Related papers: A covariant study of tensor mesons
In this paper the spectrum of quark-antiquark systems, including light mesons and tachyons, is studied in the true vacuum and in the chiral invariant vacuum. The mass gap equation for the vacua and the Salpeter-RPA equation for the mesons…
We study the dynamical generation of scalar mesons in the light quark sector ($q\in\{u,d,s\}$) and calculate the masses and widths for the $f_0(500),a_0(980)$ and $f_0(980)$. To this end we study the mixing of conventional $q\bar{q}$ and…
The full-heavy tetraquarks $bb\bar{b}\bar{b}$ and $cc\bar{c}\bar{c}$ are systematically investigated within the chiral quark model and the quark delocalization color screening model. Two structures, meson-meson and diquark-antidiquark, are…
Relativistic three-dimensional quasipotential (equal-time) equations are considered, which describe bound states of fermion and boson of spin S=0 or S=1. The spin structure of the interaction quasipotentials in such systems is studied, and…
The vast majority of mesons can be understood as quark-antiquark states. Yet, various other possibilities exists: glueballs (bound-state of gluons), hybrids (quark-antiquark plus gluon), and four-quark states (either as diquark-antidiquark…
A calculation of hadronic timelike form factors in the Poincar\'e-covariant Bethe-Salpeter formalism necessitates knowing the analytic structure of the non-perturbative quark-photon vertex in the context of the Poincar\'e-covariant…
Using the LAMP model for nuclear quark structure, we calculate the binding energy and quark structure of a $B$ meson merging with a $D$ meson. The larger-than-nucleon masses of the two heavy quarks allow for a more reliable application of…
The ladder kernel of the Bethe-Salpeter equation is amended by introducing a different flavor dependence of the dressing functions in the heavy-quark sector. Compared with earlier work this allows for the simultaneous calculation of the…
Within the formalism of relativistic quantum field theory an adequate framework for the description of two-particle bound states, such as, for instance, all conventional (i.e., non-exotic) mesons, is provided by the Poincar\'e-covariant…
The spin structure functions of the system of quasifree fermions on mass shell are studied in a consistently covariant approach. Comparison with the basic formulas following from the quark-parton model reveals the importance of the fermion…
A review is presented of past and recent attempts to build multiquark states within current models already describing ordinary mesons and baryons. This includes: coherence in the chromomagnetic interaction, tetraquarks with two heavy…
We compute the vector-meson, nucleon and delta/omega-baryon masses and their evolution with the current-quark mass using a covariant generalized Bethe-Salpeter equation approach. The interaction kernel is truncated to a dressed gluon…
In this paper we obtain a heavy meson bound state equation from the heavy quark equation of motion in heavy quark effective theory (HQET) and the heavy meson effective field theory we developed very recently. The bound state equation is a…
A symmetry-preserving treatment of mesons, within a Dyson-Schwinger and Bethe-Salpeter equations approach, demands an interconnection between the kernels of the quark gap equation and meson Bethe-Salpeter equation. Appealing to those…
The magnetic and nematic properties of the iron chalcogenides have recently been the subject of intense interest. Motivated by the proposed antiferroquadrupolar and Ising-nematic orders for the bulk FeSe, we study the phase diagram of an…
It is known that in the ladder approximation the relativistic two-fermion bound-state equation of Bethe and Salpeter has solutions corresponding to the binding energy equal to the total mass of the particles. The study of these massless…
We investigate light meson bound state contributions to six quark Green's functions and establish that the latter has poles corresponding to baryon bound states. We estimate light baryon masses including the Roper resonance. Constituent…
We present intermediate results on our ongoing investigation concerning semileptonic decays of heavy pseudoscalar mesons into pseudoscalar and vector mesons. The corresponding formfactors are evaluated at several momenta and appropriate…
Inspired by $\Xi_{cc}$ reported by LHCb Collaboration and $X(5568)$ reported by $D0$ Collaboration, the $QQ\bar{q}\bar{q}$ ($Q=c,b,s$, $q=u,d$) tetraquark states, are studied in the present work. With the help of gaussian expansion method,…
We study the structure of scalar, vector, and tensor currents for on-shell massive particles of any spin. When considering higher values for the spin of the particle, the number of form factors (FFs) involved in the decomposition of the…