51st Cracow School of Theoretical Physics
The Soft Side of the LHC
Min-Bias and the Underlying Event at the LHC
Rick Field
University of Florida
Lecture 2: Outline
How are “min-bias” collisions related to the
“underlying event”.
Zakopane, Poland, June 11-19, 2011
How well did we do at predicting the behavior of “minbias” collisions at the LHC (900 GeV and 7 TeV)?
Baryon and Strange Particle Production at the LHC:
Fragmentation tuning.
K
Kshort
u s
d s +d s
+
p
uud
Λ
CMS
Ξ−
dss
ud s
ATLAS
K-
u s
UE&MB@CMS
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 1
Toward an Understanding of
Hadron-Hadron Collisions
From Feynman-Field to the LHC
Rick Field
University of Florida
Lecture 3: Tomorrow Evening
Before Feynman-Field Phenomenology:
Feynman
The Berkeley years.
The early days of Feynman-Field
Phenomenology.
From 7 GeV/c π0’s to 1 TeV Jets!
Field
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 2
Proton-Proton Collisions
Elastic Scattering
Single Diffraction
Double Diffraction
M2
M
M1
σtot = σEL + σSD + σDD + σHC
ND
“Inelastic Non-Diffractive Component”
Hard Core
The “hard core” component
contains both “hard” and
“soft” collisions.
“Hard” Hard Core (hard scattering)
Outgoing Parton
“Soft” Hard Core (no hard scattering)
Proton
PT(hard)
Proton
Proton
Proton
Underlying Event
Underlying Event
Initial-State
Radiation
Final-State
Radiation
Outgoing Parton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 3
The Inelastic Non-Diffractive
Cross-Section
Occasionally one of
the parton-parton
collisions is hard
(pT > ≈2 GeV/c)
Proton
Proton
Majority of “minbias” events!
Proton
“Semi-hard” partonparton collision
(pT < ≈2 GeV/c)
Proton
+
Proton
+
Proton
Proton
Proton
+
Proton
Proton
+…
Multiple-parton
interactions (MPI)!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 4
The “Underlying Event”
Select inelastic non-diffractive events
that contain a hard scattering
Proton
Hard parton-parton
collisions is hard
(pT > ≈2 GeV/c)
Proton
1/(pT)4→ 1/(pT2+pT02)2
The “underlying-event” (UE)!
Proton
Given that you have one hard
scattering it is more probable to
have MPI! Hence, the UE has
more activity than “min-bias”.
Cracow School of Physics
Zakopane, June 13, 2011
Proton
+
+
Proton
Proton
Rick Field – Florida/CDF/CMS
“Semi-hard” partonparton collision
(pT < ≈2 GeV/c)
Proton
Proton
+…
Multiple-parton
interactions (MPI)!
Page 5
Allow leading hard
scattering to go to
zero pT with same
cut-off as the MPI!
Model of σND
Proton
Proton
Proton
Proton
Proton
+
Proton
“Semi-hard” partonparton collision
(pT < ≈2 GeV/c)
1/(pT)4→ 1/(pT2+pT02)2
Model of the inelastic nondiffractive cross section!
+
Proton
Proton
Proton
+
Proton
Proton
+…
Multiple-parton
interactions (MPI)!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 6
UE Tunes
Allow primary hard-scattering to
go to pT = 0 with same cut-off!
“Underlying Event”
Fit the “underlying
event” in a hard
scattering process.
Proton
Proton
1/(pT)4→ 1/(pT2+pT02)2
“Min-Bias”
“Min-Bias” (add
(ND)single & double diffraction)
Proton
Predict MB (ND)!
Proton
+
+
Proton
Proton
Proton
Single Diffraction
Predict MB (IN)!
Cracow School of Physics
Zakopane, June 13, 2011
+…
Proton
+
Proton
Proton
Double Diffraction
M2
M
Rick Field – Florida/CDF/CMS
M1
Page 7
UE Tunes
Allow primary hard-scattering to
go to pT = 0 with same cut-off!
“Underlying Event”
Fit the “underlying
event” in a hard
scattering process.
Proton
Proton
All of Rick’s tunes (except X2):
1/(pT)4→ 1/(pT2+pT02)2
A, AW, AWT,DW, DWT,
D6, D6T, CW, X1,
“Min-Bias”
“Min-Bias” (add
(ND)single & double diffraction)
and Tune Z1,
are UE tunes!
Proton
Predict MB (ND)!
Proton
+
+
Proton
Proton
Proton
Single Diffraction
Predict MB (IN)!
Cracow School of Physics
Zakopane, June 13, 2011
+…
Proton
+
Proton
Proton
Double Diffraction
M2
M
Rick Field – Florida/CDF/CMS
M1
Page 8
Charged Particle Multiplicity
Charged Multiplicity Distribution
Charged Multiplicity Distribution
1.0E+00
1.0E+00
CDF Run 2 Preliminary
1.0E-01
CDF Run 2 <Nchg>=4.5
CDF Run 2 <Nchg>=4.5
1.0E-02
Probability
Probability
1.0E-02
CDF Run 2 Preliminary
1.0E-01
1.0E-03
1.0E-04
1.0E-05
py Tune A <Nchg> = 4.3
pyAnoMPI <Nchg> = 2.6
1.0E-03
1.0E-04
1.0E-05
1.0E-06
1.0E-06
Min-Bias 1.96
1.0E-07
Min-Bias 1.96
1.0E-07
Charged Particles (|η
η|<1.0, PT>0.4 GeV/c)
Normalized to 1
Normalized to 1
Charged Particles (|η
η|<1.0, PT>0.4 GeV/c)
1.0E-08
1.0E-08
0
5
10
15
20
25
30
35
40
45
50
55
0
5
10
Number of Charged Particles
i
20
25
30
35
40
45
50
Number of Charged Particles
“Minimum Bias” Collisions
Proton
15
No MPI!
