Scalar mesons in a linear sigma model with (axial-)vector mesons

Understand

The structure of the scalar mesons has been a subject of debate for many decades.

• In this work we look for $\bar{q}q$ states among the physical resonances using an extended Linear Sigma Model that contains scalar, pseudoscalar, vector, and axial-vector mesons both in the non-strange and strange sectors.
• We perform global fits of meson masses, decay widths and amplitudes in order to ascertain whether the scalar $\bar{q}q$ states are below or above 1 GeV.
• We find the scalar states above 1 GeV to be preferred as $\bar{q}q$ states.