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Energy spectrum of hadrons in cosmic rays at sea level

Naturevolume 256pages387388 (1975) | Download Citation



BARUCH et al.1 have measured the energy spectrum of hadrons (nucleons and pions) in cosmic rays at sea level and have presented evidence for an anomalous behaviour in the energy range 2–8 TeV. For E < 2 TeV they find the differential vertical intensity to decrease with increasing energy as E−2.6±0.1, for 2 < E < 8 TeV the intensity is almost constant, and for E > 8 TeV the intensity again decreases with increasing energy (Fig. 1). The ‘step’ in the spectrum for 2 < E < 8 TeV is unexpected and Baruch et al. propose that it is produced by the interaction of a new particle, of rest mass 40–70 GeV c−2, mean lifetime > 2 × 10−7s and an interaction length of 1,000+1,000−700 gcm−2. We have made new measurements on the hadron spectrum at the higher energies in question.

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  1. 1

    Baruch, J. E. F., Brooke, G., and Kellerman, E. W., Nature, 242, 6–7 (1973); Proc. Int. Conf. Cosmic Rays (Denver), 3, 2301–2304 (1973).

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    Ashton, F., in Cosmic Rays at Ground Level (edit. by Wolfendale, A. W.), 57 (Institute of Physics, London, 1973).

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  1. Department of Physics, Durham University, Durham, UK

    • F. ASHTON
    •  & A. J. SALEH


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