Abstract
A total of 34 000 coherent events, produced on different target nuclei and at incident pion momenta from 9 to 15 GeV/ c, allows us to discuss the energy dependence of the differential cross section and of the three-pion mass spectrum. The comparison with the optical model is satisfactory. This model is then used to determine the total cross section of the unstable three-pion system on nucleons; the result is a value of about 25 mb. The value of the forward differential cross section on nucleons obtained by application of the optical model shows a tendency to increase with incident energy. A similar increase with energy is found for the forward diffractive cross section of three-pion production on hydrogen; the absolute value of this cross section is somewhat higher than the cross section determined from nuclear targets. Also the mass spectrum on nucleons derived from the present experiment is compatible with that produced on hydrogen. Furthermore, there is no evidence for abundant coherent production of A 2 and A 3. On the other hand, these two resonances seem to be present in the incoherent background.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
