Related papers: Regarding the axial-vector mesons
We develop a practical method to analyze the mixing structure of hadrons consisting of two components of quark-composite and hadronic composite. As an example we investigate the properties of the axial vector meson a1(1260) and discuss its…
We carry out a systematic study of the heavy-light meson strong decays in a chiral quark model. For the $S$-wave vectors ($D^*(2007)$, $D^{*\pm}(2010)$), $P$-wave scalars ($D^*_0(2400)$, $B^*_0(5730)$) and tensors ($D^*_2(2460)$,…
The octet-singlet $\eta -\eta^{\prime}$ mixing mass term could have a derivative $O(p^{2})$ term as found in recent analysis of the $\eta -\eta^{\prime}$ system. This term gives rise to an additional momentum-dependent pole contribution…
The contribution of the a_1(1260) meson to the amplitudes of the decays rho(770) to 4 pi, omega(782) to 5 pi, and phi(1020) to 5 pi is analyzed in the chiral model of pseudoscalar, vector, and axial vector mesons based on the generalized…
We consider the axial-vector mesons $K_1(1270)$ and $K_1(1400)$ as a mixture of two $|^3P_1\rangle$ and $|^1P_1\rangle$ states with the mixing angle $\theta$ that equal to $(-34\pm 13)^\circ$. We calculate the light-front distribution…
We perform a Faddeev calculation for the three mesons system, $\phi K \bar{K}$, taking the interaction between two pseudoscalar mesons and between a vector and a pseudoscalar meson from the chiral unitary approach. We obtain a neat…
The mixing between q-qbar meson and qqbar-qqbar tetra-quark states is examined within an effective QCD Coulomb gauge Hamiltonian model. Mixing matrix elements of the Hamiltonian are computed and then diagonalized yielding an improved…
A theoretical explanation of the observed splittings among the P~states of charmonium is given with the use of a nonsingular potential model for heavy quarkonia. We also show that the recently observed mass difference between the center of…
The one-pion exchange interaction between the kaon and the vector antikaon is investigated by solving the Schrodinger equation in the S-wave approximation. In addition to the $f_1(1285)$ particle, another bound state of $K \bar{K}^*$ is…
If neutrinos have mass, we give reasons for a possible pattern of three (squared) mass eigenvalues: $m_1^2 \simeq (2.8 - 5.8) \, \mbox{(eV)}^2 $, $m_2^2 \simeq 0.01 \, \mbox{(eV)}^2 $, $m_3^2 \simeq (1.5 - 1) \times 10^{-4} \mbox{(eV)}^2 $.…
With the assumption that the $X(1835)$ and $\eta(1760)$ recently observed by the BES Collaboration are the $3\,^1S_0$ meson states, the strong decays of these two states are investigated in the $^3P_0$ decay model. We find that the…
By using a heavy chiral unitary approach, we study the $S$ wave interactions between heavy vector meson and light pseudoscalar meson. By searching for poles of the unitary scattering amplitudes in the appropriate Riemann sheets, several…
I comment on a paper by Christoph Hanhart and Alexey Nefediev, published in Phys. Rev. D 106, 114003 (2022). The authors discuss the interpretation of mesons close to their lowest decay threshold and present a mechanism for the formation of…
We study the weight or compositeness of the $\pi\pi$-$K\bar{K}$ and $\pi\eta$-$K\bar{K}$ in the composition of the $f_0(980)$ and $a_0(980)$ resonances, respectively. Either we use the saturation of the total width and compositeness, or we…
We study the productions of p-wave mesons $K^*_{0}(1430)$, $K_{1}(1270)$ and $K_{1}(1400)$ in B decays. By the generalized factorization approach, we find that the branching ratios of $B\to K^*_{0}(1430) \phi$ are similar to those of $B\to…
By fitting the two-point correlation functions of topological charge density operators calculated on two $2+1$-flavor gauge ensembles with physical pion mass, we determine both the $\eta$ and $\eta'$ masses and also the mixing angle to be…
We calculate the masses of $J^{PC}=1^{-+}$ light exotic mesons by QCD sum rules; the masses are extracted from four-quark--hybrid mixing correlation functions. We construct several $1^{-+}$ four-quark currents and hybrid currents, and get…
The BESIII Collaboration has observed a candidate for a $c \bar c s \bar u$ tetraquark $Z_{cs}$ at $(3982.5^{+1.8}_{-2.6} \pm 2.1)$ MeV and width $(12.8^{+5.3}_{-4.4} \pm 3.0)$ MeV, while the LHCb Collaboration has observed a $Z_{cs}$…
K-matrix analysis of the $00^{++}$ wave is performed in the channels $\pi\pi,~K\bar K,~\eta\eta$ and $4\pi$ in the mass region up to 1550 MeV. The fit is based on the following data: $p\bar p ~(at~rest)\to \pi^0\pi^0\pi^0$,…
The production rates of primary vector and P-wave mesons in Z hadronic decays are analysed. The mass dependence of production rates for the bottom, charm, strange charm and three families of the light-flavour mesons is found to be very…