Boost 2011
May 22-26, 2011
The Underlying Event & Fragmentation Tuning
Rick Field
University of Florida
Outline
 LHC PYTHIA Tunes: PYTHIA 6.4 tunes (AMBT1, Z1, Z2)
and PYTHIA 8 Tune C4.
 CMS-ATLAS-ALICE (corrected) UE data at (900 GeV and 7
CMS
TeV) and comparisons with the LHC tunes.
 Baryon and Strange Particle Production at the LHC:
Outgoing Parton
Fragmentation tuning.
+ Proton
K
PT(hard)
Kshort
Underlying Event
Proton
uud
Underlying Event
d s +d s
u s
p
Initial-State Radiation
KOutgoing
Parton
u s
Boost 2011, Princeton, NJ
May 23, 2011

 
dss
ud s
ATLAS
Final-State
Radiation
UE&MB@CMS
Rick Field – Florida/CDF/CMS
Page 1
QCD Monte-Carlo Models:
High Transverse Momentum Jets
Hard Scattering
Initial-State Radiation
Hard Scattering “Jet”
Initial-State Radiation
“Jet”
Outgoing Parton
PT(hard)
Outgoing Parton
PT(hard)
Proton
“Hard Scattering” Component
AntiProton
Final-State Radiation
Outgoing Parton
Underlying Event
Underlying Event
Proton
“Jet”
Final-State Radiation
AntiProton
Underlying Event
Outgoing Parton
Underlying Event
“Underlying Event”
 Start with the perturbative 2-to-2 (or sometimes 2-to-3) parton-parton scattering and add initial and finalstate gluon radiation (in the leading log approximation or modified leading log approximation).
 The “underlying event” consists of the “beam-beam remnants” and from particles arising from soft or
semi-soft multiple parton interactions (MPI).
The “underlying
event” is“jet”
an unavoidable
 Of course the outgoing colored partons fragment
into hadron
and inevitably “underlying event”
background to most collider observables
observables receive contributions from initial
and final-state radiation.
and having good understand of it leads to
more precise collider measurements!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 2
Traditional Approach
CDF Run 1 Analysis Charged Particle Df Correlations
Leading Calorimeter Jet or
Charged Jet #1
Leading Charged Particle Jet or
PT > PTmin |h| < hcut
Direction
Leading Charged Particle or
2
“Transverse” region
very sensitive to the
“underlying event”!
Away RegionZ-Boson
“Toward-Side” Jet
Df
“Toward”
“Transverse”
“Transverse”
“Away”
Leading Object
Direction
Df
“Toward”
“Transverse”
“Transverse”
Transverse
Region
f
Leading
Object
Toward Region
Transverse
Region
“Away”
Away Region
0
-hcut
“Away-Side” Jet
h
+hcut
 Look at charged particle correlations in the azimuthal angle Dfrelative to a leading object (i.e.
CaloJet#1, ChgJet#1, PTmax, Z-boson). For CDF PTmin = 0.5 GeV/c hcut = 1.
 Define |Df| < 60o as “Toward”, 60o < |Df| < 120o as “Transverse”, and |Df| > 120o as
“Away”.
 All three regions have the same area in h-f space, Dh×Df = 2hcut×120o = 2hcut×2/3. Construct
densities by dividing by the area in h-f space.
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 3
ATLAS Tune AMBT1
Judith Katzy LPCC
MB&UE working group
meeting, May 31, 2010.
Emily Nurse ICHEP,
July 24, 2010.
ATLAS-CONF-2010-031
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 4
ATLAS Tune AMBT1
Subset of the
“min-bias” data!
Attempt to fit a subset of
the “min-bias” data
(Nchg ≥ 6) where the
contamination due to
diffraction is expected to
be small!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 5
PYTHIA Tune Z1
 All my previous tunes (A, DW, DWT, D6,
D6T, CW, X1, and X2) were PYTHIA 6.4
tunes using the old Q2-ordered parton
showers and the old MPI model (really 6.2
tunes)!
 I believe that it is time to move to PYTHIA
6.4 (pT-ordered parton showers and new
MPI model)!
 Tune Z1: I started with the parameters of
ATLAS Tune AMBT1, but I changed LO* to
CTEQ5L and I varied PARP(82) and PARP(90)
to get a very good fit of the CMS UE data at 900
GeV and 7 TeV.
 The ATLAS Tune AMBT1 was designed to fit
the inelastic data for Nchg ≥ 6 and to fit the
PTmax UE data with PTmax > 10 GeV/c. Tune
AMBT1 is primarily a min-bias tune, while
Tune Z1 is a UE tune!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
PARP(90)
PARP(82)
Color
Connections
Diffraction
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Underlying Event
Final-State
Radiation
UE&MB@CMS
Page 6
PYTHIA Tune Z1
Tune Z1
(R. Field CMS)
Tune AMBT1
(ATLAS)
CTEQ5L
LO*
PARP(82) – MPI Cut-off
1.932
2.292
PARP(89) – Reference energy, E0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.25
PARP(77) – CR Suppression
1.016
1.016
PARP(78) – CR Strength
0.538
0.538
0.1
0.1
PARP(83) – Matter fraction in core
0.356
0.356
PARP(84) – Core of matter overlap
0.651
0.651
PARP(62) – ISR Cut-off
1.025
1.025
PARP(93) – primordial kT-max
10.0
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
21
MSTP(82) – Double gaussion matter distribution
4
4
MSTP(91) – Gaussian primordial kT
1
1
MSTP(95) – strategy for color reconnection
6
6
Parameter
Parton Distribution Function
Parameters not
shown are the
PYTHIA 6.4 defaults!
PARP(80) – Probability colored parton from BBR
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 7
CMS UE Data
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
1.2
CMS Preliminary
D6T
7 TeV
data uncorrected
Theory + SIM
Charged Particle Density
Charged Particle Density
CMS Preliminary
0.8
900 GeV
DW
0.4
CMS
7 TeV
data uncorrected
pyZ1 + SIM
0.8
900 GeV
0.4
CMS
Tune Z1
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
30
35
40
45
50
0
5
10
15
20
25
30
35
40
45
50
PT(chgjet#1) GeV/c
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7 TeV  CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” charged particle density,
on the “transverse” charged particle density,
dN/dhdf, as defined by the leading charged
dN/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
with pT > 0.5 GeV/c and |h| < 2.0. The data
are uncorrected and compared with PYTHIA
are uncorrected and compared with PYTHIA
Tune DW and D6T after detector simulation
Tune Z1 after detector simulation (SIM).
(SIM).
Color reconnection suppression.
Color reconnection strength.
Boost 2011, Princeton, NJ
May 23, 2011
Tune Z1 (CTEQ5L)
PARP(82) = 1.932
PARP(90) = 0.275
PARP(77) = 1.016
PARP(78) = 0.538
Rick Field – Florida/CDF/CMS
Tune Z1 is a PYTHIA 6.4 using
pT-ordered parton showers and
the new MPI model!
