Few-Body Systems最新文献

We describe the statistical Schlessinger Point Method. Grounded in analytic function theory, this method returns an objective assessment of the information contained in any data under consideration, which is independent of assumptions about underlying dynamics, and thus free from practitioner-induced bias. As a test to its robust nature and versatility, we apply it to a fully data-driven extraction of the proton, pion, and deuteron radii.

We construct Darboux transformations for a particular class of (1+2)-dimensional spin-zero systems governed by the Duffin–Kemmer–Petiau (DKP) equation. These transformations, consisting of two algorithms, are based on an adaptation of results for coupled Korteweg-de Vries equations, and on the close relationship between the DKP and the Klein–Gordon equation. We derive the explicit form of solutions and potentials pertaining to the Darboux-transformed DKP equation, and we state a reality condition for the transformed potentials. Our results are illustrated by an application.

In this paper, we analyze the properties of heavy quarkonia in a curved space-time with conical geometry induced by a topological defect, namely a cosmic string. The particles moving within the latter space are under the influence of an extended version of the Cornell potential. Assuming that the cosmic string space time is torsion free, the full spectrum of each particle is obtained by solving the Schrödinger equation using the extended Nikiforov–Uvarov method. It is observed that the gravitational field of the topological defect acts on the energy levels in a manner similar to the Zeeman effect due to the magnetic field. However, in the limit of the flat Minkowski space-time ((alpha rightarrow 1)), we recover the classical mass spectra of heavy quarkonia for the extended Cornell potential. The numerical outcomes of this study are overall found in good agreement with experimental data and other relevant theoretical works. Thus, to illustrate the effect of the topological defect graphically, mass spectra, wave functions and radial probability densities are plotted for (P-)states at different values of (alpha ). It is found that, at large values of the quantum number n, the mass spectra of heavy quarkonia exhibit saturation effect governed by the topological parameter.

We study the production of ground and excited axial charmonia in processes, (e^- e^+ rightarrow h_c(nP) + eta _c(n'S)), and (e^- e^+ rightarrow chi _{c1}(nP) + h_c(n'P)) for (n,n'=1,2), through leading order tree-level diagrams (sim O(alpha _{em} alpha _s)), which proceed through exchange of a virtual photon and an internal gluon line connecting two quark lines in the triangle quark loop part of the diagram at center of mass energy, (sqrt{s}=10.6,{textrm{GeV}}). We employ the framework of (4times 4) Bethe–Salpeter equation, and calculate their cross sections. These studies might be of interest for future experiments at B-factories, since (h_c, eta _c), and (chi _{c1}, h_c) production might provide opportunities for observing (h_c) with higher statistics in future.

In this study, the relativistic quantum motion of spin-0 scalar bosons within the framework of Morris–Thorne-type wormhole space-time accompanied by a cosmic string is studied. We tackle the problem by solving the relativistic Klein–Gordon equation using the confluent Heun equation. We determine the ground state energy level, denoted as (E_{1,m}), as well as the corresponding wave function, denoted as (psi _{1,m}). Interestingly, the investigation reveals that both the cosmic string parameter and the wormhole throat radius have an impact on the relativistic eigenvalue solution, thereby modifying the energy spectrum. Furthermore, the presence of the quantum flux field induces a shift in the energy levels, leading to the gravitational analogue of the Aharonov–Bohm effect.

The role and impact of dynamical diquark correlations that appear within three-quark bound states (baryons), owing largely to the mechanisms responsible for the emergence of hadron masses, can be addressed via the computation of baryon electromagnetic transition form factors (TFFs). Herein, we describe a procedure based upon continuum Schwinger methods to evaluate such physical objects. For illustration purposes, we specialize on the (gamma ^{(*)}p rightarrow N(1535)frac{1}{2}^-) TFF, in which the interference between the different diquark correlations plays a determining role. Albeit limited to a symmetry-preserving treatment of a vector (otimes ) vector contact-interaction model of quantum chromodynamics, both the mathematical procedure and numerical results serve as benchmarks for more sophisticated calculations to be developed in the future.

Microscopic nuclear theory is based on the tenet that atomic nuclei can be accurately described as collections of point-like nucleons interacting via two- and many-body forces obeying nonrelativistic quantum mechanics—and the concept of the ab initio approach is to calculate nuclei accordingly. The forces are fixed in free-space scattering and must be accurate. We will critically review the history of this approach from the early beginnings until today. An analysis of current ab initio calculations reveals that some mistakes of history are being repeated today. The ultimate goal of nuclear theory are high-precision ab initio calculations which, as it turns out, may be possible only at the fifths order of the chiral expansion. Thus, for its fulfillment, nuclear theory is still facing an enormous task.

It is well known that exactly solvable models play an extremely important role in many fields of quantum physics. In this study, the Schrödinger equation is applied for a solution of a two-dimensional (2D) problem for two particles enclosed in a circle, confined in an oscillatory well, trapped in a magnetic field, interacting via the Coulomb, Kratzer, and modified Kratzer potentials. In the framework of the Nikiforov–Uvarov method, we transform 2D Schrödinger equations with potentials for which the three-dimensional Schrödinger equation is exactly solvable, into a second-order differential equation of a hypergeometric-type via transformations of coordinates and particular substitutions. Within this unified approach which also has pedagogical merit, we obtain exact analytical solutions for wave functions in terms of special functions such as a hypergeometric function, confluent hypergeometric function, and solutions of Kummer’s, Laguerre’s, and Bessel’s differential equations. We present the energy spectrum for any arbitrary state with the azimuthal number m. Interesting aspects of the solutions unique to the 2D case are discussed.