Tetraquarks with charm in coupled-channel formalism

Abstract

The relativistic four-quark equations are found in the framework of coupled-channel formalism. The dynamical mixing of the meson-meson states with the four-quark states is considered. The approximate solutions of these equations using the method based on the extraction of leading singularities of the amplitudes are obtained. The four-quark amplitudes of cryptoexotic mesons including the quarks of three flavours (u, d, s) and the charmed quark are constructed. The poles of these amplitudes determine the masses of tetraquarks. The mass values of low-lying tetraquarks are calculated.Comment: 21 pages, pdf, minor typos in the text correcte

New charmonium states in QCD sum rules: A concise review

“…The X(4160) was identified as a 2 ++ state in two recent works: generated from a relativistic four quark equations in ref. [200], and from a coupled channel approach using a vector-vector interaction in ref. [177].…”

Masses of open charm and bottom tetraquark states in a relativized quark model

“…Those calculations include diquark-antidiquark picture, compact tetraquark, mixture of quark-antiquark and four quark components, and molecular sceneario, which intends to reveal the nature of D * s0 (2317). Some calculations indicate the D * s0 (2317) can be treated as a tetraquark state [40,41], while others give much higher masses of the four quark components than that of D * s0 (2317) as well as the DK threshold [42][43][44][45][46]. For the molecular scenario, most works indicate that a weekly bounded DK state can be obtained [47][48][49], while others suggest the attraction between these two pseudoscalar mesons is not strong enough to form bound state [50].…”

Exploration of charmed pentaquarks

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