Few-Body Systems最新文献

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.

Motivated by the recent discovery of single heavy tetraquark structures, (T_{cbar{s}0}^a (2900)^{++}) and (T_{cbar{s}0}^a(2900)^0) by the LHCb collaboration, masses and magnetic moments of singly heavy pentaquark states are estimated in this work. To classify the singly heavy pentaquark structures, we employ the special unitary representation. By using the SU(3) flavor representation, singly heavy pentaquark states are classified into the allowed flavor multiplets. Also, by using the extension of the Gursey-Radicati mass formula and the effective mass scheme, masses of singly heavy pentaquark states are estimated. Further, magnetic moments of singly heavy pentaquarks have been calculated using the effective mass and the screened charge schemes. A thorough comparison of our results shows reasonable agreement with the available theoretical data and may be helpful for future experimental studies.

The static dipole polarizability of metastable states in the kaonic helium atoms is studied. We use the complex coordinate rotation method to properly account for the resonant nature of the states. Our calculations show that some of the states are not stable with respect to collisional quenching in a dense helium target and should not be detected in the experiment.

In this paper, we study quantum droplets in one dimension under the influence of spacetime curvature by redefining the momentum operator, resulting in a maximum length and a minimum momentum, consistent with anti-de Sitter space (AdS). By examining this effect through the (alpha ) parameter on the exact solution of free quantum droplets, we found that the relationship between the number of atoms and the chemical potential differs from the ordinary case. Additionally, we discovered that the flat-top shape can disappear and transform into a Gaussian shape in the presence of the maximum length (minimum momentum). Moreover, we found that the interaction of quantum droplets with spacetime curvature causes them to have a larger size. We also studied this effect on the variational solution via Gaussian ansatz for small droplets, we concluded that (alpha ) decreases the stability and self-localisation of the quantum droplets.