CTEQ5L) and PYTHIA 6.4 Tune Z2* (CTEQ6L) and PYTHIA 8 Tune 4C* (CTEQ6L). All 3 were tuned to the CMS leading chgjet “transAVE” UE data at 900 GeV and 7 TeV.
Similar to Tune 4C by Corke and Sjöstrand!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 18
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
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 19
CMS Common PlotsCMS Common PlotsObservable 900 GeV 7 TeV
MB1: dNchg/d Nchg ≥ 1
|| < 0.8 pT > 0.5 Gev/c & 1.0 GeV/c
Done
QCD-10-024
Done
QCD-10-024
MB2: dNchg/dpT Nchg ≥ 1 || < 0.8 Stalled Stalled
MB3: Multiplicity Distribution
|| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/cStalled Stalled
MB4: <pT> versus Nchg
|| < 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
|| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/c
Done
FSQ-12-020
Done
FSQ-12-020
Direct charged particles (including leptons) corrected to the particle level with no corrections for SD or DD.
Note that all the “common plots” requireat least one charged particle with
pT > 0.5 GeV/c and || < 0.8!This done so that the plots are
less sensitive to SD and DD.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 20
MB Common Plots 7 TeVMB Common Plots 7 TeV
Direct charged particles (including leptons) corrected to the particle level with no corrections for SD or DD.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 21
CDF Common PlotsCDF Common PlotsObservable 300 GeV 900 GeV 1.96 TeV
MB1: dNchg/d Nchg ≥ 1
|| < 0.8 pT > 0.5 Gev/c & 1.0 GeV/cDone Done Done
MB2: dNchg/dpT Nchg ≥ 1 || < 0.8 In progress In progress In progress
MB3: Multiplicity Distribution
|| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/cIn progress In progress In progress
MB4: <pT> versus Nchg
|| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/cIn progress In progress In progress
UE1: Transverse Nchg & PTsum as defined by the leading charged particle, PTmax
|| < 0.8 pT > 0.5 GeV/c & 1.0 GeV/c
pT > 0.5 GeV/c
Done
pT > 0.5 GeV/c
Done
pT > 0.5 GeV/c
Done
Direct charged particles (including leptons) corrected to the particle level with no corrections for SD or DD.
R. Field, C. Group, and D. Wilson.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 22
MB Common Plots 900 GeVMB Common Plots 900 GeV
Direct charged particles (including leptons) corrected to the particle level with no corrections for SD or DD.
Pseudo-Rapidity Distribution: dN/d
1.4
1.6
1.8
2.0
2.2
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
At least 1 charged particle
CDF
CMS
ATLAS ALICE
Pseudo-Rapidity Distribution: dN/d
0.95
1.00
1.05
1.10
1.15
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Av
erag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>1.0 GeV/c)
900 GeV
At least 1 charged particle
CDF
CMSATLASALICE
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 23
New CDF MB DataNew CDF MB DataPseudo-Rapidity Distribution: dN/d
0
1
2
3
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
1.96 TeV
300 GeV
900 GeV
CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
At least 1 charged particle
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on on pseudo-rapidity distribution of charged particles, dN/d, with pT > 0.5 GeV/c. Events are required to have at least one charged particle with || < 0.8 and pT > 0.5 GeV/c. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Pseudo-Rapidity Distribution: dN/d
1.5
2.0
2.5
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
At least 1 charged particle
CDF
CMS
Pseudo-Rapidity Distribution: dN/d
0
1
2
3
4
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
1.96 TeV
300 GeV
900 GeV
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
At least 1 charged particle
7 TeV
Tune Z1
CDF
CDFCDF
CMS
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 24
New CDF MB DataNew CDF MB Data
New Corrected CDF data at 300 GeV, 900 GeV, and 1.96 TeV on on pseudo-rapidity distribution of charged particles, dN/d, with pT > 1.0 GeV/c. Events are required to have at least one charged particle with || < 0.8 and pT > 1.0 GeV/c. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Pseudo-Rapidity Distribution: dN/d
0.5
1.0
1.5
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
1.96 TeV
300 GeV
900 GeV
CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>1.0 GeV/c)
