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1.
Using the Nikiforov-Uvarov (NU) method, pseudospin and spin symmetric solutions of the Dirac equation for the scalar and vector Hulthén potentials with the Yukawa-type tensor potential are obtained for an arbitrary spin-orbit coupling quantum number κ. We deduce the energy eigenvalue equations and corresponding upper- and lower-spinor wave functions in both the pseudospin and spin symmetry cases. Numerical results of the energy eigenvalue equations and the upper- and lower-spinor wave functions are presented to show the effects of the external potential and particle mass parameters as well as pseudospin and spin symmetric constants on the bound-state energies and wave functions in the absence and presence of the tensor interaction.  相似文献   

2.
According to the general principle of non-equilibrium thermodynamics, we propose a set of macroscopic transport equations for the spin transport and the charge transport. In particular, the spin torque is introduced as a generalized `current density' to describe the phenomena associated with the spin non-conservation in a unified framework. The Einstein relations and the Onsager relations between different transport phenomena are established. Specifically, the spin transport properties of the isotropic non-magnetic and the isotropic magnetic two-dimensional electron gases are fully described by using this theory, in which only the macroscopic-spin-related transport phenomena allowed by the symmetry of the system are taken into account.  相似文献   

3.
We introduce an approach to extract the spin transfer to A in polarized proton-proton collision, based on the relation between single spin asymmetry and the polarization of A production. With 4 × 10^6 ∧ events simulated for a PHENIX detector system, DLL = 0.1598 ± 0.0343 is retrieved by the approach and it agrees very well with the input value of 0.1429. The approach is further tested and confirmed with ‘bunch shuffling' method for the simulated events as well as experimental events collected at PHENIX in 2003. It is concluded that one can correctly extract the spin transfer without detailed understanding of acceptance correction even if the correction is significantly large in PHENIX experiment by using the approach described here. The method can be generally used for spin transfer study.  相似文献   

4.
5.
Nine low-lying electronic states of the AsP molecule,includingΣ~ ,Π,andΔsymmetries with singlet, triplet,and quintet spin multiplicities,are studied using multi-reference configuration interaction method. The potential energy curves and the spectroscopic constants of these nine states are determined,and compared with the experimental observed data as well as other theoretical works available at present. Three quintet states are reported for the first time.Furthermore,the analytical potential energy functions of these states are fitted using Murrell-Sorbie function and least square fitting method.  相似文献   

6.
In this work, the spin dynamics of a centrosymmetric WSe_2 bilayer has been investigated by the two-color timeresolved Kerr rotation together with helicity-resolved transient reflectance techniques. Two depolarization processes associated with the direct transition are discovered at a low temperature of 10 K, with the characteristic decaying time of~3.8 ps and ~20 ps, respectively. The short decay time of ~3.8 ps is suggested to be the exciton spin lifetime of the WSe_2 bilayer, which is limited by the short exciton lifetime of the WSe_2 bilayer and the rapid intervalley electron–hole exchange interaction between K+and K-valley in the same layer as that of monolayer. The long decay time of ~20 ps is suggested to be the spin lifetime of photo-excited electrons, whose spin relaxation is governed by the rapid intervalley scattering from the K valley to the global minimum Σ valley and the subsequent interlayer charge transfer in WSe_2 bilayer.Our experimental results prove the existence of the spin-polarized excitons and carriers even in centrosymmetric transition metal dichalcogenides(TMDCs) bilayers, suggesting their potential valleytronic and spintronic device applications.  相似文献   

7.
MY  Ali  J  Poulter 《中国物理 B》2013,(6):549-552
In this work we study the correlation function of the ground state of a two-dimensional fully frustrated Ising model as well as spin glass. The Pfaffian method is used to calculate free energy and entropy as well as the correlation function. We estimate the exponent of spin correlation function for the fully frustrated model and spin glass. In this paper an overview of the latest results on the spin correlation function is presented.  相似文献   

