Article
Physics, Particles & Fields
Rui Gao, Zhi-Hui Guo, J. A. Oller, Hai-Qing Zhou
Summary: In this work, we study the mixing of the QCD/QCD-like axion and light-flavor mesons pi(0), eta, eta' within the framework of U(3) chiral perturbation theory up to next-to-leading order. We calculate the axion-meson mixing formulas in the U(3) delta-expansion scheme and provide the axion-meson mixing relations in terms of the pi(0)-eta-eta' mixing parameters and their masses. Recent lattice simulations on the eta-eta' systems can provide valuable inputs for constraining the unknown low-energy constants. We also explore the relation of the mass and decay constant of the axion based on our updated calculations, and investigate the two-photon couplings of the light-flavor mesons and axion in the U(3) chiral theory up to next-to-leading order in the delta-counting scheme.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Physics, Multidisciplinary
Qing-Sen Chen, Hui-Feng Fu, Yong-Liang Ma, Qing Wang
Summary: The researchers derived the chiral effective Lagrangian for excited heavy-light mesons from QCD under proper approximations, focusing on specific chiral partners. They calculated low energy constants including the masses of the chiral partners, with the calculated spectrum for the excited mesons found to be roughly consistent with experimental data. Additionally, their results suggest that the quantum numbers of B-J(5970) can be identified as 1(-) or 2(-).
COMMUNICATIONS IN THEORETICAL PHYSICS
(2021)
Article
Physics, Particles & Fields
M. Benayoun, L. DelBuono, F. Jegerlehner
Summary: The BHLS2 variant of the generic hidden local symmetry (HLS) model is not fully satisfactory in describing the tau dipion spectra, but it performs well in dealing with the annihilation sector. By introducing an additional breaking term, the issue with the tau dipion spectra is solved and the mixing properties of the [π(0), η, η'] system can be included consistently within this extended model.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Astronomy & Astrophysics
M. K. Volkov, A. A. Pivovarov, K. Nurlan
Summary: In this study, the branching fractions of the decays & tau;- & RARR; K-& pi;+& pi;- & nu;& tau;, & tau;- & RARR; K-& pi;0 & pi;0 & nu;& tau;, and & tau;- & RARR; over bar K0 & pi;- & pi;0 & nu;& tau; are calculated using the U(3) x U(3) Nambu-Jona-Lasinio-type chiral model. Four intermediate channels are considered, including the contact channel and channels with intermediate axial-vector, vector, and pseudoscalar mesons. The obtained results, which take into account additional resonance states, are in good agreement with experimental data.
Article
Physics, Particles & Fields
Fang Lu, Hong-Wei Ke, Xiao-Hai Liu, Yan-Liang Shi
Summary: In this work, the weak decay between two heavy baryons B-i(1/2(+)) -> B-f(3/2(+)) is studied using the light-front quark model with three-quark picture for baryon. The general form of transition amplitude of B-i(1/2(+)) -> B-f(3/2(+)) is derived, and two specific cases of transitions are analyzed: the weak decays of single heavy baryon Sigma(b) -> Sigma*(c) and the decays of double-charmed baryon Xi(cc) -> Sigma*(c) (Xi*(c)). The hadronic form factors are computed for the transitions and applied to study the decay widths of the semileptonic and non-leptonic decays. Future measurements on these channels will provide constraints on the nonperturbative parameter in the wavefunctions and test the model predictions.
EUROPEAN PHYSICAL JOURNAL C
(2023)
Article
Astronomy & Astrophysics
Yaroslav Balytskyi
Summary: The decays of eta and eta' mesons provide a unique opportunity to study low energy Quantum Chromodynamics and search for new physics beyond the Standard Model. However, recent experimental results on the rare decays of eta(') -> pi 0 (eta) gamma gamma cannot be consistently explained by the Vector Meson Dominance and Linear Sigma Model using the same set of parameters. We attribute this tension to the existence of a leptophobic dark photon 13, and find representative parameter values that can consistently describe these three decays. Unlike existing strategies, we propose using the mismatch between these decays to constrain the parameters of the hypothetical dark photon. Additionally, we discuss possible signatures of a sub-GeV 13 boson in heavy meson decays.