At least 1 charged particle
Pseudo-Rapidity Distribution: dN/d
0.8
0.9
1.0
1.1
1.2
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>1.0 GeV/c)
900 GeV
At least 1 charged particle
CDF
CMS
Pseudo-Rapidity Distribution: dN/d
0.5
1.0
1.5
2.0
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
Pseudo-Rapidity
Ave
rag
e N
um
ber
1.96 TeV
300 GeV
900 GeV
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>1.0 GeV/c)
At least 1 charged particle
7 TeV
Tune Z1
CDF
CDFCDF
CMS
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 25
Energy Dependence dN/dEnergy Dependence dN/d
CMS data at 7 TeV and 900 GeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on dN/d at = 0 with pT > 0.5 GeV/c as a function of the center-of-mass energy. Events are required to have at least one charged particle with || < 0.8 and pT > 0.5 GeV/c. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Pseudo-Rapidity Distribution: dN/d(=0)
1.0
1.5
2.0
2.5
3.0
3.5
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ave
rag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
At least 1 charged particle
CDF black dotsCMS red squares
Pseudo-Rapidity Distribution: dN/d(=0)
1.0
1.5
2.0
2.5
3.0
3.5
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ave
rag
e N
um
ber
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
At least 1 charged particle
Tune Z1
CDF black dotsCMS red squares
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 26
Energy Dependence dN/dEnergy Dependence dN/d
CMS data at 7 TeV and 900 GeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on dN/d at = 0 with pT > 1.0 GeV/c as a function of the center-of-mass energy. Events are required to have at least one charged particle with || < 0.8 and pT > 1.0 GeV/c. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Pseudo-Rapidity Distribution: dN/d(=0)
0.5
1.0
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0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ave
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>1.0 GeV/c)
At least 1 charged particle
Tune Z1
CDF black dotsCMS red squares
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 27
Total Number of Charged Total Number of Charged ParticlesParticles
Ecm Nchg error NchgDen error
300 GeV 2.241 0.175 0.223 0.017
900 GeV 3.012 0.203 0.300 0.020
1.96 TeV 3.439 0.186 0.342 0.019
7 TeV 4.782 0.063 0.476 0.006
8.0
8.0
dd
dNNchg
CDF and CMS data on the pseudo-rapidity distribution, dN/d, for charged with pT > 0.5 GeV/c and || < 0.8 for events with at least one charged particle with pT > 0.5 GeV/c and || < 0.8.
CDF and CMS data total number of charged particles with pT > 0.5 GeV/c and || < 0.8 for events with at least one charged particle with pT > 0.5 GeV/c and || < 0.8 plotted versus the center-of-mass energy (log scale). The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Pseudo-Rapidity Distribution: dN/d
0
1
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Pseudo-Rapidity
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300 GeV
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
At least 1 charged particle
7 TeV
Number of Charged Particles
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Center-of-Mass Energy (TeV)
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
<Nchg> = 4.8!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 28
Total Number of Charged Total Number of Charged ParticlesParticles
CDF and CMS data total number of charged particles with pT > 0.5 GeV/c and || < 0.8 for events with at least one charged particle with pT > 0.5 GeV/c and || < 0.8 plotted versus the center-of-mass energy (log scale). The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Number of Charged Particles
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Center-of-Mass Energy (TeV)
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
Number of Charged Particles
1.0
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Center-of-Mass Energy (TeV)
Rat
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
Divided by 300 GeV Value
CDF and CMS data ratio of the total number of charged particles with pT > 0.5 GeV/c and || < 0.8 for events with at least one charged particle with pT > 0.5 GeV/c and || < 0.8 plotted versus the center-of-mass energy (log scale). The data are divided by the value at 300 GeV.
