New insights on low energy $$\pi N$$ π N scattering amplitudes

π-N charge exchange and π +-π 0 scattering at low energies ∗

N = 4 scattering amplitudes and the deformed

Some time ago the general tree-level scattering amplitudes of N = 4 Super Yang–Mills theory were expressed as certain Graßmannian contour integrals. These remarkable formulas allow to clearly expose the super-conformal, dual super-conformal, and Yangian symmetries of the amplitudes. Using ideas from integrability it was recently shown that the building blocks of the amplitudes permit a natural ...

Multichannel parametrization of pi N scattering amplitudes and extraction of resonance parameters

We present results of a new multichannel partial-wave analysis for πN scattering in the c.m. energy range 1080 to 2100 MeV. This work explicitly includes ηN and KK channels and the single pion photoproduction channel. Resonance parameters were extracted by fitting partial-wave amplitudes from all considered channels using a multichannel parametrization that is consistent with S-matrix unitarity...

Separation of S – wave pseudoscalar and pseudovector amplitudes in π − p ↑ → π + π − n reaction on polarized target

Isospin Breaking Corrections to Low - Energy π − K Scattering

We evaluate the matrix elements for the processes π 0 K 0 → π 0 K 0 and π − K + → π 0 K 0 in the presence of isospin breaking terms at leading and next-to-leading order. As a direct application the relevant combination of the S-wave scattering lengths involved in the pion-kaon atom lifetime is determined. We discuss the sensitivity of the results with respect to the input parameters.