Extensive Air Shower and cosmic ray physics above 10 17 ev M. Bertaina Univ. Torino & INFN ISMD 2015, Wildbad Kreuth 5-9 October 2015
Outline:» Part I: A general overview of cosmic ray science.» Part II: The interconnection between cosmic ray and particle physics.» I will mention aspects that will be discussed in detail in the talks that follow in this session (S. Ostapchenko, R. Ulrich, D. Veberic, R. Abbasi).» A few key slides taken by J. Pinfold and R. Engel review talks at ICRCs 2013 and 2015. 2
Part I: A general overview of cosmic ray science 3
~10 2 /m 2 /second ~E -2.7 Indirect measurements (from EAS) Knee Direct measurements balloons, satellites ~E -3.1 ~1/m 2 /year ~1/km 2 /year Ankle ~E -2.7 ~1/km 2 /millen. 4
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E < 10 14 ev 6
Extensive Air Showers (EAS) E > 10 14 ev 7
R. Engel (KIT) 8
Development in atmosphere of EAS produced by protons or Fe nuclei at E=10 15 ev Hadronic Interaction Models needed to simulate the particle interactions in atmosphere: EPOS, QGSjet, SIBYLL, They are embedded in a software that simulates the EAS cascade in atmosphere such as CORSIKA. Astroparticle Physics 9
EAS detection techniques measurement of radio signal
E > 10 17 ev 11
12 R. Engel (KIT)
COSMIC RAY SPECTRUM direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? 13
Technical: direct to ground based experiments direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? 14
Origin of the knee? direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? 15
1 What is the origin of the knee? knee 1a The energetic limit of the acceleration mechanism of galactic c.r.? E max ~ Z 10 15 ev Cut-off in the spectrun of single elements E k (Z) Z=1 Z=7 Z=26 ~Z Acceleration in Supernova Remnant B~3µG M. Bertaina 1b It is due to the limit due to the increase of probability to escape probability of galactic confinement? Astroparticle Physics 16 P escape ~ rigidity ~ 1/Z
Results in the knee region ) 1.5 sr -1 s -1 ev -2 (m 2.5 di/de x E 17 10 16 10 EAS-TOP (1999) Akeno (1992) Yakutsk (2008) GAMMA (2008) TUNKA-133 (2013) TUNKA-25 (2013) IceTop (2013) TIBET-III (2008) 15 10 14 10 KASCADE all (2013) KASCADE H (2013) KASCADE medium (2013) KASCADE Fe (2013) KASCADE-Grande all (2012,2013) KASCADE-Grande H (2013) ) KASCADE-Grande He+CNO+Si (2013) KASCADE-Grande Fe (2013) 15 10 16 10 17 10 18 10 E(eV) M.B., Comptes Rendus (2014) 17
Origin of the ankle? (transition between galactic/extra-galactic CRs) direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? R. Engel (KIT) 18
2 the ankle marks the transition between galactic and extra galactic cosmic rays? KNEE ANKLE GZK Limit γ=2.7 γ=3.0 γ=2.7 Extra-galactic component? Limit of galactic C.R.? 19
KASCADE-Grande results: ) 1.5 sr -1 s -1 ev -2 (m 2.5 di/de x E 17 10 16 10 15 10 AUGER (2013) HiResII (2008) KASCADE-Grande all QGSJet-II (2012) TUNKA-133 (2013) KASCADE-Grande heavy QGSJet-II (2011) KASCADE-Grande light QGSJet-II (2013) 14 10 13 10 IceTop (2013) TA (2013) TIBET-III (2008) KASCADE all QGSJet-II (2013) KASCADE H-Si QGSJet-II (2013) KASCADE Fe QGSJet_II (2013) 16 10 17 10 18 10 19 10 10 E/eV 20 M.B., Comptes Rendus (2014) 20
Composition vs Energy M.B., Comptes Rendus (2014) 21
Anisotropies direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? R. Engel (KIT) 22