Factor of 2.1 increase! Number of Charged Particles
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Generator Level Theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
Tune Z1
Number of Charged Particles
1.0
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Center-of-Mass Energy (TeV)
Rat
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
Divided by 300 GeV Value
RDF Preliminary Corrected Data
Generator Level Theory
Tune Z1
The data are compared with PYTHIA 6.4 Tune Z1
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 29
Total Number of Charged Total Number of Charged ParticlesParticles
CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the total number of charged particles (including PTmax) as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Total Number of Charged Particles
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
<NchgTOT> = 3.44
Total Number of Charged Particles
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CDF Preliminary Corrected Data
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900 GeV
<NchgTOT> = 3.01
Total Number of Charged Particles
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300 GeV
<NchgTOT> = 2.24
CDF Preliminary Corrected Data
Total Number of Charged Particles
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CMS Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
7 TeV
<NchgTOT> = 4.78
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 30
Total Number of Charged Total Number of Charged ParticlesParticles
CMS and CDF data on the total number of charged particles (including PTmax) as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Total Number of Charged Particles
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1.96 TeV
300 GeV
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7 TeVRDF Preliminary Corrected Data
Total Number of Charged Particles
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeVRDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
Total Number of Charged Particles
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PTmax (GeV/c)
Ave
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
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7 TeVRDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune 4C*(dashed lines)
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 31
““Associated” Charged Particle DensityAssociated” Charged Particle Density
Corrected CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the “associated” charged particle density in the “toward”, “away”, and “transverse” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Associated" Charged Particle Density: dN/dd
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Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
1.96 TeV
"Transverse"
CDF Preliminary Corrected Data
"Associated" Charged Particle Density: dN/dd
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Ch
arg
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Den
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Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
900 GeV
"Transverse"
CDF Preliminary Corrected Data
"Associated" Charged Particle Density: dN/dd
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Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
300 GeV
"Transverse"
CDF Preliminary Corrected Data
Associated Charged Particle Density: dN/dd
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CDF Preliminary corrected data
Tune Z1 generator level
Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
1.96 TeV
"Transverse"
Associated Charged Particle Density: dN/dd
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CDF Preliminary corrected data
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Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
900 GeV
"Transverse"
Associated Charged Particle Density: dN/dd
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CDF Preliminary corrected data
Tune Z1 generator level
Charged Particles (||<0.8, PT>0.5 GeV/c)
"Away"
"Toward"
300 GeV
"Transverse"
The data are compared with PYTHIA Tune Z1.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 32
““Toward” Associated DensityToward” Associated Density
At low center-of-mass energies PTmax carries almost all the momentum of the “toward” parton (i.e. z ≈ 1) leaving very little momentum for the other particles in the “jet”.
“Toward” Parton“Away” Parton
“PTmax” Particle
300 GeV
“Associated” Toward Particles
“Away” Particles
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 33
““Toward” Associated DensityToward” Associated Density
At higher center-of-mass energies the same PTmax carries less of the momentum of the “toward” parton (i.e. z < 1) leaving more momentum for the other particles in the “jet”.
“Toward” Parton“Away” Parton
“PTmax” Particle
1.96 TeV
“Associated” Toward Particles
“Away” Particles
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 34
““Transverse” Charge Particle Fraction Transverse” Charge Particle Fraction
CMS and CDF data on the fraction of charged particle in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The plot shows the “transverse” Nchg divided by the total Nchg. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Transverse" Fraction of Charged Particles
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV900 GeV
7 TeV
Transverse/Total
"Transverse" Fraction of Charged Particles
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV900 GeV
7 TeV
RDF Preliminary Corrected Data
Generator Level Theory Tune Z2* (solid lines)Tune Z1 (dashed lines)
Transverse/Total
"Transverse" Fraction of Charged Particles
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1.96 TeV
300 GeV900 GeV
7 TeV
RDF Preliminary Corrected Data
Generator Level Theory Tune Z2* (solid lines)Tune 4C* (dashed lines)
Transverse/Total
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 35
““Associated” Charged Particle DensityAssociated” Charged Particle Density
Corrected CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the “associated” charged particle density in the “toward”, “away”, and “transverse” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Toward" Charged Particle Density: dN/dd
0.0
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PTmax (GeV/c)
"To
war
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Ch
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CDF PreliminaryCorrected Data 1.96 TeV
300 GeV
900 GeV
"Away" Charged Particle Density: dN/dd
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PTmax (GeV/c)
"Aw
ay"
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arg
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CDF PreliminaryCorrected Data 1.96 TeV
300 GeV
900 GeV
"Transverse" Charged Particle Density: dN/dd
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CDF Preliminary Corrected Data 1.96 TeV
300 GeV
900 GeV
The data are compared with PYTHIA Tune Z1.
