Transcript

Reconstruction of total muon number in KASCADE-Grande

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

KASCADE-Grande

•Area of 0.5km2

•370m2 of detector surface

•Threshold of 5MeV for e/+

Number of charged particles Nch

KASCADE Array

• 192 stations• 622m2 detector surface• Threshold 230MeV for

Number of muons N

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

Determine composition with Ne and N

1·1017eV - 2 ·1017eV

Erice, 7th July 2004 Jurriaan van Buren for the KASCADE-Grande Collaboration

KASCADE-Grande reconstruction

• Energy deposit of shower particles in scintillation detector• Additional contribution from the conversion of gamma component and

hadrons• Lateral Energy Correction Function (LECF) gives average energy deposit

per charged lepton • particle densities in detector• Fit of density distribution with Lateral Distribution Functions

• shower core and first estimate of particle numbers Ne, (N)

• arrival times to determine shower direction • combined fit to obtain better results• derive muon number from KASCADE array muon detectors

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

Fiducial area• KASCADE Stations mostly between 275 – 625m• measure

• false reconstructed shower cores at border of Grande Array• definition of fiducial area 600·600m2

r<11m, 11m<r<30m, r>30m

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

Lateral density function for muons

)25.4()(

)5.4(1

2)(

5.42

2 ss

s

r

r

r

r

r

Nr

s

mol

s

molmol

1017eV, p + Fe, 22 °

32

0

2

0

1

02 10

1128.0

)(

ppp

o r

r

r

r

r

r

r

Nr

with r0=430m

NKG-function:

with rmol=590m, s=1.2

Modified Lagutin function:

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

Reconstruction accuracy

MC

MC

N

NNN

• Error of ≈ 30% in region of full efficiency• In radius region of most events error of ≈ 20%

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

Reconstruction accuracy

MC

MC

N

NNN

• Error ≈ 30% in region of full efficiency• In radius region of most events error ≈ 10%

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration

First data

Erice, 7th July 2004 Jurriaan van Buren for KASCADE-Grande Collaboration


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