Coherent production on nuclei by $\pi$ and $K$ mesons (experiment)

Some experimental methods useful for detecting coherent processes are compared. Experimental results of coherent production by pi and K mesons are discussed. High statistics results were obtained from a counter experiment performed at CERN. The optical model for multiple scattering is shown to fit the data of 3 pi , 5 pi , and K pi pi production very well, while some doubts as to its application to K* (890) production remain. Coherent production of K*(890), a non- diffractive process, is clearly observed. A model for this process including Coulomb production, strong production, and their interference, is discussed. A fit to 10 data points, the integrated coherent production cross-sections on five elements and three beam momenta, gives 0< Gamma (K* to K gamma )<80 keV. (29 refs).