  We propose an improved quark coalescence model for spin alignment of vector
mesons and polarization of baryons by spin density matrix with phase space
dependence. The spin density matrix is defined through Wigner functions. Within
the model we propose an understanding of spin alignments of vector mesons
$\phi$ and $K^{*0}$ (including $\bar{K}^{*0}$) in the static limit: a large
positive deviation of $\rho_{00}$ for $\phi$ mesons from 1/3 may come from the
electric part of the vector $\phi$ field, while a negative deviation of
$\rho_{00}$ for $K^{*0}$ may come from the electric part of vorticity tensor
fields. Such a negative contribution to $\rho_{00}$ for $K^{*0}$ mesons, in
comparison with the same contribution to $\rho_{00}$ for $\phi$ mesons which is
less important, is amplified by a factor of the mass ratio of strange to light
quark times the ratio of $\left\langle \mathbf{p}_{b}^{2}\right\rangle $ on the
wave function of $K^{*0}$ to $\phi$ ($\mathbf{p}_{b}$ is the relative momentum
of two constituent quarks of $K^{*0}$ and $\phi$). These results should be
tested by a detailed and comprehensive simulation of vorticity tensor fields
and vector meson fields in heavy ion collisions.
