Newly observed exotic doubly charmed meson $T^{+}_{cc}$

Abstract

The mass and current coupling of the newly observed doubly charmed four-quark state T + cc are calculated in the context of the QCD two-point sum rule method. The T + cc is treated as an axialvector tetraquark with quark content ccud. Computations are carried out by taking into account quark, gluon and mixed condensates up to dimension 10. Central value for the mass m = (3868 ± 124) MeV of this tetraquark extracted from our analysis is below the two-meson D 0 D * (2010) + threshold which is equal to m = 3875.09 MeV. This result is compatible with recent measurements of the LHCb collaboration.

Colour and baryon number fluctuation of preconfinement system in production process and T_cc structure

“…The static properties of this resonance have been well predicted by both assumptions as tetraquark or molecule [13][14][15] though some potential models of multiquark state fail to give the mass [16]. Since the observation of this T cc state, discussions of double-heavy four quark states in both molecular configuration [17][18][19][20][21][22][23][24][25][26][27][28][29] and tetraquark picture [30][31][32][33] are performed to explain the static and/or decay properties. However, T cc can be taken as an excellent example for the study of the production mechanism (rather than via decay or static properties) to gain insight on the hadronic structure, and to shed light on the confinement mechanism.…”

Magnetic dipole moments of the $T_{cc}^+$ and $Z_V^{++}$ tetraquark states

“…The discovery of the first doubly charmed tetraquark state will, undoubtedly, usher in a new era in the study of hadron spectroscopy and improve our understanding of the non-perturbative nature of the strong interaction. After the experimental discovery, some spectroscopic properties and decay channels of the T + cc state have been investigated within different theoretical models [16][17][18][19][20][21]. Note that the spectroscopic parameters and different decay modes of the scalar and pseudoscalar T cc states as well as the T bc and T bb states of different quantum numbers were already investigated in Refs.…”

Interactions of the doubly charmed state $T_{cc} ^+$ with a hadronic medium

“…Even before the experimental discovery of this doubly charmed tetraquark state, there was a debate concerning its fundamental aspects, such as its decay/formation mechanisms and underlying structure [3][4][5][6][7][8][9][10][11][12][13][14]. Its discovery obviously stimulated the appearance of more studies employing different theoretical approaches [15][16][17][18][19][20][21][22][23][24][25][26][27]. In particular, several works have investigated the implications of the T + cc structure (hadron molecule or compact tetraquark) for the observables.…”