Tune A!
AntiProton
Data at 1.96 TeV on the charged particle multiplicity (pT > 0.4 GeV/c, |η
η| < 1) for “min-bias”
collisions at CDF Run 2 (non-diffractive cross-section).
The data are compared with PYTHIA Tune A and Tune A without multiple parton
interactions (pyAnoMPI).
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 9
55
PYTHIA Tune A Min-Bias
“Soft” + ”Hard”
Charged Particle Density
1.0E+00
Pythia 6.206 Set A
CDF Min-Bias Data
Charged Density dN/dη dφ dPT (1/GeV/c)
1.0E-01
Ten decades!
1.8 TeV |η
η|<1
1.0E-02
12% of “Min-Bias” events
have PT(hard) > 5 GeV/c!
PT(hard) > 0 GeV/c
1.0E-03
1% of “Min-Bias” events
have PT(hard) > 10 GeV/c!
1.0E-04
1.0E-05
CDF Preliminary
1.0E-06
0
2
4
6
8
PT(charged) (GeV/c)
10
12
14
Lots of “hard” scattering in
“Min-Bias” at the Tevatron!
Comparison of PYTHIA Tune A with the pT distribution of charged particles for “min-bias”
collisions at CDF Run 1 (non-diffractive cross-section).
pT = 50 GeV/c!
PYTHIA Tune A predicts that 12% of all “Min-Bias” events are a result of a hard 2-to-2
parton-parton scattering with PT(hard) > 5 GeV/c (1% with PT(hard) > 10 GeV/c)!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 10
MB Tunes
“Underlying Event”
Predict the “underlying
event” in a hard
scattering process!
Proton
Proton
“Min-Bias” (ND)
Proton
Fit MB (ND).
Proton
+
Proton
+
Proton
Proton
Proton
+
Proton
Proton
+…
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 11
MB Tunes
“Underlying Event”
Predict the “underlying
event” in a hard
scattering process!
Proton
Proton
Most of Peter Skand’s tunes:
S320 Perugia
0, S325 Perugia X,
“Min-Bias”
(ND)
S326 Perugia 6
are MB tunes!
Proton
Fit MB (ND).
Proton
+
Proton
+
Proton
Proton
Proton
+
Proton
Proton
+…
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 12
MB+UE Tunes
“Underlying Event”
Fit the “underlying
event” in a hard
scattering process!
Proton
Proton
Most of Hendrik’s “Professor”
tunes: ProQ20, P329
are MB+UE!
Simultaneous fit
to both MB & UE
“Min-Bias” (ND)
Proton
Fit MB (ND).
Proton
+
Proton
+…
Cracow School of Physics
Zakopane, June 13, 2011
+
Proton
Proton
Proton
+
Proton
Proton
The ATLAS AMBT1 Tune is an MB+UE tune, but
because they include in the fit the ATLAS UE data
with PTmax > 10 GeV/c (big errors) the LHC UE data
does not have much pull (hence mostly an MB tune!).
Rick Field – Florida/CDF/CMS
Page 13
LHC MB Predictions: 900 GeV
Charged Particle Density: dN/dη
η
Charged Particle Density: dN/dη
η
5
5
RDF Preliminary
Charged Particle Density
Charged Particle Density
RDF Preliminary
4
3
2
ALICE INEL
UA5 INEL
INEL = HC+DD+SD
900 GeV
1
pyDW INEL (2.67)
-2.5
-2.0
-1.5
-1.0
3
2
1
pyS320 INEL (2.70)
Charged Particles (all pT)
0
-3.0
4
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0
-3.0
UA5
-2.5
-2.0
-1.5
pyDW_10mm (3.04)
pyS320_10mm (3.09)
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
PseudoRapidity η
PseudoRapidity η
“Minimum Bias” Collisions
“Minimum Bias” Collisions
Proton
ALICE
NSD = HC+DD
900 GeV
Proton
Proton
Proton
Compares the 900 GeV ALICE data with PYTHIA Tune DW and Tune S320
Perugia 0. Tune DW uses the old Q2-ordered parton shower and the old MPI
model. Tune S320 uses the new pT-ordered parton shower and the new MPI
model. The numbers in parentheses are the average value of dN/dη
η for the region
|η
η| < 0.6.
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 14
3.0
LHC MB Predictions: 900 GeV
Charged Particle Density: dN/dη
η
Charged Particle Density: dN/dη
η
5
5
RDF Preliminary
Charged Particle Density
Charged Particle Density
RDF Preliminary
4
3
2
ALICE INEL
Off by 11%!
UA5 INEL
INEL = HC+DD+SD
900 GeV
1
-2.0
-1.5
-1.0
2
UA5
ALICE
1
pyDW_10mm (3.04)
pyS320_10mm (3.09)
pyS320 INEL (2.70)
5
-0.5
0.0
4
Charged Particle Density
-2.5
3
NSD = HC+DD
η GeV
Charged Particle Density: dN/dη
900
pyDW INEL (2.67)
Charged Particles (all pT)
0
-3.0
4
RDF Preliminary
0.5
1.0
1.5
2.0
2.5
3.0
0
-3.0
-2.5
-2.0 times
-1.5 1.11
-1.0
3
0.5
1.0
1.5
2.0
2.5
“Minimum Bias” Collisions
“Minimum Bias” Collisions
2
Proton
1
0.0
PseudoRapidity η
PseudoRapidity η
Proton
-0.5
INEL = HC+DD+SD
900 GeV
Charged Particles (all pT)
Proton
ALICE INEL
UA5 INEL
pyDW times 1.11 (2.97)
pyS320 times 1.11 (3.00)
Proton
0
-3.0 ALICE
-2.5 -2.0 -1.5
-1.0 with
-0.5 0.0PYTHIA
0.5
1.0
1.5Tune
2.0
2.5
3.0 and Tune S320
Compares the 900 GeV
data
DW
-ordered ηparton shower and the old MPI
Perugia 0. Tune DW uses the old Q2PseudoRapidity
model. Tune S320 uses the new pT-ordered parton shower and the new MPI
model. The numbers in parentheses are the average value of dN/dη
η for the region
|η
η| < 0.6.
