Two-body Wave Functions, Compositeness, And The Internal Structure Of Dynamically Generated Resonances

摘要

Recently, the compositeness, defined as the norm of a two-body wave functionfor bound and resonance states, has been investigated to discuss the internalstructure of hadrons in terms of hadronic molecular components. From thestudies of the compositeness, it has been clarified that the two-body wavefunction of a bound state can be extracted from the residue of the scatteringamplitude at the bound state pole. Of special interest is that the two-bodywave function from the scattering amplitude is automatically normalized. Inparticular, while the compositeness is unity for energy-independentinteractions, it deviates from unity for energy-dependent interactions, whichcan be interpreted as a missing-channel contribution. In this manuscript, weshow the formulation of the two-body wave function from the scatteringamplitude, evaluate the compositeness for several dynamically generatedresonances such as $f_{0} (980)$, $\Lambda (1405)$, and $\Xi (1690)$, andinvestigate their internal structure in terms of the hadronic molecularcomponents.