"Transverse" Charged Particle Density: dN/dd
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CDF Preliminary corrected data
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Charged Particles (||<0.8, PT>0.5 GeV/c)
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"Toward" Charged Particle Density: dN/dd
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CDF Preliminary corrected data
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Charged Particles (||<0.8, PT>0.5 GeV/c)
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"Away" Charged Particle Density: dN/dd
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Tune Z1 generator level
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 36
““Associated” Charged PTsum DensityAssociated” Charged PTsum Density
Corrected CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the “associated” charged PTsum density in the “toward”, “away”, and “transverse” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Toward" Charged PTsum Density: dPT/dd
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GeV
/c)
Charged Particles (||<0.8, PT>0.5 GeV/c)
CDF PreliminaryCorrected Data
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"Away" Charged PTsum Density: dPT/dd
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"Transverse" Charged PTsum Density: dPT/dd
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The data are compared with PYTHIA Tune Z1.
"Toward" Charged PTsum Density: dPT/dd
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corrected dataTune Z1 generator level
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"Away" Charged PTsum Density: dPT/dd
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"Transverse" Charged PTsum Density: dPT/dd
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HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 37
UE Common PlotsUE Common Plots"Transverse" Charged Particle Density: dN/dd
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Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
ATLAS (solid blue)ALICE (open black)
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"Transverse" Charged PTsum Density: dPT/dd
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"Transverse" Charged Particle Density: dN/dd
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"Transverse" Charged Particle Density: dN/dd
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"Transverse" Charged PTsum Density: dPT/dd
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"Transverse" Charged Particle Density: dN/dd
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Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
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RDF Preliminary corrected data
Tune Z1 generator level
"Transverse" Charged PTsum Density: dPT/dd
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Charged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
"Transverse" Charged Particle Density: dN/dd
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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
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900 GeVCharged Particles (|| < 0.8, PT > 0.5 GeV/c)
CMS (solid red)ATLAS (solid blue)ALICE (open black)
RDF Preliminary corrected data
Tune Z1 generator level
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 38
CDF versus CMSCDF versus CMS
CDF and CMS data at 900 GeV/c on the charged particle density in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"TransAVE" Charged Particle Density: dN/dd
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Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
RDF Preliminary corrected data
CMS
CDF
"TransAVE" Charged PTsum Density: dPT/dd
0.00
0.26
0.52
0.78
0 4 8 12 16 20
PTmax (GeV/c)
PT
sum
Den
sit
y (G
eV
/c)
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
RDF Preliminary corrected data
CMS
CDF
CDF and CMS data at 900 GeV/c on the charged PTsum density in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"TransAVE" Charged Particle Density: dN/dd
0.00
0.25
0.50
0.75
0 4 8 12 16 20
PTmax (GeV/c)
Ch
arg
ed P
arti
cle
Den
sity
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
RDF Preliminary corrected data
CMS
CDF
ATLASALICE
"TransAVE" Charged PTsum Density: dPT/dd
0.00
0.26
0.52
0.78
0 4 8 12 16 20
PTmax (GeV/c)
PT
sum
Den
sit
y (G
eV
/c)
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeV
RDF Preliminary corrected data
CMS
CDF
ATLAS
ALICE
CDF versus LHCCDF versus LHC
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 39
““TransAVE” DensityTransAVE” Density
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transAVE” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
"TransAVE" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
ed P
arti
cle
Den
sity
RDF Preliminary Corrected Data
Generator Level Theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged PTsum Density: dPT/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
PT
sum
Den
sit
y (G
eV
/c)
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeVRDF Preliminary
Corrected DataGenerator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged PTsum density in the “transAVE” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 40
““TransAVE” vs ETransAVE” vs Ecmcm
Corrected CMS data at 900 GeV and 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transAVE” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale). The data are compared with PYTHIA 6.4 Tune Z1 and Tune Z2*.