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 15
3.0
ATLAS INEL dN/dη
None of the tunes fit the
ATLAS INEL dN/dη
η
data with PT > 100
MeV! They all predict
too few particles.
Off by 20-50%!
The ATLAS Tune
AMBT1 was designed to
fit the inelastic data for
Nchg ≥ 6 with pT > 0.5
GeV/c!
Cracow School of Physics
Zakopane, June 13, 2011
Soft particles!
Rick Field – Florida/CDF/CMS
Page 16
CMS dN/dη
Charged Particle Density: dN/dη
η
8
CMS
Charged Particle Density
7 TeV
6
4
RDF Preliminary
2
Tune DW
CMS NSD data
pyDW generator level
All pT
dashed = ND solid = NSD
0
-3.0
-2.5
-2.0
-1.5
-1.0
Soft particles!
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
PseudoRapidity η
Generator level dN/dη
η (all pT). Shows the NSD = HC + DD and the HC = ND
contributions for Tune DW. Also shows the CMS NSD data.
“Minimum Bias” Collisions
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Off by 50%!
Rick Field – Florida/CDF/CMS
Proton
Page 17
PYTHIA Tune DW
If one increases the pT
the agreement
improves!
Charged Particle Density: dN/dη
η
5
Charged Particle Density
RDF Preliminary
4
η| < 0.8
At Least 1 Charged Particle |η
900 GeV
ALICE INEL data
pyDW generator level
pT > 0.15 GeV/c
Tune DW
3
pT > 0.5 GeV/c
2
pT > 1.0 GeV/c
1
0
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
PseudoRapidity η
ALICE inelastic data at 900 GeV on the dN/dη
η distribution for charged particles (pT >
PTmin) for events with at least one charged particle with pT > PTmin and |η
η| < 0.8 for
PTmin = 0.15 GeV/c, 0.5 GeV/c, and 1.0 GeV/c compared with PYTHIA Tune DW at the
generator level.
“Minimum Bias” Collisions
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Proton
Rick Field – Florida/CDF/CMS
Page 18
PYTHIA Tune DW
Diffraction
contributes less at
harder scales!
Charged Particle Density: dN/dη
η
5
Charged Particle Density
RDF Preliminary
4
η| < 0.8
At Least 1 Charged Particle |η
900 GeV
ALICE INEL data
pyDW generator level
pT > 0.15 GeV/c
3
Tune DW
pT > 0.5 GeV/c
2
pT > 1.0 GeV/c
1
dashed = ND solid = INEL
0
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
PseudoRapidity η
ALICE inelastic data at 900 GeV on the dN/dη
η distribution for charged particles (pT >
PTmin) for events with at least one charged particle with pT > PTmin and |η
η| < 0.8 for
PTmin = 0.15 GeV/c, 0.5 GeV/c, and 1.0 GeV/c compared with PYTHIA Tune Z1 at the
generator level (dashed = ND, solid = INEL).
“Minimum Bias” Collisions
Proton
Cannot
trust PYTHIA 6.2 modeling of diffraction!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 19
Min-Bias Collisions
Charged Particle Density: dN/dη
η
Charged Particle Density: dN/dη
η
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 η
-2
-1
0
1
2
3
Pseudo-Rapidity η
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 η, (1/NNSD) dN/dη
η.
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 η, (1/NINEL) dN/dη
η.
“Minimum Bias” Collisions
Okay not perfect, but remember
Proton
we know that SD and DD are not modeled well!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 20
4
PYTHIA Tune Z1
Charged Particle Density: dN/dη
η
5
Charged Particle Density
RDF Preliminary
4
ALICE INEL data
pyZ1 generator level
η| < 0.8
At Least 1 Charged Particle |η
900 GeV
pT > 0.15 GeV/c
3
pT > 0.5 GeV/c
2
pT > 1.0 GeV/c
1
0
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
PseudoRapidity η
ALICE inelastic data at 900 GeV on the dN/dη
η distribution for charged particles (pT >
PTmin) for events with at least one charged particle with pT > PTmin and |η
η| < 0.8 for
PTmin = 0.15 GeV/c, 0.5 GeV/c, and 1.0 GeV/c compared with PYTHIA Tune Z1 at the
generator level.
“Minumum Bias” Collisions
Okay
not perfect, but remember
Proton
Proton
we do not know if the SD & DD are correct!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 21
NSD Multiplicity Distribution
Charged Multiplicity Distribution
1.0E-01
RDF Preliminary
data CMS NSD
pyZ1 generator level
Difficult to produce
enough events with
large multiplicity!
CMS
Probability
1.0E-02
7 TeV
900 GeV
1.0E-03
Charged Particles
(all PT, |η
η|<2.0)
Tune Z1
1.0E-04
0
20
40
60
80
100
Number of Charged Particles
Generator level charged multiplicity distribution (all pT, |η
η| < 2) at 900 GeV and 7
TeV. Shows the NSD = HC + DD prediction for Tune Z1. Also shows the CMS
NSD data.
