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Title: North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment

Abstract

The north-south asymmetry for cosmic-ray particles was measured with one instrument of the PAMELA satellite-borne experiment in the period June 2006-May 2009. The analysis has been performed by two independent methods: by comparing the count rates in regions with identical geomagnetic conditions and by comparing the experimental distribution of particle directions with the simulated distribution that would be in the case of an isotropic particle flux. The dependences of the asymmetry on energy release in the PAMELA calorimeter and on time have been constructed. The asymmetry (N{sub n} - N{sub s})/(N{sub n} + N{sub s}) is 0.06 {+-} 0.004 at the threshold energy release in the calorimeter and gradually decreases with increasing energy release. The observed effect is shown to be produced by electrons in the energy range 10-100 GeV.

Authors:
 [1];  [2];  [3];  [4];  [5];  [6];  [7]; ;  [2];  [6];  [2];  [5];  [6];  [2];  [7]; ; ;  [1]; ;  [8] more »; « less
  1. 'MEPhI' National Research Nuclear University (Russian Federation)
  2. Structure of Florence and Physics Department of University of Florence, INFN (Italy)
  3. Structure of Naples and Physics Department of University of Naples, INFN (Italy)
  4. Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)
  5. Structure of Bari and Physics Department of University of Bari, INFN (Italy)
  6. Structure of Trieste and Physics Department of University of Trieste, INFN (Italy)
  7. Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
  8. Structure of Rome Tor Vergata and Physics Department of University of Rome Tor Vergata, INFN (Italy)
Publication Date:
OSTI Identifier:
22210513
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 117; Journal Issue: 2; Other Information: Copyright (c) 2013 Pleiades Publishing, Ltd.; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AUGMENTATION; CALORIMETERS; COMPARATIVE EVALUATIONS; COSMIC RADIATION; COUNTING RATES; DISTRIBUTION; ELECTRONS; GEV RANGE; NORTH-SOUTH ASYMMETRY; PARTICLES; SATELLITES; SIMULATION; THRESHOLD ENERGY

