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Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande using the Y-ratio. J.C. Arteaga-Velázquez for the KASCADE-Grande Collaboration IFM, Universidad Michoacana Morelia, Michoacan , Mexico. - PowerPoint PPT Presentation
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JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 1 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
J.C. Arteaga-Velázquez for the KASCADE-Grande
Collaboration
IFM, Universidad MichoacanaMorelia, Michoacan, Mexico
1) The KASCADE-Grande experiment2) Data selection and systematics3) Y parameter 4) Energy spectrum5) Conclusions
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 2 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 3 ECRS, Moscow, July, 2012
E = 1016 - 1018 eV
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 4 ECRS, Moscow, July, 2012
What is the origin of the knee?
What is the source of the E = 1015 – 1018 eV cosmic rays?
Galactic-extragalactic transition?
Second knee (~1017
eV )?
Composition?
Z or A dependence?
Acceleration/propagation?
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
Details:-Nμ
-192 stations- 622 m2 total-Eμ 230 MeV
Details: - Nch
- e//- 37 10 m2 stations- E 3 MeV
Grande Station
detector
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 5 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
N Precision: < 25%
Nch Precision: < 15 %
CORSIKA/QGSJET II
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 6 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
After correction: < 10%
correction function is used: CF(N, ,, xcore, ycore)
Nch Precision: < 15 %
CORSIKA/QGSJET II
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 7 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
A = 1.37 105 m2 A = 1.52 105 m2
PRL Y-ratio analysis (2011)PRL 107, 171194 (2011)
This Y-ratio analysis
= [0 , 30] = [0 , 40]
Teff = 1173 days Teff = 1434 days
lg(E/GeV) > 7.4lg(E/GeV) > 7.4
CORSIKA/QGSJET II simulations: • E = 1015 – 31018 eV.• H, He, C, Si, Fe.• = -3.
Exp = 2.5 1013 m2 s srExp = 2 1013 m2 s sr
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 8 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
Corrected for attenuation in the atmosphere (CIC method).
Heavy
Light
Divide data into two mass groups according to:
YCIC 0.84
YCIC < 0.84
YCICCUT = 0.84
By applying a cut:
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 9 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
The YCICCUT is independent of energy, core position and zenith angle
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 10 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 11 ECRS, Moscow, July, 2012
Calibration formula exploit correlation of Nch-Nμ with primary mass
PRL 107, 171194 (2011)Astropart.Phys. 36, 183 (2012)
QGSJET IIQGSJET II
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
CORSIKA/QGSJET II
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 12 ECRS, Moscow, July, 2012
Energy spectraNot corrected for shower fluctuations
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
lg(Ek/GeV) = 7.94 0.08
= -0.14
CORSIKA/QGSJET II
1= -3.01 0.01
2= -3.15 0.03
Soft break in all-particle energy spectrumSoft break in all-particle energy spectrum
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 13 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
CORSIKA/QGSJET II
lg(Ek/GeV) = 7.84 0.08
= -0.47
1= -2.72 0.01
2= -3.19 0.04
Break in energy spectrum of heavy componentBreak in energy spectrum of heavy component
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 14 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
CORSIKA/QGSJET II = -3.4 0.01
• Deviation at HE from a power law? More statistics needed to justify or exclude the spectral recurrence of light nuclei
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 1 5 ECRS, Moscow, July, 2012
•Statistically (still) in agreement with a single power-law
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 1 6 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
Spectra obtained using different YCIC cuts
Heavy
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 1 7 ECRS, Moscow, July, 2012
Light
Equivalent to different hadronic interaction models
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
KASCADE vs KASCADE-Grande
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 1 8 ECRS, Moscow, July, 2012
Astropart. Phys. 24,(2005)
Conclusions
1) The all-particle energy spectrum of cosmic rays presents a soft break at E107.94 GeV (QGSJET II).
2) The spectrum of the heavy mass component of cosmic rays shows a knee at E107.84 eV (QGSJET II).
3) All spectra for the heavy component obtained using different YCIC cuts show a knee feature.
4) Need more statistics to investigate light component at HE (underway, by increasing effective area and zenith angle interval).
5) In the framework of the QGSJET II model, the contribution of the misclassified Si/Fe events to the light component is small.
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 19 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 20 ECRS, Moscow, July, 2012
Thank you
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 21 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 22 ECRS, Moscow, July, 2012
Backup slides
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 23 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
All particle
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 24 ECRS, Moscow, July, 2012
Separation of the light and heavy mass groups of cosmic rays in KASCADE-Grande
using the Y-ratio
JC.Arteaga, IFM, Universidad Michoacana ([email protected]) 25 ECRS, Moscow, July, 2012
