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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 -

We report a measurement of the negative pion electromagnetic form factor in the range of space-like four-momentum transfer 0.014 < q2 < 0.122 (GeV/c)2. The measurement was made by the NA7 collaboration at the CERN SPS, by observing the interaction of 300 GeV pions with the electrons of a liquid hydrogen target. The form factor is fitted by a pole form with a pion radius of = 0.657 +- 0.012 fm

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The EM formfactor of the pion has been studied in the time-likeregion by measuring σ(e+e− → π+π−) normalized to σ(e+e− → μ+μ−). Results have been obtained for q2 down to the physical threshold