Medium Effects of Low Energy Pions

E. Friedman

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Medium Effects of Low Energy Pions

E. Friedman

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Abstract

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.

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E. Friedman. 2003-10-01. Medium Effects of Low Energy Pions. https://arxiv.org/abs/nucl-th/0310002

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