Corrected CMS data at 900 GeV and 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged PTsum density in the “transAVE” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale). The data are compared with PYTHIA 6.4 Tune Z1 and Tune Z2*.
The data are “normalized” by dividing by the corresponding value at 300 GeV.
"TransAVE" Charged Particle Density: dN/dd
0.2
0.5
0.8
1.1
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ch
arg
ed P
arti
cle
Den
sity
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransAVE" Charged PTsum Density: dPT/dd
0.2
0.5
0.8
1.1
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ch
arg
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PT
su
m D
ens
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(GeV
/c)
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransAVE" Charged Particle Density Ratio
1.0
1.8
2.6
3.4
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
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Rat
io
Divided by 300 GeV Value
RDF Preliminary corrected data
generator level theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransAVE" Charged PTsum Density Ratio
1.0
2.0
3.0
4.0
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
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Ra
tio
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/cDivided by 300 GeV Value
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransAVE" Charged Particle Density Ratio
1.0
2.1
3.2
4.3
0.1 1.0 10.0 100.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
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Ra
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Divided by 300 GeV Value
RDF Preliminary corrected data
generator level theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransAVE" Charged PTsum Density Ratio
1.0
2.0
3.0
4.0
0.1 1.0 10.0 100.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
ity
Rat
io
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
Divided by 300 GeV Value
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 41
MB versus the UEMB versus the UE"Transverse" Charged Particle Density: dN/dd
0.0
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0.9
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
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" C
ha
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d D
ens
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
Overall density
"Transverse" Charged Particle Density: dN/dd
0.0
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0.4
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0 5 10 15 20 25
PTmax (GeV/c)
"Tra
nsv
ers
e"
Ch
arg
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y
CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
900 GeVOverall density
"Transverse" Charged Particle Density: dN/dd
0.0
0.2
0.4
0 2 4 6 8 10 12 14
PTmax (GeV/c)
"Tra
nsv
ers
e"
Ch
arg
ed
Den
sit
y CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
300 GeVOverall density
Corrected CDF data on the charged particle density, in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty and are compared with the overall charged particle density (straight lines).
"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
nsv
erse
" C
har
ged
Den
sity CMS Preliminary
Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
7 TeV
Overall density
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 42
MB versus the UEMB versus the UE
Charged Particle Density
0.0
0.2
0.4
0.6
0.8
1.0
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
Ch
arg
ed D
ens
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS squaresCDF dots
Overall
At least 1 charged particle
"Transverse"5 < PTmax < 6 GeV/c
Overall Charged Particle Density
0.20
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0.1 1.0 10.0
Center-of-Mass Energy (TeV)
Ch
arg
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ensi
ty
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
"Transverse" Charged Particle Density: dN/dd
0.2
0.4
0.6
0.8
1.0
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
nsv
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e"
Ch
arg
ed
Den
sit
y RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS red squaresCDF blue dots
Corrected CDF and CMS data on the overall density of charged particles with pT > 0.5 GeV/c and || < 0.8 for events with at least one charged particle with pT > 0.5 GeV/c and || < 0.8 and on the charged particle density, in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
"Transverse" Charged Particle Density: dN/dd
0.2
0.4
0.6
0.8
1.0
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
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Ch
arg
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Den
sit
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Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
RDF Preliminary Corrected Data
Tune Z1 Generator Level
PYTHIA Tune Z1
CMS red squaresCDF blue dots
Overall Charged Particle Density
0.20
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0.40
0.50
0.60
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
Ch
arg
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ensi
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS red squaresCDF blue dots
At least 1 charged particle
RDF Preliminary Corrected Data
Tune Z1 Generator Level
PYTHIA Tune Z1
Charged Particle Density
0.0
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0.1 1.0 10.0
Center-of-Mass Energy (TeV)
Ch
arg
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ensi
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Charged Particles (||<0.8, PT>0.5 GeV/c)
CMS squaresCDF dots
Overall
At least 1 charged particle
"Transverse"5 < PTmax < 6 GeV/c
RDF Preliminary Corrected Data
Tune Z1 Generator Level
PYTHIA Tune Z1
Amazing!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 43
““Transverse”/OverallTransverse”/Overall"Transverse" Charged Particle Density Ratio
1.2
1.4
1.6
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2.0
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
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Den
sit
y R
atio
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
RDF Preliminary Corrected Data
CMS red squaresCDF blue dots
"Transverse" divided by Overall
"Transverse" Charged Particle Density Ratio
1.0
1.5
2.0
2.5
0 5 10 15 20 25 30 35
PTmax (GeV/c)
"Tra
nsv
ers
e"
Ch
arg
ed
Den
sit
y R
atio RDF Preliminary
Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
"Transverse" divided by overall
7 TeV
Corrected CDF and CMS data on the charged particle density ratio, in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The ratio corresponds to the “transverse” charged particle density divided by the overall charged particle density (Nchg ≥ 1).
