Spin structure in meson spectroscopy with an effective scalar confinement of quarks

Evidence from meson spectroscopy is presented to support the view that the effective interaction between quark-antiquark pairs is a long-range scalar confining force, together with a short-range Coulomb-type vector exchange governed by the underlying quantum chromodynamics. As a result, it is prediced that the ${}_{}{}^3{}_{}{}^{}P$-wave charmed mesons and mesons of the type ($b\overline{u}$) and ($b\overline{s}$) will be inverted multiplets. Discovery of such an effect would provide strong evidence for an effective scalar confining force. It is argued, on the basis of the systematics of the tensor force in the ordinary mesons, that there are important induced tensor forces in the $I=1\mathrm{}$ and $I=\frac{1}{2}$ $P$-wave meson multiplets. A qualitative discussion suggests that the induced tensor forces are due to couplings of the $J=1\mathrm{}$, $I=1\mathrm{}$ and $I=\frac{1}{2}$ mesons to open decay channels. As a result, the $A_1$, $B$, $Q_A$, and $Q_B$ mesons appear to have substantial mixings with $\left(q\overline{q}\right)\left(q\overline{q}\right)$ configurations.