Speaker
Description
Aiming at a self-consistent description of multiquark hadrons (such as tetraquarks, pentaquarks, hexaquarks, etc.) by means of QCD sum rules, we note that the entirety of contributions to two- or three-point correlation functions involving, respectively, two or one multiquark interpolating operators may be straightforwardly disentangled into two disjoint subsets comprising of unambiguously identifiable members:
• On the one hand, there are all those “multiquark-phile” contributions that indeed may support the multiquark state of interest. In the case of flavour-exotic tetraquarks, by definition composed of four (anti-)quarks of mutually different flavours, such tetraquark-phile contributions necessarily involve at least two gluon exchanges of appropriate topology.
• On the other hand, there are all those contributions that definitely do not bear any relation to the multiquark in the focus of interest and, consequently, should be discarded from one’s multiquark analysis by application of some QCD sum-rule formalism.
Needless to say, exclusively the former subset should enter any “multiquark-adequate” QCD sum-rule description of exotic hadrons.
