Amplitude analysis of $J/\psi \to K^0 \Sigma^+ \bar{p}$

by Lena Pöpping (Ruhr-Universitaet Bochum (DE))

Friday 9 Jan 2026, 14:30 → 15:15 Europe/Zurich

NB2/158 (RUB)

Abstract:

The search for excited nucleon and hyperon states is a challenging topic in hadron physics due to their highly non-perturbative three-quark nature.
The BESIII experiment produces a large number of $J/\psi$ mesons, which can be used to study excited nucleon and hyperon states in decays such as $J/\psi \to K^0 \Sigma^+ \bar{p}$, providing complementary information to data from scattering experiments.
This presentation covers the fundamentals of amplitude analysis for three-body decays, using the helicity formalism with Dalitz-plot decomposition to describe a spinful final state, before fitting the amplitude model to experimental data using the maximum-likelihood method.
The application of different energy-dependent parametrisations, such as the $K$-matrix formalism, are discussed, as well as the extraction of resonance properties by locating the poles of the amplitude in the complex energy plane.