engleski

In-medium production of 2Pi^0, Eta, and Pi^0 by Pi^- at 750 MeV/c

We present new data on 2pi0 production by 750 MeV/c pi-on hydrogen and the complex nuclei C, Al, and Cu, in search of the proposed medium modifications of the f0(400-1200), or sigma, state. We have found that the pi0pi0 invariant mass spectra for the four targets are different. The data indicate that nuclear absorption is mainly responsible for the change in the shape of the 2pi0 invariant mass spectra for the complex targets. There is no hint of a narrow peak in the pipi invariant mass around 2mpi. We have also measured single pi0 and eta production on the above nuclei, in support of our investigation of nuclear final-state interaction processes. We observed strong eta absorption in nuclei.

in-medium production

nije evidentirano