Year: 2018
Type: article
Abstract: We use a symmetry-preserving truncation of meson and baryon bound-state equations in quantum field theory in order to develop a unified description of systems constituted from light and heavy quarks. In particular, we compute the spectrum and leptonic decay constants of ground-state pseudoscalar and vector mesons: ${q}^{\ensuremath{'}}\overline{q}$, ${Q}^{\ensuremath{'}}\overline{Q}$, with ${q}^{\ensuremath{'}}$, $q=u$, $d$, $s$ and ${Q}^{\ensuremath{'}}$, $Q=c$, $b$, and the masses of ${J}^{P}=3/{2}^{+}$ baryons and their first positive-parity excitations, including those containing one or more heavy quarks. This Poincar\'e-covariant analysis predicts that such baryons have a complicated angular momentum structure. For instance, the ground states are all primarily $S$ wave in character, but each possesses $P$-, $D$- and $F$-wave components, with the $P$-wave fraction being large in the $qqq$ states, and the first positive-parity excitation in each channel having a large $D$-wave component, which grows with increasing current-quark mass, but also exhibits features consistent with a radial excitation. The configuration space extent of all such baryons decreases as the mass of the valence-quark constituents increases.
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2786750519