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
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
1) Quality cuts 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
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
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
3) Muon correction functions N corrected N no corrected Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
3) Muon correction functions N corrected N 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 Width ~ 0.14 Use bin log10(N) = 0.1 Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
4) The muon spectra teff = 754.3 days Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
4) The muon spectra Importance of the N correction function Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
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
6) Attenuation curves Get attenuation curves Choose the closest curve to N() 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
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
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
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
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
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
8) Conversion into Energy Systematic error in reconstruction of energy: Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Energy spectrum Assuming mixed composition Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Energy spectrum Change Ne cut to access region of lower energies? Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Energy spectrum Systematics due to uncertainty in primary composition H Fe Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Energy spectrum Kreta v1.18/04 vs v1.18/02 Good agreement! Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
9) Energy spectrum Energy spectrum from muon data – J.C. Arteaga Karlsruhe, December 2008
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