Role of the tetraquark in the chiral phase transition

Abstract

We investigate the implications of a tetraquark field on chiral symmetry restoration at nonzero temperature. In order for the chiral phase transition to be cross-over, as shown by lattice QCD studies, a strong mixing between scalar quarkonium and tetraquark fields is required. This leads to a light ($\sim0.4$ GeV), predominantly tetraquark state, and a heavy ($\sim1.2$ GeV), predominantly quarkonium state in the vacuum, in accordance with recently advocated interpretations of spectroscopy data. The mixing even increases with temperature and leads to an interchange of the roles of the originally heavy, predominantly quarkonium state and the originally light, predominantly tetraquark state. Then, as expected, the scalar quarkonium is a light state when becoming degenerate in mass with the pion as chiral symmetry is restored at nonzero temperature.Comment: 4 pages, 2 figure

Nuclear matter within a dilatation-invariant parity doublet model: The role of the tetraquark at nonzero density

“…[23] at finite temperature and vanishing density, we find that also at nonzero density a light tetraquark field has a strong influence on the medium properties of the system due to the interplay of two condensates, the tetraquark and the chiral (quark-antiquark) condensates. Interestingly, the described scenario and also the values of the coupling constants are in agreement with the work of Ref.…”

“…It can be coupled to the model following Refs. [7,23]. (iii) The dilaton/glueball field G can also be easily added to the meson sector according to the requirement of dilatation invariance and the corresponding trace anomaly [20].…”

Isf0(1710)a glueball?

“…Indeed, in the two-flavor case the resonance f 0 (500) as a tetraquark/molecular field has been already included in a simplified version of the eLSM [41], in which chiral symmetry restoration at nonzero temperature has been studied, and in the extension of the eLSM to the baryonic sector [42]. The role of f 0 (500) is important because it induces a strong attraction between nucleons and affects the properties of nuclear matter at nonzero density.…”

Large-Npion scattering at finite temperature: Thef0(500)and chiral restoration

“…Moreover, chiral partners in the scalar-pseudoscalar sector are understood through degeneration of correlators and susceptibilities [26], something which is also directly seen in lattice data [4,5]. The role of the f 0 ð500Þ state for chiral restoration could become more complicated if its possible tetraquark component is also considered at finite temperature [27].…”