Page 8
PYTHIA 6.2 Tunes
UE Parameters
ISR Parameter
Parameter
Tune AW
Tune DW
Tune D6
PDF
CTEQ5L
CTEQ5L
CTEQ6L
MSTP(81)
1
1
1
MSTP(82)
4
4
4
PARP(82)
2.0 GeV
1.9 GeV
1.8 GeV
PARP(83)
0.5
0.5
0.5
PARP(84)
0.4
0.4
0.4
PARP(85)
0.9
1.0
1.0
PARP(86)
0.95
1.0
1.0
PARP(89)
1.8 TeV
1.8 TeV
1.8 TeV
PARP(90)
0.25
0.25
0.25
PARP(62)
1.25
1.25
1.25
PARP(64)
0.2
0.2
0.2
PARP(67)
4.0
2.5
2.5
MSTP(91)
1
1
1
PARP(91)
2.1
2.1
2.1
PARP(93)
15.0
15.0
15.0
Uses CTEQ6L
Reduce PARP(82) by
factor of 1.8/1.9 = 0.95
Everything else the same!
Tune A energy dependence!
(not the default)
Intrinsic KT
CMS: We wanted a CTEQ6L version of Tune Z1 in a hurry!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 9
PYTHIA Tune Z2
My guess!
Tune Z1
(R. Field CMS)
Tune Z2
(R. Field CMS)
CTEQ5L
CTEQ6L
PARP(82) – MPI Cut-off
1.932
1.832
PARP(89) – Reference energy, E0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.275
PARP(77) – CR Suppression
1.016
1.016
PARP(78) – CR Strength
0.538
0.538
0.1
0.1
PARP(83) – Matter fraction in core
0.356
0.356
PARP(84) – Core of matter overlap
0.651
0.651
PARP(62) – ISR Cut-off
1.025
1.025
PARP(93) – primordial kT-max
10.0
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
21
MSTP(82) – Double gaussion matter distribution
4
4
MSTP(91) – Gaussian primordial kT
1
1
MSTP(95) – strategy for color reconnection
6
6
Parameter
Parton Distribution Function
PARP(80) – Probability colored parton from BBR
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Reduce PARP(82) by
factor of 1.83/1.93 = 0.95
Everything else the same!
Page 10
PYTHIA Tune Z2
My guess!
Tune Z1
(R. Field CMS)
Tune Z2
(R. Field CMS)
CTEQ5L
CTEQ6L
PARP(82) – MPI Cut-off
1.932
1.832
PARP(89) – Reference energy, E0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.275
PARP(77) – CR Suppression
1.016
1.016
PARP(78) – CR Strength
0.538
0.538
0.1
0.1
PARP(83) – Matter fraction in core
0.356
0.356
PARP(84) – Core of matter overlap
0.651
0.651
PARP(62) – ISR Cut-off
1.025
1.025
PARP(93) – primordial kT-max
10.0
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
21
MSTP(82) – Double gaussion matter distribution
4
4
MSTP(91) – Gaussian primordial kT
1
1
MSTP(95) – strategy for color reconnection
6
6
Parameter
Parton Distribution Function
PARP(80) – Probability colored parton from BBR
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Reduce PARP(82) by
factor of 1.83/1.93 = 0.95
Everything else the same!
PARP(90) same
For Z1 and Z2!
Page 11
PYTHIA 8 Tunes
R. Corke and T. Sjöstrand
CTEQ6L
MRST LO** CTEQ6L
PT0 = PARP(82)
e = PARP(90)
Tevatron
LHC
pT0(W)=pT0(W/W0)e e = PARP(90) pT0 = PARP(82) W = Ecm
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 12
PYTHIA Tune Z2
Tune Z2
(R. Field CMS)
PY8 Tune C4
(Corke-Sjöstrand)
CTEQ6L
CTEQ6L
PARP(82) – MPI Cut-off
1.832
2.085
PARP(89) – Reference energy, E0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.19
PARP(77) – CR Suppression
1.016
PARP(78) – CR Strength
0.538
Parameter
Parton Distribution Function
PARP(80) – Probability colored parton from BBR
0.1
PARP(83) – Matter fraction in core
0.356
PARP(84) – Core of matter overlap
0.651
PARP(62) – ISR Cut-off
1.025
PARP(93) – primordial kT-max
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
MSTP(82) – Double gaussion matter distribution
4
MSTP(91) – Gaussian primordial kT
1
MSTP(95) – strategy for color reconnection
6
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
PARP(90) much
different!
Page 13
CMS UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
2.0
CMS Preliminary
CMS Preliminary
data corrected
Tune Z1 generator level
7 TeV
PTsum Density (GeV/c)
Charged Particle Density
1.6
1.2
0.8
900 GeV
CMS
0.4
Tune Z1
data corrected
Tune Z1 generator level
1.6
7 TeV
1.2
CMS
0.8
900 GeV
Tune Z1
0.4
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
10
PT(chgjet#1) GeV/c
Boost 2011, Princeton, NJ
May 23, 2011
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” charged particle density,
dN/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
are corrected and compared with PYTHIA
Tune Z1 at the generator level.
CMS corrected
data!
20
 CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” charged PTsum density,
dPT/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
are corrected and compared with PYTHIA
Tune Z1 at the generator level.
Very nice agreement!
Rick Field – Florida/CDF/CMS
CMS corrected
data!
Page 14
PYTHIA 6.4 Tune Z2
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
2.0
CMS Preliminary
CMS Preliminary
data corrected
Tune Z2 generator level
7 TeV
PTsum Density (GeV/c)
Charged Particle Density
1.6
1.2
0.8
900 GeV
Tune Z2
0.4
data corrected
Tune Z2 generator level
1.6
7 TeV
1.2
0.8
900 GeV
Tune Z2
0.4
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7 TeV  CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” charged PTsum density,
on the “transverse” charged particle density,
dPT/dhdf, as defined by the leading charged
dN/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
with pT > 0.5 GeV/c and |h| < 2.0. The data
are corrected and compared with PYTHIA
are corrected and compared with PYTHIA
Tune Z2 at the generator level.
Tune Z2 at the generator level.
CMS corrected
data!
Boost 2011, Princeton, NJ
May 23, 2011
Not good! Bad energy dependence!
Rick Field – Florida/CDF/CMS
CMS corrected
data!
