Based on Pomeron exchange model, elastic production of vector meson in electro-proton interaction is investigated with both linear and non-linear Pomeron trajectory. A numerical calculation for J/psi production is per...Based on Pomeron exchange model, elastic production of vector meson in electro-proton interaction is investigated with both linear and non-linear Pomeron trajectory. A numerical calculation for J/psi production is performed. The effect of the energy scale so and photon virtuality Q(2) on differential cross section are also predicted. A good agreement with experimental data is obtained. Our conclusions are that the Pomeron exchange model is a successful description of J/psi electro-production, the dependence of the differential cross sections on Q2 is negligible, the linear trajectory is a good approximation to non-linearity of the Pomeron trajectory, and the value of the energy scale parameter so is dependent on the momentum transfer, namely its effect is moderate at low momentum transfer but it causes no difference at high momentum transfer vertical bar t vertical bar >= 1.25 GeV2.展开更多
The confined longitudinal-optical (LO) phonon and surface-optical (SO) phonon modes of a free-standing annular cylindrical quantum dot are derived within the framework of dielectric continuum approximation. It is ...The confined longitudinal-optical (LO) phonon and surface-optical (SO) phonon modes of a free-standing annular cylindrical quantum dot are derived within the framework of dielectric continuum approximation. It is found that there exist two types of SO phonon modes: top SO (TSO) mode and side SO(SSO) mode in a cylindrical quantum annulus. Numerical calculation on CdS annulus system has been performed. Results reveal that the two different solutions of SSO mode distribute mainly at the inner or outer surfaces of the annulus. The dispersion relations and the coupling intensions of phonons in a quantum annulus are compared with those in a cylindrical quantum dot. It is found that the dispersion relations of the two different structures are similar, but the coupling intension of the phonon-electron interaction in quantum annulus is larger than that in quantum dot. The Hamiltonians describing the free phonon modes and their interactions with electrons in the system are also derived.展开更多
文摘Based on Pomeron exchange model, elastic production of vector meson in electro-proton interaction is investigated with both linear and non-linear Pomeron trajectory. A numerical calculation for J/psi production is performed. The effect of the energy scale so and photon virtuality Q(2) on differential cross section are also predicted. A good agreement with experimental data is obtained. Our conclusions are that the Pomeron exchange model is a successful description of J/psi electro-production, the dependence of the differential cross sections on Q2 is negligible, the linear trajectory is a good approximation to non-linearity of the Pomeron trajectory, and the value of the energy scale parameter so is dependent on the momentum transfer, namely its effect is moderate at low momentum transfer but it causes no difference at high momentum transfer vertical bar t vertical bar >= 1.25 GeV2.
基金the Scientific and Technology Project of Guangzhou Municipal Government under Grant No.2004J1-C0327
文摘The confined longitudinal-optical (LO) phonon and surface-optical (SO) phonon modes of a free-standing annular cylindrical quantum dot are derived within the framework of dielectric continuum approximation. It is found that there exist two types of SO phonon modes: top SO (TSO) mode and side SO(SSO) mode in a cylindrical quantum annulus. Numerical calculation on CdS annulus system has been performed. Results reveal that the two different solutions of SSO mode distribute mainly at the inner or outer surfaces of the annulus. The dispersion relations and the coupling intensions of phonons in a quantum annulus are compared with those in a cylindrical quantum dot. It is found that the dispersion relations of the two different structures are similar, but the coupling intension of the phonon-electron interaction in quantum annulus is larger than that in quantum dot. The Hamiltonians describing the free phonon modes and their interactions with electrons in the system are also derived.