arXiv:hep-ph/0305025·v1·High Energy Physics — Phenomenology
Implications of a DK Molecule at 2.32 GeV
T.Barnes (1,2)🇺🇸 · F.E.Close (3)🇬🇧 · H.J.Lipkin (4,5,6) ((1) Physics Division, Oak Ridge National Laboratory, (2) Department of Physics and Astronomy, University of Tennessee, (3) Department of Theoretical Physics, University of Oxford, (4) Department of Particle Physics, Weizmann Institute of Science, (5) Faculty of Exact Sciences, Tel Aviv University, (6) High Energy Physics Division, Argonne National Laboratory)🇮🇱
Abstract
We discuss the implications of a possible quasinuclear DK bound state at 2.32 GeV. Evidence for such a state was recently reported in D_s^+pi^o by the BaBar Collaboration. We first note that a conventional quark model c-sbar assignment is implausible, and then consider other options involving multiquark systems. An I=0 c sbar n nbar baryonium assignment is one possibility. We instead favor a DK meson molecule assignment, which can account for the mass and quantum numbers of this state. The higher-mass scalar c-sbar state expected at 2.48 GeV is predicted to have a very large DK coupling, which would encourage formation of an I=0 DK molecule. Isospin mixing is expected in hadron molecules, and a dominantly I=0 DK state with some I=1 admixture could explain both the narrow total width of the 2.32 GeV state as well as the observed decay to D_s^+ pi^o. Additional measurements that can be used to test this and related scenarios are discussed.
Comments: 6 pages, 1 figure