PDF《Hidden-charm Pentaquark States in》

2 II. YIELD RATIOS OF DIFFERENT HIDDEN-CHARM PENTAQUARK STATES In this section, we derive the yield formalism of the hidden-charm pentaquark states in the quark combination models based on the basic ideas. We ?rst begin with a quark-antiquark system as general as possible. Then we simplify the results by adopting a few explicit assumptions and/or approximations. Finally we present some interesting results for the yield ratios of di?erent hidden-charm pentaquark states. A. The yield formalism of the hidden-charm pentaquark states We start from a color-neutral quark-antiquark system with Nqi quarks of ?avor qi (qi = u, d, s, c) and N? qi antiquarks of ?avor ? qi (? qi = ? u, ? d, ? s, ? c). All these qu........