Related papers: $\eta(1295)\to3\pi$ decays

We study the mixing of the scalar glueball into the isosinglet mesons $f_0 (1370)$, $f_0(1500)$, and $f_0(1710)$ to describe the two-body decays to pseudoscalars. We use an effective Hamiltonian and employ the two-angle mixing scheme for…

Using a sample of $(225.2\pm 2.8)\times 10^6$ $J/\psi$ events collected with the Beijing Spectrometer (BESIII) at the Beijing Electron-Positron Collider, CP and $P$ violating decays of $\eta$, $\eta'$ and $\etac$ into $\pi^+\pi^-$ and…

Using $1.09\times10^{9}$ $J/\psi$ events collected by the BESIII experiment in 2012, we study the $J/\psi\rightarrow\gamma\eta^{\prime}\pi^{+}\pi^{-}$ process and observe a significant abrupt change in the slope of the…

The mechanism of the four-quark production of the light scalar isovector four-quark state $a_0(980)$ in the $D\to\eta\pi e^+\nu_e$ decays is discussed. It is shown that the characteristic features of the shape of the $\eta\pi$ mass spectra…

The $N\pi^0\pi^0$ decays of positive-parity $N^*$ and $\Delta^*$ resonances at about 2\,GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances:…

Based on $2.7 \times 10^9~\psi(3686)$ decays collected with the BESIII detector, the radiative decay $\psi(3686)\to\gamma2(\pi^{+}\pi^{-})\eta$ is investigated to measure properties of S- and P-wave charmonium states. The branching fraction…

We make a theoretical study of the $\eta(1405) \to \pi^{0} f_0(980)$ and $\eta(1405) \to \pi^{0} a_0(980)$ reactions with an aim to determine the isospin violation and the mixing of the $f_0(980)$ and $a_0(980)$ resonances. We make use of…

Estimated are the contributions of the following mechanisms responsible for the decay $f_1(1285)\to f_0(980)\pi^0\to\pi^+\pi^-\pi^0$: 1) the contribution of the $a^0_0(980)-f_0(980)$ mixing, $f_1(1285)\to a_0(980)\pi^0\to (K^+K^-+K^0\bar…

Recently, the Belle Collaboration has measured the $\Lambda_c^+ \to \eta \Lambda \pi^+$ decay and reported the $\eta\Lambda$ and $\Lambda\pi^+ $ invariant mass distributions, which show the clear signals of the resonances $\Lambda(1670)$…

Angular distributions in the final state of pi0-eta photoproduction on nucleons are considered. As a formal base the familiar isobar model is used in which the (pi0 eta N) state is a product of the resonance decay into eta-Delta(1232) and…

Recent BESIII data on radiative $J/\psi$ decays from $\sim 10^{10}$ $J/\psi$ samples should significantly advance our understanding of the controversial nature of $\eta(1405/1475)$. This motivates us to develop a three-body unitary…

The decay $\eta \to 3 \pi$ proceeds exclusively through isospin violating operators and is therefore an excellent probe to examine the strength of isospin breaking in the strong interaction. The latter can be expressed through the quark…

One of the objectives of the vast physics programme of the recently comissioned WASA-at-COSY facility is the study of fundamental symmetries via the measurements of the eta and eta-prime mesons decays. Especially interesting are isospin…

We present a study of the resonant structure of the decay $D^0 \to K_{\rm L}^0\pi^+\pi^-$, using quantum-correlated $D^0\bar{D}^0$ data produced at $\sqrt{s}=3.773$ GeV. The data sample was collected by the BESIII experiment and corresponds…

Possible manifestations of the isospin-breaking mixing of the $a^0_0(980)$ and $f_0(980)$ resonances are analyzed in the $D^0\to K^0_S \pi^+\pi^-$ and $D^0\to K^0_S\eta\pi^0$ decays. It is shown that the $a^0_0(980)-f_0(980)$ mixing has the…

Motivated by the resent BESIII Collaboration measurements of the process $D^+\to\pi^+\eta\eta$, we investigate this process by considering the contribution from the resonance $a_0(980)$, which is generated by $S$-wave pseudoscalar…

We propose to study the $a_0(980)$ and the $\Lambda(1670)$ resonances in the $\Lambda^+_c \to \pi^+ \eta \Lambda$ decay via the final state interactions of the $\pi^+ \eta$ and $\eta \Lambda$ pairs. The weak interaction part proceeds…

Using data samples collected at center of mass energies of $\sqrt{s}$ = 4.009, 4.226, 4.257, 4.358, 4.416 and 4.599 GeV with the BESIII detector operating at the BEPCII storage ring, we search for the isospin violating decay…

The decays of $J/\psi\to \eta\phi f_0(980) (\eta\to \gamma\gamma, \phi \to K^+K^-, f_0(980)\to\pi^+\pi^-)$ are analyzed using a sample of $5.8 \times 10^{7}$ $J/\psi$ events collected with the BESII detector at the Beijing Electron-Positron…

We present results of a study of the decay $J/\psi\rightarrow\omega\eta\pi^+\pi^-$ using a sample of $(225.2\pm2.8)\times10^6$ $J/\psi$ events collected by the BESIII detector, and report the observation of a new process of…