Page 15
PYTHIA 8 Tune C4
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
2.0
CMS Preliminary
CMS Preliminary
data corrected
PY8 Tune C4 generator level
7 TeV
PTsum Density (GeV/c)
Charged Particle Density
1.6
1.2
0.8
900 GeV
PY8 Tune C4
0.4
data corrected
PY8 Tune C4 generator level
1.6
7 TeV
1.2
0.8
900 GeV
PY8 Tune C4
0.4
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
0.0
0
10
20
30
40
50
60
70
80
90
100
0
10
20
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
PT(chgjet#1) GeV/c
 CMS preliminary data at 900 GeV and 7 TeV  CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” charged PTsum density,
on the “transverse” charged particle density,
dPT/dhdf, as defined by the leading charged
dN/dhdf, as defined by the leading charged
particle jet (chgjet#1) for charged particles
particle jet (chgjet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2.0. The data
with pT > 0.5 GeV/c and |h| < 2.0. The data
are corrected and compared with PYTHIA 8
are corrected and compared with PYTHIA 8
Tune C4 at the generator level.
Tune C4 at the generator level.
CMS corrected
data!
Boost 2011, Princeton, NJ
May 23, 2011
Not good! PTsum too small!
Rick Field – Florida/CDF/CMS
CMS corrected
data!
Page 16
Transverse Ratio: PTsum/Nchg
"Transverse" Charged Particle Ratio: PTsum/Nchg
"Transverse" Charged Particle Ratio: PTsum/Nchg
1.6
1.6
CMS Preliminary
data corrected
Tune Z1 generator level
1.4
7 TeV
PTsum/Nchg (GeV/c)
PTsum/Nchg (GeV/c)
CMS Preliminary
1.2
900 GeV
1.0
Tune Z1
0.8
data corrected
Tune Z2 generator level
1.4
7 TeV
1.2
900 GeV
1.0
Tune Z2
0.8
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.6
0.6
0
10
20
30
40
50
60
70
80
90
0
100
10
20
30
40
50
60
70
80
90
100
PT(chgjet#1) GeV/c
PT(chgjet#1) GeV/c
"Transverse" Charged Particle Ratio: PTsum/Nchg
1.6
CMS Preliminary
PTsum/Nchg (GeV/c)
 CMS preliminary data at 900 GeV and 7 TeV
on the “transverse” ratio PTsum/Nchg as
defined by the leading charged particle jet
(chgjet#1) for charged particles with pT > 0.5
GeV/c and |h| < 2.0 compared with PYTHIA
Tune Z1, Z2, and PY8C4 at the generator
level.
data corrected
PY8 Tune C4 generator level
1.4
7 TeV
1.2
900 GeV
1.0
PY8 Tune C4
0.8
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Z1 good! PY8C4 and Z2 Bad!
0.6
0
10
20
30
40
50
60
70
80
90
PT(chgjet#1) GeV/c
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 17
100
Energy Dependence
CTEQ6L: PARP(90) = 0.19
"Transverse" Charged PTsum Density: Ratio
"Transverse" Charged Particle Density: Ratio
3.0
3.0
CMS Preliminary
PY8C4
data corrected
generator level theory
2.5
Charged Density Ratio
Charged Density Ratio
CMS Preliminary
2.0
1.5
Z1
Z2
1.0
7 TeV divided by 900 GeV
data corrected
generator level theory
2.5
PY8C4
2.0
Z1
1.5
Z2
1.0
7 TeV divided by 900 GeV
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.5
0.5
0
5
10
15
PT(chgjet#1) GeV/c
CTEQ6L: PARP(90) =0.275
20
25
30
 CMS data on the energy dependence (7 TeV
divided by 900 GeV) of the “transverse”
charged particle density as defined by the
leading charged particle jet (chgjet#1) for
charged particles with pT > 0.5 GeV/c and |h|
< 2.0 compared with PYTHIA Tune Z1, Z2,
and PY8C4 at the generator level.
CMS corrected
data!
Boost 2011, Princeton, NJ
May 23, 2011
0
5
CTEQ5L: PARP(90) =0.275
10
15
20
25
30
PT(chgjet#1) GeV/c
 CMS data on the energy dependence (7 TeV
divided by 900 GeV) of the “transverse”
charged PTsum density as defined by the
leading charged particle jet (chgjet#1) for
charged particles with pT > 0.5 GeV/c and |h|
< 2.0 compared with PYTHIA Tune Z1, Z2,
and PY8C4 at the generator level.
Duh! The energy dependence depends on
Z1 and PY8C4 good! Z2 Bad!
both PARP(90) and the structure function!
Rick Field – Florida/CDF/CMS
CMS corrected
data!
Page 18
PYTHIA Tune Z2*
Tune Z2
(R. Field CMS)
Tune Z2*
(CMS)
PY8 Tune C4
(Corke-Sjöstrand)
CTEQ6L
CTEQ6L
CTEQ6L
PARP(82) – MPI Cut-off
1.832
1.927
2.085
PARP(89) – Reference energy, E0
1800.0
1800.0
1800.0
PARP(90) – MPI Energy Extrapolation
0.275
0.225
0.19
PARP(77) – CR Suppression
1.016
1.016
PARP(78) – CR Strength
0.538
0.538
0.1
0.1
PARP(83) – Matter fraction in core
0.356
0.356
PARP(84) – Core of matter overlap
0.651
0.651
PARP(62) – ISR Cut-off
1.025
1.025
PARP(93) – primordial kT-max
10.0
10.0
MSTP(81) – MPI, ISR, FSR, BBR model
21
21
MSTP(82) – Double gaussion matter distribution
4
4
MSTP(91) – Gaussian primordial kT
1
1
MSTP(95) – strategy for color reconnection
6
6
Parameter
Parton Distribution Function
PARP(80) – Probability colored parton from BBR
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
CMS GEN Group: Working
on an improved Z2 tune (Tune
Z2*) using the Professor (A.
Knutsson & M. Zakaria).
Page 19
ATLAS UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.5
RDF Preliminary
RDF Preliminary
7 TeV
ATLAS corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
"Transverse" Charged Density
1.2
0.8
ATLAS
900 GeV
0.4
Tune Z1
7 TeV
ATLAS corrected data
Tune Z1 generator level
1.0
ATLAS
900 GeV
0.5
Tune Z1
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
Charged Particles (|h|<2.5, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0
5
10
15
20
25
PTmax (GeV/c)
PTmax (GeV/c)
 ATLAS published data at 900 GeV and 7 TeV  ATLAS published data at 900 GeV and 7 TeV
on the “transverse” charged particle density,
on the “transverse” charged PTsum density,
dN/dhdf, as defined by the leading charged
dPT/dhdf, as defined by the leading charged
particle (PTmax) for charged particles with
particle (PTmax) for charged particles with
pT > 0.5 GeV/c and |h| < 2.5. The data are
pT > 0.5 GeV/c and |h| < 2.5. The data are
corrected and compared with PYTHIA Tune
corrected and compared with PYTHIA Tune
Z1 at the generator level.
Z1 at the generrator level.
