Review
Physics, Nuclear
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Summary: The study reviews the application of the large-Nc approach to the tetraquark states, exploring the differences in internal structure between multiquark states and ordinary hadrons, as well as the mechanisms of tetraquark state formation. Analyzing the energy balance of various schemes in the static limit provides clarification on the mechanisms at work in the formation of tetraquarks.
PROGRESS IN PARTICLE AND NUCLEAR PHYSICS
(2021)
Article
Astronomy & Astrophysics
Peter Kovacs, Gyozo Kovacs, Francesco Giacosa
Summary: The phase diagram of quantum chromodynamics (QCD) was investigated by varying the number of colors Nc within a Polyakov loop quark-meson chiral model. The results showed that the critical point(s) changed their positions and characteristics with different numbers of colors, and a distinct symmetry was observed in the phase diagram at large Nc.
Article
Astronomy & Astrophysics
Nikhil Karthik, Rajamani Narayanan
Summary: By computing the collinear quark structure of a large-N-c pion, we find that the internal structures of a pion in the large-N-c and N-c = 3 theories are quite similar, with observed differences potentially arising from different perturbative QCD evolution under similar initial conditions.
Article
Astronomy & Astrophysics
Yuanyuan Hu, Jinfeng Liao, Enke Wang, Qian Wang, Hongxi Xing, Hui Zhang
Summary: This paper demonstrates how heavy ion collisions can serve as a powerful platform for studying doubly charmed exotic hadrons, providing valuable insights into the dynamics of hadron structures in a charm-rich environment. The yields of T-cc(+) and its isospin partners in Pb-Pb collisions show significant enhancements compared to proton-proton collisions. The results on rapidity, transverse momentum dependence, and elliptic flow coefficient can be further tested by future experimental measurements.
Article
Physics, Particles & Fields
H. Sundu, S. S. Agaev, K. Azizi
Summary: Spectroscopic parameters and widths of the fully open-flavor axial-vector and pseudoscalar tetraquarks XAV and X-PS were calculated using QCD sum rule methods. The masses and current couplings were determined through two-point sum rule computations, taking into account various vacuum condensates. Decay modes were considered to evaluate the full width of XAV and X-PS. By employing the QCD light-cone sum rule method and soft-meson approximation, the partial widths of these decay modes were determined, providing predictions that may be useful in future experimental studies of multiquark hadrons.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Miguel Angel Escobedo
Summary: The study investigates the transitions between different color states of a static quark-antiquark pair in a thermal medium using nonperturbative methods in the infinite mass limit of QCD. The research is significant as it can contribute to future developments in effective field theories and be combined with other techniques like lattice QCD or AdS/CFT to gain nonperturbative insights into the evolution of quarkonium in a medium. The investigation also examines the expressions obtained in the large N-c limit to simplify phenomenological models of quarkonium in a plasma.
Article
Physics, Particles & Fields
Yu-Ji Shi, Ye Xing, Zhen-Xing Zhao
Summary: We conducted a SU(3) analysis on heavy meson weak decays into a pseudoscalar meson and a fully-light tetraquark in 10 or 27 representation, reducing the SU(3) representation tensor for the tetraquarks and listing all the flavor components. The decay channels studied include B/D -> U/T P l nu, B/D -> U/T P, and Bc -> U/T P/D, with U/T representing a fully-light tetraquark in 10 or 27 representation and P being a pseudoscalar meson. We also identified the golden decay channels expected to have higher observability in experiments.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Astronomy & Astrophysics
S. S. Agaev, K. Azizi, B. Barsbay, H. Sundu
Summary: This article calculates the masses, couplings, and widths of the fully heavy scalar tetraquarks X4Q = QQQQ, Q = c, b by modeling them as four-quark systems composed of axial-vector diquark and antidiquark. The masses m(') and couplings f(') are computed using the QCD sum rule method and taking into account a nonperturbative term. The possible decay modes and partial widths of the tetraquarks are also evaluated. Comparisons are made with other theoretical predictions and experimental observations.
Article
Multidisciplinary Sciences
Hagop Sazdjian
Summary: This article examines the interplay between compact and molecular structures in tetraquarks using an effective field theory approach. It is found that a compact tetraquark, when coupled to mesonic clusters, evolves into a new bound state with both compact and molecular structures. In the strong-coupling limit, the evolution may result in a shallow bound state of the molecular type. The large Nc properties of QCD also support the formation of the strong-coupling regime, potentially explaining the existence of many shallow bound states.
Article
Physics, Particles & Fields
Jorge Baeza-Ballesteros, Pilar Hernandez, Fernando Romero-Lopez
Summary: This study presents the first lattice investigation of pion-pion scattering with varying number of colors. The researchers used lattice simulations with four degenerate quark flavors to focus on two scattering channels. They extracted the scattering amplitude and matched the results to Chiral Perturbation Theory, providing valuable insights into the pion-pion scattering process.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Multidisciplinary
U. Ozdem, K. Azizi
Summary: In this study, the magnetic dipole moment of the newly observed charged hidden-charmed open strange Z(cs)(3985)(-) state was calculated using experimental and theoretical data. The quantum numbers and quark composition of the state were determined, and the magnetic dipole moment was estimated in both compact diquark-antidiquark and molecular pictures. The results from both pictures were consistent within the errors, indicating the accessibility of the magnetic dipole moment measurement in experiments.
EUROPEAN PHYSICAL JOURNAL PLUS
(2021)
Article
Astronomy & Astrophysics
Wolfgang Lucha, Dmitri Melikhov, Hagop Sazdjian
Summary: The study discusses the operator product expansion (OPE) and quark hadron duality for two-point Green functions of tetraquark currents. It emphasizes that the factorizable part of the OPE series for such Green functions is saturated by ordinary hadrons and cannot be related to potential tetraquark bound states. Possible exotic tetraquark states may be present in the nonfactorizable parts of these Green functions, particularly in N-c-subleading contributions.
Article
Physics, Multidisciplinary
Yong-Xing Song, Duo-Jie Jia
Summary: Inspired by the recent observation of the first doubly charmed tetraquark T(cc), this study applies linear Regge relation and mass scaling to analyze low-lying mass spectra of doubly heavy tetraquarks. The computed masses indicate that all low-lying states of doubly heavy tetraquarks, except for the ground states of nonstrange bb tetraquarks, are unstable and would decay into two heavy-light mesons.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2023)
Article
Astronomy & Astrophysics
Hong-Tao An, Si-Qiang Luo, Zhan-Wei Liu, Xiang Liu
Summary: This study systematically investigates various configurations of the fully heavy pentaquark system using the variational method, and concludes that no stable states exist in this system.
Review
Physics, Nuclear
Thomas R. Richardson, Matthias R. Schindler, Roxanne P. Springer
Summary: This paper presents a method for ordering two-nucleon interactions based on their scaling with the number of QCD colors. It discusses the application of this method to two- and three-nucleon interactions, as well as weak and BSM interactions, and raises some open questions in the field.
ANNUAL REVIEW OF NUCLEAR AND PARTICLE SCIENCE
(2023)