Elementary-particle approach to some nuclear pion reactions

An Elementary Approach to Some Analytic Asymptotics

Fredman and Knuth have treated certain recurrences, such as M(O) 1 and M(n + 1) min (aM(k) + 3M(nk)) O 1, by means of auxiliary recurrences such as J" 0 if 0 _< x < 1, h(x) l+h(x/cz)+h(x//) ifl_<x< The asymptotic behavior of h(x) as x oo with a and 3 fixed depends on whether log a/logf is rational or irrational. The solution of Fredman and Knuth used analytic methods in bo...

Asymptotic Behavior of Pion Clusters in Different Nuclear Reactions

Diffusion - Limited Aggregation Processes with 3 - Particle Elementary Reactions

A diffusion-limited aggregation process, in which clusters coalesce by means of 3-particle reaction, A + A + A → A, is investigated. In one dimension we give a heuristic argument that predicts logarithmic corrections to the mean-field asymptotic behavior for the concentration of clusters of mass m at time t, C m (t) ∼ m −1/2 (log(t)/t) 3/4 , for 1 ≪ m ≪ t/ log(t). The total concentration of clu...

In-Medium Properties of Vector Mesons in Elementary Nuclear Reactions

While the vacuum properties of most hadrons are known to reasonable accuracy today, it is a much-debated question how these properties change in nuclear matter. In particular for the light vector mesons there have been various theoretical predictions regarding their in-medium properties. One of the expected in-medium effects is the so-called ’collisinal broadening’ of the meson spectral functio...

Double Pion Production Reactions

We report on reactions producing two pions induced by real and virtual photons or nucleons. The role of different resonances in these reactions is emphasized. Novel results on coherent 2π photoproduction in nuclei are also reported. 1 Double pion photoproduction on the nucleon. The γN → π+π−N reaction is attracting attentions of both theoretical and experimental groups and is bound to play a si...