Quark structure of the X(3872) and χb(3P) resonances

We discuss the nature of the chi(b)(3P) and X(3872) mesons. Are the chi(b)(3P)'s standard b (b) over bar mesons or b (b) over bar states with a significative continuum component? Is the X(3872) a c (c) over bar state with continuum coupling effects or a meson-meson molecule? To do that, we compare quark model and unquenched quark model results for the mass barycenter and splittings of the chi(b)(3P) multiplet. Future and more precise experimental results will discriminate between the two interpretations. In the case of the X(3872), we interpret it as a c (c) over bar core plus higher Fock components due to the coupling to the meson-meson continuum, and thus we think that it is compatible with the meson chi(c1)(2P), with J(PC) = 1(++). The J(PC) = 1(++) quantum numbers are in agreement with the experimental results found by the LHCb collaboration. In our view, the X(3872)'s mass is lower than the quark model's predictions because of self-energy shifts. We also provide an estimation of the open charm/bottom strong decay modes of the X(3872) and chi(b)(3P) mesons, such as X(3872) -> D (D) over bar* and chi(b2)(3P) -> B (B) over bar, and radiative transitions.