Article
Astronomy & Astrophysics
R. M. Moita, J. P. B. C. de Melo, K. Tsushima, T. Frederico
Summary: In a unified covariant constituent quark model, the electroweak properties of light and charmed D and Ds pseudoscalar mesons were investigated. The flavor decomposition of the elastic electromagnetic form factors, electromagnetic charge radii, and weak decay constants was calculated and a discussion on the SU(3) and SU(4) symmetry breaking was made. A comparison with the pion and kaon properties was used to highlight the Higgs contribution to the structure of these mesons.
Article
Astronomy & Astrophysics
Yang Li, James P. Vary
Summary: We propose an analytically solvable 3D light-front Hamiltonian model that extends light-front holography by incorporating finite mass quarks and a longitudinal confinement term. This model is believed to be a suitable improved analytic approximation to low-resolution scale QCD. It maintains desired Lorentz symmetries and shows improved agreement with experimental mass spectroscopy and other properties of light mesons. Notably, the model also respects chiral symmetry and the Gell-Mann-Oakes-Renner relation.
Article
Astronomy & Astrophysics
Hao Xu
Summary: The chiral interactions of the hidden charm D (D) over bar* system are studied using chiral effective field theory in this paper. The interacting potentials of the S-wave D (D) over bar* system are calculated and their behaviors in coordinate space and bound state properties are investigated. The study indicates an interacting strength ordering among the considered channels and predicts multiple structures in the D (D) over bar* mass region.
Article
Astronomy & Astrophysics
Xin Liu
Summary: In this article, we propose to comprehensively study the decays of Bc -> J/psi M within the improved perturbative QCD formalism. These theoretical predictions need to be verified by experiments at the upgraded Large Hadron Collider and the forthcoming Circular Electron-Positron Collider. The focus is on investigating the factorizable-emission-suppressed or-forbidden decays and examining the relative ratios between branching fractions.
Article
Astronomy & Astrophysics
Jisu Kim, Su Houng Lee
Summary: The masses of vector and axial vector mesons as well as nucleon and delta resonance are calculated in the chiral symmetry restored vacuum. It is found that the mass degeneracy occurs among chiral partners in the chiral symmetry restored vacuum, while parity partners remain nondegenerate. The masses of nucleon and delta are also reduced in the chiral symmetric vacuum.
Article
Biochemistry & Molecular Biology
Chenglong Wang, Jingang Wang, Chunyang Wang
Summary: The study investigates the electronic transitions and chirality of three isomers of huge conjugated systems, forming a ribbon-shaped polycyclic aromatic hydrocarbons molecule. By analyzing electromagnetic interaction decomposition over distance, it is found that the chirality reversal is caused by symmetrical fracture in the Z direction and in-plane polarization along the Y direction.
Article
Physics, Nuclear
Miklos Zetenyi, Deniz Nitt, Michael Buballa, Tetyana Galatyuk
Summary: This study investigates the reaction pi(-)p -> ne(+)e(-) using an effective Lagrangian model, predicting the differential cross section and spin density matrix elements at different masses. The cross section in the studied energy range is mainly influenced by the Born and N(1520) contributions.
Article
Astronomy & Astrophysics
T. M. Aliev, T. Barakat, K. Simsek
Summary: The gravitational formfactors of the rho, pi, and K mesons were calculated using the quark part of the energy-momentum tensor current within the light-cone sum rules method. Results show that the nonconservation of the energy-momentum tensor current leads to the appearance of multiple formfactors.
Article
Physics, Nuclear
T. M. Aliev, T. Barakat, K. Simsek
Summary: The study estimates the strong coupling constants of spin-3/2 to spin-1/2 doubly heavy baryon transitions with light vector mesons using the light-cone QCD sum rules method, and calculates the widths of radiative decays BQQ-> BQQ gamma with the vector-meson dominance ansatz. The results for these decay widths are compared to predictions from other approaches.
EUROPEAN PHYSICAL JOURNAL A
(2021)
