CRMC: an interface to cosmic ray event generators
Ralf Ulrich, Colin Baus, Tanguy Pierog
Karlsruhe Institute of Technology, Germany
Forward Physics WG Meeting CERN, August 2013
Outline
Link between cosmic ray air showers and CERN
Extensive air showers as Minimum-Bias laboratories
The tool to run almost all cosmic ray event generators: CRMC
Possible application: Resampling
Impact of LHC measurements on air shower observables
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Extensive Air Shower
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Extensive Air Shower
CORSIKA+COAST
Billions of interactions
All energies
No energy is lost, just
transported
Forward physics
matters
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Interactions in Extensive Air Shower
Number of Interactions
Energies beyond accelerators
19
106
Extensive Air Shower, proton, 10 eV
However, mostly in SPS range
5
10
Peak of Muon
Production In EAS
~35 GeV
104
Uncertainty: extrapolation of
hadronic interactions
103
Primary Particle
102
Phase space (!)
Energy
LHC fixed target
10
SPS fixed target
1
10
12
14
16
→ Very different impact on different
EAS observables
18
lg(E/eV)
Proton, 1019eV
100 Highest Energy Interactions
108
Individual Sub-Showers
Individual Sub-Showers
107
107
106
Muons
Energy Deposit [GeV cm2/g]
109
Proton, 1019eV
100 Highest Energy Interactions
108
105
106
105
104
104
103
102
3
10
0
200 400 600
800 1000 1200 1400 1600 1800 2000 2200
Depth [g/cm2]
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0
200 400 600 800 1000 1200 1400 1600 1800 2000 2200
Depth [g/cm2]
CRMC, an interface to cosmic ray event generators
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“Astrophysics” at LHC – Air-Showers + Forward Physics
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Astrophysical Neutrinos
The first two real astrophysical neutrino candidates
PeV energies
Electron neutrino structure
Atmospheric prompt charm production ?
ICECUBE: Phys. Rev. Lett. 111, 021103 (2013)
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Direct Sensitivity to Particle Physics
Measure cross sections in extensive air showers from fluctuations
TeV to PeV energies
Possible with high quality air shower observations
10-1
Equivalent c.m. energy spp
1
10
[TeV]
102
110
Nam et al. 1975 [30]
2.36TeV
7TeV 14TeV
LHC
[mb]
0.9TeV
Siohan et al. 1978 [31]
600
Baltrusaitis et al. 1984 [2]
100
90
Mielke et al. 1994 [32]
σinel (Proton-Proton)
Cross section (proton-air) [mb]
700
Knurenko et al. 1999 [19]
500
Honda et al. 1999 [20]
Belov et al. 2007 [18]
Aglietta et al. 2009 [33]
400
Aielli et al. 2009 [34]
QGSJet01c
This work
QGSJetII.3
Sibyll 2.1
300
200
1111
10
Epos 1.99
80
ATLAS 2011
CMS 2011
ALICE 2011
TOTEM 2011
UA5
CDF/E710
This work (Glauber)
70
QGSJet01
QGSJetII.3
Sibyll2.1
Epos1.99
Pythia 6.115
Phojet
60
50
40
30
1212
10
1313
10
1414
1515
1616
1717
10
10
10
10
log
(Energy/eV)
Energy
[eV]
10
1818
10
1919
10
2020
10
103
104
s
105
[GeV]
Auger: Phys. Rev. Lett. 109, 062002 (2012)
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Cosmic Ray Models and First LHC Data
Astropart.Phys. 35 (2011) 98-113
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Cosmic Ray Models and Recent LHC Data: LHCb
e.g.
Comparison on event generator level:
Forward energy flow
Forward Lambda production, strangeness
More in preparation...
Eur.Phys.J. C73 (2013) 2421
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Cosmic Ray Models and Recent LHC Data: CMS
Very forward underlying event:
JHEP 1304 (2013) 072
In CMS:
Used for pPb and PbPb (and forward pp) detector studies and
correction factors
Where relevant, also event generator comparisons are performed
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Cosmic Ray Models and Recent LHC Data: TOTEM
Forward charged multiplicities: Europhys.Lett. 98 (2012) 31002
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Status
Good description of main hadronic particle production
Constrains from Modeling (mainly Glauber+Gribov) AND extensive
air shower data work and are useful at LHC
Models work over wide range in primary energies and for a variety
projectile/target combinations (without re-tuning)
Widely used already now: CMS, LHCb, also ATLAS, TOTEM (and
ALICE ?)