ATLAS publication – arXiv:1012.0791
December 3, 2010
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 20
CMS-ATLAS UE Data
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.6
RDF Preliminary
RDF Preliminary
CMS: Chgjet#1
data corrected
Tune Z1 generator level
Charged Particle Density
Charged Particle Density
1.6
1.2
0.8
CMS (red)
ATLAS (blue)
ATLAS: PTmax
0.4
Tune Z1
data corrected
Tune Z1 generator level
1.2
0.8
CMS (red)
ATLAS (blue)
Tune Z1
0.4
Charged Particles (PT > 0.5 GeV/c)
7 TeV
Charged Particles (PT > 0.5 GeV/c)
7 TeV
0.0
0.0
0
5
10
15
20
25
30
0
10
20
30
40
50
60
70
80
90
PTmax or PT(chgjet#1) (GeV/c)
PTmax or PT(chgjet#1) (GeV/c)
 CMS preliminary data at 7 TeV on the “transverse” charged particle density, dN/dhdf, as
defined by the leading charged particle jet (chgjet#1) for charged particles with pT > 0.5 GeV/c
and |h| < 2.0 together with the ATLAS published data at 7 TeV on the “transverse” charged
particle density, dN/dhdf, as defined by the leading charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 2.5 The data are corrected and compared with PYTHIA
Tune Z1 at the generator level.
Amazing agreement!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 21
100
ATLAS UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
"Transverse" Ratio: PT >2.5
0.1 and > 0.5 GeV/c
RDF Preliminary
1.5
0.5
7 TeV
0.0
0
2
4
6
ATLAS corrected data
RDF
Tune Z1 generator level
2.0
Charge Particle Density
3.0
PT > 0.1 GeV/c
Tune Z1
1.0
PTsum Density (GeV/c)
2.0
RDF Preliminary
4.0
ATLAS corrected data
Tune Z1 generator level
"Transverse" Ratio 0.1/0.5
"Transverse" Charged Density
2.5
2.0
ATLAS
PT > 0.5 GeV/c
8
PT > 0.1 GeV/c
ATLAS corrected data
Tune Z1 generator level
Tune Z1
1.5
1.0
ATLAS
PT > 0.5 GeV/c
0.5
7 TeV
Charged Particles (|h|<2.5)
1.0
Preliminary
Charged Particles (|h|<2.5)
0.0
10
12
PTmax (GeV/c)
14
16
18
20
0
2
4
Charge PTsum Density
6
7 TeV
8
10
12
14
16
18
20
PTmax (GeV/c)
Charged Particles (|h|<2.5)
0.0
 ATLAS published data
at 7 TeV on the
 ATLAS published data at 7 TeV on the
0
2
4
6
8
10
12
14
16
18
20
“transverse” charged particle density,
“transverse” charged PTsum density,
dN/dhdf, as defined by the leading charged PTmax (GeV/c)
dPT/dhdf, as defined by the leading charged
particle (PTmax) for charged particles with
particle (PTmax) for charged particles with
pT > 0.5 GeV/c and pT > 0.1 GeV/c (|h| < 2.5).
pT > 0.5 GeV/c and pT > 0.1 GeV/c (|h| < 2.5).
The data are corrected and compared with
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
PYTHIA Tune Z1 at the generator level.
ATLAS publication – arXiv:1012.0791
December 3, 2010
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 22
ALICE UE Data
"Transverse" Charged PTsum Density: dPT/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.5
RDF Preliminary
RDF Preliminary
7 TeV
ALICE corrected data
Tune Z1 generator level
PTsum Density (GeV/c)
"Transverse" Charged Density
1.2
0.8
900 GeV
0.4
ALICE
Tune Z1
7 TeV
ALICE corrected data
Tune Z1 generator level
1.0
900 GeV
0.5
ALICE
Tune Z1
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
Charged Particles (|h|<0.8, PT>0.5 GeV/c)
0.0
0.0
0
5
10
15
20
25
0
5
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged particle
density, dN/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generator level.
Boost 2011, Princeton, NJ
May 23, 2011
15
20
25
PTmax (GeV/c)
PTmax (GeV/c)
I read the points off
with a ruler!
10
 ALICE preliminary data at 900 GeV and 7
TeV on the “transverse” charged PTsum
density, dPT/dhdf, as defined by the leading
charged particle (PTmax) for charged
particles with pT > 0.5 GeV/c and |h| < 0.8.
The data are corrected and compared with
PYTHIA Tune Z1 at the generrator level.
ALICE UE Data: Talk by S. Vallero
MPI@LHC 2010 Glasgow, Scotland
November 30, 2010
Rick Field – Florida/CDF/CMS
Page 23
PYTHIA Tune Z1
Oops Tune Z1 is
"Transverse"
slightly high
at CDF!Charged Particle Density: dN/dhdf
"Transverse" Charged Particle Density: dN/dhdf
1.2
Charged Particle Density
"Transverse" Charged Density
1.2
CMS Preliminary
7 TeV
data uncorrected
pyZ1 + SIM
0.8
900 GeV
0.4
CMS
Tune Z1
Charged Particles (|h|<2.0, PT>0.5 GeV/c)
0.0
CDF Run 2
1.96 TeV
data corrected
pyZ1 generator level
0.8
Tune Z1
0.4
"Leading Jet"
MidPoint R=0.7 |h(jet#1)|<2
CDF
Charged Particles (|h|<1.0, PT>0.5 GeV/c)
0.0
0
5
10
15
20
25
30
35
40
45
50
0
50
PT(chgjet#1) GeV/c
100
150
200
250
300
350
400
PT(jet#1) (GeV/c)
 CMS preliminary data at 900 GeV and 7 TeV  CDF published data at 1.96 TeV on the
on the “transverse” charged particle density,
“transverse” charged particle density,
dN/dhdf, as defined by the leading charged
dN/dhdf, as defined by the leading
particle jet (chgjet#1) for charged particles
calorimeter jet (jet#1) for charged particles
with pT > 0.5 GeV/c and |h| < 2. The data are
with pT > 0.5 GeV/c and |h| < 1.0. The data
uncorrected and compared with PYTHIA
are corrected and compared with PYTHIA
Tune Z1 after detector simulation.
Tune Z1 at the generator level.
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 24
UE Summary & Conclusions
We now have lots of corrected UE data from
the LHC! Tune Z1 (CTEQ5L) does nice job
of fitting the CMS, ATLAS, and ALICE UE
data at 900 GeV and 7 TeV! But Tune Z1 is
a little high at CDF (1.96 TeV)!
I still dream of a
“universal” tune that
fits the UE at all
energies! Need to
simultaneously tune
LHC plus CDF
(“professor” tune)!
CTEQ6L Tune: PYTHIA 6.4 Tune Z2 and
PYTHIA 8 Tune C4 both use CTEQ6L, but do
not fit the LHC UE data as well as Tune Z1.
Next Step: More PYTHIA 6.4 and
PYTHIA 8 tunes.
to look
more
CMSTime
GEN Group:
Working
on an
improved
tune (Tune Z2*) and an
closely at Sherpa
andZ2HERWIG++!