“Minumum Bias” Collisions
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Okay not perfect!
But not that bad!
Rick Field – Florida/CDF/CMS
Proton
Page 22
MB versus UE
Divide be 2π
π
Charged Particle Density: dN/dη
η
2.5
8
CMS Data
CMS Data
PYTHIA Tune Z1
PYTHIA Tune Z1
Charged Particle Density
Charged Particle Density
Charged Particle Density: dN/dη
ηdφ
φ
6
NSD = ND + DD
4
Tune Z1
CMS
2
pyZ1 ND = dashed
pyZ1 NSD = solid
7 TeV
NSD (all pT)
2.0
1.5
1.0
0.5
pyZ1 ND = dashed
7 TeV
NSD (all pT)
pyZ1 NSD = solid
0.0
0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-2
-1
0
1
2
3
4
Pseudo-Rapidity η
Pseudo-Rapidity η
CMS NSD data on the charged particle
CMS NSD data on the charged particle rapidity
rapidity distribution at 7 TeV compared
distribution at 7 TeV compared with PYTHIA
with PYTHIA Tune Z1. The plot shows the
Tune Z1. The plot shows the average number of
average number of charged particles per
charged particles per NSD collision per unit η−φ,
NSD collision per unit η, (1/NNSD) dN/dη
η.
(1/NNSD) dN/dη
ηdφ
φ.
“Minimum Bias” Collisions
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Proton
Rick Field – Florida/CDF/CMS
Page 23
MB versus UE
Charged Particle Density: dN/dη
ηdφ
φ
ηdφ
φ
Transverse Charged Particle Density: dN/dη
2.5
RDF Preliminary
CMS Data
PYTHIA Tune Z1
PYTHIA Tune Z1
Charged Particle Density
Charged Particle Density
2.5
2.0
Factor of 2!
1.5
1.0
Charged Particles (|η
η| < 2, all pT)
0.5
Tune Z1
CMS
2.0
Tune Z1
1.0
0.5
7 TeV ND
pyZ1 ND = dashed
7 TeV
NSD (all pT)
0.0
NSD = ND + DD
1.5
pyZ1 NSD = solid
0.0
0
5
10
15
20
25
-4
-3
-2
-1
0
1
2
3
Pseudo-Rapidity η
PT max (GeV/c)
Shows the density of charged particles in
the “transverse” region as a function of
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
Outgoing Parton
CMS NSD data on the charged particle rapidity
distribution at 7 TeV compared with PYTHIA
Tune Z1. The plot shows the average number of
charged particles per NSD collision per unit η−φ,
(1/NNSD) dN/dη
ηdφ
φ.
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 24
MB versus UE
Charged Particle Density: dN/dη
ηdφ
φ
ηdφ
φ
"Transverse" Charged Particle Density: dN/dη
2.5
CMS Data
ATLAS
2.0
Charged Particle Density
"Transverse" Charged Density
2.5
Factor of 2!
1.5
RDF Preliminary
1.0
ATLAS corrected data
Tune Z1 generator level
0.5
Charged Particles (pT > 0.1 GeV/c, |η
η|<2.5)
7 TeV
CMS
PYTHIA Tune Z1
2.0
Tune Z1
1.0
0.5
pyZ1 ND = dashed
7 TeV
NSD (all pT)
0.0
NSD = ND + DD
1.5
pyZ1 NSD = solid
0.0
0
2
4
6
8
10
12
14
16
18
20
-4
-3
PTmax (GeV/c)
-2
-1
0
1
2
3
Pseudo-Rapidity η
ATLAS data on the density of charged
particles in the “transverse” region as a
function of PTmax for charged particles (pT
> 0.1 GeV/c, |η
η| < 2.5) at 7 TeV compared
with PYTHIA Tune Z1.
Outgoing Parton
CMS NSD data on the charged particle rapidity
distribution at 7 TeV compared with PYTHIA
Tune Z1. The plot shows the average number of
charged particles per NSD collision per unit η−φ,
(1/NNSD) dN/dη
ηdφ
φ.
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 25
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.
INEL
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
+
Λ
Ξ−
ud s
dss
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).
(K++ K-)
(π
π++ π-)
(p + p)
(π
π++ π-)
=
Strange Meson
Non-strange Meson
=
Non-strange Baryon
Non-strange Meson
Kshort
(π
π++ π-)
=
Strange Meson
Non-strange Meson
Single-strange Baryon
(Λ
Λ + Λ)
=
2Kshort
Strange Meson
(Ξ
Ξ + Ξ)
2Kshort
Double-strange Baryon
=
Strange Meson
Step 3: Look at the pT dependence of the particle yields and ratios.
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 26
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
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!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 27
4
Kaon Production
Charged Kaons Rapidity: dN/dY
Rapidity Distribution Ratio: Kaons/Pions
0.3
0.6
ALICE Data
+
ALICE Data
(K +K )
dN/dY
0.4
0.2
Tune Z1
900 GeV
INEL (all pT)
+
π++π
π-)
(K +K )/(π
ALICE
PYTHIA Tune Z1
dN/dY Particle Ratio
ALICE
PYTHIA Tune Z1
-
0.2
0.1
pyZ1 NSD = dashed
pyZ1 INEL = solid
Tune Z1
900 GeV
INEL (all pT)
0.0
0.0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-2
-1
0
1
2
3
Rapidity Y
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.
ALICE INEL data on the charged kaon to
charged pion rapidity ratio at 900 GeV
compared with PYTHIA Tune Z1.
(K++ K-)
(π
π++ π-)
=
Strange Meson
Non-strange Meson
“Minimum Bias” Collisions
Protonshortage of Kaons in PYTHIA
ProtonTune Z1!