8.
In this work,we study the effects of the Weyl corrections on the p-wave superfluid phase transition in terms of an EinsteinMaxwell theory coupled to a complex vector field.In the probe limit,it is observed that the phase structure is significantly modified owing to the presence of the higher order Weyl corrections.The latter,in general,facilitates the emergence of the superfluid phase as the condensate increases with the Weyl coupling measured byγ.Moreover,several features about the phase structure of the holographic superfluid are carefully investigated.In a specific region,the phase transition from the normal phase to the superfluid phase is identified to be the first order,instead of being the second order,as in the cases for many holographic superconductors.By carrying out a numerical scan of model parameters,the boundary dividing these two types of transitions is located and shown to be rather sensitive to the strength of Weyl coupling.Also,a feature known as"Cave of Winds",associated with the emergence of a second superfluid phase,is observed for specific choices of model parameters.However,it becomes less prominent and eventually disappears asγincreases.Furthermore,for temperature in the vicinity of the critical one for vanishing superfluid velocity,denoted by T0,the supercurrent is found to be independent of the Weyl coupling.The calculated ratio,of the condensate with vanishing superfluid velocity to that with maximal superfluid velocity,is in good agreement with that predicted by Ginzburg-Landau theory.While compared with the impact on the phase structure owing to the higher curvature corrections,the findings in our present study demonstrate entirely different characteristics.Further implications are discussed.  相似文献   

9.
When a boson interacts with another to form a composite system with SO(3) dynamic symmetry, it is shown that there exists the q-deformed 5osonic excitation satisfying the q-deformed Heisenberg commutation relation in the quasi-classical limit that the angular momentum j for SO(3) is large, but not infinite. In second quantization this quasi-excitation is associated with the boson realization of SO(3) Lie algebra. Physically, the phenomena of q-deformed excitation can happen in many models of quantum dynamics, such as super emission from a system of many identical two-level atoms, the spin wave in Heisenberg chain, the high spin precession and the coherent output of Bose-Einstein atoms in a trap. Especially, in these models, the deformation parameter q is well defined intrinsically by a conservative quantity, such as the total atomic number and the angular momentum.  相似文献   

10.
《中国物理 B》2021,30(6):60310-060310
We have investigated the dynamics of bright solitons in a spin–orbit coupled spin-1 Bose–Einstein condensate analytically and numerically. By using the hyperbolic sine function as the trial function to describe a plane wave bright soliton with a single finite momentum, we have derived the motion equations of soliton's spin and center of mass, and obtained its exact analytical solutions. Our results show that the spin–orbit coupling couples the soliton's spin with its center-of-mass motion, the spin oscillations induced by the exchange of atoms between components result in the periodical oscillation of center-of-mass, and the motion of center of mass of soliton can be viewed as a superposition of periodical and linear motions. Our analytical results have also been confirmed by the direct numerical simulations of Gross–Pitaevskii equations.  相似文献   

11.
T. Haas 《中国物理 C》2010,34(9):1254-1258
After the end of data taking in 2007,the experiments H1 and ZEUS have entered into an intense phase of data analysis.Recent results of this effort on neutral (NC) and charged current (CC) cross sections at high Q 2,the longitudinal structure function F L,inclusive diffraction,heavy flavour production and on searches for glueballs are presented.Also shown are results of a combined analysis on inclusive NC and CC cross sections performed by H1 and ZEUS using HERA-I data.  相似文献   

12.
We discuss recent progress in extracting the excited meson spectrum and radiative transition form factors from lattice QCD.We mention results in the charmonium sector,including the first lattice QCD calculation of radiative transition rates involving excited charmonium states,highlighting results for high spin and exotic states.We present recent results on a highly excited isovector meson spectrum from dynamical anisotropic lattices.Using carefully constructed operators we show how the continuum spin of extracted states can be reliably identified and confidently extract excited states,states with exotic quantum numbers and states of high spin.This spectrum includes the first spin-four state extracted from lattice QCD.We conclude with some comments on future prospects.  相似文献   

