Eur. Phys. J. A (2014) 50: 57
https://doi.org/10.1140/epja/i2014-14057-2

Regular Article - Theoretical Physics

Meson-baryon components in the states of the baryon decuplet

¹ Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Apartado 22085, 46071, Valencia, Spain
² Department of Physics, Liaoning Normal University, 116029, Dalian, China
³ Kavli Institute for Theoretical Physics China, 100190, Beijing, China
⁴ School of Physics and Nuclear Energy Engineering and International Research Center for Nuclei and Particles in the Cosmos, Beihang University, 100191, Beijing, China

^* e-mail: aceti@ific.uv.es

Received: 22 October 2013
Revised: 20 January 2014
Accepted: 19 February 2014
Published online: 18 March 2014

Abstract

We apply an extension of the Weinberg compositeness condition on partial waves of L = 1 and resonant states to determine the weight of the meson-baryon component in the Δ(1232) resonance and the other members of the baryon decuplet. We obtain an appreciable weight of πN in the Δ(1232) wave function, of the order of 60%, which looks more natural when one recalls that experiments on deep inelastic and Drell Yan give a fraction of πN component of 34% for the nucleon. We also show that, as we go to higher energies in the members of the decuplet, the weights of the meson-baryon component decrease and they already show a dominant part for a genuine, non-meson-baryon, component in the wave function. We write a section to interpret the meaning of the Weinberg sum rule when it is extended to complex energies and another one for the case of an energy-dependent potential.