The muon component in extensive air showers and its relation to hadronic multiparticle

The muon component in The muon component in extensive air showers extensive air showers

and its relation to and its relation to hadronic multiparticle hadronic multiparticle

productionproduction

Christine Meurer Johannes BlümerRalph EngelAndreas HaungsMarkus Roth

andthe HARP Collaboration HARP Detector, CERN

Auger Observatory, Argentina

HSS 08.09.2006 Fermilab/USA Christine Meurer 2/30

Auger

Outline

• Relation of muons in extensive air showers (EAS) to hadronic interactions

• Comparison: EAS – fixed target experiment

• Investigation of phase space

• Existing accelerator data

• New measurements: NA49 and HARP

• Conclusions and outlook


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Motivation

Interpretation of CR data Interpretation of CR data relies heavily on MC relies heavily on MC simulationssimulations

MC uncertainties arise MC uncertainties arise predominantly from predominantly from hadronic interaction modelshadronic interaction models

MuonsMuons are one of the main are one of the main ingredients to infer E, Aingredients to infer E, A

Muon component is very Muon component is very sensitive to hadronic sensitive to hadronic interactionsinteractions

Which hadronic interactions are of major Which hadronic interactions are of major importance for muon production?importance for muon production?


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Composition at the knee

KASCADET. Antoni et al.Astropart.Phys.24(2005)1

Differences mainly due to muon Differences mainly due to muon productionproduction

or

total


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Muon production in EASproton E =10proton E =101515eV eV = 0°= 0°Primary

particle

CORSIKA simulations:CORSIKA simulations:• QGSJET-01QGSJET-01• GHEISHAGHEISHA

1

2

3

• On average 6 interactions before muon productionOn average 6 interactions before muon production• Number of generations increases with smaller Number of generations increases with smaller

muon energy thresholdmuon energy threshold

number of generations


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Muon energy on ground

lateral distance R

Primaryparticle

Core

p

+

+

+

e-e+

+

00

-

-

p-

-

-

n

e-e+

p

+

p

-

EE smaller for larger smaller for larger distancesdistances

proton E =10proton E =101515eV eV = 0°= 0°

muon energy


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Relation of muons to hadronic interactions

Last interaction

p

++

+

++

e-e+

+

00

-

-

p

--

-

-

n

e-e+

p

+

p

-

proton E =10proton E =101515eV eV = = 0°0°GHEISHAGHEISHA QGSJET01QGSJET01

mother

detected muon

grandmother

grandmother motherpion 72.3% 89.2%

nucleon 20.9% -

kaon 6.5% 10.5%

grandmother energy


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EAS vs fixed target experiment

+ Several targets Several targets + Forward direction accessibleForward direction accessible+ Relevant energy range: 8-1000 GeV Relevant energy range: 8-1000 GeV

Grandmother particle = beam particleGrandmother particle = beam particleMother particle = secondary particleMother particle = secondary particle

p+C

p

++

+

++

e-e+

+

00

-

-

p

--

-

-

n

e-e+

p

+

p

-


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Rapidity of pions

mpEy zln

Rapidity:Rapidity:

Forward hemisphereForward hemispheredominatingdominating

Interesting rangeInteresting range::0.3 < y/y0.3 < y/ybeambeam< 1.1< 1.1

EAS: EAS: KASCADE range: 50-200mKASCADE range: 50-200mNucleons (~160GeV) + airNucleons (~160GeV) + air

Fixed target: Fixed target: p(160GeV) + air, p(160GeV) + Cp(160GeV) + air, p(160GeV) + C(QGSJET-01)(QGSJET-01) yybeambeam = 5.8 = 5.8


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Rapidity of pions

Energy loss/muon decay: muons not detected

No pion decay, but further interactions




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Rapidity of kaons

Energy loss/muon decay: muons not detected

No significant differences because of further interactions→ decay energy of

kaons higher than for pions



Interesting rangeInteresting range::0.3 < y/y0.3 < y/ybeambeam< 1.1< 1.1

Forward hemisphereForward hemispheredominatingdominating


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xlab of secondary and K



K


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Transverse momentum of and Kpptt distribution in EAS similar to distribution in EAS similar to pptt distribution in distribution in fixed target fixed target simulation. simulation. → → Low transverse Low transverse momenta of interestmomenta of interest




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Phase space: E~160GeV

y/ybeam 0.3-1.1pt(GeV) 0.0-0.7

KK

KASCADE range: 50-200m; KASCADE range: 50-200m; Nucleons (~160GeV) + AirNucleons (~160GeV) + Air

EASEAS EASEAS


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Phase space: E~ 40GeV

y/ybeam 0.3-1.1pt(GeV) 0.0-1.0

KASCADE-Grande range: 200-500m; KASCADE-Grande range: 200-500m; Nucleons (~40GeV) + AirNucleons (~40GeV) + Air

KKEASEAS EASEAS


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Existing accelerator data: p+Be

Data: p+Be → +XEAS: p+air → +X


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Existing p+C data: Barton et al.