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Technical Information
Available event generators:
QGSJet01, QGJSetII.3, QGSJetII.4, EPOS1.99, EPOS1.99lhc,
SIBYLL2.1, DPMJETIII, and some others
Example to generate 100 4.4 ATeV pPb collisions with QGSJetII-04:
bin/crmc -o hepmc -p3500 -P-1380 -n100 -m7 -i2112 -I822080
Output: hepmc, hepmc.gz, lhe, lhe.gz, root
Authors: Colin Baus, Tanguy Pierog, Ralf Ulrich
email to: colin.baus@kit.edu
Package also available by default in the:
From: http://www.auger.de/~rulrich
CMSSW framework as GribovGlauberInterface
In the genser package:
/afs/cern.ch/sw/lcg/external/MCGenerators_lcgcmt65/crmc/1.0/x86_64- slc5- gcc47- opt/bin/crmc
Via genser in the ATLAS offline software
Paper as documentation in preparation
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Resampling (e.g. Elasticity)
kinel = 1 − Emax/Etot
Redistributing of energy among the leading particle and the other
secondaries.
Algorithm changes the interaction elasticity while conserving the
total energy
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[g/cm2]
Impact on Air Showers Observables
SIBYLL, original
19
SIBYLL, elasticity(10 eV) × 0.6
19
SIBYLL, elasticity(10 eV) × 0.2
850
Modifying the elasticity
<Xmax>
800
L
IBYL
Observe impact at LHC
AND
n, S
750
proto
700
iron
in Extensive Air Showers
YLL
, SIB
1818
Auger (PRL 2010)
18.5
10
1919
10
19.5
2020
10
dN/dEπ0 [1/GeV]
Energy
[eV]
SIBYLL
10-4
kela× 0.6
Probability
650
SIBYLL, original
0.1
SIBYLL, elasticity(1019eV) × 0.6
SIBYLL, elasticity(1019eV) × 0.2
0.08
kela× 0.2
-5
10
0.06
0.04
10-6
0.02
10-7
0
0
0
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1000
2000
3000
4000
5000
6000
7000
Eπ0 [GeV]
1000
2000
3000
4000
5000
6000
7000
Total Energy in CASTOR [GeV]
CRMC, an interface to cosmic ray event generators
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2
S
,T
LA
HF
AT
OR HF
S,
ST al,
al,
FC T2
CA FC
CM
DC
,Z
Cf
LH
SIBYLL
EPOS 1.99
QGSJet
1200
QGSJetII
1000
[1/GeV]
DC
,Z
Cf
LH
0.0016
EPOS 1.99
QGSJetII
0.0008
0.0006
400
0.0004
0.0002
-10
-5
0
5
0
0
10
500
1000
1500
2000
2500
η
SIBYLL
0.1
EPOS
T2
0.08
3000
∑E
3500
[GeV]
had
QGSJet
dN/dEπ0 [1/GeV]
dN/dNch
QGSJet
0.001
600
200
CASTOR
0.0012
800
0
SIBYLL
0.0014
had
1400
∑E
1600
dN/d
dE/dη [GeV]
Model Differences in the Forward Detectors
SIBYLL
EPOS
10-4
LHCf
QGSJet
QGSJetII
QGSJetII
10-5
0.06
10-6
0.04
0.02
10-7
0
0
10
20
30
40
50
0
60
1000
2000
3000
4000
Nch
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5000
6000
7000
Eπ0 [GeV]
16
CMS
Tracker
ECAL
PreShower
Probability
Connection to Air Shower Physics
SIBYLL, original
0.1
SIBYLL, elasticity(1019eV) × 0.6
SIBYLL, elasticity(1019eV) × 0.2
0.08
0.06
CASTOR
0.04
Solenoid
0.02
HF
HCAL
0
0
1000
2000
3000
4000
Equivalent c.m. energy spp
6
10
850
7TeV
LHC
5000
6000
7000
Total Energy in CASTOR [GeV]
air
shower
[g/cm2]
Height
Muon Chambers
[TeV]
107
14TeV
to
pro
800
IBY
S
n,
LL
Xmax
Size
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<Xmax>
750
700
n
te
x
rE
sio
LL
IBY
n, S
iro
n
ge
650
Au
16.5
17
1017
17.5
Auger (PRL 2010)
1818
10
Energy
18.5
[eV]
CRMC, an interface to cosmic ray event generators
1919
10
19.5
2020
10
17
Summary
Summary
Extensive air shower data constrains event generators
Cosmic ray models flexible and well suited to describe hadronic bulk
particle production
Cosmic ray models can be used at LHC for efficiency corrections
Furthermore: many measurements can be compared directly to these
models
With CRMC the production of events is almost trivial
Already used in many analyses
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