Probing the nature ofZc(′)states via theη

Abstract

The nature of the so-called X Y Z states is a long-standing problem. It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules. In the present work we analyze the Z ( ) c → η c ρ decay using both approaches. Such channel might provide useful insights on the nature of the Z ( ) c , helping discriminating between the two different models.

The hidden-charm pentaquark and tetraquark states

“…The Z c (3900)/Z c (4020) → η c ρ decays were studied within both tetraquark and molecular pictures in Ref. [498]. The counterparts of Z c and their decay modes were studied in Ref.…”

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

“…Indeed, there are attempts to treat it as the tightly bound diquark-antidiquark state [27][28][29][30], as the four-quark bound state composed of conventional mesons [31][32][33][34][35][36][37][38][39], or as the threshold cusp [40,41].…”

Magnetic and quadrupole moments of the Zc(3900)

“…Since the mass of Z ± c (3900) is very close to X(3872), it can be advised as the charged partner of the X(3872) in a tetraquark scenario. The properties of the Z ± c (3900) particle have been investigated with different theoretical models and approaches [18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Although the spectroscopic properties of these particles have been studied adequately, the internal structure and nature of the X(3872) and Z ± c (3900) particles have not been fully understood yet.…”