Few-Body Systems最新文献

A method for the direct integration of the three-dimensional Faddeev equations with respect to the breakup T-matrix in momentum space for three-body systems with differing masses is presented. The Faddeev equations are explicitly formulated without imposing symmetry or antisymmetry requirements on the two-body t-matrices, thus accounting for mass differences between the three interacting particles. An algorithm for the algebraic determination of non-relativistic wave functions for three-body systems with arbitrary masses is given. Furthermore, it is directly demonstrated how the domain of logarithmic singularities in the integral kernels of the Faddeev equations is significantly altered by varying the masses of the interacting particles. The developed method for traversing logarithmic singularities is tested using the example of calculating the total cross sections for elastic neutron-deuteron scattering and breakup reaction.

We have done a systematic no-core shell-model study of (^{20-23})Na isotopes. The low-energy spectra of these sodium isotopes consisting of natural and un-natural parity states were reported, considering three realistic interactions: inside nonlocal outside Yukawa (INOY), charge-dependent Bonn 2000 (CDB2K), and the chiral next-to-next-to-next-to-leading order (N(^3)LO). We also present the mirror energy differences in the low-energy spectra of (|T_z|) = 1/2 mirror pair ((^{21})Na - (^{21})Ne). Apart from the energy spectra, we have also reported the electromagnetic transition strengths and moments. Finally, considering all three realistic interactions, we report the point-proton radii and neutron skin thicknesses.

In this work, the behavior of a lithium (Li) atom within a noncentral interacting endohedral fullerene under spherical confinement and in a quantum plasma environment is investigated. The relevant Schrödinger wave equation is solved using a hybrid approach that combines the tridiagonal matrix method and the asymptotic iteration method. Through this solution, the system’s energy levels, probability densities, dipole polarizabilities, and oscillator strengths are calculated. The changes in plasma density, plasma shielding effect, and endofullerene parameters significantly influence the dynamics of these fundamental properties. Specifically, the analysis of oscillator strengths reveals the strength of electromagnetic interactions during transitions within the system and details how these transitions are affected by plasma, endofullerene confinement, spherical confinement, and angular interactions. Changes in dipole polarizability illustrate how the atom evolves under the influence of these external factors, while differences in oscillator strengths play a critical role in understanding the efficiency of electronic transitions and the system’s interaction with electromagnetic waves. This work contributes to a better understanding of endohedral molecular systems in quantum plasma environments and provides a valuable foundation for modeling the properties of such systems. Moreover, as it serves as an important reference for broader investigations into the dynamics of noncentral endohedral fullerene and quantum plasma interactions at the atomic and molecular levels, it sheds light on future experimental and theoretical studies.

It is shown that the quantum Hamiltonian characterising a non-relativistic electron under the influence of an external spherical symmetric electromagnetic potential exhibits a supersymmetric structure. Both cases, spherical symmetric scalar potentials and spherical symmetric vector potentials are discussed in detail. The current approach, which includes the spin-(frac{1}{2}) degree of freedom, provides new insights to known models like the radial harmonic oscillator and the Coulomb problem. We also find a few new exactly solvable models, one of them exhibiting a new mixed type of shape invariance containing translation and scaling of potential parameters. The fundamental role as Witten parity played by the spin-orbit operator is high-lighted.

A recent study from the LHCb detector analyzed the (J/psi eta ) mass spectrum from (B^+rightarrow J/psi eta K^+) decays, reporting the branching fraction ratios as (F_{X}equiv frac{mathcal {B}r(B^+rightarrow psi ' K^+)times mathcal {B}r(psi 'rightarrow J/psi eta )}{mathcal {B}r(B^+rightarrow psi (2S) K^+)times mathcal {B}r(psi (2S)rightarrow J/psi eta )}) for (psi '=psi _2(3823),psi (4040)), which are ((5.95^{+3.38}_{-2.55})times 10^{-2}) and ((40.60pm 11.20)times 10^{-2}), respectively. Also, the products related to (B_{X}equiv mathcal {B}r(B^+rightarrow psi 'K^+)times mathcal {B}r(psi 'rightarrow J/psi eta )) branching fractions are (B_{psi _2(3823)}=(1.25^{+0.71}_{-0.53}pm 0.04)times 10^{-6}) and (B_{psi (4040)}=(8.53pm 2.35pm 0.30)times 10^{-6}). This represents the first calculation of this branching fraction using factorization. Our calculations indicate that (F_X) is (F_{psi _{2}(3823)}=(6.55pm 1.88)times 10^{-2}) and (F_{psi (4040)}=(14.33pm 4.15)times 10^{-2}) at (mu =m_b/2). We have estimated (B_{psi _{2}(3823)}=(0.26pm 0.05)times 10^{-6}) at (mu =m_b/2) and (B_{psi (4040)}=(2.88pm 0.64)times 10^{-6}) at (mu =2m_b).

The n-body problem, a cornerstone of celestial mechanics, has been the subject of extensive research for centuries, with particular emphasis on the complexities of the three-body problem under various perturbations. These perturbations include oblateness, triaxiality, radiation pressure, and the effects of Coriolis and centrifugal forces. Recent advancements have shifted focus to systems involving more than three bodies, with notable work in the four-body problem. In this study, we extend the analysis to the five-body problem, examining its chaotic behavior and identifying regions of libration points. By varying the masses of the bodies across distinct surface points, we analyze the system’s dynamics, uncovering fractal zones within the problem. Additionally, we perform a stability analysis of the libration points, offering new insights into the behavior and stability of the five-body system. This research contributes to a deeper understanding of multi-body interactions and their implications in both theoretical and applied contexts.

The variational Monte Carlo method is employed to conduct a comprehensive investigation of the compressed ground and excited states of plasma-embedded lithium atom within impenetrable spherical boxes of varying radii. The study focuses on the low-lying excited doublet states 1(s^{{2}})ns, 1(s^{{2}}n)p, and 1(s^{{2}}n)d, utilizing plasma potentials such as the screened Coulomb (SCP), exponential cosine screened Coulomb (ECSCP), and Hulthén potentials. Energy eigenvalues are determined using appropriate trial wave functions, which account for electron–electron repulsion and spin parts to adhere to the Pauli Exclusion Principle. Moreover, two factors related to the wave function of the compressed system and ECSCP model are considered. The results reveal an intriguing relative ordering for the lithium atom using the three plasma models, with many of the findings being significant contributions yet to be explored.

The three-dimensional Schrödinger equation, where a non-linearity is caused by the introduction of an energy-dependent potential, is solved in the case of Energy-Dependent Manning-Rosen Potential (EDMRP) by means of extended quantum supersymmetry (EQS) combined with shape invariance, and Nikiforov–Uvarov (N–U) methods, using in both cases the Pekeris approximation for the centrifugal term. On the one hand, after determining the potential parameters according to experimental data, EQS and N–U results are compared to the numerical ones to show the effectiveness of our calculations. On the other hand, the effects of the non-linearity introduced via energy-dependent potentials in the Schrödinger equation are shown through a comparison made between energy-dependent and position-only-dependent cases of the Manning-Rosen potential. We considered some diatomic molecules CO(^{+}), BO, and CN with the experimental values of their potential parameters. Our results allowed us to consider, as a particular case, the three-dimensional energy-dependent Hulthén potential.