Decays of the X(3872) and theχc1(2P)charmonium state

Abstract

We reexamine the rescattering mechanism for the X(3872), as a candidate for the 2P charmonium state {chi}{sub c1}(2P), decaying to J/{psi}{rho}({omega}) through exchanging D{sup (*)} mesons between intermediate states D(D) and D*(D*). We evaluate the dispersive part, as well as the absorptive one, of the rescattering amplitude and find that the contribution from the dispersive part is dominant even when X(3872) lies above the threshold of the neutral channel th{sub n}=m{sub D{sup 0}}+m{sub D*{sup 0}}. We predict R{sub {rho}}{sub /{omega}}{approx_equal}1 for the m{sub X} region scanned by experiments. Meanwhile, we also estimate the rate of X{yields}D{sup 0}D{sup 0}{pi}{sup 0}. Our results favor a charmonium interpretation of X(3872) when it lies slightly below the threshold of D{sup 0}D*{sup 0}. Furthermore, we evaluated the width of X{yields}J/{psi}{rho} with the help of a phenomenological effective coupling constant g{sub X}, and find the total width of X(3872) to be in the range of 1-2 MeV.