New Predictions for Multiquark Hadron Masses

The recent reported charmed-strange resonance at 2.32 GeV/c suggests a possible multiquark state. Three types of multiquark bound states are reviewed. A previous model-independent variational approach considers a tetraquark with two heavy antiquarks and two light quarks as a heavy antidiquark with the color field of a quark bound to the two light quarks with a wave function like that of a heavy baryon. Results indicate that a charmed-strange tetraquark c̄s̄ud or a bottom-strange tetraquark b̄s̄ud with this “diquarkheavy-baryion” wave function is not bound, in contrast to “molecular-type” D − K and B −K wave functions. However, a charmed-bottom tetraquark c̄b̄ud might be bound with a very narrow weak decay mode. A “moleculartype” D − B state can have an interesting Bcπ decay with a high energy pion, I. THREE TYPES OF MULTIQUARK STATES The recent observation [1] of a charmed-strange state at 2.32 GeV that decays into Dsπ o suggests a possible four-quark state (tetraquark). [2–8] ∗Supported in part by grant from US-Israel Bi-National Science Foundation and by the U.S. Department of Energy, Division of High Energy Physics, Contract W-31-109-ENG-38.