Corrected CDF and CMS data on the charged particle density ratio, in the “transverse” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 for 5 < PTmax < 6 GeV/c. The ratio corresponds to the “transverse” charged particle density divided by the overall charged particle density (Nchg ≥ 1). The data are plotted versus the center-of-mass energy (log scale).
Amazing!
"Transverse" Charged Particle Density Ratio
1.2
1.4
1.6
1.8
2.0
0.1 1.0 10.0
Center-of-Mass Energy (TeV)
"Tra
nsv
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" C
ha
rged
Den
sit
y R
atio
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS red squaresCDF blue dots
"Transverse" divided by Overall
RDF Preliminary Corrected Data
Tune Z1 Generator Level
PYTHIA Tune Z1
The “transAVE” = “transverse” density increasesfaster with center-of-mass energy than the overall density (Nchg ≥ 1)!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 44
““transMAX/MIN” NchgDentransMAX/MIN” NchgDen
Corrected CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transMAX” and “transMIN” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 4 8 12 16 20
PTmax (GeV/c)
"Tra
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ers
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Ch
arg
ed
Den
sit
y CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"
1.96 TeV
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
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0 4 8 12 16 20
PTmax (GeV/c)
"Tra
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Den
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CDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"900 GeV
"Transverse" Charged Particle Density: dN/dd
0.00
0.24
0.48
0.72
0 2 4 6 8 10 12 14
PTmax (GeV/c)
"Tra
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" C
ha
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d D
ens
ity CDF Preliminary
corrected data
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"
300 GeV
The data are compared with PYTHIA 6.4 Tune Z1 and Tune Z2*.
"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 4 8 12 16 20
PTmax (GeV/c)
"Tra
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" C
ha
rge
d D
ens
ity
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"
1.96 TeV
CDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged Particle Density: dN/dd
0.0
0.4
0.8
1.2
0 4 8 12 16 20
PTmax (GeV/c)
"Tra
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ers
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Ch
arg
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Den
sit
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Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"900 GeV
CDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged Particle Density: dN/dd
0.00
0.24
0.48
0.72
0 2 4 6 8 10 12 14
PTmax (GeV/c)
"Tra
nsv
erse
" C
ha
rge
d D
ens
ity
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"300 GeV
CDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 45
““tranMIN” Nchg FractiontranMIN” Nchg Fraction
CMS and CDF data on the fraction of charged particles in the “transMIN” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The plot shows “transMIN” Nchg divided by the overall “transverse” Nchg. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
"Transverse" Fraction of Charged Particles
0.05
0.15
0.25
0.35
0 5 10 15 20 25 30
PTmax (GeV/c)
Ave
rag
e F
ract
ion
RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV900 GeV
7 TeV
Transverse/Total
"Transverse" Fraction of Charged Particles
0.05
0.15
0.25
0.35
0 5 10 15 20 25 30
PTmax (GeV/c)
Ave
rag
e F
ract
ion
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV900 GeV
7 TeV
RDF Preliminary Corrected Data
Generator Level Theory Tune Z2* (solid lines)Tune Z1 (dashed lines)
Transverse/Total
"Transverse" Fraction of Charged Particles
0.05
0.15
0.25
0.35
0 5 10 15 20 25 30
PTmax (GeV/c)
Ave
rag
e F
ract
ion
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV900 GeV
7 TeV
RDF Preliminary Corrected Data
Generator Level Theory Tune Z2* (solid lines)Tune 4C* (dashed lines)
Transverse/Total
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 46
““transMAX/MIN” NchgDentransMAX/MIN” NchgDen
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transMAX” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
"TransMAX" Charged Particle Density: dN/dd
0.0
0.7
1.4
2.1
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
ed
Par
ticl
e D
ens
ity
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
RDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransMIN" Charged Particle Density: dN/dd
0.00
0.22
0.44
0.66
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
ed P
arti
cle
Den
sity
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeVRDF Preliminary
Corrected DataGenerator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transMIN” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 47
““transDIF/AVE” NchgDentransDIF/AVE” NchgDen
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transAVE” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transDIF” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty. The data are compared with PYTHIA Tune Z1 and Tune Z2*.
