1. 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
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

2. Outline Structure of the talk Quality cuts Efficiency studies
Muon correction functions
The muon spectra
The Integral flux
Attenuation curves
Adding muon data with the CIC method
Conversion into Energy
Energy spectrum
Summary
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

3. 1) Quality cuts Data sets: MC data: Kreta v1.18.03
KG data: Kreta v
Quality cuts:
0   < 40o
Rectangle: A  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

4. 2) Efficiency studies
Working in region of maximum efficiency (E  2.5  1016 eV)
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

5. 3) Muon correction functions
N corrected for systematic effects:
N corrected
N no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

6. 3) Muon correction functions
N corrected
N no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

7. 3) Muon correction functions
N corrected
N no corrected
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

8. 3) Muon correction functions
Distribution of the systematic error of corrected N
Width ~  Use bin log10(N) = 0.1
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

9. 4) The muon spectra teff = 754.3 days
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

10. 4) The muon spectra Importance of the N correction function
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

11. 5) The integral flux
Work in region of maximum efficiency and statistics
Apply cut at constant J(>N)
For a given J, get N()
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

12. 6) Attenuation curves Get attenuation curves
Choose the closest curve to N()
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

13. 6) Attenuation curves
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

14. 6) Attenuation curves
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
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

15. 7) Adding muon data with CIC method
Find reference angle ref for normalization:
ref = mean = 23.7o
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

16. 7) Adding muon data with CIC method
Muon spectra after applying CIC method
Good agreement: Difference from vertical spectrum is less than 3σ
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

17. 7) Adding muon data with CIC method
Adding all muon spectra after applying CIC method
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

18. 8) Conversion into Energy
FLUKA/QGSJET II
Fit in region of maximum efficiency and statistics
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

19. 8) Conversion into Energy
Systematic error in reconstruction of energy:
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

20. 9) Energy spectrum Assuming mixed composition
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

21. 9) Energy spectrum Change Ne cut to access region of lower energies?
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

22. 9) Energy spectrum
Systematics due to uncertainty in primary composition H Fe
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

23. 9) Energy spectrum Kreta v1.18/04 vs v1.18/02 Good agreement!
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

24. 9) Energy spectrum
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008

25. 9) Summary
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.
Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008