Outgoing Parton
PT(hard)
Initial-State Radiation
Proton
Proton
Underlying Event
Underlying Event
Sorry not enough time to
show all the LHC tunes!
improved PY8C4 tune (Tune C4*) using the
Professor (A. Knutsson & M. Zakaria).
Outgoing Parton
Final-State
Radiation
ATLAS Tuning Effort (A. Buckley, J. Katzy et al.): AMBT1, AUET1
(Herwig+Jimmy). Coming soon AUET2 (Herwig + Jimmy), AMBT2!
Four stage approach: Flavor, FS fragmentation, ISR, MPI.
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 25
Min-Bias Collisions
Charged Particle Density: dN/dh
Charged Particle Density: dN/dh
6
CMS Data
ALICE Data
PYTHIA Tune Z1
PYTHIA Tune Z1
Charged Particle Density
Charged Particle Density
8
6
NSD = ND + DD
4
Tune Z1
CMS
2
pyZ1 ND = dashed
pyZ1 NSD = solid
7 TeV
NSD (all pT)
4
2
Tune Z1
INEL (all pT)
0
ALICE
INEL = NSD + SD
pyZ1 NSD = dashed
pyZ1 INEL = solid
900 GeV
0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
Pseudo-Rapidity h
-2
-1
0
1
2
3
Pseudo-Rapidity h
 CMS NSD data on the charged particle
rapidity distribution at 7 TeV compared
with PYTHIA Tune Z1. The plot shows the
average number of particles per NSD
collision per unit h, (1/NNSD) dN/dh.
 ALICE NSD data on the charged particle
rapidity distribution at 900 GeV compared
with PYTHIA Tune Z1. The plot shows the
average number of particles per INEL
collision per unit h, (1/NINEL) dN/dh.
“Minimum Bias” Collisions
Okay not perfect, but remember
Proton
we know that SD and DD are not modeled well!
Proton
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 26
4
Baryon & Strange Particle
Production at the LHC
 Strange Particle Production in Proton-Proton Collisions at 900 GeV with
ALICE at the LHC, arXiv:1012.3257 [hep-ex] December 18, 2010.
INEL
 Production of Pions, Kaons and Protons in pp Collisions at 900 GeV with
ALICE at the LHC, arXiv:1101.4110 [hep-ex] January 25, 2011.
 Strange Particle Production in pp Collisions at 900 GeV and 7 TeV, CMS
Paper: arXiv:1102.4282 [hep-ex] Feb 21, 2011, submitted to JHEP.
Step 1: Look at the overall particle yields (all pT).
-
K
K
Kshort
p
u s
u s
d s +d s
uud
+

 
ud s
dss
INEL
NSD
I know there are
more nice results
from the LHC, but
this is all I can show
today. Sorry!
Step 2: Look at the ratios of the overall particle yields (all pT).
Step 3: Look at the pT dependence of the particle yields and ratios.
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 27
Kaon Production
Kshort Rapidity Distribution: dN/dY
Kshort Rapidity Distribution: dN/dY
0.5
0.4
CMS
CMS Data
PYTHIA Tune Z1
0.4
CMS & ALICE Data
INEL = NSD + SD
PYTHIA Tune Z1
7 TeV
0.3
dN/dY
dN/dY
CMS NSD
0.3
0.2
900 GeV
900 GeV
0.2
0.1
0.1
ALICE INEL
Tune Z1
NSD (all pT)
0.0
pyZ1 NSD = solid
Tune Z1
pyZ1 INEL = dashed
0.0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
Rapidity Y
-2
-1
0
1
2
3
4
Rapidity Y
 CMS NSD data on the Kshort rapidity
 CMS NSD data on the Kshort rapidity
distribution at 7 TeV and 900 GeV
distribution at 900 GeV and the ALICE point
compared with PYTHIA Tune Z1. The plot
at Y = 0 (INEL) compared with PYTHIA
shows the average number of Kshort per NSD
Tune Z1. The ALICE point is the average
collision per unit Y, (1/NNSD) dN/dY.
number of Kshort per INEL collision per unit Y
at Y = 0, (1/NINEL) dN/dY.
“Minimum Bias” Collisions
Proton shortage of Kaons in PYTHIA
No overall
Proton Tune Z1!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 28
Kaon Production
Charged Kaons Rapidity: dN/dY
Rapidity Distribution Ratio: Kaons/Pions
Rapidity Distribution Ratio: Kshort/Kaons
0.3
0.8
0.6
ALICE Data
ALICE Data
ALICE
dN/dY
0.4
0.2
PYTHIA Tune Z1
ALICE Data
-
Kshort/(K++K-)
(K +K )
0.6
0.4
0.2
0.2
0.1
pyZ1 NSD = dashed
GeV
TuneINEL
Z1(all pT)
pyZ1 INEL900
= solid
900 GeV
INEL (all pT)
0.0
INEL (all pT)
-3
-2
-1
0
Tune Z1
900 GeV
0.0
0.0
-4
(K++K-)/(++-)
ALICE
PYTHIA Tune Z1
dN/dY Particle Ratio
dN/dY Particle Ratio
PYTHIA Tune Z1
+
-4 1
-3 2
-2 3
-1 4
Rapidity Y
0
-4
1
-3 2
Rapidity Y
 ALICE INEL data on the charged kaon
rapidity distribution at 900 GeV compared
with PYTHIA Tune Z1. The plot shows the
average number of charged kaons per INEL
collision per unit Y at Y = 0, (1/NINEL)
dN/dY.
-2 3
-1 4
0
1
2
3
Rapidity Y
 ALICE INEL data on the charged kaon to
charged pion rapidity ratio at 900 GeV
compared with PYTHIA Tune Z1.
“Minimum Bias” Collisions
Protonshortage of Kaons in PYTHIA
ProtonTune Z1!
No overall
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 29
4
Kaon Production
CMS measures (1/NNSD) dN/dY
Kshort Rapidity Distribution: dN/dY
0.5
CMS Data
PYTHIA Tune Z1
dN/dY
0.4
7 TeV
0.3
0.2
900 GeV
0.1
I have plotted the same data twice!
NSD (all pT)
This is the
correct way!
0.0
-4
-3
-2
-1
0
1
2
3
4
versus |Y| from 0 → 2
Rapidity Y
 Rick’s plot of the CMS NSD data on the Kshort
rapidity distribution at 7 TeV and 900 GeV.
The plot shows the average number of Kshort
per NSD collision per unit Y, (1/NNSD) dN/dY,
versus Y from -2 → 2.
 Real CMS NSD data on the Kshort rapidity
distribution at 7 TeV and 900 GeV. The plot
shows the average number of Kshort per NSD
collision per unit Y, (1/NNSD) dN/dY, versus
|Y| from 0 → 2.
Warning: I am not plotting what CMS actually measures!
