Exotic meson-meson molecules and compact four-quark states

Abstract

We present an exact calculation of S and P wave QQnn states using different standard nonrelativistic quark-quark potentials. We explore in detail the charm and bottom sectors looking for bound states that could be measured within existing facilities. Against the proliferation of four-quark states sometimes predicted in the literature, we found a small number of candidates to be stable. We analyze their properties in a trial to distinguish between compact and molecular states. Possible decay modes are discussed.

Two-photon and one-photon–one-vector meson decay widths of thef0(1370),f2(1270)Branz1, Geng2, Oset3 2010Phys. Rev. D476300View full textAdd to dashboardCite

“…However, apart from the works mentioned earlier [32][33][34] there are works in this direction in Refs. [38,39], which also conclude that the states of lower energy are mostly of mesonic nature.…”

The hidden-charm pentaquark and tetraquark states

“…Especially the dimeson, dibaryon and pentaquark molecular systems with two charm/bottom quarks are particularly interesting, which have have been studied using various models [852,853,854,855,856,857], QCD sum rules [858,859] as well as the lattice QCD [860,861,862]. These hadrons may be produced either at LHC or through heavy ion collisions or through higher bottomonium decays.…”

Analysis of the scalar, axialvector, vector, tensor doubly charmed tetraquark states with QCD sum rules

“…Up to now, no experimental candidates for the doubly charmed tetraquark states ccqq or qq cc have been observed. There have been several works on the doubly heavy tetraquark states, such as potential quark models [17][18][19][20][21][22][23], QCD sum rules [24][25][26], heavy quark symmetry [27][28][29], lattice QCD [30][31][32], etc.…”