No overall
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 28
4
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
+
π++π
π-)
(K +K )/(π
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
-2 3
0
1
2
3
Rapidity Y
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.
-1 4
ALICE INEL data on the charged kaon to
charged pion rapidity ratio at 900 GeV
compared with PYTHIA Tune Z1.
(K++ K-)
(π
π++ π-)
=
Strange Meson
Non-strange Meson
“Minimum Bias” Collisions
Protonshortage of Kaons in PYTHIA
ProtonTune Z1!
No overall
Cracow School of Physics
Zakopane, June 13, 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
Rapidity Y
versus |Y| from 0 → 2
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!
Cracow School of Physics
Zakopane, June 13, 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
(Λ
Λ+Λ
Λ)
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
(Λ
Λ+Λ
Λ)/(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
Single-strange Baryon
(Λ
Λ + Λ)
=
NSD collision per unit Y, (1/NNSD) dN/dY.
2Kshort
Strange Meson
“Minimum Bias” Collisions
Proton Tune Z1!
Oops!Proton
Not enough Lambda’s in PYTHIA
Cracow School of Physics
Zakopane, June 13, 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)
Ξ −+Ξ
Ξ −)/(2Kshort)
(Ξ
CMS
CMS Data
−
(Ξ
Ξ +Ξ
Ξ )
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
Double-strange Baryon
(Ξ
Ξ + Ξ)
=
NSD collision per unit Y, (1/NNSD) dN/dY.
2Kshort
Strange Meson
“Minimum Bias” Collisions
Proton Tune Z1!
Yikes! Proton
Way too few Cascade’s in PYTHIA
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 32
PYTHIA Fragmentation
Parameters
Can we increase the overall rate of strange baryons by varying a few
fragmentation parameters?
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 .
This work is very preliminary!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 33
PYTHIA Fragmentation
Parameters
Can we increase the overall rate of strange baryons by varying a few
fragmentation parameters?
Warning!
This may cause
problems
PARJ(1) : (D = 0.10) is P(qq)/P(q),
the suppression
of diquark-antidiquark
pair production in
fitting the LEPproduction.
data. If so Notation: PARJ(1) = qq/q
the colour field, compared with quark–antiquark
we must understand why!
We
not want of
one
tune for
PARJ(2) : (D = 0.30) is P(s)/P(u),
thedo
suppression
s quark
pair production in the field
+
e e and
another
one for
compared with u or d pair production.
Notation:
PARJ(2)
= s/u.
hadron-hadron collisions!
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 .
This work is very preliminary!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 34
PYTHIA Fragmentation
Parameters
Rapidity Distribution Ratio: (Lam+LamBar)/(2Kshort)
Rapidity Distribution Ratio: Kaons/Pions
0.5
0.3
s/u: 0.3 -> 0.5
dN/dY Particle Ratio
PYTHIA Tune Z1
0.2
-
+
-
PYTHIA Tune Z1
us/s: 0.4 -> 1.0
0.1
Z1 default
qq/q: 0.1 -> 0.2
Λ+Λ
Λ)/(2Kshort)
(Λ
qq/q: 0.1 -> 0.2
0.4
0.3
0.2
us/s: 0.4 -> 1.0
0.1
s/u: 0.3 -> 0.5
Z1 default
7 TeV
NSD (all pT)
900 GeV
INEL (all pT)
_
CMS Data
(K +K )/(π
π +π
π)
+
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
−
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
_
−
(Ξ
Ξ −+Ξ
Ξ −)/(2Kshort)
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
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 35
4
Kaon Production
Kshort Rapidity Distribution: dN/dY
Kshort Rapidity Distribution: dN/dY
0.5
0.5
CMS Data
PYTHIA Tune Z1
PYTHIA Tune Z1C
Charged Particle Ratio
dN/dY
0.4
CMS Data
7 TeV
0.3
0.2
900 GeV
0.1
CMS
NSD (all pT)
0.4
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.3
0.2
900 GeV
0.1
Tune Z1
CMS
NSD (all pT)
0.0
7 TeV
Tune Z1C
0.0
-4
-3
-2
-1
0
1
2
3
4
-4
-3
Rapidity Y
-2
-1
0
1
2
3
Rapidity Y
CMS NSD data on the Kshort rapidity
distribution at 7 TeV and 900 GeV compared
with PYTHIA Tune Z1. The plot shows the
average number of Kshort per NSD collision
per unit Y, (1/NNSD) dN/dY.
CMS dNSD ata on the Kshort rapidity
distribution at 7 TeV and 900 GeV compared
with PYTHIA Tune Z1C. The plot shows the
average number of Kshort per NSD collision
per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton
Proton
For Kaon production
Tune Z1 and Z1C are
almost identical!
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 36
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
0.0
1
-4
2
-3
Tune Z1C
(K +K
)/(π
π +π
π 0.12
)
PYTHIA Tune Z1C
qq/q:
0.1
->
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
Rapidity Y
-1
-4
0
-3
1
Rapidity Y
CMS NSD data on the Kshort rapidity
distribution at 7 TeV and 900 GeV compared
with PYTHIA Tune Z1. The plot shows the
average number of Kshort per NSD collision
per unit Y, (1/NNSD) dN/dY.
-2
2
-1
3
0
4
1
2
3
Rapidity Y
CMS dNSD ata on the Kshort rapidity
distribution at 7 TeV and 900 GeV compared
with PYTHIA Tune Z1C. The plot shows the
average number of Kshort per NSD collision
per unit Y, (1/NNSD) dN/dY.
“Minimum Bias” Collisions
Proton
Proton
For Kaon production
Tune Z1 and Z1C are
almost identical!
