Main results of the KASCADE and KASCADE-Grande experiments

Andrea Chiavassa Università degli Studi di Torino

ISVHCRI 2018 – Nagoya 21-25 May 2018

1 • EAS arrays located @Campus North KIT. • Data Taking Terminated end 2012. • KASCADE • 1014muon components • CORSIKA • EAS simulation code • Unique frame including different high and low energy hadronic interaction models • Analysis Methods • From the comparison of the moments of EAS parameters distributions to the use of the shapes of the distributions. • Elemental groups spectra. • Event by event separation in primary mass groups. 2 KASCADE KIT Campus North, Detector Particle Active Threshold Karlsruhe 110 m, a.s.l. Area (m2) Array: Liquid Scintillators e/γ 490 5 MeV Array: Plastic Scintillators μ 622 230 MeV μ tracking detector μ 128x4 800 MeV Central Detector Calorimeter: Liquid ionization h 304x8 50 GeV chambers Trigger layer: Plastic Scintillators μ 208 490 MeV Top cluster: Plastic Scintillators e/γ 23 5 MeV Top layer: Liquid ionization chambers e/γ 304 5 MeV Multi-wire proportional chambers μ 129x2 2.4 GeV Limited streamer tubes μ 250 2.4 GeV

Nucl. Instr. And Meth. A513 (2003) 490 3 KASCADE EAS parameters resolution

Log Ne=4.1  σNe = 18% Log Ne=6.0  σNe = 4% 푡푟 푁휇  404  σ 푡푟 <5% 푁휇 σEh < 15%

Nucl. Instr. And Meth. A513 (2003) 490 4 Test of Hadronic Interaction Models • Correlation between observables measured with the central detector and the array • Number of hadrons • Hadronic energy sum • Number of electrons • Number of muons • None of the models gave a complete description of the data. • Data were analysed before the beginning of the LHC operation. • Models developed using the KASCADE data then also used to J. Phys. G: Nucl. Part. Phys. 34 (2007) 2581 compare the LHC experimental data.

5 Ne spectrum • Shower Size at the knee decreases with atmospheric depth

• ЛNe in agreement with ЛEAS • Knee is a feature of the primary spectrum

Astroparticle Physics 19 (2003) 703 6 Mass groups spectra

푡푟 • Unfolding of Ne vs 푁휇 spectra

18  N Nucl dJ N  2AT n p sin cosdLog Ed i   n 10 ni 0 dLog10 E  p ((LogN , LogN tr ), LogE)  s  r dLogN dLogN tr n e    n n n e  

• sn  shower fluctuation • εn  detection efficiency • rn  reconstruction errors

Astroparticle Physics 24 (2005) 1 Astroparticle Physics 31 (2009) 86 7 • Results depend on the high energy hadronic interaction models • QGSJet  He more abundant element at the knee • SIBYLL 2.1  C more abundant element at the knee • Knee energy increases with primary mass • Fe knee not observed • Strong indication for a rigidity dependent knee

Astroparticle Physics 24 (2005) 1 Astroparticle Physics 31 (2009) 86 8 Event by event mass group separation

• Y = Ln N’e / Ln N’μ

• Ln N’e = Ln Ne(θ) – X/Лe (secθ -1) 푡푟 • Ln N’μ = Ln 푁휇 (θ) – X/Лμ (secθ -1)

Astroparticle Physics 16 (2002) 373 9 Energy range extension up to 1016 eV: from KASCADE to KASCADE-Grande

Grande array  cover an area of 0.5 km2

Detector Detected Detection Detect EAS Technique or area compone (m2) nt

Grande Charged Plastic 37x10 particles Scintillators

KASCADE Electrons, Liquid 490 array e/g g Scintillators

KASCADE Muons Plastic 622 array  (Eth=230 Scintillators MeV)

MTD Muons Streamer Tubes 4x128 (Tracking) (Eth=800 MeV)