13.
俞伟林   《中国物理 C》2010,34(9):1476-1478
Generalized Parton Distributions (GPDs) provide a way to access total angular momenta of partons and give a multidimensional picture of the nucleon structure.Deeply Virtual Compton Scattering (DVCS) is the most direct exclusive process to study GPDs.Different azimuthal cross-section asymmetries with respect to beam helicity,beam charge,and target polarization have been measured in the HERMES experiment.A recoil detector was installed at HERMES to directly detect the recoil proton.  相似文献   

14.
D. G. Richards 《中国物理 C》2010,34(9):1281-1285
Theoretical and computational advances have enabled not only the masses of the ground states,but also some of the low-lying excited states to be calculated using Lattice Gauge Theory.In this talk,I look at recent progress aimed at understanding the spectrum of baryon excited states,including both baryons composed of the light u and d quarks,and of the heavier quarks.I then describe recent work aimed at understanding the radiative transitions between baryons,and in particular the N-Roper transition.I conclude with the prospects for future calculations.  相似文献   

15.
We investigate the AdS/QCD duality for the two-point correlation functions of the lowest dimension scalar meson and scalar glueball operators,in the case of the Soft Wall holographic model of QCD.Masses and decay constants as well as gluon condensates are compared to their QCD estimates.In particular,the role of the boundary conditions for the bulk-to-boundary propagators is emphasized.  相似文献   

16.
S. Aoki 《中国物理 C》2010,34(9):1236-1240
We report on new attempt to investigate baryon-baryon interactions in lattice QCD.From the Bethe-Salpeter (BS) wave function,we have successfully extracted the nucleon-nucleon (NN) potentials in quenched QCD simulations,which reproduce qualitative features of modern NN potentials.The method has been extended to obtain the tensor potential as well as the central potential and also applied to the hyperonnucleon (YN) interactions,in both quenched and full QCD.  相似文献   

17.
The scheme-scale ambiguity that has plagued perturbative analysis in QCD remains on obstacle to making precise tests of the theory.Many attempts have been done to resolve the scale ambiguity.In this regard the BLM,EC,PMS and CORGI approaches are more distinct.We try to employ these methods to fix the scale ambiguity at NLO,NNLO and even in more higher order approximations.By optimizing the renormalization scale,there will be a possibility to predicate higher order terms.We present general results for predicted terms at any order,using different optimization methods.Some observable as specific examples will be used to indicate the validity of scale fixing to predicate the higher order terms.  相似文献   

18.
蒋宇  李宁  孙为民  宗红石 《中国物理 C》2010,34(9):1324-1327
In this paper we calculate the equation of state (EOS) of QCD at zero temperature and finite chemical potential by using several models of quark propagators including the Dyson-Schwinger equations (DSEs) model,the hard-dense-loop (HDL) approximation and the quasi-particle model.The results are analyzed and compared with the known results in the literature.  相似文献   

19.
We use the constituent quark model to extract polarized parton distributions and finally polarized nucleon structure function.Due to limited experimental data which do not cover whole (x,Q 2 ) plane and to increase the reliability of the fitting,we employ the Jacobi orthogonal polynomials expansion.It will be possible to extract the polarized structure functions for Helium,using the convolution of the nucleon polarized structure functions with the light cone moment distribution.The results are in good agreement with available experimental data and some theoretical models.  相似文献   

20.
K. Maltman 《中国物理 C》2010,34(9):1350-1354
The two highest precision determinations of α s (M 2 Z ),that based on the analysis of short-distancesensitive lattice observables,and that based on an analysis of hadronic τ decay data,have,until very recently,given results which are not in good agreement.I review new versions of these analyses which bring the two determinations into excellent agreement,and discuss prospects for additional future improvements.  相似文献   

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