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 37
Lambda Production
(Lam+LamBar) Rapidity Distribution: dN/dY
(Lam+LamBar) Rapidity Distribution: dN/dY
0.25
0.25
_
CMS Data
(Λ
Λ+Λ
Λ)
PYTHIA Tune Z1
dN/dY
0.20
0.15
0.10
900 GeV
0.05
0.00
-4
-3
-2
-1
7 TeV
0.20
(Λ
Λ+Λ
Λ)
CMS
0.15
0.10
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
0.05
NSD (all pT)
Tune Z1
CMS
NSD (all pT)
_
CMS Data
PYTHIA Tune Z1C
Charged Particle Ratio
7 TeV
900 GeV
Tune Z1C
0.00
0
1
2
3
4
-4
-3
-2
-1
0
1
2
3
Rapidity Y
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.
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
Not bad! Many
Tune Z1C!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 38
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
(Λ
Λ+Λ
Λ)
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
(Λ
Λ+Λ
Λ)/(2Kshort)
Tune0.05
Z1C
qq/q: 0.1 -> 0.12NSD (all pT)
us/s: 0.4 -> 0.8
TuneNSDZ1
(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
(Λ
Λ+Λ
Λ)
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
Not bad! Many
Tune Z1C!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 39
Cascade Production
(Cas+CasBar) Rapidity Distribution: dN/dY
(Cas+CasBar) Rapidity Distribution: dN/dY
0.03
CMS Data
−
0.03
_
Charged Particle Ratio
(Ξ
Ξ +Ξ
Ξ )
PYTHIA Tune Z1
7 TeV
dN/dY
0.02
CMS
900 GeV
0.01
PYTHIA Tune Z1C
_
−
7 TeV
CMS
0.02
0.01
Tune Z1
NSD (all pT)
−
(Ξ
Ξ −+Ξ
Ξ −)
CMS Data
−
Tune Z1C
qq/q: 0.1 -> 0.12
us/s: 0.4 -> 0.8
NSD (all pT)
900 GeV
Tune Z1C
0.00
0.00
-4
-3
-2
-1
0
1
2
3
4
-4
-3
-2
-1
0
1
2
3
Rapidity Y
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.
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!
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 40
Cascade Production
(Cas+CasBar) Rapidity Distribution: dN/dY
(Cas+CasBar) Rapidity Distribution:
dN/dYDistribution Ratio: (Cas+CasBar)/(2Kshort)
Rapidity
0.03
0.05
CMS Data
−
CMS Data
CMS
0.01
0.04
PYTHIA Tune Z1 & Z1C
Charged Particle Ratio
dN/dY Particle Ratio
dN/dY
0.02
7 TeV
0.03
0.02
900 GeV
0.00
-2
-1
0
0.00
1 -4
PYTHIA Tune Z1C
0.02
−
_
−
CMS
7 TeV
_
−
(Ξ
Ξ −+Ξ
Ξ −)
−
(Ξ
Ξ −+Ξ
Ξ −)/(2Kshort)
7 TeV
Z1C
0.01
Tune Z1C
qq/q: 0.1 -> 0.12
NSD (all pT)
us/s: 0.4 -> 0.8
0.01
Tune Z1 NSD (all pT)
NSD (all pT)
-3
CMS Data
−
(Ξ
Ξ +Ξ
Ξ )
PYTHIA Tune Z1
-4
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!
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 41
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
PYTHIA
Tune
Z1Z1
&&
Z1C
7 TeV
0.03
0.10
0.02
900 GeV
0.05
0.01
-2
-1
0
0.00
1 -4
−
__−
_
−
0.02
CMS
7 TeV
7 TeV
_
−
(Ξ
Ξ −+Ξ
Ξ −)
−Ξ −+Ξ
− −)/(2K
Ξ(Ξ
+Ξ
Ξ Ξ)/(Λ
Λ+Λ
Λ)short)
PYTHIA Tune Z1C(Ξ
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:
us/s:
0.40.4
->->
0.80.8
Tune Z1 NSD (all pT)
NSD (all pT)
-4
0.04
0.15
0.03
_
−
−
CMS
Data
CMS
Data
(Ξ
Ξ +Ξ
Ξ )
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!
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 42
Transverse Momentum
Distributions
PT Distribution: Kshort
PT Distribution: Lam+LamBar
1.0E+01
1.0E+00
CMS Data
CMS Data
PYTHIA Tune Z1 & Z1C
1.0E+00
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
_
(Λ
Λ+Λ
Λ)
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
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 the
pT dependence!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
10
Rick Field – Florida/CDF/CMS
Page 43
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
−
(Ξ
Ξ +Ξ
Ξ )
Z1
1.0E-03
NSD (|Y| < 2))
_
Ξ −+Ξ
Ξ −)
(Ξ
−
Z1C
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.
(normalized to 1) compared with PYTHIA
The plot shows the average number of
Tune Z1 & Z1C.
particles per NSD collision per unit pT,
(1/NNSD) dN/dpT for |Y| < 2.
“Minimum Bias” Collisions
Proton
Proton
PYTHIA Tune
Z1 & Z1C are a bit off on the
pT dependence!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 44
Particle Ratios versus PT
PT Particle Ratio: (Lam+LamBar)/(2Kshort)
0.8
Particle Ratio: (Lam+LamBar)/(2Kshort)
0.8
_
CMS Data
_
(Λ
Λ+Λ
Λ)/(2Kshort)
PYTHIA Tune Z1 & Z1C
Λ+Λ
Λ)/(2Kshort)
(Λ
ALICE Data
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.
