1 / 27

M. Bertaina a,* , G. Battistoni b , S. Muraro b , G. Navarra a , A. Stamerra c

The primary spectrum in the transition region between direct and indirect measurements (10 TeV – 10 PeV). M. Bertaina a,* , G. Battistoni b , S. Muraro b , G. Navarra a , A. Stamerra c a) Universita’ di Torino and INFN Torino, Italy b) Universita’ di Milano and INFN Milano, Italy

steel-rivas
Download Presentation

M. Bertaina a,* , G. Battistoni b , S. Muraro b , G. Navarra a , A. Stamerra c

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The primary spectrum in the transition region between direct and indirect measurements (10 TeV – 10 PeV) M. Bertainaa,*, G. Battistonib, S. Murarob, G. Navarraa, A. Stamerrac a) Universita’ di Torino and INFN Torino, Italy b) Universita’ di Milano and INFN Milano, Italy c) Universita’ di Siena and INFN Pisa, Italy * At present JSPS fellow at RIKEN, Japan TAUP Conference, Sendai 11-15 September 2007

  2. The basic question: Based on the experimental data collected so far from ‘direct’ and indirect experiments, is it possible to extract the primary spectrum of the different components? The main request: The proposed solution should be compatible with the majority of the experimental data, if possible, obtained using different techniques and observables, sensitive to different primary particles and characteristics of their cascades in air.

  3. The ‘all particle’ spectrum 10TeV 10PeV Overlapping region

  4. Techniques ‘Direct’ measurements (balloons): Emulsion Chambers (JACEE & RUNJOB) 10 TeV - ~500 TeV Calorimeters (ATIC & CREAM) 50 GeV – 200 TeV Good charge resolution but low statistics Sensitive to the first interaction of the primary particle Indirect measurements (EAS arrays): Electromagnetic component (scintillators) > 100 TeV Muons (tracking detectors, scintillators) > MeV/GeV (surface), TeV (underground) Hadrons (calorimeters) > 500 GeV Cherenkov light (telescopes) > 15 TeV High statistics Energy and composition extracted from comparison with simulations

  5. target (～10cm) spacer (～20cm) thin EC(～5c.u.) diffuser (～4cm) RUNJOB Emulsion chamber on balloon A = 0.4 m2; obs time: 1437.5 h, exposure 575 m2h

  6. New calorimeters ATIC Atic-2 20 days Antarctica flight Exp. about 0.3 of RUNJOB BGO calorimeter: 1.15 lint

  7. Measurement Techniques of Air Showers

  8. PRIMARY PROTON FLUX FROM HADRON FLUX DATA KASCADE CALORIMETER 500 GeV – 1 PeV Nucl. Instr. Meth. A513 (2003) 490 KASCADE

  9. He & CNO (80 – 250 TeV)from Cherenkov light & HE muons: EAS-TOP & MACRO Total exposure 20,000 h m2 sr x 15 of direct exp. Astrop. Phys., 21 (2004) 223 Proc. 28th ICRC, 1 (2003) 115 Proc. 29th ICRC, HE11 (2005) 101

  10. MACRO and EAS-TOP are separated by 1100 - 1300 m of rock corresponding to a threshold Em 1.3 - 1.6 TeV. EAS-TOP (Cherenkov detector): total energy through the amplitude of the detected Cherenkov light signal. Energy uncertainties: 28% stat.+ syst • MACRO (as a m detector): • EAS from primaries with En > 1.3 TeV/n • EAS geometry through the m track • (~20 m uncertainty) . He + CNO

  11. KEY POINT OF THE ANALYSIS 250TeV • Beams are well defined: • p at Eo < 50 TeV • p+He at 50 < Eo < 100 TeV • p+He+CNO at Eo > 100 TeV 80 TeV • E ≈ 80 TeV Nmp ≈ NmHe • E ≈ 250 Tev Nmp ≈ NmHe ≈ NmCNO • Same efficiency (inside 15%) in • TeV m production. Relative • abundances are not distorted Primary Energy (TeV) Our simulation agrees with Forti et al., Phys rev. D 42, 3668 (1990) using: Em,th = 1.6 TeV and q = 35o

  12. Cherenkov light: H.E.S.S.Iron: 15 – 150 TeV

  13. Ne – Nm (TeV) E = 1 - 30 PeV EAS-TOP KASCADE Ne – Nm (GeV) E = 1 - 30 PeV

  14. unfolding KASCADE: energy spectra of single mass groups Measurement: KASCADE array data 900 days; 0-18o zenith angle 0-91m core distance lg Ne > 4.8; lg Nmtr > 3.6  685868 events Searched: EandA of the Cosmic Ray Particles Given: Neand Nmfor each single event solve the inverse problem with y=(Ne,Nmtr) and x=(E,A)

  15. The most exploited technique in the past (MUTRON, Alkoffer, etc…) The muon spectrum --> All nucleon spectrum MACRO (Em>1.3 TeV) AMANDA (Em>300 GeV) HEMAS: F0 = (5.0±0.1) cm-2s-1sr-1GeVgp-1A , gp = 2.79±0.04 SIBYLL: F0 = (4.1±0.1) cm-2s-1sr-1GeVgp-1A , gp = 2.77±0.05 F0,H = (0.106±0.007) m-2s-1sr-1TeV-1, gH = 2.70±0.02 MACRO Coll., Phys. Rev. D, Vol. 52 p.3793 (1995) AMANDA Coll., 28th ICRC, HE 2.1 p.1211 (2003)

  16. The new FLUKA Code G. Battistoni et al 29th ICRC 6, 309 (2005)

  17. L3 and Fluka: agree < 10% Vertical flux  FLUKA sim.  L3 data L3+Cosmics S. Muraro, Ph.D. Thesis, 2006 Univ. Milano

  18. L3 and Fluka: agree < 10% Inclined flux (q=53-58)  FLUKA sim.  L3 data S. Muraro, Ph.D. Thesis, 2006 Univ. Milano

  19. Example: proton and helium component Primary Spectrum AMS-BESS fit 2001 Modified NASA spectrum [G.D.Badhwar and P.M.O'Neill, Adv. Space Res. Vol.17, No. 2 (1996) 7.] (proton and helium only) to take into account AMS 1998 and BESS data. S. Muraro Include Solar Modulation model  Date dependent

  20. Atmospheric muons at mountain altitude We compared FLUKA simulations with the experimental data of atmospheric muons taken at the top of Mt. Norikura, Japan, with the BESS detector. 2770 m above sea level (11.2 GV). The energy range for muons extends up to 100 GeV.

  21. BESS 99 @ Mt. NorikuraPhys. Lett. B 564 (2003), 8 – 20 2,700 m asl Geomagnetic Cut-off: 11.2 GV m- cone of ~11o Looks better at higher energies  FLUKA sim.  BESS data m+ S. Muraro

  22. All particle spectrum g~2.6

  23. The Proton Spectrum gp~2.7 Nice agreement among all techniques

  24. The Helium Spectrum gHe~2.55 Some discrepancies, but high He flux is preferred

  25. The CNO spectrum gCNO~2.55 At PeV energies the spectrum is divided only in 3-5 mass groups, therefore, fluxes might be slightly overestimated. Direct measurements report often C+O

  26. The Iron Spectrum gFe~2.55 gFe~2.65 CAUTION: the definition of Fe group depends on the experiment

  27. A plausible answer from the data…. g=2.65

More Related