th / 9 71 10 58 v 1 2 6 N ov 1 99 7 Information entropy as a measure of the quality of a nuclear density distribution

ar X iv : n uc l - th / 9 71 10 54 v 1 2 6 N ov 1 99 7 The π + – emission puzzle in 4 Λ He decay

We re-examine the puzzling π emission from the weak decay of 4ΛHe and propose an explanation in terms of a three–body decay of the virtual Σ. Such a resolution of the π decay puzzle is consistent with the calculated Σ probability in light Λ hypernuclei as well as the experimentally observed π energy spectrum and s–wave angular distribution. Typeset using REVTEX

n uc l - th / 9 61 10 19 v 2 1 1 N ov 1 99 6 SUNY - NTG - 96 - 42 The Two - Pion Exchange NN Potential in Nuclear Matter and Nuclear Stability

A meson exchange model of the ππ interaction which fits free ππ scattering data is used to calculate the interactions of pions in nuclear matter as a function of nuclear density. Polarization of the nuclear medium by the pions results in a marked increase in the s-wave ππ attraction at low energy. The influence of this effect on the nucleon-nucleon interaction is a corresponding increase with d...

ar X iv : n uc l - th / 9 71 10 28 v 1 1 4 N ov 1 99 7 A clue to the mechanism of Λ K + production in pp - reactions ∗

ar X iv : n uc l - th / 9 71 10 31 v 1 1 8 N ov 1 99 7 HUPD - 9722 Effect of ρN channel in the γN → ππN reactions

n uc l - th / 9 71 10 53 v 1 2 5 N ov 1 99 7 USC ( NT ) - 97 - 09 , nucl - th / 9711053 Chiral Perturbation Theory

Chiral symmetry serves as a guiding principle in low-energy hadron dynamics. An effective lagrangian, which explicitly breaks chiral symmetry via a small mass term, allows for a systematic method of calculating higher order corrections to tree-level results. This is applied to radiative muon capture on hydrogen, and to proton-proton π 0 production near threshold. Both processes pose theoretical...