arXiv subjects
Publications and source records attributed to C-R. Ji.
Using heavy quark symmetry we construct an energy sum rule relating the form factor of a heavy flavored meson $ξ(w)$ to the light quark energy distribution. We find that the current available data for $ξ(w)$ is consistent with a broad energy distribution rather than with that of a pure quark/anti-quark bound state, indicating a large nonvalence content.
We study the implications of Lorentz symmetry for hadronic structure by formulating a manifestly covariant constituent quark model and find full covariance for any Lorentz transformation requires utilizing a variable quantization surface. Even though time-reversal invariance mandates a unique orientation for the surface's direction, we investigated alternative choices and find small numerical sensitivity to different directions. We also calculate the static properties of the low lying pseudoscalar mesons and compare results with existing noncovariant calculations. We conclude that there is a little sensitivity of the calculated observables to the choice of the formalism, provided relativity is properly implemented.
We study the most general, relativistic, constituent $q{\overline q}$ meson wave function within a new covariant framework. We find that by including a tensor wave function component, a pure valence quark model is now capable of reproducing not only all static pion data ($f_π$, $\langle r_π^2 \rangle$) but also the distribution amplitude, form factor $(F_π(Q^2))$, and structure functions. Further, our generalized spin wave function provides a much better detailed description of meson properties than models using a simple relativistic extension of the $S=L=0$ nonrelativistic wave function.