Related papers: Effect of $\eta$--$\eta'$ mixing on $D \to PV$ dec…

We study the role of a possible nonet of light scalar mesons in the still interesting $\eta \to 3\pi$ decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear…

The decays of $B$ mesons to a charmless vector ($V$) and pseudoscalar ($P$) meson are analyzed within a framework of flavor SU(3) in which symmetry breaking is taken into account through ratios of decay constants in tree ($T$) amplitudes.…

Matrix elements of flavor-diagonal light quark pseudoscalar densities and axial anomaly operators between vacuum and {\eta} and {\eta}' meson states have been determined. This has been done by evaluating current-current correlators of…

The decays eta, eta-prime -> pi^+ pi^- gamma are investigated within an approach that combines one-loop chiral perturbation theory with a coupled channel Bethe-Salpeter equation which satisfies unitarity constraints and generates vector…

Recently, the BESIII Collaboration reported the first observation of the decays $\chi_{cJ} \to \eta \eta \eta^\prime$ in order to search for the $1^{-+}$ exotic state $\eta_1(1855)$. A partial wave analysis of the $\eta \eta^\prime$…

Underlying mixing of scalar mesons is studied in $\eta'\rightarrow \eta\pi\pi$ decay within a generalized linear sigma model of low-energy QCD which contains two nonets of scalar mesons and two nonets of pseudoscalar mesons (a…

Analyses of various experimental measurements all indicate that the mixing angle $\theta_{K_1}$ of $K_1(1270)$ and $K_1(1400)$ is in the vicinity of $33^\circ$ or $57^\circ$. However, whether $\theta_{K_1}$ is greater or less than…

We consider the branching ratios and CP asymmetry in the B meson decays into two pseudoscalar mesons in the generalized factorization approximation. We also investigate the possible effects of the enhanced chromomagnetic interaction b --> s…

A phenomenological analysis of radiative $V\to P\gamma$ and $P\to V\gamma$ decays is performed with the purpose of determining the gluonic content of the $\eta$ and $\eta^\prime$ wave functions. Our results show that within our model there…

The decay $\eta'\rightarrow\pi^0\gamma\gamma$ is studied theoretically in the framework of the Vector Meson Dominance model (VMD). We find theoretically a significant contribution of the interference of $\omega-\rho$ and provide theoretical…

The mixing of $S-D$ partial waves for the heavy meson pairs in the decays $\Upsilon(5S) \to [B^* \bar B+ {\rm c.c.}] \pi$ and $\Upsilon(5S) \to B^* \bar B^* \pi$ is considered. It is argued that this mixing, enhanced by the heavy meson…

We show how the nuclear medium affects the masses of the $\eta$ and $\eta'$ mesons. The change should be easily detectable for dense matter and/or strong $\eta(\eta')N\bar N$ coupling. We also find that the $\eta-\eta'$ mixing angle is less…

We calculate the strong decay couplings for $\rho \to \pi\pi$, $\phi\to KK$, $K^* \to K\pi$ and $D^*\to D\pi$ in a unified and consistent approach based on the impulse approximation, nonperturbative solutions of the quark-gap equation and…

Dalitz plot of the $\eta' \to \eta\pi^+\pi^-$ decay is studied using the data collected with the VES spectrometer in two different exclusive reactions. The coefficients for the matrix element squared decomposition are measured on the…

We report the first measurements of the branching fractions: $B(\psi(2S) -> \gamma \eta') = (1.54 \pm 0.31 \pm 0.23) x 10^{-4}$ and $B(\psi(2S) -> \gamma \eta) = (0.53 \pm 0.31 \pm 0.08) x 10^{-4}$. The $\psi(2S)$ to $\gamma \eta'$ result…

Rare decays of light mesons may be a discovery window for a new weakly coupled forces hidden at low energy QCD scale. BES-III Collaboration reported the observation of the rare decay $\eta'\rightarrow\pi^0\gamma\gamma$. The observed decay…

The study on $\rho-\omega$ mixing is mainly focused on vector mesons decay with isospin I=1, namely $\rho(\omega)\to\pi^+\pi^-$ process. In this paper, we present the study of $\rho-\omega$ mixing in $\rho(\omega)\to\pi^+\pi^-\pi^0$ (I=0)…

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 in this work. The axion-meson mixing formulas are calculated…

In a sample of 6.6 million produced B mesons we have observed decays B -> eta' K, with branching fractions BR(B+ -> eta' K+ = 6.5 +1.5 -1.4 +- 0.9) x $10^{-5}$ and BR(B0 -> eta' K0 = 4.7 +2.7 -2.0 +- 0.9) x $10^{-5}$. We have searched with…

We present estimates of the charming penguin contribution to B => K pi, pi pi,K eta, K eta' decays due to intermediate charmed meson states. We find that this contribution is indeed significant for B => K pi decays, and its inclusion,…