The (3π)-nucleon collision in coherent production on nuclei at 40 GeV/c

Coherent 3π production on nine different nuclear targets has been studied using a 40 GeV/c π− beam at the Serpukhov accelerator (CERN-Serpukhov experiment no. 5). The absorption in nuclear matter of the produced system has been measured, analysing the data on the different nuclear targets. Identica results are obtained from the differential cross sections and from the coherent nuclear cross sections. The 1+ waves show a very weak absorption, definitely smaller than 0− and 2− waves. No influence on the absorption comes from the spin-flip amplitudes, which have been found to be negligible in the coherent region.