PAMELA measurements of cosmic-ray proton and helium spectra

Science

Volumn 332, Issue 6025, 2011, Pages 69-72

  Adriani, O ^a,b   Barbarino, G C ^c,d   Bazilevskaya, G A ^e   Bellotti, R ^f,g   Boezio, M ^h   Bogomolov, E A ⁱ   Bonechi, L ^a,b   Bongi, M ^b   Bonvicini, V ^h   Borisov, S ^j,k,l   Bottai, S ^b   Bruno, A ^f,g   Cafagna, F ^g   Campana, D ^d   Carbone, R ^d,k   Carlson, P ^m   Casolino, M ^j   Castellini, G ⁿ   Consiglio, L ^d   De Pascale, M P ^j,k   De Santis, C ^j,k   De Simone, N ^j,k   Di Felice, V ^j   Galper, A M ^l   Gillard, W ^m   Grishantseva, L ^l   Jerse, G ^h,o   Karelin, A V ^l   Koldashov, S V ^l   Krutkov, S Y ⁱ   Kvashnin, A N ^e   Leonov, A ^l   Malakhov, V ^l   Malvezzi, V ^j   Marcelli, L ^j   Mayorov, A G ^l   Menn, W ^p   Mikhailov, V V ^l   Mocchiutti, E ^h   Monaco, A ^f,g   Mori, N ^a,b   Nikonov, N ^i,j,k   Osteria, G ^d   Palma, F ^j,k   Papini, P ^b   Pearce, M ^m   Picozza, P ^j,k   Pizzolotto, C ^h   Ricci, M ^q   Ricciarini, S B ^b   Rossetto, L ^m   Sarkar, R ^h   Simon, M ^p   Sparvoli, R ^j,k   Spillantini, P ^a,b   Stozhkov, Y I ^e   Vacchi, A ^h   Vannuccini, E ^b   Vasilyev, G ⁱ   Voronov, S A ^l   Yurkin, Y T ^l   Wu, J ^m,r   Zampa, G ^h   Zampa, N ^h   Zverev, V G ^l   more..

^a UNIVERSITY OF FLORENCE   (Italy)

^b INFN SEZIONE DI FIRENZE   (Italy)

^c UNIVERSITY OF NAPLES FEDERICO II   (Italy)

^d INFN SEZIONE DI NAPOLI   (Italy)

^e LEBEDEV PHYSICAL INSTITUTE   (Russian Federation)

^f UNIVERSITY OF BARI   (Italy)

^g INFN SEZIONE DI BARI   (Italy)

^h SEZIONE DI TRIESTE   (Italy)

ⁱ IOFFE INSTITUTE   (Russian Federation)

^j INFN SEZIONE DI ROMA   (Italy)

^k UNIVERSITY OF ROME TOR VERGATA   (Italy)

^l NATIONAL RESEARCH NUCLEAR UNIVERSITY MEPHI   (Russian Federation)

^m ALBANOVA UNIVERSITY CENTER   (Sweden)

ⁿ IFAC CNR   (Italy)

^o UNIVERSITY OF TRIESTE   (Italy)

^p UNIVERSITY OF SIEGEN   (Germany)

^q INFN LABORATORI NAZIONALI DI FRASCATI   (Italy)

^r CHINA UNIVERSITY OF GEOSCIENCES   (China)

more..

Author keywords

[No Author keywords available]

Indexed keywords

HELIUM; PROTON;

ACCELERATION; COSMIC RAY; HELIUM; PLANETARY ATMOSPHERE; POWER LAW; SPECTRUM;

ACCURACY; ARTICLE; ASTRONOMY; CHEMICAL STRUCTURE; COSMIC RADIATION; MAGNETIC FIELD; PRIORITY JOURNAL;

EID: 79953268948     PISSN: 00368075     EISSN: 10959203     Source Type: Journal    
DOI: 10.1126/science.1199172     Document Type: Article

References (37)