• Shower core and arrival • Shower Size (Nch number of •  Size (E>230 MeV) direction charged particles) •KASCADE array  detectors – Grande array – Grande array •Fit Lagutin Function • Fit NKG like ldf Nucl. Instr. Meth. A620 (2010) 202 10 In each Shower Size bin we obtain the distribution of the difference between the Shower Size determined by the KASCADE and the Grande arrays

Nch,G  Nch,K

Nch,K

~100%

Systematic differences  < 5-8%

Grande resolution  < 15%

Nucl. Instr. Meth. A620 (2010) 202 11 All particle energy spectrum

• Primary energy estimated from a combination of Nch and N • To take into account EAS attenuation in atmosphere we use five different angular bins • Calibration by QGSJetII-02

•Spectrum cannot be described by a single power law •Concavity above 1016 eV •Steepening at ~8x1016 eV significance 2.1σ

Astroparticle Physics 36, (2012) 183 12 Spectral features are visible in the spectra calibrated with all interaction models

Advances in Space Research 53, (2014) 1456-1469 13 Event by event separation in two mass

groups by the Nch/N ratio

• Electron poor events (i.e. heavy primaries) are those with k values greater than the solid line

• Heavy primaries mass group spectrum: cut between C and Si (QGSJetII-02)

• QGSJetII-02

log (N / N )  log (N / N ) k  10 ch  10 ch  H log10 (Nch / N )Fe  log10 (Nch / N )H Phys. Rev. Lett. 107 (2011) 171104 14 Heavy primaries mass group spectrum: cut between C and Si (QGSJetII-02) • Energy spectra of the samples obtained by an event selection based on the k parameter

• Spectrum of the electron

poor sample: k>(kC+kSi)/2  steepening observed with increased significance  3.5s

• Spectrum of electron rich events  can be described by a single power law  hints of a hardening above 1017 eV

16.92  0.04 g1  2.76  0.02 Eb  10 eV g2  3.24  0.05 Phys. Rev. Lett. 107 (2011) 171104 15 Investigations of the electron rich sample

Statistics increased by 36% adding new data sets and increasing the effective area

To enhance possible structures of the electron rich sample 

k < (kC+kHe)/2 Phys. Rev. D 87, 081101(R) (2013) 16 • Spectra obtained enhancing the electron-rich event selection show a hardening above 1017 eV

g1  3.25  0.05 g2  2.79  0.08

17.08  0.08 Eb = 10 eV

Nmeas = 579 Nexp = 467

-09 P(N>Nmeas)≈7.23x10

5.8s significance

Phys. Rev. D 87, 081101(R) (2013)

KASCADE+KASCADE-Grande joined analysis, γ-ray limits. Sibyll2.3c test: talk by D. Kang

17 Search for Large Scale Anisotropies • East-West method • Data set from December 2003 to October 2011 (107 events)

• q<40° & Log Nch > 5.2

J. Phys.: Conf. Ser. 531 012001 18 N attenuation in atmosphere Updates: Poster by J.C. Arteaga-Velázquez (#25)

QGSJetII-02 QGSJetII-04 SIBYLL2.1 EPOS-LHC KG-Data -2 +99 +208 +47 +174 +229 L (gcm ) 709 ± 30−78 768 ± 65−219 743 ± 56−98 848 ± 38−115 1256 ± 85−232 s +2.04 +1.48 +1.99 +1.34 C.L. (%) 2.08 6.96 2.34 9.07

Astroparticle Physics 95, (2017) 25 19 EAS Studies @KIT

• Proof-of-principle of radio detection (LOPES) • EAS GHZ emission (CROME)

• Xmax measurement by radio detection (LOPES) • Energy cross calibration by radio detection (TUNKA-REX)

• KCDC • Web portal: KASCADE data released for a general audience • https://kcdc.ikp.kit.edu • KASCADE data storage and preservation

20 Conclusions KASCADE+KASCADE-Grande

 High Resolution cosmic ray studies in the 1014

 Toward mass groups spectra

 Knee  Light primaries  Heavy knee @8x1016-1017 eV  Ankle like feature of the light component

 Test of High Energy Hadronic Interaction models

 Large Scale Anisotropy  Diffuse γ-ray flux

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