In this Letter, we study the molecular alignment and orientation driven by two elliptically polarized laser pulses.It is shown that the field-free molecular alignment can be achieved in a three-dimensional（3D） case,...In this Letter, we study the molecular alignment and orientation driven by two elliptically polarized laser pulses.It is shown that the field-free molecular alignment can be achieved in a three-dimensional（3D） case, while the field-free molecular orientation is only along the x and y directions, and that the field-free alignment and orientation along different axes are related to the populations of the rotational states. It is demonstrated that changing the elliptic parameter is efficient for controlling both in-pulse and post-pulse molecular alignment and orientation. The delay time also has an influence on the field-free molecular alignment and orientation.展开更多
We investigate the spin density matrix of Ω− in the Cartesian coordinate system of baryon-antibaryon pairs produced in e+e−annihilation.Using the helicity formalism of Jacob and Wick,we derive the expression for the ...We investigate the spin density matrix of Ω− in the Cartesian coordinate system of baryon-antibaryon pairs produced in e+e−annihilation.Using the helicity formalism of Jacob and Wick,we derive the expression for the spin-3/2 density matrices.Our analysis is based on the angular distribution of the process e+e−→ψ(3686)→Ω−Ω¯^(+ )in the BESIII experiment.By decomposing the polarization state of Ω− particles along different coordinate axes,we examine the polarization dependence of the cross-section.Our results demonstrate that Ω− particles exhibit varying degrees of tensor polarization along the x-,y-,and z-axes,as well as weak vector polarization and rank-3 tensor polarization along the y-axis.To the best of our knowledge,this is the first study to calculate the polarization dependence of the cross-section distributions for the annihilation process e+e−→Ω−Ω¯^(+).Our theoretical predictions are in good agreement with the experimental measurements.展开更多
基金supported by the National Natural Science Foundation of China(No.11674198)the Taishan Scholar Project of Shandong Province
文摘In this Letter, we study the molecular alignment and orientation driven by two elliptically polarized laser pulses.It is shown that the field-free molecular alignment can be achieved in a three-dimensional（3D） case, while the field-free molecular orientation is only along the x and y directions, and that the field-free alignment and orientation along different axes are related to the populations of the rotational states. It is demonstrated that changing the elliptic parameter is efficient for controlling both in-pulse and post-pulse molecular alignment and orientation. The delay time also has an influence on the field-free molecular alignment and orientation.
基金Supported by the National Natural Science Foundation of China(12247121)。
文摘We investigate the spin density matrix of Ω− in the Cartesian coordinate system of baryon-antibaryon pairs produced in e+e−annihilation.Using the helicity formalism of Jacob and Wick,we derive the expression for the spin-3/2 density matrices.Our analysis is based on the angular distribution of the process e+e−→ψ(3686)→Ω−Ω¯^(+ )in the BESIII experiment.By decomposing the polarization state of Ω− particles along different coordinate axes,we examine the polarization dependence of the cross-section.Our results demonstrate that Ω− particles exhibit varying degrees of tensor polarization along the x-,y-,and z-axes,as well as weak vector polarization and rank-3 tensor polarization along the y-axis.To the best of our knowledge,this is the first study to calculate the polarization dependence of the cross-section distributions for the annihilation process e+e−→Ω−Ω¯^(+).Our theoretical predictions are in good agreement with the experimental measurements.