I am old and I like to see both sides so I assumed symmetry about Y = 0 and plotted the same data on both
sides (Y → -Y). The way CMS does it is the correct way! But my way helps me see better what is going on.
Please refer to the CMS publication for the official plots!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 30
Lambda Production
(Lam+LamBar) Rapidity Distribution: dN/dY
0.25
Rapidity Distribution Ratio: (Lam+LamBar)/(2Kshort)
0.5
_
CMS Data
(+)
7 TeV
PYTHIA Tune Z1
dN/dY Particle Ratio
dN/dY
0.20
0.15
0.10
900 GeV
0.05
CMS
NSD (all pT)
0.00
-4
-3
-2
-1
1
_
CMS
0.4
(+)/(2Kshort)
7 TeV
0.3
0.2
Factor of 1.5!
0.1
Tune Z1
NSD (all pT)
Tune Z1
0
CMS Data
PYTHIA Tune Z1
0.0
2
3
4
-4
-3
Rapidity Y
-2
-1
0
1
2
3
4
Rapidity Y
 CMS NSD data on the Lambda+AntiLambda  CMS NSD data on the Lambda+AntiLambda to
rapidity distribution at 7 TeV and 900 GeV
2Kshort rapidity ratio at 7 TeV compared with
compared with PYTHIA Tune Z1. The plot
PYTHIA Tune Z1.
shows the average number of particles per
NSD collision per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton Tune Z1!
Oops!Proton
Not enough Lambda’s in PYTHIA
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 31
Cascade Production
Rapidity Distribution Ratio: (Cas+CasBar)/(2Kshort)
(Cas+CasBar) Rapidity Distribution: dN/dY
0.03
CMS Data

dN/dY Particle Ratio
7 TeV
dN/dY
0.02
CMS
900 GeV
0.01
PYTHIA Tune Z1
0.04
7 TeV
0.03
Factor of 2!
0.02
0.01
Tune Z1
NSD (all pT)
( + )/(2Kshort)
CMS
CMS Data

( + )
PYTHIA Tune Z1
_
0.05
_
Tune Z1
NSD (all pT)
0.00
0.00
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-2
-1
0
1
2
3
4
Rapidity Y
Rapidity Y
 CMS NSD data on the Cascade-+AntiCascade-  CMS data on the Cascade-+AntiCascade- to
rapidity distribution at 7 TeV and 900 GeV
2Kshort rapidity ratio at 7 TeV compared with
compared with PYTHIA Tune Z1. The plot
PYTHIA Tune Z1.
shows the average number of particles per NSD
collision per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton Tune Z1!
Yikes! Proton
Way too few Cascade’s in PYTHIA
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 32
PYTHIA Fragmentation
Parameters
Can we increase the overall rate of strange baryons without messing up
anything else?
 PARJ(1) : (D = 0.10) is P(qq)/P(q), the suppression of diquark-antidiquark pair production in
the colour field, compared with quark–antiquark production. Notation: PARJ(1) = qq/q
 PARJ(2) : (D = 0.30) is P(s)/P(u), the suppression of s quark pair production in the field
compared with u or d pair production. Notation: PARJ(2) = s/u.
 PARJ(3) : (D = 0.4) is (P(us)/P(ud))/(P(s)/P(u)), the extra suppression of strange diquark
production compared with the normal suppression of strange quarks.
Notation: PARJ(3) = us/u .
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 33
PYTHIA Fragmentation
Parameters
Rapidity Distribution Ratio: (Lam+LamBar)/(2Kshort)
Rapidity Distribution Ratio: Kaons/Pions
0.5
0.3
dN/dY Particle Ratio
-
+
PYTHIA Tune Z1
us/s: 0.4 -> 1.0
0.1
Z1 default
qq/q: 0.1 -> 0.2
(+)/(2Kshort)
qq/q: 0.1 -> 0.2
0.4
0.3
0.2
us/s: 0.4 -> 1.0
0.1
Z1 default
s/u: 0.3 -> 0.5
7 TeV
NSD (all pT)
900 GeV
INEL (all pT)
_
CMS Data
-
(K +K )/( + )
s/u: 0.3 -> 0.5
PYTHIA Tune Z1
0.2
+
dN/dY Particle Ratio
ALICE Data
0.0
0.0
-4
-3
-2
-1
0
1
2
3
-4
4
-3
-2
-1
0
1
2
3
4
Rapidity Y
Rapidity Y
Rapidity Distribution Ratio: (Cas+CasBar)/(2Kshort)
0.05
_
( + )/(2Kshort)
CMS Data
dN/dY Particle Ratio
 PYTHIA Tune Z1C: Same as Tune Z1
except qq/q is increased 0.1 → 0.12 and
us/s is increased from 0.4 → 0.8.
PYTHIA Tune Z1
0.04
qq/q: 0.1 -> 0.2
us/s: 0.4 -> 1.0
0.03
0.02
s/u: 0.3 -> 0.5
0.01
NSD (all pT)
Z1 default
7 TeV
0.00
-4
-3
-2
-1
0
1
2
3
Rapidity Y
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 34
4
Kaon Production
Kshort Rapidity Distribution: dN/dY Rapidity Distribution Ratio: Kaons/Pions
Kshort Rapidity Distribution: dN/dY
0.5
0.2
Charged Particle Ratio
dN/dY Particle Ratio
0.3
CMS Data
ALICE Data
PYTHIA
7 TeV Tune Z1 & Z1C
PYTHIA Tune Z1
0.4
dN/dY
0.5
0.3
CMS Data
0.2
9000.1
GeV
0.1
CMS
NSD (all pT)
Tune Z1
INEL (all pT)
0.0
-4
-3
-2
-1
900 GeV
0
Rapidity Y
0.0
1
-4
2
-3
Tune Z1C
+
-
+
-
(K +K
)/(
)
PYTHIA Tune Z1C
qq/q:
0.1+
-> 0.12
0.4
7 TeV
us/s: 0.4 -> 0.8
0.3
Z1C
0.2
900 GeV
Z1
0.1Tune Z1C
CMS
qq/q: 0.1 -> 0.12
NSD (all pT)
us/s: 0.4 -> 0.8
Tune Z1C
0.0
3
-2
4
-1
-4
0
-3
1
Rapidity Y
-2
2
-1
3
0
4
1
2
3
Rapidity Y
 CMS dNSD ata on the Kshort rapidity
 CMS NSD data on the Kshort rapidity
distribution at 7 TeV and 900 GeV compared
distribution at 7 TeV and 900 GeV compared
with PYTHIA Tune Z1C. The plot shows the
with PYTHIA Tune Z1. The plot shows the
average number of Kshort per NSD collision
average number of Kshort per NSD collision per
per unit Y, (1/NNSD) dN/dY.
unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton
Proton
For Kaon production
Tune Z1 and Z1C are
almost identical!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 35
4
Lambda Production
(Lam+LamBar) Rapidity Distribution: dN/dY
(Lam+LamBar) Rapidity Distribution:
dN/dYDistribution Ratio: (Lam+LamBar)/(2Kshort)
Rapidity
0.25
0.5
CMS Data
PYTHIA Tune Z1
0.10
0.05
0.00
-3
-2
-1
0.3
0.2
900 GeV
0.1
1-4
2-3
0.20
0.15
7 TeV
CMS
7 TeV
(+)
Z1C
0.10
Tune Z1C
qq/q: 0.1 -> 0.12
Z1
us/s: 0.4 -> 0.8
900 GeV
Tune Z1C
0.00
0.0
0
(+)/(2Kshort)
Tune0.05
Z1C
qq/q: 0.1 -> 0.12NSD (all pT)
us/s: 0.4 -> 0.8
TuneNSD
Z1(all pT)
CMS
NSD (all pT)
Charged Particle Ratio
dN/dY Particle Ratio
dN/dY
0.15
0.4
_
_
CMS Data
PYTHIA Tune Z1C
PYTHIA Tune Z1 & Z1C
0.20
-4
0.25
_
CMS Data
7 TeV
(+)
3-2
Rapidity Y
4-1
0 -4
1 -3
Rapidity Y
 CMS NSD data on the Lambda+AntiLambda
rapidity distribution at 7 TeV and 900 GeV
compared with PYTHIA Tune Z1. The plot
shows the average number of particles per
NSD collision per unit Y, (1/NNSD) dN/dY.
2 -2
3 -1
4 0
1
2
3
Rapidity Y
 CMS NSD data on the Lambda+AntiLambda
rapidity distribution at 7 TeV and 900 GeV
compared with PYTHIA Tune Z1. The plot
shows the average number of particles per
NSD collision per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton more Lambda’s in PYTHIA
Proton
Not bad! Many
Tune Z1C!
Boost 2011, Princeton, NJ
May 23, 2011
4
Rick Field – Florida/CDF/CMS
Page 36
Cascade Production
(Cas+CasBar) Rapidity Distribution: dN/dY
(Cas+CasBar) Rapidity Distribution:
dN/dY
Rapidity
Ratio: (Cas+CasBar)/(Lam+LamBar)
Rapidity
Distribution
Ratio: (Cas+CasBar)/(2Kshort)
0.05
0.20
CMS Data
dN/dY
dN/dY Particle
Particle Ratio
Ratio
PYTHIA Tune Z1
dN/dY
0.02
CMS
0.01
0.00
-3
CMS Data
PYTHIA
Tune
& Z1C
Tune
Z1Z1
& Z1C
0.04 PYTHIA
7 TeV
0.15
0.03
0.10
0.02
900 GeV
0.05
0.01
-2
-1
0
0.00
1 -4
__
_
_
( + )
 +
 )/(2K
(
short)
PYTHIA Tune Z1C( + )/(+)
CMS
Data
CMS
Data
( + )
0.02
CMS
7 TeV
7 TeV
7 TeV
Z1C
Z1C
0.01
Z1
Tune
Z1C
Tune
Z1C
qq/q:
0.12
qq/q:
0.10.1
-> ->
0.12
NSD (all pT)
us/s:
0.4
->
us/s: 0.4 -> 0.80.8
NSD (all
(all pT)
pT)
Tune Z1 NSD
NSD (all pT)
-4
0.03
_
Charged Particle Ratio
0.03
Tune Z1C
qq/q: 0.1 -> 0.12
Z1
us/s: 0.4 -> 0.8
900 GeV
Tune Z1C
0.00
2 -3
3 -2
4 -1
Rapidity Y
0 -4
1 -3
Rapidity Y
 CMS NSD data on the Cascade-+AntiCascaderapidity distribution at 7 TeV and 900 GeV
compared with PYTHIA Tune Z1. The plot
shows the average number of particles per
NSD collision per unit Y, (1/NNSD) dN/dY.
2 -2
3 -1
4 0
1
2
3
Rapidity Y
 CMS NSD data on the Cascade-+AntiCascaderapidity distribution at 7 TeV and 900 GeV
compared with PYTHIA Tune Z1. The plot
shows the average number of particles per NSD
collision per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Wow!Proton
PYTHIA Tune Z1C looks veryProton
nice here!
Boost 2011, Princeton, NJ
May 23, 2011
4
Rick Field – Florida/CDF/CMS
Page 37
Transverse Momentum
Distributions
PT Distribution: Kshort
PT Distribution: Lam+LamBar
1.0E+01
1.0E+00
CMS Data
CMS Data
1.0E-01
1.0E-02
Z1C
1.0E-03
1.0E-04
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
NSD (|Y| < 2))
_
(+)
1.0E-02
Z1C
Z1
1.0E-03
1.0E-04
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
NSD (|Y| < 2))
Z1
1.0E-05
7 TeV
PYTHIA Tune Z1 & Z1C
1.0E-01
dN/dPT (GeV/c)
dN/dPT (1/GeV/c)
7 TeV
PYTHIA Tune Z1 & Z1C
1.0E+00
1.0E-05
0
1
2
3
4
5
6
7
8
9
10
0
1
PT (GeV/c)
2
3
4
5
6
7
8
9
PT (GeV/c)
 CMS NSD data on the Kshort transverse
momentum distribution at 7 TeV compared
with PYTHIA Tune Z1 & Z1C. The plot
shows the average number of particles per
NSD collision per unit pT, (1/NNSD) dN/dpT
for |Y| < 2.
 CMS NSD data on the Lambda+AntiLambda
transverse momentum distribution at 7 TeV
compared with PYTHIA Tune Z1 & Z1C.
The plot shows the average number of
particles per NSD collision per unit pT,
(1/NNSD) dN/dpT for |Y| < 2.
“Minimum Bias” Collisions
Proton
PYTHIA Tune
Z1 & Z1C are a bit off on theProton
pT dependence!
Boost 2011, Princeton, NJ
May 23, 2011
10
Rick Field – Florida/CDF/CMS
Page 38
Transverse Momentum
Distributions
Cas+CasBar PT Distribution: dN/dPT
PT Distribution: Cas+CasBar
1.0E+00
1.0E-01
CMS Data
PYTHIA Tune Z1 & Z1C


( + )
Z1C
Z1
1.0E-03
NSD (|Y| < 2))
_


( + )
1.0E-02
7 TeV
PYTHIA Tune Z1 & Z1C
_
Probability
dN/dPT (1/GeV/c)
CMS Data
7 TeV
Z1C
1.0E-01
Z1
1.0E-02
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
NSD (|Y| < 2))
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
Normalized to 1
1.0E-03
1.0E-04
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
PT (GeV/c)
PT (GeV/c)
 CMS NSD data on the Cascade-+AntiCascade-  CMS NSD data on the Cascade-+AntiCascadetransverse momentum distribution at 7 TeV
transverse momentum distribution at 7 TeV
compared with PYTHIA Tune Z1 & Z1C. The
(normalized to 1) compared with PYTHIA
plot shows the average number of particles per
Tune Z1 & Z1C.