Data: p+C → +XEAS: p+air → +X


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Data: p+C → +XEAS: p+air → +X

New p+C data: NA49, HARP

Existing: proton beam → 21% of grandmother particleStill needed: pion beam → 72% of grandmother particle


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NA49: p+C @ 158 GeV/c

C.Alt et al. (NA49 collaboration) hep-ex/0606028C.Alt et al. (NA49 collaboration) hep-ex/0606028

Error of NA49 data:Error of NA49 data:stat. error stat. error ~ 5%~ 5%syst. error syst. error ~ 5%~ 5%

Comparison: models – data:Comparison: models – data:SIBYLL and QGSJET-II: SIBYLL and QGSJET-II: reasonable agreement with datareasonable agreement with dataQGSJET-01: QGSJET-01: overestimation of factor ~ 1.5overestimation of factor ~ 1.5


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NA49: p+C @ 158 GeV/c

C.Alt et al. (NA49 collaboration) hep-ex/0606028C.Alt et al. (NA49 collaboration) hep-ex/0606028

QGSJET-01: QGSJET-01: soft soft -spectra-spectraQGSJET-II: QGSJET-II: hard hard -spectra-spectra


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HARP: p+C @ 12 GeV/c

Ongoing analysis: p+C @ 12 GeV/cOngoing analysis: p+C @ 12 GeV/cSelection of secondary particles (Selection of secondary particles () ) in forward hemisphere using the drift in forward hemisphere using the drift chambers.chambers.No of events: No of events: 1,000k1,000kNo of events after cuts:No of events after cuts: 450k 450k

0 1 2 3 4 5 6 7 8 9 10

p

e

k

TOFCERENKOV

TOF CERENKOV

CERENKOVCALORIMETER

Separation of particle Separation of particle types using different types using different detector componentsdetector components

p (GeV/c)


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HARP: p+C @ 12 GeV/c

Ongoing analysis: p+C @ 12 GeV/cOngoing analysis: p+C @ 12 GeV/cSelection of secondary particles (Selection of secondary particles () ) in forward hemisphere using the drift in forward hemisphere using the drift chambers.chambers.No of events: No of events: 1,000k1,000kNo of events after cuts:No of events after cuts: 450k 450k

0 1 2 3 4 5 6 7 8 9 10

p

e

k

TOFCERENKOV

TOF CERENKOV

CERENKOVCALORIMETER

Separation of particle Separation of particle types using different types using different detector componentsdetector components

p (GeV/c)

CERENKOV

TOF

CAL


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HARP preliminary

HARP preliminary HARP preliminary HARP preliminary

HARP preliminary HARP preliminary

p+C→±+X, pbeam=12 GeV/c

• leading particle effect• Comparison with models in preparation• Error: stat. and syst. error

→ syst. error: kaon subtraction in progress


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Error estimation

Stat. errorStat. error Syst. errorSyst. error

4%

20%

rel.

erro

r

rel.

erro

r

p (MeV/c) p (MeV/c)

Dominant contributions to syst. error:• Tertiary subtraction• Momentum scale


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Conclusions• Interpretation of CR data relies heavily on MC simulations

• Muons are main ingredients to infer E, A

• Fixed target experiments are very important for understanding of muon production in extensive air showers

• Relevant hadronic interactions for muon production are in the energy range: 8 – 1000 GeV phase space region: forward hemisphere

• New (2006) fixed target measurements: NA49: p+C @ 158GeV/c HARP: p+C @ 12 GeV/c

• Comparison: data – models: SIBYLL and QGSJET-II in good agreement with data, QGSJET-01 overestimation of factor ~ 1.5 in dN/dy

• Outlook: further measurements/analyses planed by NA49, HARP and MIPP


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Planed future measurements/analysesEnergy range and

phase space of interest

Ebeam 8-1000 GeV

p 0.5-11.0 GeV/c

0-300 mrad

p+C @ 15 GeV/c+C @ 12 GeV/c

p+C and +C @ 30, 40, 50, 158GeV/c

p+C, +C and K+C@ 20, 60, 120GeV/c


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R. Engel


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References

[Baker61] Phys. Rev. Lett. 7 (1961) 101 (AGS)[Dekkers65] Phys. Rev. B 137 (1965) 962 (CERN)[Allaby70] CERN Yellow Report 70-12 (1970) (CERN)[Cho71] Phys. Rev. D 4 (1971) 1967 (ZGS)[Eichten72] Nucl. Phys. B 44 (1972) 333 (CERN)[Antreasyan79] Phys. Rev. D 19 N3 (1979) 764 (Fermilab)[Barton83] Phys. Rev. D 27 (1983) 2580 (Fermilab)[Abbott92] Phys. Rev. D 45 (1992) 3906 (AGS)[NA49_06] hep-ex/0606028 (SPS)[HARP06] ISVHECRI 06, Weihai (PS)

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The muon component in extensive air showers and its relation to hadronic multiparticle

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