Abstract
The constituent counting rules, i.e., the scaling behavior of amplitudes (in terms of the number of fundamental constituents) for exclusive processes when high energy scales are present, have been known for decades, and have been borne out in a number of experiments. Such scaling would be sensitive, in particular, to possible exotic multiquark content. Here we examine how one may use the rules to test for pentaquarks in electroproduction, or for tetraquarks in \(e^+ e^-\) annihilation. An interesting new type of scaling (separate Mandelstam s and t behavior) arises in the forward scattering direction. The correct scaling arises naturally in AdS/QCD, in which the amplitudes can be computed explicitly.
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Supported in part by the U.S. National Science Foundation under Grant No. PHY-1403891.
This article belongs to the Topical Collection “NSTAR 2017—The International Workshop on the Physics of Excited Nucleons”.
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Lebed, R.F. Constituent Counting Rules and Exotic Hadrons. Few-Body Syst 59, 106 (2018). https://doi.org/10.1007/s00601-018-1427-2
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DOI: https://doi.org/10.1007/s00601-018-1427-2