Single-strange Baryon
(Λ
Λ + Λ)
=
2Kshort
Strange Meson
Single-strange Baryon
(Λ
Λ + Λ)
=
2Kshort
Strange Meson
“Minimum Bias” Collisions
Tune Z1C Proton
is not too bad but a bit off on the
pT dependence!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 45
Particle Ratios versus PT
PT Particle Ratio: (Cas+CasBar)/(Lam+LamBar)
PT Particle Ratio: (Cas+CasBar)/(2Kshort)
0.15
CMS Data
−
−
(Ξ
Ξ +Ξ
Ξ )/(2Kshort)
0.10
0.25
PT Particle Ratio
PYTHIA Tune Z1 & Z1C
PT Particle Ratio
_
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
CMS Data
−
_
_
−
(Ξ
Ξ −+Ξ
Ξ −)/(Λ
Λ+Λ
Λ)
PYTHIA Tune Z1 & Z1C
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.
Double-strange Baryon
Double-strange Baryon
(Ξ
Ξ + Ξ)
(Ξ
Ξ + Ξ)
=
=
2Kshort
Single-strange Baryon
Strange Meson
(Λ
Λ + Λ)
“Minimum Bias” Collisions
Proton
Tune Z1C
is not too bad but a bit off onProton
the pT dependence!
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 46
Particle Ratios versus PT
PT Particle Ratio: Kaons/Pions
Rapidity Distribution Ratio: Kaons/Pions
0.60
0.3
ALICE Data
(K +K )/(π
π +π
π)
+
+
-
ALICE Data
(K++K-)/(π
π++π
π-)
PYTHIA Tune Z1 & Z1C
0.40
dN/dY Particle Ratio
PT Particle Ratio
PYTHIA Tune Z1 & Z1C
-
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
=
-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.
(K++ K-)
(π
π++ π-)
-4
-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.
Strange Meson
Non-strange Meson
“Minimum Bias” Collisions
Tune Z1C isProton
not too bad but a way off on the
pT dependence!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 47
4
Particle Ratios versus PT
PT Particle Ratio: (P+Pbar)/Pions
Rapidity Distribution Ratio: (P+Pbar)/Pions
0.4
PYTHIA Tune Z1 & Z1C
_
(p+p)/(π
π++π
π-)
ALICE Data
PYTHIA Tune Z1 & Z1C
dN/dY Particle Ratio
PT Particle Ratio
0.12
_
π++π
π-)
(p+p)/(π
ALICE Data
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.
Non-strange Baryon
(p + p)
=
(π
π++ π-)
Non-strange Meson
“Minimum Bias” Collisions
Tune Z1CProton
is not too bad but way off on the
pT dependence!
Proton
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 48
MB versus UE
Charged Particle Density: dN/dη
ηdφ
φ
ηdφ
φ
Transverse Charged Particle Density: dN/dη
2.5
RDF Preliminary
CMS Data
PYTHIA Tune Z1
PYTHIA Tune Z1
Charged Particle Density
Charged Particle Density
2.5
2.0
Factor of 2!
1.5
1.0
Charged Particles (|η
η| < 2, all pT)
0.5
Tune Z1
CMS
2.0
Tune Z1
1.0
0.5
7 TeV ND
pyZ1 ND = dashed
7 TeV
NSD (all pT)
0.0
NSD = ND + DD
1.5
pyZ1 NSD = solid
0.0
0
5
10
15
20
25
-4
-3
-2
-1
0
1
2
3
Pseudo-Rapidity η
PT max (GeV/c)
Shows the density of charged particles in
the “transverse” region as a function of
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
Outgoing Parton
CMS NSD data on the charged particle rapidity
distribution at 7 TeV compared with PYTHIA
Tune Z1. The plot shows the average number of
charged particles per NSD collision per unit η−φ,
(1/NNSD) dN/dη
ηdφ
φ.
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 49
UE Particle Type
Log Scale!
ηdφ
φ
Transverse Charged Particle Density: dN/dη
Transverse Particle Density: dN/dη
ηdφ
φ
2.5
10.000
RDF Preliminary
PYTHIA Tune Z1
PYTHIA Tune Z1
2.0
Particle Density
Charged Particle Density
RDF Preliminary
1.5
1.0
Charged Particles (|η
η| < 2, all pT)
7 TeV ND
charged particles
(π
π++π
π-)
1.000
(K++K-)
_
(p+p
)
_
0.100
Λ+Λ
Λ)
(Λ
0.010
−
Tune Z1
7 TeV ND
0
5
10
15
20
25
0
5
10
Shows the density of charged particles in
the “transverse” region as a function of
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
PT(hard)
Initial-State Radiation
Initial-State Radiation
Proton
Underlying Event
Proton
Proton
Underlying Event
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
25
Outgoing Parton
PT(hard)
Outgoing Parton
20
Shows the density of particles in the
“transverse” region as a function of PTmax
for charged particles (All pT, |η
η| < 2) at 7
TeV from PYTHIA Tune Z1.
Outgoing Parton
Underlying Event
15
PTmax (GeV/c)
PT max (GeV/c)
Proton
−
(|η
η| < 2, all pT)
0.001
0.0
_
Ξ −+Ξ
Ξ −)
(Ξ
0.5
Outgoing Parton
Rick Field – Florida/CDF/CMS
Underlying Event
Final-State
Radiation
Page 50
MB versus UE
"Transverse" Particle Density: dN/dη
ηdφ
φ
ηdφ
φ
Charged Particle Density: dN/dη
0.15
0.15
RDF Preliminary
Charged Particle Density
PYTHIA Tune Z1
Particle Density
RDF Preliminary
Kshort
0.10
Factor of ~2!
