Consistency of pion-pion phase shifts with analyticity

Reanalysis of pion pion phase shifts from K → ππ decays

We re-investigate the impact of isospin violation for extracting the s-wave ππ scattering phase shift difference δ 0 (M K) − δ 2 (M K) from K → ππ decays. Compared to our previous analysis in 2003, more precise experimental data and improved knowledge of low-energy constants are used. In addition, we employ a more robust data-driven method to obtain the phase shift difference δ 0

Analyticity constrained pion-nucleon analysis

A brief progress report is given on the partial wave analysis of pion-nucleon scattering. Fixed-t constraints are implemented with the expansion techniques and for the forward amplitudes with accurate data a solution is found. Extending the analysis away from the forward direction will require a careful data amalgamation. c ­ Copyright owned by the author(s) under the terms of the Creative Comm...

Consistency of the chiral pion-pion scattering amplitudes with axiomatic constraints.

Pion interferometry with pion-source-medium interactions.

An extended pion source, which can be temporarily created by a high energy nuclear collision, will also absorb and distort the outgoing pions. We discuss how this effect alters the interferometric pattern of the two-pion momentum correlation function. In particular, we show that the two-pion correlation function decreases rapidly when the opening angle between the pions increases. The opening-a...

Pion - Pion Scattering Information

We show how the reaction e-e’+ n-n’y can be used to study the dipion system in states of even charge conjugation (and even angular momentum). In particular, its utility for experimentally investigating an I = 0, J = 0 resonance (e-meson) is discussed in detail. (Submitted to Phys. Rev. ) * Work supported by the U. S. Atomic Energy Commission. t N. S. F. Graduate Fellow. To lowest order in the f...