Citation Formats

Karelin, A. V., E-mail: karelin@hotbox.ru, Adriani, O., Barbarino, G. C., Bazilevskaya, G. A., Bellotti, R., Boezio, M., Bogomolov, E. A., Bonechi, L., Bongi, M., Bonvicini, V., Bottai, S., Bruno, A., Vacchi, A., Vannuccini, E., Vasilyev, G. I., Voronov, S. A., Galper, A. M., Danilchenko, I. A., Donato, C. De, Santis, C. De, and and others. North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment. United States: N. p., 2013. Web. doi:10.1134/S1063776113100129.
Karelin, A. V., E-mail: karelin@hotbox.ru, Adriani, O., Barbarino, G. C., Bazilevskaya, G. A., Bellotti, R., Boezio, M., Bogomolov, E. A., Bonechi, L., Bongi, M., Bonvicini, V., Bottai, S., Bruno, A., Vacchi, A., Vannuccini, E., Vasilyev, G. I., Voronov, S. A., Galper, A. M., Danilchenko, I. A., Donato, C. De, Santis, C. De, & and others. North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment. United States. doi:10.1134/S1063776113100129.
Karelin, A. V., E-mail: karelin@hotbox.ru, Adriani, O., Barbarino, G. C., Bazilevskaya, G. A., Bellotti, R., Boezio, M., Bogomolov, E. A., Bonechi, L., Bongi, M., Bonvicini, V., Bottai, S., Bruno, A., Vacchi, A., Vannuccini, E., Vasilyev, G. I., Voronov, S. A., Galper, A. M., Danilchenko, I. A., Donato, C. De, Santis, C. De, and and others. Thu . "North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment". United States. doi:10.1134/S1063776113100129.
@article{osti_22210513,
title = {North-south asymmetry for high-energy cosmic-ray electrons measured with the PAMELA experiment},
author = {Karelin, A. V., E-mail: karelin@hotbox.ru and Adriani, O. and Barbarino, G. C. and Bazilevskaya, G. A. and Bellotti, R. and Boezio, M. and Bogomolov, E. A. and Bonechi, L. and Bongi, M. and Bonvicini, V. and Bottai, S. and Bruno, A. and Vacchi, A. and Vannuccini, E. and Vasilyev, G. I. and Voronov, S. A. and Galper, A. M. and Danilchenko, I. A. and Donato, C. De and Santis, C. De and and others},
abstractNote = {The north-south asymmetry for cosmic-ray particles was measured with one instrument of the PAMELA satellite-borne experiment in the period June 2006-May 2009. The analysis has been performed by two independent methods: by comparing the count rates in regions with identical geomagnetic conditions and by comparing the experimental distribution of particle directions with the simulated distribution that would be in the case of an isotropic particle flux. The dependences of the asymmetry on energy release in the PAMELA calorimeter and on time have been constructed. The asymmetry (N{sub n} - N{sub s})/(N{sub n} + N{sub s}) is 0.06 {+-} 0.004 at the threshold energy release in the calorimeter and gradually decreases with increasing energy release. The observed effect is shown to be produced by electrons in the energy range 10-100 GeV.},
doi = {10.1134/S1063776113100129},
journal = {Journal of Experimental and Theoretical Physics},
number = 2,
volume = 117,
place = {United States},
year = {Thu Aug 15 00:00:00 EDT 2013},
month = {Thu Aug 15 00:00:00 EDT 2013}
}
  • The deflection of electrons in the Earth's magnetic field in the energy range 75-250 GeV (the so-called east-west effect) has been measured with the PAMELA satellite-borne experiment. The results are presented for various L-shells. The data obtained can be used to construct mathematical models that describe the structure of the Earth's magnetic field and to refine the already existing models. These data can also be directly applied to estimate the positron fraction in cosmic-ray electron fluxes both in the PAMELA experiment and in other satellite-borne experiments.
  • Using a data base extending from 1955 through 1980 we find that the northern hemisphere of the sun was decidedly more active than the southern hemisphere for the period 1959 through 1970. From 1971 through 1980 there was no systematic asymmetry. Extending the time period through 1984, but using a different data base, we find an apparent change around October 1982, after which there are decidedly more flares occurring in the southern hemisphere of the sun than in the northern hemisphere. Examination of the diurnal variation amplitude present in the extremely high energy (approximately 100 GeV) cosmic radiation measurements indicatesmore » a consistent north/south asymmetry until about 1971 which we suggest is the result of the asymmetric solar activity.« less
  • Data are presented from underground cosmic ray telescopes in both the northern and southern hemisphere from 1965 to 1983, analyzed as a function of interplanetary magnetic field (IMF) sense, to examine the long-term properties of the cosmic ray density gradient perpendicular to the ecliptic plane, delN/sub p/. Yearly cosmic ray solar diurnal variation vectors for IMF (B) away from and toward the sun are obtained; these vectors include a contribution from the B x delN/sub p/ anisotropy, from which the predominant direction of the perpendicular gradient, delN/sub p/, is inferred. These data are compared with the north-south asymmetry in activitymore » on the sun for the same period, based both on comprehensive flare index data and on solar events associated with type II radio emission. The cosmic ray data up to the 1969-1971 solar polar field reversal are consistent with a perpendicular cosmic ray gradient pointing southward, observed by telescopes in both hemispheres. The solar activity data indicate a statistically significant excess of activity in the sun's northern hemisphere from 1959 through 1970, which may well be the cause for this southward perpendicular cosmic ray gradient during this period. After the 1969-1971 reversal the solar activity data become reasonably symmetrically divided between the two solar hemispheres. The northern hemisphere cosmic ray data show some evidence of a northward pointing cosmic ray gradient after 1971, while data from the southern hemisphere telescopes continue to indicate a southward pointing gradient.« less
  • The north--south asymmetry of ionizing cosmic rays was measured in Turku, Finland, in the geomagnetic latitude of 58.3 deg N and at the altitude of 49 m above the sea level at the zenith angle of 80 deg . The result obtained, A = 0.107, supports Burhury's view of the onigin of this asymmetry. (auth)