On the Role of One Pion Exchange and Heavy Quark Spin Symmetry in Heavy Meson Molecules

Abstract

In this contribution we consider the theoretical description of heavy mesonantimeson molecules from the effective field theory perspective. We are interested in the role of one pion exchange and heavy quark spin symmetry in the low energy description of the molecular states. We find that pion exchanges are weaker than naively expected. As a consequence, at lowest order in the effective expansion, the heavy meson-antimeson dynamics are driven by contact range interactions that are in turn heavily constrained by heavy quark spin symmetry. We find that if the X(3872) DD¯*${m{Dar D*}}$ is a bound state with quantum numbers JPC = 1++, we should expect the existence of a 2++ DD¯*${m{Dar D*}}$ molecule with a mass of 4012 MeV. If we also assume the X(3915) resonance to be molecular, we end up deriving the location of three new states with masses of 3710, 3820 and 3855 MeV.