Few-Body Systems最新文献

In this paper, we investigate the quantum dynamics of scalar and oscillator fields in a topological defect space-time background under the influence of rainbow gravity’s. The rainbow gravity’s are introduced into the considered cosmological space-time geometry by replacing the temporal part (dt rightarrow frac{dt}{mathcal {F}(chi )}) and the spatial part (dx^i rightarrow frac{dx^i}{mathcal {H} (chi )}), where (mathcal {F}, mathcal {H}) are the rainbow functions and (0 le chi =|E|/E_p <1) is the dimensionless parameter. We derived the radial equation of the Klein–Gordon equation and its oscillator equation under rainbow gravity’s in topological space-time. To obtain eigenvalue of the quantum systems under investigations, we set the rainbow functions (mathcal {F}(chi )=1) and (mathcal {H}(chi )=sqrt{1-beta ,chi ^p}), where (p=1,2). We solve the radial equations through special functions using these rainbow functions and analyze the results. In fact, it is shown that the presence of cosmological constant, the topological defect parameter (alpha ), and the rainbow parameter (beta ) modified the energy spectrum of scalar and oscillator fields in comparison to the results obtained in flat space.

We study the influence of a symmetrically spherical potential on the harmonic oscillator. The symmetrically spherical potential consists of a repulsive short-range potential inspired by the power-exponential potential. By dealing with s-wave in the region where the repulsive short-range potential is significant, we show how the energy levels of the three-dimensional harmonic oscillator are modified by the short-range potential influence. Furthermore, we show that a non-null revival time with regard to the s-state exists.

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.

So far, many constituent quark models have been applied to describe the internal configuration of light and heavy baryons and also for determining their static properties Among all static quantities, the mass and the magnetic moment of baryons are the most interesting observables which provide direct information on the dynamics of strong interaction and color confinement phenomenon. In this work, through the quark–diquark model we analytically compute the mass and the magnetic moment of light and heavy baryons in their ground state. To this aim, we use the Bethe–Salpeter equation in the presence of Hellmann potential with the onepionexchange contribution to determine the mass and the wave function of baryons. Using the spin-flavor structure of constituent quarks we calculate the magnetic moment of light, single and double heavy baryons and compare them with existing data and other modeldependent predictions. We will also predict the mass and the magnetic moment of unobserved triply heavy baryons relevant for the present and future high energy colliders.

In this manuscript, we suggest a relativistic distorted wave approach for the prediction of structural properties and photoionization cross sections of highly charged ions in a non-ideal classical plasma (NICP) environment. The pseudopotential, obtained from a sequential solution of the Bogolyubov chain equations, is used to describe screened interactions in the plasma. We solve the Dirac equation to obtain wave functions and energies. Detailed calculations are carried out for the photoionization of the highly ionized H-like S(^{15+}) ions for an illustrative purpose. The NICP effects on the energies, transition rates, ionization potentials, and photoionization cross sections are investigated. Comparing our results with other available experimental and theoretical data, we find satisfactory agreement. Apart from its fundamental importance, the present study has implications for a range of fields, including astrophysics, nuclear fusion and laboratory plasma experiments.

Nucleon form factors at large momentum transfer are important for understanding the transition from nonperturbative to perturbative QCD and have been the focus of experiment and phenomenology. We calculate proton and neutron electromagnetic form factors (G_{E,M}(Q^2)) from first principles using nonperturbative methods of lattice QCD. We have accumulated large Monte Carlo statistics to study form factors up to momentum transfer (Q^2lesssim 8text { GeV}^2) with a range of lattice spacings as well as quark masses that approach the physical point. In this paper, results of initial analyses are presented and compared to experiment, and potential sources of systematic uncertainty are discussed.