0.05
Kshort (|η
η| < 2, all pT)
Tune Z1
Kshort
PYTHIA Tune Z1
0.10
0.05
Kshort (all pT)
Tune Z1
7 TeV ND
7 TeV ND
0.00
0.00
0
5
10
15
20
25
-4
-3
-2
-1
0
1
2
3
Pseudo-Rapidity η
PT max (GeV/c)
Shows the density of Kshort particles in the
“transverse” region as a function of PTmax
for charged particles (All pT, |η
η| < 2) at 7
TeV from PYTHIA Tune Z1.
Shows the Kshort pseudo-rapidity distribution (all
pT) at 7 TeV from PYTHIA Tune Z1. The plot
shows the average number of particles per ND
collision per unit η−φ, (1/NND) dN/dη
ηdφ
φ.
Outgoing Parton
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 51
MB versus UE
Charged Particle Density: dN/dη
ηdφ
φ
"Transverse" Particle Density: dN/dη
ηdφ
φ
0.12
0.12
_
(p+p)
RDF Preliminary
RDF Preliminary
Charged Particle Density
Particle Density
PYTHIA Tune Z1
0.08
Factor of ~2!
0.04
Tune Z1
_
PYTHIA Tune Z1
(p+p)
0.08
0.04
7 TeV ND (all pT)
Tune Z1
7 TeV ND (|η
η| < 2,all pT)
0.00
0.00
0
5
10
15
20
25
-4
-3
-2
-1
0
1
2
3
Pseudo-Rapidity η
PT max (GeV/c)
Shows the density of P+antiP particles in
the “transverse” region as a function of
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
Shows the P+antiP pseudo-rapidity distribution
(all pT) at 7 TeV from PYTHIA Tune Z1. The
plot shows the average number of particles per
ND collision per unit η−φ, (1/NND) dN/dη
ηdφ
φ.
Outgoing Parton
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Rick Field – Florida/CDF/CMS
Page 52
MB versus UE
"Transverse" Particle Density: dN/dη
ηdφ
φ
_
0.04
(Λ
Λ+Λ
Λ)
RDF Preliminary
PYTHIA Tune Z1
Particle Density
ηdφ
φ
Charged Particle Density: dN/dη
0.03
Factor of ~2!
0.02
0.01
Tune Z1
_
RDF Preliminary
Charged Particle Density
0.04
7 TeV ND (|η
η| < 2,all pT)
(Λ
Λ+Λ
Λ)
PYTHIA Tune Z1
0.03
0.02
0.01
Tune Z1
7 TeV ND (all pT)
0.00
0.00
0
5
10
15
20
25
-4
-3
-2
-1
0
1
2
3
PT max (GeV/c)
Shows the density of Λ+antiΛ
Λ particles in
the “transverse” region as a function of
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
Shows the Λ+antiΛ
Λ pseudo-rapidity distribution
(all pT) at 7 TeV from PYTHIA Tune Z1. The
plot shows the average number of particles per
ND collision per unit η−φ, (1/NND) dN/dη
ηdφ
φ.
Outgoing Parton
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
4
Pseudo-Rapidity η
Rick Field – Florida/CDF/CMS
Page 53
MB versus UE
"Transverse" Particle Density: dN/dη
ηdφ
φ
_
0.04
(Λ
Λ+Λ
Λ)
RDF Preliminary
PYTHIA Tune Z1
Particle Density
ηdφ
φ
Charged Particle Density: dN/dη
RDF Preliminary
0.03
Factor of ~2!
0.02
0.01
Tune Z1
7 TeV ND (|η
η| < 2,all pT)
Charged Particle Density
0.04
PYTHIA Tune Z1
_
(Λ
Λ+Λ
Λ)
0.03
0.02
0.01
Tune Z1
7 TeV ND (all pT)
0.00
Coming soon! Measurements
from-2 CMS,
-4
-3
-1
0
1
2
3
4
15
20
25
ATLAS,
and
ALICE
on
the
strange
η
Pseudo-Rapidity
PT max (GeV/c)
particles and baryons in the
Shows the density of Λ+antiΛ
Λ particles in
Shows the Λ+antiΛ
Λ pseudo-rapidity distribution
“underlying
event”.
the “transverse” region as a function of
(all p ) at 7 TeV from PYTHIA Tune Z1. The
0.00
0
5
10
PTmax for charged particles (All pT, |η
η| < 2)
at 7 TeV from PYTHIA Tune Z1.
T
plot shows the average number of particles per
ND collision per unit η−φ, (1/NND) dN/dη
ηdφ
φ.
Outgoing Parton
PT(hard)
“Minimum Bias” Collisions
Initial-State Radiation
Proton
Proton
Underlying Event
Outgoing Parton
Proton
Underlying Event
Proton
Final-State
Radiation
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 54
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
Λ
u s
d s +d s
ud s
K-
p
Ξ−
u s
uud
dss
PT Distributions: PYTHIA does not describe correctly the pT distributions
of heavy particles (MC softer than the data). None of the fragmentation
parameters I have looked at changes the pT distributions. Hence, if one
looks at particle ratios at large pT you can see big discrepancies between
data and MC (out in the tails of the distributions)! “Minimum Bias” 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.
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 55
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
Λ
u s
d s +d s
ud s
K-
p
Ξ−
u s
uud
dss
Warning! The Tune Z1C fragmentation
does notmay
describe
correctly the pT distributions
PT Distributions: PYTHIA
parameters
cause problems
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
looks at particle ratios at large
you
canone
seetune
big for
discrepancies between
T
+
and distributions)!
another one for
data and MC (out in the tailseofe the
hadron-hadron collisions!“Minimum Bias” 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.
Cracow School of Physics
Zakopane, June 13, 2011
Rick Field – Florida/CDF/CMS
Page 56