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The energy spectrum from the KASCADE-Grande muon data. Juan Carlos Arteaga-Velázquez for the KASCADE-Grande Collaboration. Institute of Physics and Mathematics Universidad Michoacana. - PowerPoint PPT Presentation
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The energy spectrum from the KASCADE-Grande muon data
Juan Carlos Arteaga-Velázquezfor the KASCADE-Grande Collaboration
Institute of Physics and MathematicsUniversidad Michoacana
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Outline
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Structure of the talk
1) Quality cuts
2) Efficiency studies
3) Muon correction functions
4) The muon spectra
5) The Integral flux
6) Attenuation curves
7) Adding muon data with the CIC method
8) Conversion into Energy
9) Energy spectrum
10) Summary
Data sets:
MC data: Kreta v1.18.03
KG data: Kreta v1.18.04
Quality cuts:
0 < 40o
Rectangle: A 1.924 x 105 m2
Ndtg > 19
Successfully reconstructed
Nctot
log10(Nctot/8.5) > 2.9 log10(Ne/3.5) -10/3.5
N ≥ 2 105
Ne ≥ 1 105
Sven´s data quality base - No hardware, clock problems - Anka cut - No missing muon clusters
Iact & 1
Fanka < 4
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
1) Quality cuts
2) Efficiency studies
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Working in region of maximum efficiency (E 2.5 1016 eV)
3) Muon correction functions
N corrected for systematic effects:
N correctedN no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
3) Muon correction functions
N correctedN no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
3) Muon correction functions
N correctedN no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
3) Muon correction functions
Distribution of the systematic error of corrected N
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Width ~ 0.14 Use bin log10(N) = 0.1
4) The muon spectra
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
teff = 754.3 days
4) The muon spectra
Importance of the N correction function
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
p1 = -2.19 0.02
p1 = -2.43 0.02
5) The integral flux
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Apply cut at constant J(>N)
For a given J, get N()
Work in region of maximum efficiency and statistics
6) Attenuation curves
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Get attenuation curves Choose the closest curve to N()
6) Attenuation curves
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
6) Attenuation curves
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
2 per degree of freedom when using a polynomial of 2nd and 1st degree in Sec for the fit
In general, lower values for Pol. 2nd degree
7) Adding muon data with CIC method
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Find reference angle ref for normalization:
ref = mean = 23.7o
7) Adding muon data with CIC method
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Muon spectra after applying CIC method
Good agreement: Difference from vertical spectrum is less than 3σ
7) Adding muon data with CIC method
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Adding all muon spectra after applying CIC method
8) Conversion into Energy
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Fit in region of maximum efficiency and statistics
FLUKA/QGSJET II
8) Conversion into Energy
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Systematic error in reconstruction of energy:
9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Assuming mixed composition
9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Change Ne cut to access region of lower energies?
9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Systematics due to uncertainty in primary composition
H
Fe
9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
Kreta v1.18/04 vs v1.18/02
Good agreement!
9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Summary
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
A preliminary all-particle primary energy spectrum was obtained from the muon data of KASCADE-Grande using the CIC method.
Agreement between results from Kreta v1.18/04 and v1.18/02.
According to CIC method, muon spectra corresponding to different are in good agreement.
By taking into account muon correction functions a change in slope of muon spectra is observed.
Calculation of systematics with new Kreta version are under way.
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