Four-quark structure of the Zc(3900) , Z(4430) , and

Goerke Fabian

¹

,

Thomas Gutsche

²

,

Mikhail A. Ivanov

³

et al.

Abstract

Four-quark structure of the Z c (3900), Z(4430), and X b (5568) states

Treating Zc(3900) and Z(4430) as the ground state and first radially excited tetraquarks

“…[24]. But we are not going to make far-reaching conclusions from similar estimates: From our point of view, in the lack of direct measurements of Γ(Z → J/ψπ), the best what can be done is calculation of theoretical prediction for R Z , which equals in our case to R Z = 4.73 ± 1.88.…”

“…The same decay modes Z + (4430) → J/ψπ + ; ψ ′ π + were revisited in a covariant quark model in Ref. [24].…”

“…The decays of the Z ± c (3900) resonances were a subject of studies in the framework of alternative methods [24,33,35], as well. Thus, the decay channels Z c (3900) → J/ψπ; ψ ′ π; h c (1P )π were calculated in a phenomenological Lagrangian approach by modeling Z c (3900) as a hadronic moleculeDD ⋆ with J P = 1 + [33].…”

“…The aim is to reveal their internal quark-gluon structure and determine their parameters, such as the masses, current couplings (pole residues) and width of decay modes. Thus, Z(4430) was interpreted as the diquark-antidiquark [13][14][15][16][17][18][19], molecular state [20][21][22][23][24], the threshold effect [25] and hadro-charmonium composite [26].…”

“…The widths of the decay modes Z + c (3900) → J/ψπ + ; η c ρ + ;D 0 D ⋆+ ;D ⋆0 D + were extracted in Ref. [24] in a covariant quark model. Let us note also the work [39], where the Z c (3900) → h c π decay was analyzed in the light front model.…”