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On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times from extensive air showers: Application for Pierre Auger Observatory. N . Arsene 1,2 , H. Rebel 3 , O. Sima 2
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On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times from extensive air showers: Application for Pierre Auger Observatory. N. Arsene1,2, H. Rebel 3, O. Sima 2 1ISS Bucharest, Romania, 2University of Bucharest, Romania, 3KIT, Karlsruhe, Germany
Content : • Cosmic rays energy spectrum • Extensive air showers (EAS) • EAS experimental techniques at the Pierre Auger Observatory (PAO) • Methods to determine mass of primary cosmic ray • On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times • Results and outlook
1. Cosmic rays energy spectrum Greisen–Zatsepin–Kuzmin cutoff (GZK cutoff) 5 x 1019 eV
2. Extensive air showers (EAS) ( Xmaxp - XmaxFe ) ≈100 g cm-2 Gaisser–Hillas : Nishimura–Kamata–Greisen (NKG) approximation : Nch = the total number of charged particles s = “age” parameter r0 = Moliere radius ~ 79 m C = constant
2. Extensive air showers (EAS) Heck D. et al.[3] Longitudinal EAS development. MC simulations with CORSIKA
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Southern Hemisphere, Argentina Surface 3000 km2 1600 surface detectors water Cherenkov (SD) 4 stations fluorescence detectors A. Creusot [4]
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Water Cherenkov tanks AUGER COLABORATION [5] altitude 1500 m diameter 3.6 m height 1.55 m detects : muons, electrons, positrons, photons
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Surface detectors reconstruction AUGER COLABORATION [5] , Eveniment recorded by Pierre Auger Observatory , E = 5 x 1018 eV Primary energy :
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Fluorescence detectors (FD) Jos Bellido, for the ́ Pierre Auger Collaboration [6] 3.5 m x 3.5 m spherical mirror -> 440 PMT camera Field of view 300 azimuth x 28.60 elevation 1 pixel -> 1.50
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Fluorescence detectors (FD) reconstraction Shower Detector Plane reconstruction : nSDP errors ̴ tenths of a degree Shower Axis reconstruction : AUGER COLABORATION [5] Shower axis errors ̴ 1 degree
3. EAS experimental techniques at the Pierre Auger Observatory (PAO) Fluorescence detectors (FD) reconstraction AUGER COLABORATION [5] Eveniment recorded by PAO, zenith angle = 56º , distance core - FD detector = 13 km
4. Methods to determine mass of primary cosmic ray Dependence of Xmax : M. Risse [8] Longitudinal showers profile . MC simulations, E=10^19 eV, vertical
4. Methods to determine mass of primary cosmic ray Correlation between Xmax and Nµ (Patrick Younk and Markus Risse, 2009) : Patrick Younka, Markus Rissea [9] Xmax - Nµ distribution , E = 1019 eV, zenith = 45 ͦ. Average per 1000 simulations using Conex code with QGSJET-01 model • Ideal detectors • Real detectors : σ Nµ = 20 % • σXmax = 20 g cm-2
4. Methods to determine mass of primary cosmic ray Time asymmetry in the shower development Hernan Wahlberg, for the Pierre Auger Collaboration [10] Position of maximum asymmetry vs. primary energy for different models and primaries. Hernan Wahlberg, for the Pierre Auger Collaboration [10] Asymmetry development for the different samples t ½ = mean risetime r = radius ζ = azimuth angle Θ = zenith angle
5. On the possibility to discriminate the mass of the primary cosmic ray using the muon arrival times Proposed by H. Rebel et al. for KASCADE colaboration, 2003 [12]
6. Results and outlook Azimuthal distributions of muons in observable plane.p, E=8x10^17eV, zenith=30,S->N, CORSIKA - QGSJET01 model
6. Results and outlook Momentum distribution of muons at ground , CORSIKA simulations – QGSJET01 model
6. Results and outlook Distribution of arrival times of muons at ground , CORSIKA simulations – QGSJET01 model
6. Results and outlook Distribution of the reconstructed atmospheric depth of muon production , CORSIKA simulations – QGSJET model
6. Results and outlook Distribution of the reconstructed atmospheric depth of muon production using infill array detectors, average over 10 simulations (left) and 100 simulations (right) 30 +/- 3 muons in infill detectors Fe, E=8x10^17 eV 20 +/- 2 muons in infill detectors p, E=8x10^17 eV Xmax mup≈400 g cm-2 Xmax muFe ≈250 g cm-2
6. Outlook Average number of muons per square meter as a function of radial distance to the core of the shower. Averaged over 100 showers with one sigma as error bars. Zero inclination. [11] • - Analisys of a large set of CORSIKA simulations with primary energy above 10^18 eV • - Find maximum distribution of the reconstructed atmospheric depth of muons production • Possibility to implement this method as a complementary method for determine the primary cosmic ray mass • in Pierre Auger Experiment
Bibliography : [1] Engel R. et. Al. 2011, Annu Rev. Nucl. Part. Sci. 61:467-89 [2] Diego GarcaGamez, 2010, Dpto. de FsicaTeorica y del Cosmos & CAFPE Universidad de Granada [3] Heck D et al 1998 FZKA Report Forschungszentrum Karlsruhe 6019 [4] A. Creusot, 2010, Latest results of the Pierre Auger Observatory, Nuclear Instruments and Methods in Physics Research A 662 (2012) S106–S112 [5] AUGER COLABORATION, Properties and performance of the prototype instrument for the Pierre Auger Observatory, Nuclear Instruments and Methods in Physics Research A 523 (2004) 50–95 [6] JosBellido, for the ́ Pierre Auger Collaboration, Mass Composition Studies of the Highest Energy Cosmic Rays, arXiv:0901.3389v1 [astro-ph.HE]. [7] M. Unger, et al [Pierre Auger Collaboration], Proc. 30th ICRC, , Merida, (2007), arXiv:0706.1495v1 [astro-ph]. [8] M. Risse, ActaPhys.Polon. B35 ,1787, (2004), arXiv:astro-ph/0402300v1. [9] Patrick Younka, Markus Rissea, Sensitivity of the correlation between the depth of shower maximum and the muon shower size to the cosmic ray composition, 10.1016/j.astropartphys.2012.03.001. [10] HernanWahlberg, for the Pierre Auger Collaboration, Mass composition studies using the surface detector of the Pierre Auger Observatory , Nuclear Physics B (Proc. Suppl.) 196 (2009) 195–198 . [11] Jochem D. Haverhoek, 2006 , Ultra High Energy Cosmic Ray Extensive Air Shower simulations using CORSIKA [12]I.M.Brancus ,H.Rebel, A.F.Badea et. al. J.Phys.G29:453-474,2003 Features of Muon Arrival Time Distributions of High Energy EAS at Large Distances From the Shower Axis
M. Unger, et al [7] Auger results for the Mean Xmax measurements as a function of energy