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The negative kaon electromagnetic form factor has been measured in the space-like q2 range 0.015-0.10 (GeV/c)2 by the direct scattering of 250 GeV kaons from electrons at the CERN SPS. It is found that the kaon mean square charge radius = 0.34 +/- 0.05 fm2. From data collected simultaneously for πe scattering, the difference between the charged pion and kaon mean square radii (which is less sensitive to systematic errors) is found to be -

The amplitude and phase of the cosmic-ray anisotropy are well established experimentally between 10 11 eV and 10 14 eV. The study of their evolution in the energy region 10 14-10 16 eV can provide a significant tool for the understanding of the steepening ("knee") of the primary spectrum. In this Letter, we extend the EAS-TOP measurement performed at E 0 ≈ 10 14 eV to higher energies by using the full data set (eight years of data taking). Results derived at about 10 14 and 4 × 10 14 eV are compared and discussed. Hints of increasing amplitude and change of phase above 10 14 eV are reported. The significance of the observation for the understanding of cosmic-ray propagation is discussed.

The extended TeV gamma-ray source ARGO J2031+4157 (or MGRO J2031+41) is positionally consistent with the Cygnus Cocoon discovered by Fermi-LAT at GeV energies in the Cygnus superbubble. Reanalyzing the ARGO-YBJ data collected from 2007 November to 2013 January, the angular extension and energy spectrum of ARGO J2031+4157 are evaluated. After subtracting the contribution of the overlapping TeV sources, the ARGO-YBJ excess map is fitted with a two-dimensional Gaussian function in a square region of 10 • × 10 • , finding a source extension σ ext = 1. • 8 ± 0. • 5. The observed differential energy spectrum is dN/dE = (2.5 ± 0.4) × 10 −11 (E/1 TeV) −2.6±0.3 photons cm −2 s −1 TeV −1 , in the energy range 0.2-10 TeV. The angular extension is consistent with that of the Cygnus Cocoon as measured by Fermi-LAT and the spectrum also shows a good connection with the one measured in the 1-100 GeV energy range. These features suggest to identify ARGO J2031+4157 as the counterpart of the Cygnus Cocoon at TeV energies. The Cygnus Cocoon, located in the star-forming region of Cygnus X, is interpreted as a cocoon of freshly accelerated cosmic rays related to the Cygnus superbubble. The spectral similarity with supernova remnants (SNRs) indicates that the particle acceleration inside a superbubble is similar to that in an SNR. The spectral measurements from 1 GeV to 10 TeV allows for the first time to determine the possible spectrum slope of the underlying particle distribution. A hadronic model is adopted to explain the spectral energy distribution.

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