Related papers: Unstable molecular state with unstable constituent
We present a covariant approach to describe the low--lying scalar, pseudoscalar, vector and axialvector mesons as quark--antiquark bound states.This approach is based on an effective interaction modeling of the non--perturbative structure…
Considering the fact that, a wide range of variation in masses of various states of heavy pseudoscalar and vector mesons can be seen in different models and the experimental data on masses of many of these states is not yet currently…
Novel relativistic expressions are used to calculate the weak decay constants of pseudoscalar and vector mesons within the constituent quark model. Meson wave functions satisfy the quasipotential equation with the complete relativistic…
The mass spectrum of heavy pseudoscalar mesons, described as quark-antiquark bound systems, is considered within the Bethe-Salpeter formalism with momentum-dependent masses of the constituents. This dependence is found by solving the…
We show the instability of a charged massive scalar field in bound states around Kerr-Sen black holes. By matching the near and far region solutions of the radial part in the corresponding Klein-Gordon equation, one can show that the…
Bound q\bar q systems are studied in the framework of different 3-dimensional relativistic equations derived from the Bethe-Salpeter equation with the instantaneous kernel in the momentum space. Except the Salpeter equation, all these…
We study the heavy-light mesons in a relativistic model, which is derived from the instantaneous Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation on the heavy quark. The kernel we choose is based on scalar confining…
The interplay between the various measures of quantum correlations are well known in stable optical and electronic systems. Here, for the first time, we study such foundational issues in unstable quantum systems. Specifically we study…
Salpeter equations with potential functions rising to infinity in configuration space do not automatically predict stable bound states. For this to happen, also the Lorentz behaviour of the involved Bethe-Salpeter kernels is crucial. At…
In the framework of effective quantum field theory we address the definition of physical quantities characterizing unstable particles. With the aid of a one-loop calculation, we study this issue in terms of the charge and the magnetic…
The relativistic quantum string quark model, proposed earlier, is applied to all mesons, from pion to $\Upsilon$, lying on the leading Regge trajectories (i.e., to the lowest radial excitations in terms of the potential quark models). The…
For a two-particle bound-state equation closer to its Bethe-Salpeter origins than Salpeter's equation, with effective-interaction kernel deliberately forged such as to ensure, in the limit of zero mass of the bound-state constituents, the…
We study the stability of the coherence of a state of a quantum system under the effect of an interaction with another quantum system at short time. We find an expression for evaluating the order of magnitude of the time scale for the onset…
The Bethe-Salpeter equation is a non-perturbative, relativistic and covariant description of two-body bound states. We derive the classical Bethe-Salpeter equation for two massive point particles (with or without spin) in a bound…
The Bethe-Salpeter equation for system of two oppositely charged particles not only reproduces the Coulomb spectrum, but, for enough large coupling constant ${\cal C}>\frac{\pi}{4}$, predicts additional levels not predicted by the…
We have developed a quantum field theoretic framework for scalar and pseudoscalar meson mixing and oscillations in time. The unitary inequivalence of the Fock space of base (unmixed) eigenstates and the physical mixed eigenstates is proven…
A method to determine the admissibility of symbolic sequences and to find the unstable periodic orbits corresponding to allowed symbolic sequences for the diamagnetic Kepler problem is proposed by using the ordering of stable and unstable…
There have been many demonstrations of the utility of the Dyson-Schwinger equations of QCD as a systematic, phenomenological framework for describing the perturbative and non-perturbative dynamics of hadrons in terms of Euclidean Green…
A Self Consistent Field Theory description of equilibrium, but non uniform, configurations adopted by semi flexible liquid crystal molecules is presented. Two cases are considered, isotropic-nematic phase boundaries, and topological defects…
In the framework of the instantaneous Bethe Salpeter equation we investigate weak decays of B and D mesons. Mesons are described as q-bar q states interacting via a mixture of a scalar and a vector confining kernel and a one gluon exchange.…