X(3872) is not a true molecule

作者：Coito Susana^*; Rupp George; van Beveren Eef

来源：European Physical Journal C, 2013, 73(3): 2351.

DOI：10.1140/epjc/s10052-013-2351-8

A solvable coordinate-space model is employed to study the c (c) over bar component of the X(3872) wave function, by coupling a confined P-3(1) c (c) over bar state to the almost unbound S-wave D-0(D) over bar*(0) channel via the P-3(0) mechanism. The two-component wave function is calculated for different values of the binding energy and the transition radius a, always resulting in a significant c (c) over bar component. However, the long tail of the D-0(D) over bar*(0) wave function, in the case of small binding, strongly limits the c (c) over bar probability, which roughly lies in the range 7-11 %, for the average experimental binding energy of 0.16 MeV and a between 2 and 3 GeV-1. Furthermore, a reasonable value of 7.8 fm is obtained for the X(3872) r.m.s. radius at the latter binding energy, as well as an S-wave D-0(D) over bar*(0) scattering length of 11.6 fm. Finally, the S-matrix pole trajectories as a function of coupling constant show that X(3872) can be generated either as a dynamical pole or as one connected to the bare c (c) over bar confinement spectrum, depending on details of the model. From these results we conclude that X(3872) is not a genuine meson-meson molecule, nor actually any other mesonic system with non-exotic quantum numbers, due to inevitable mixing with the corresponding quark-antiquark states.

• 出版日期2013-3