Random path of Cosmic Rays 23
amplitude of dipole A. Castellina (COMPOSITION 2015) 24
IceCube & IceTop Where does this anisotropy comes from? Why it changes above hundred TeV? Tsunesada, ICRC 2013
End of spectrum? direct measurements 1 part/m 2 /year EAS knee(s) 1 part/km 2 /year ankle end of spectrum? R. Engel (KIT) 26
The cosmic microwave background at 3 0 K makes the Universe opaque to the cosmic rays of extreme energy K. Greisen - G.T.Zatsepin & V.A.Kuz min (1966) GZK Cutoff p+γ! p+π 0 p+γ! n+π + E thr =6.8 10 19 ev l=1/σρ=6mpc ρ~410 γ/cm 3 p σ=135mbarn Cosmic rays with energy E> 7 10 19 ev must have their sources within 50Mpc M. Bertaina Astroparticle Physics 27
ORIGIN and PROPAGATION of UHECRs GZK cut-off for protons p + γ p + γ p + γ 2,7K 2,7K 2,7K Δ Δ Δ n + π p + π p + e + + 0 + e Photo-dissociation for heavier nuclei A + γ A + γ A + γ 2,7K 2,7K 2,7K ( A 1) ( A 2) A + e + + + + N 2N e Laboratory System: E proton = 10 20 ev; E photon: 0.5 mev Proton reference system: E proton = 0 ev ; E photon: 300 MeV Energie (ev) Cosmic rays with energy E> 7 10 19 ev must have their sources within 50Mpc 28 Propagation distance (Mpc)
Other possibility: end of spectrum due to the fact that sources are running out of steam Globus et al. (ICRC 2015) 29
Cosmic Ray Propagation in our Galaxy Deflection angle < 1 degree at 10 20 ev for protons 30
Anisotropy Hints >60 EeV Statistically limited evidence for Comic Ray Anisotropy above 5.7x 10 19 ev in the North and South E > 5.7x 10 19 ev 20 o smoothing 5 σ pretrial TA # of events correlating with AGN, ordered in energy (integral plot) Auger Auger preliminary isotropy expect. 3 σ pretrial P5 Presentation 12/3/13 Auger
The connection with the knee and the highest energies Galactic Extra-Galactic 32
Part II: The interconnection between cosmic rays and particle physics 33
Slide 2 Pierog. Lo spettro dei raggi cosmici Inserire tutte le animazioni del passato (vedi S.Vito) Models tuned here LHC data s GZK ~300 TeV 10 5 extrapolation 10 3 extrapolation
R. Engel (ICRC 2015) 35
Rapidity regions of CR experiments and LHC detectors Pinfold, ICRC 2013 CR exp.
R. Engel (ICRC 2015) 37
R. Engel (ICRC 2015) 38
Pinfold, ICRC 2013
R. Engel (ICRC 2015) 40
R. Engel (ICRC 2015) 41
Shortcomings of the hadronic interaction models R. Engel (ICRC 2015) 42
43 Pierre Auger Collaboration (ICRC 2015)
Shortcomings of the hadronic interaction models Xmax distributions Pierre Auger Collaboration (ICRC 2015) 44
CONCLUSIONS A review of the current understanding of cosmic ray data at different energies has been presented. The interpretation of CR data requires the knowledge of the physics of hadronic interactions in atmosphere, but at the same time provides a means to cross-check the validity of the physics principles embedded in the models. Hadronic interaction models do a fairly well job not only in the interpretation of EAS cascades in atmosphere but also of LHC data. However, shortcomings exist! LHC data are extremely helpful in fine tuning the models and give solid bases for the extrapolation at high energies. CR remain the sole mean to test hadronic interactions at energies well beyond those reachable with colliders. CRs and accelerator data provide an excellent mix of information to understand the physics of interactions! 45
THANK YOU 46