NSD collision per unit pT, (1/NNSD) dN/dpT for
|Y| < 2.
“Minimum Bias” Collisions
Proton
PYTHIA Tune
Z1 & Z1C are a bit off on theProton
pT dependence!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 39
Particle Ratios versus PT
PT Particle Ratio: (Lam+LamBar)/(2Kshort)
0.8
Particle Ratio: (Lam+LamBar)/(2Kshort)
0.8
_
CMS Data
_
ALICE Data
(+)/(2Kshort)
PYTHIA Tune Z1 & Z1C
(+)/(2Kshort)
0.6
Z1C
Z1C
Ratio
PT Particle Ratio
PYTHIA Tune Z1 & Z1C
0.6
0.4
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.2
Z1
NSD (|Y| < 2)
0.4
0.2
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
900 GeV
7 TeV
INEL (|Y| < 0.75)
0.0
Z1
0.0
0
1
2
3
4
5
6
7
8
9
10
0
PT (GeV/c)
1
2
3
4
5
6
PT (GeV/c)
 CMS NSD data on the Lambda+AntiLambda  ALICE INEL data on the Lambda+AntiLambda
to 2Kshort ratio versus pT at 7 TeV (|Y| < 2)
to 2Kshort ratio versus pT at 900 GeV (|Y| < 0.75)
compared with PYTHIA Tune Z1 & Z1C.
compared with PYTHIA Tune Z1 & Z1C.
“Minimum Bias” Collisions
Tune Z1C Proton
is not too bad but a bit off on the
pT dependence!
Proton
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 40
Particle Ratios versus PT
PT Particle Ratio: (Cas+CasBar)/(Lam+LamBar)
PT Particle Ratio: (Cas+CasBar)/(2Kshort)
0.15
CMS Data

0.30
Z1C
0.05
NSD (|Y| < 2)
0.00
0
1
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
7 TeV
2
3
4
_
( + )/(+)
PYTHIA Tune Z1 & Z1C
0.25
PT Particle Ratio
0.10
_
CMS Data

( + )/(2Kshort)
PYTHIA Tune Z1 & Z1C
PT Particle Ratio
_
Z1C
0.20
0.15
0.10
Z1
NSD (|Y| < 2)
Z1
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.05
7 TeV
0.00
5
6
7
8
0
1
2
3
4
5
6
7
8
PT (GeV/c)
PT (GeV/c)
 CMS NSD data on the Cascade-+AntiCascade-  CMS NSD data on the Cascade-+AntiCascadeto Lambda+AntiLambda ratio versus pT at 7
to 2Kshort ratio versus pT at 7 TeV (|Y| < 2)
TeV (|Y| < 2) compared with PYTHIA Tune Z1
compared with PYTHIA Tune Z1 & Z1C.
& Z1C.
“Minimum Bias” Collisions
Proton
Tune Z1C
is not too bad but a bit off on Proton
the pT dependence!
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 41
Particle Ratios versus PT
PT Particle Ratio: Kaons/Pions
Rapidity Distribution Ratio: Kaons/Pions
0.60
0.3
ALICE Data
+
+
-
ALICE Data
(K +K )/( + )
PYTHIA Tune Z1 & Z1C
(K++K-)/(++-)
PYTHIA Tune Z1 & Z1C
0.40
dN/dY Particle Ratio
PT Particle Ratio
-
Z1C
Z1
0.20
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
900 GeV
INEL (|Y| < 0.75)
0.2
Z1C
0.1
900 GeV
INEL (all pT)
0.00
Z1
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.0
0
1
2
PT (GeV/c)
3
4
-4
-3
Tails of the pT distribution.
Way off due to the wrong pT!
 ALICE INEL data on the charged kaons to
charged pions ratio versus pT at 900 GeV (|Y| <
0.75) compared with PYTHIA Tune Z1 & Z1C.
-2
-1
0
1
2
3
Rapidity Y
 ALICE INEL data on the charged kaon to
charged pion rapidity ratio at 900 GeV
compared with PYTHIA Tune Z1.
“Minimum Bias” Collisions
Tune Z1C isProton
not too bad but a way off on the
pT dependence!
Proton
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 42
4
Particle Ratios versus PT
PT Particle Ratio: (P+Pbar)/Pions
Rapidity Distribution Ratio: (P+Pbar)/Pions
0.4
_
(p+p)/(++-)
ALICE Data
PYTHIA Tune Z1 & Z1C
_
(p+p)/(++-)
ALICE Data
PYTHIA Tune Z1 & Z1C
dN/dY Particle Ratio
PT Particle Ratio
0.12
0.3
Z1C
0.2
Z1
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.1
900 GeV
INEL (|Y| < 0.75)
Z1C
0.09
0.06
Z1
0.03
900 GeV
INEL (all pT)
0.0
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.00
0
1
2
PT (GeV/c)
3
4
-4
-3
Tails of the pT distribution.
Way off due to the wrong pT!
-2
-1
0
1
2
3
4
Rapidity Y
 ALICE INEL data on the Proton+AntiProton to  ALICE INEL data on the Proton+AntiProton
charged pions ratio versus pT at 900 GeV (|Y| <
to charged pion rapidity ratio at 900 GeV
0.75) compared with PYTHIA Tune Z1 & Z1C.
compared with PYTHIA Tune Z1 & Z1C.
“Minimum Bias” Collisions
Tune Z1CProton
is not too bad but way off on the
pT dependence!
Proton
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 43
Fragmentation Summary
Not too hard to get the overall yields of
baryons and strange particles roughly right
at 900 GeV and 7 TeV. Tune Z1C does a
fairly good job with the overall particle
yields at 900 GeV and 7 TeV.
K+
Kshort

u s
d s +d s
ud s
K-
p
 
u s
uud
dss
Warning! The Tune Z1C fragmentation
PT Distributions: PYTHIA
does notmay
describe
parameters
cause correctly
problems the pT distributions
fitting
data.None
If so of the fragmentation
of heavy particles (MC softer
thanthe
theLEP
data).
must understand
why!
parameters I have looked atwe
changes
the pT distributions.
Hence, if one
We dop not
want
one
tune
for
looks at particle ratios at large
you
can
see
big
discrepancies between
T
+e- and another one for
e
data and MC (out in the tails of the distributions)! “Minimum Bias” Collisions
hadron-hadron collisions!
ATLAS Tuning Effort: Fragmentation Proton
flavor tuning at the one of the four stages.
Proton
Other Fragmentation Tuning: There is additional tuning involving jet
shapes, FSR, and ISR that I did not have time to include in this talk.
Boost 2011, Princeton, NJ
May 23, 2011
Rick Field – Florida/CDF/CMS
Page 44