"TransAVE" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
ed P
arti
cle
Den
sity
RDF Preliminary Corrected Data
Generator Level Theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"TransDIF" Charged Particle Density: dN/dd
0.0
0.5
1.0
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0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
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arti
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Den
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1.96 TeV
300 GeV
900 GeV
7 TeV
Charged Particles (||<0.8, PT>0.5 GeV/c)
RDF Preliminary Corrected Data
Generator Level Theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 48
““transMAX” NchgDen vs EtransMAX” NchgDen vs Ecmcm
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transMAX” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8. The data are corrected to the particle level with errors that include both the statistical error and the systematic uncertainty.
Corrected CMS and CDF data on the charged particle density in the “transMAX” region as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
"TransMAX" Charged Particle Density: dN/dd
0.0
0.7
1.4
2.1
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
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arti
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Den
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Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
RDF Preliminary Corrected Data
"TransMAX" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ch
arg
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arti
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Den
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RDF Preliminary Corrected Data
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 49
““Transverse” NchgDen vs ETransverse” NchgDen vs Ecmcm
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transMAX” and “transMIN” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
Ratio of CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV to the value at 300 GeV for the charged particle density in the “transMAX” and “transMIN” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
The data are compared with PYTHIA Tune Z1 and Tune Z2*.
"Transverse" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ch
arg
ed P
arti
cle
Den
sity
RDF Preliminary corrected data
generator level theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransMIN"
"TransMAX"
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged Particle Density Ratio
1.0
2.4
3.8
5.2
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
ity
Rat
io
"TransMIN"
Divided by 300 GeV Value"TransMAX"
RDF Preliminary corrected data
generator level theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
Tune Z2* (solid lines)Tune Z1 (dashed lines)
<transMIN> = 4.7
<transMAX> = 2.7
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 50
““Transverse” NchgDen vs ETransverse” NchgDen vs Ecmcm
Corrected CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV on the charged particle density in the “transAVE” and “transDIF” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
Ratio of CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV to the value at 300 GeV for the charged particle density in the “transAVE” and “transDIF” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
"Transverse" Charged Particle Density: dN/dd
0.2
0.5
0.8
1.1
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Ch
arg
ed P
arti
cle
Den
sity
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransDIF"
"TransAVE"
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged Particle Density Ratio
1.0
1.8
2.6
3.4
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
ity
Rat
io
"TransDIF"
"TransAVE"
Divided by 300 GeV Value
RDF Preliminary corrected data
generator level theory
Charged Particles (||<0.8, PT>0.5 GeV/c)
5.0 < PTmax < 6.0 GeV/c
CMS solid dotsCDF solid squares
Tune Z2* (solid lines)Tune Z1 (dashed lines)
The data are compared with PYTHIA Tune Z1 and Tune Z2*.
