Constituent counting rule for exclusive production of heavy quarkoniumlike exotic resonance and a light hadron

Abstract

The exclusive processes are considered, where a point-like source of heavy quark-antiquark pairs $Q\bar{Q}$, e.g. their electromagnetic current, produces a pair consisting of a heavy quarkoniumlike exotic meson (tetraquark) or baryon (pentaquark) and a light meson or an antibaryon. For a sufficiently large mass of the heavy quark $m_Q$ there is a range of the energy $E$ above the $Q\bar{Q}$ threshold, where $E\ll m_Q$ and still the energy is large compared to the strong interaction scale, $E\gg {\Lambda }_{QCD}$. It is shown that in this energy range, where the heavy quarks are nonrelelativistic, a specific `intermediate asymptotic' behavior sets in determined by the number $n$ of the pairs of constituent quarks, with the rate scaling as $E^{1-n}$.

Comments: 10 pages, 3 figures