Search

Recently, we completed a comprehensive investigation of a huge part of the entire meson spectrum by considering both quarkonia and open-flavour mesons by means of a single common framework which unites the homogeneous Bethe-Salpeter equation that describes mesons as quark-antiquark bound states and the Dyson-Schwinger equation that governs the full quark propagator: Adopting two (as a matter of fact, not extremely diverse) models that attempt to grasp all principal aspects of the effective strong interactions entering identically in both these equations, we derived within this unique setup, for all mesons analysed, their masses and leptonic decay constants as well as, for the pseudoscalar ones among these mesons, their in-hadron condensates. Here, as a kind of promotion or teaser, we give but a few examples of the resulting collections of data, laying the main emphasis on the dependence of our insights on the effective-interaction model underlying all such outcomes., Comment: 8 pages, 6 figures, contributed to "XIII Quark Confinement and the Hadron Spectrum - Confinement2018" (31 July - 6 August 2018, Maynooth University, Ireland)

Exploiting an interplay of the Bethe-Salpeter equation enabling us to regard mesons as bound states of quark and antiquark and the Dyson-Schwinger equation controlling the dressed quark propagator, we amend existing studies of quarkonia by a comprehensive description of open-flavour mesons composed of all conceivable combinations of quark flavour. Employing throughout a fixed set of model parameters, we predict some basic characteristics of these mesons, i.e., their masses, leptonic decay constants and corresponding in-hadron condensates entering in a generalized formulation of the Gell-Mann-Oakes-Renner relation., Comment: 5 pages, 6 figures, contributed to "QCD@Work 2018 - International Workshop on Quantum Chromodynamics: Theory and Experiment" (25 - 28 June 2018, Matera, Italy)

We discuss charmed mesons in the covariant Dyson-Schwinger-Bethe-Salpeter-equation approach. In particular we computed masses, leptonic decay constants, and an orbital-angular-momentum decomposition for a basic set of states. We also report an efficient way to treat the two coupled quark propagator dressing functions via a single function., Comment: 10 pages, 8 figures, 'XII Confinement and the hadron spectrum'-proceedings contribution

In a covariant Bethe-Salpeter-equation approach and with a rainbow-ladder truncated model of QCD, we investigate the use of an effective interaction with the goal of reproducing QCD phenomenology. We extend previous studies and present results for ground and excited meson states in the bottomonium and charmonium systems, where the results are surprisingly good for most states. In addition, we formulate a critical outlook on states with exotic quantum numbers as well as the light-quark domain., Comment: 9 pages, 7 figures, re-revised version incorporating reviewer comments

Following up on earlier work, we investigate possible effects of a dressed quark-gluon vertex in heavy-light mesons. In particular, we study corrections to the popular rainbow-ladder truncation of the Dyson-Schwinger-Bethe-Salpeter equation system. We adopt a simple interaction kernel which reduces the resulting set of coupled integral equations to a set of coupled algebraic equations, which are solved numerically. In this way, we extend previous studies to quark-antiquark systems with unequal current-quark masses, at first for the pseudoscalar case, and investigate the resulting set of problems and solutions. We attempt to find patterns in - as well as to quantify corrections to - the rainbow-ladder truncation. In addition, we open this approach to phenomenological predictions of the heavy quark symmetry., Comment: 6 pages, 8 figures, presented by Maria Gomez-Rocha at Light-Cone 2014, NC State University, Raleigh, USA, 26 - 30 May, 2014, updated regarding reviewer comments

We investigate capabilities of the effective interaction in a rainbow-ladder truncated meson model of QCD within a covariant Landau-gauge Bethe-Salpeter-equation approach. Based upon past success for the light- as well as heavy-quark domains, we discuss the range of applicability and features of an effort with comprehensive phenomenological claim and goals., Comment: 6 pages, 2 figures, talk presented by C. Popovici at Light-Cone 2014, NC State University, Raleigh, USA, 26 - 30 May, 2014; added/updated references

We study hadronic decays of mesons and baryons in the context of the Dyson-Schwinger equations of QCD. Starting from a well-established effective interaction in rainbow-ladder truncation, we consistently calculate all ingredients of the appropriate decay diagrams. The resulting strong couplings are presented as functions of the quark mass from the chiral limit up to the respective decay thresholds. In particular, we investigate the \rho \pi \pi and for the first time the \Delta N \pi transitions. Both meson and baryon results compare well to available lattice QCD results as well as experimental data and present the first step towards a comprehensive covariant study of hadron resonances in the Dyson-Schwinger approach.

Employing an approach based on the Green functions of Landau-gauge QCD, some selected results from a calculation of meson and baryon properties are presented. A rainbow-ladder truncation to the quark Dyson-Schwinger equation is used to arrive at a unified description of mesons and baryons by solving Bethe-Salpeter and covariant Faddeev equations, respectively., Comment: 6 pages, 4 figures; Plenary talk given at the 5-th Int. Conf. on Quarks and Nuclear Physics, Beijing, September 21-26,2009

We present selected results from a calculation of meson and nucleon observables in a Green-function approach. A rainbow-ladder truncation of QCD's Dyson-Schwinger equations is used to solve the respective meson, diquark and quark-diquark Bethe-Salpeter equations. It allows for a simultaneous description of meson and nucleon masses and electromagnetic properties from an effective quark-gluon interaction. The results describe a hadronic quark core which agrees with lattice data for heavy quarks whereas pion-cloud effects are missing towards the chiral limit. The neutron's Dirac form factor is negative due to the presence of axial-vector diquark correlations., Comment: 5 pages, 2 figures; talk given at the 8th Conference "Quark Confinement and the Hadron Spectrum", Mainz, Germany, September 1-6, 2008