<transAVE> = 3.1
<transDIF> = 2.2
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 51
““TransMIN/DIF” vs ETransMIN/DIF” vs Ecmcm
Ratio of CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV to the value at 300 GeV for the charged particle density in the “transMIN”, and “transDIF” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
Ratio of CMS data at 7 TeV and CDF data at 1.96 TeV, 900 GeV, and 300 GeV to the value at 300 GeV for the charged PTsum density in the “transMIN”, and “transDIF” regions as defined by the leading charged particle (PTmax) for charged particles with pT > 0.5 GeV/c and || < 0.8 with 5 < PTmax < 6 GeV/c. The data are plotted versus the center-of-mass energy (log scale).
"Transverse" Charged Particle Density Ratio
1.0
2.4
3.8
5.2
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
ity
Rat
io
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransDIF"
"TransMIN"5.0 < PTmax < 6.0 GeV/c
Divided by 300 GeV Value
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
"Transverse" Charged PTsum Density Ratio
1.0
2.6
4.2
5.8
0.1 1.0 10.0
Center-of-Mass Energy (GeV)
Pa
rtic
le D
ens
ity
Rat
io
Charged Particles (||<0.8, PT>0.5 GeV/c)
"TransDIF"
"TransMIN"
5.0 < PTmax < 6.0 GeV/c
Divided by 300 GeV Value
CMS solid dotsCDF solid squares
RDF Preliminary corrected data
generator level theory
Tune Z2* (solid lines)Tune Z1 (dashed lines)
The data are compared with PYTHIA Tune Z1 and Tune Z2*.
<transMIN> = 4.7
<transDIF> = 2.2
<transMIN> = 5.7
<transDIF> = 2.6
The “transMIN” (MPI-BBR component) increasesmuch faster with center-of-mass energy
than the “transDIF” (ISR-FSR component)!Duh!!
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 52
““Tevatron” to the LHCTevatron” to the LHC
Tune Z2* & 4C*CDF
CDF
CDF
CMS"TransAVE" Charged Particle Density: dN/dd
0.0
0.5
1.0
1.5
0 5 10 15 20 25 30
PTmax (GeV/c)
Ch
arg
ed P
arti
cle
Den
sity
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
13 TeV PredictedRDF Preliminary
Corrected DataGenerator Level Theory
Tune Z2* (solid lines)Tune 4C* (dashed lines)
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 53
““Tevatron” to the LHCTevatron” to the LHC
Tune Z2* & 4C*CDF
CDF
CDF
CMS"TransAVE" Charged PTsum Density: dPT/dd
0.0
0.6
1.2
1.8
0 5 10 15 20 25 30
PTmax (GeV/c)
PT
sum
Den
sity
(G
eV/c
)
Charged Particles (||<0.8, PT>0.5 GeV/c)
1.96 TeV
300 GeV
900 GeV
7 TeV
13 TeV Predicted
Tune Z2* (solid lines)Tune 4C* (dashed lines)
RDF Preliminary Corrected Data
Generator Level Theory
HEP Seminar - Baylor Waco, January 21, 2014
Rick Field – Florida/CDF/CMS Page 54
Summary & ConclusionsSummary & Conclusions
The “transMIN” (MPI-BBR component) increases much faster with center-of-mass energy than the “transDIF” (ISR-FSR component)! Previously we only knew the energy dependence of “transAVE”.
The “transverse” density increases faster with center-of-mass energy than the overall density (Nchg ≥ 1)! However, the “transverse” = “transAVE” region is not a true measure of the energy dependence of MPI since it receives large contributions from ISR and FSR.
We now have at lot of MB & UE data at300 GeV, 900 GeV, 1.96 TeV, and 7 TeV!
We can study the energy dependence more precisely than ever before!
PYTHIA 6.4 Tune Z1 & Z2* and PYTHIA 8 Tune 4C* do a fairly good job in describing the energy deperdence of the UE, however there is room for improvement! The parameterization PT0(Ecm) = PT0(Ecm/E0) seems to work!
What we are learning shouldallow for a deeper understanding of MPI
which will result in more precisepredictions at the future
LHC energies of 13 & 14 TeV!