Medium Effects of Low Energy Pions
Abstract
Description
Fits of pion-nucleus potentials to large sets of pionic atom data reveal departures of parameter values from the corresponding free $πN$ parameters. These medium effects can be quantitatively reproduced by a chiral-motivated model where the pion decay constant is modified in the medium or by including the empirical on-shell energy dependence of the amplitudes. No consistency is obtained between pionic atoms and the free $πN$ interaction when an extreme off-shell chiral model is used. The role of the size of data sets is briefly discussed.
12 pages, 3 figures, 1 table. To appear in Acta Physica Polonica B, proceedings of XXVIII Mazurian Lakes Conference on Physics
12 pages, 3 figures, 1 table. To appear in Acta Physica Polonica B, proceedings of XXVIII Mazurian Lakes Conference on Physics