1. P. O. Lagage, C. J. Cesarsky, Astron. Astrophys. 118, 223 (1983).
2. V. L. Ginzburg, S. I. Syrovatskii, The Origin of Cosmic Rays (Macmillan, New York, 1964).
3. M. A. Malkov, L. O.'C. Drury, Rep. Prog. Phys. 64, 429 (2001).
4. A. W. Strong, I. V. Moskalenko, Astrophys. J. 509, 212 (1998).
5. F. C. Jones, A. Lukasiak, V. Ptuskin, W. Webber, Astrophys. J. 547, 264 (2001).
6. F. Donato et al., Astrophys. J. 563, 172 (2001).
7. M. Amenomori et al., Science 314, 439 (2006).
8. O. Adriani et al., Nature 458, 607 (2009).
9. O. Adriani et al., Phys. Rev. Lett. 102, 051101 (2009).
10. O. Adriani et al., Phys. Rev. Lett. 105, 121101 (2010).
11. C. Grimani, Class. Quantum Gravity 26, 235009 (2009).
12. N. Arkani-Hamed, D. P. Finkbeiner, T. R. Slatyer, N. Weiner, Phys. Rev. D 79, 015014 (2009).
13. G. Kane, R. Lu, S. Watson, Phys. Lett. B 681, 151 (2009).
14. PAMELA comprises a number of high-performance detectors, capable of identifying particles through the determination of charge (Z), rigidity (R = pc/|Z|e, where p is the momentum of a particle of charge Ze, c is the speed of light, and e is the electron charge), and velocity (β = v/c, where v is the velocity) over a wide energy range. The device is built around a permanent magnet with a six-plane double-sided silicon microstrip tracker, providing absolute charge information and track-deflection (η = ±1/R, with the sign depending on the sign of the charge derived from the curvature direction) information. A scintillator system, composed of three double layers of scintillators (S1, S2, S3 in fig. S2) provides the trigger, a time-of-flight measurement, and an additional estimation of absolute charge. A silicontungsten tracking calorimeter, a bottom scintillator (S4), and a neutron detector are used to perform leptonhadron discrimination. An anticoincidence system is used off-line to reject spurious event triggers generated by particles interacting in the apparatus. Respect to balloonborne experiments, PAMELA has the advantage of a substantially longer period of uninterrupted observing time. Furthermore, taking data in space is not affected by environmental systematics such as those due to correction for secondary particles produced in the residual atmosphere that affects balloon-borne experiments. A more detailed description of PAMELA and the analysis methodology can be found in (32, 33) and in the SOM.
15. L. J. Gleeson, W. I. Axford, Astrophys. J. 154, 1011 (1968).
16. J. P. Wefel et al., in Proceedings of the 30th International Cosmic Ray Conference, R. Caballero et al., Eds. (Universidad Nacional Autónoma de México, Mexico City, 2008), vol. 2, pp. 31-34.
17. H. S. Ahn et al., Astrophys. J. Lett. 714, L89 (2010).
18. K. Asakimori et al., Astrophys. J. 502, 278 (1998).
19. M. Hareyama, RUNJOB collaboration, J. Phys. Conf. Ser. 31, 159 (2006).
20. W. Menn et al., Astrophys. J. 533, 281 (2000).
21. M. Boezio et al., Astrophys. J. 518, 457 (1999).
22. M. Boezio et al., Astropart. Phys. 19, 583 (2003).
23. S. Haino et al., Phys. Lett. B 594, 35 (2004).
24. AMS Collaboration, Phys. Lett. B 490, 27 (2000).
25. A. W. Strong, I. V. Moskalenko, V. S. Ptuskin, Annu. Rev. Nucl. Part. Sci. 57, 285 (2007).
26. The changing spectral characteristics of the proton spectrum between 30 and 230 GV may be partly due to heliospheric effects. Although solar-modulation effects are considered negligible above 30 GV in the spherical force-field approximation (15), more detailed models, which use the full Parker equation to describe the propagation of cosmic rays in a two- or three-dimensional heliosphere (34, 35), may be needed to fully understand the impact of this effect.
27. D. Caprioli, P. Blasi, E. Amato, Astroparticle Phys.; preprint available at http://arxiv.org/abs/1007.1925.v2 (2010).
28. D. C. Ellison, D. J. Patnaude, P. Slane, P. Blasi, S. Gabici, Astrophys. J. 661, 879 (2007).
29. V. I. Zatsepin, N. V. Sokolskaya, Astron. Astrophys. 458, 1 (2006).
30. T. Sanuki et al., Adv. Space Res. 27, 761 (2001).
31. H. S. Ahn et al., Adv. Space Res. 37, 1950 (2006).
32. P. Picozza et al., Astropart. Phys. 27, 296 (2007).
33. M. Casolino et al., Adv. Space Res. 42, 455 (2008).
34. J. R. Jokipii, E. H. Levy, W. B. Hubbard, Astrophys. J. 213, 861 (1977).
35. M. S. Potgieter, J. Atmos. Sol. Terr. Phys. 70, 207 (2008).
36. A. E. Vladimirov et al., preprint available at http://arxiv. org/abs/1008.3642v1 (2010).
37. We thank P. Blasi, F. Donato, P. Lipari, and I. Moskalenko for helpful discussions concerning the interpretation of our results and D. Marinucci for helpful discussions on statistical methods. We acknowledge support from the Italian Space Agency, Deutsches Zentrum für Luft- und Raumfahrt, the Swedish National Space Board, the Swedish Research Council, the Russian Space Agency (Roscosmos), and the Russian Foundation for Basic Research.