Scattering ofK+Particles

An experiment has been performed to investigate the relative probability of scattering of $K_{\pi 2}$ and $\tau$ mesons. If, as is thought on the basis of the analysis of Dalitz and others, these particles differ in spin-parity properties, they may be expected to have different scattering cross sections, and the relative proportions of $\tau$ and $K_{\pi 2}$ mesons in a beam of scattered $K$ particles would differ from their relative proportions in a beam of directly-produced particles. In the present experiment, a measurement was made of the composition of a $K^{+}$-particle beam in which it is estimated that more than ∼75% of the particles had undergone scattering. Comparison with other results on the composition of beams consisting predominantly of directly-produced particles indicates that the relative numbers of $\tau$ and $K_{\pi 2}$ mesons are unchanged, within ∼30%. The results are therefore consistent with the assumption that the $\tau$ and $K_{\pi 2}$ are the same particle.