Related papers: $D \bar{D}^*$ and $\pi \psi$ interactions in a uni…
We study the scaling of meson-meson scattering amplitudes with the number of colors, $N_\text{c}$. We use lattice calculations in a theory with $N_\text{f}=4$ degenerate flavors, with $N_\text{c}=3-6$ and pion mass $M_\pi\approx 560$ MeV.…
A dynamical approach is developed to predict the $\pi N$ scattering amplitudes starting with the constituent quark models. The first step is to apply a variational method to solve the three-quark bound state problem. The resulting wave…
A resonance-like structure in the $\pi^\pm \psi(2S)$ mass spectrum arising in $B \to K \pi^\pm \psi(2S)$ has recently been reported. It is noted that the mass of this structure, $4433 \pm 4 \pm 1$ MeV, is not far from the threshold for…
The $T_{c\bar{s}}$ state observed in the decay $D_{s1}(2460)^+ \to D_s^+\pi^+\pi^-$ provides direct evidence for an isovector open-charm tetraquark state with strangeness. We develop a unified theoretical framework that consistently…
Exclusive measurements of the quasi-free $pn \to pp\pi^-$ and $pp \to pp\pi^0$ reactions have been performed by means of $pd$ collisions at $T_p$ = 1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have…
A recent analysis of data on the two photon production of the $\eta_c$ and its decay to $K(K\pi)$ has determined the $K\pi$ $S$-wave amplitude in a "model-independent" way assuming primarily that the additional kaon is a spectator in this…
The strong decay $\psi(4040)\to D\bar D$ is anomalously suppressed despite ample phase space, whereas the $D\bar D^*$ and $D_s\bar D_s$ channels remain sizable. In this work, we study this suppression and the associated open-charm hierarchy…
Recently, the Weinberg compositeness condition of a bound state was generalized to account for resonant states and higher partial waves. We apply this extension to the case of the $\Lambda(1520)$ resonance and quantify the weight of the…
The mass spectrum of heavy pseudoscalar mesons, described as quark-antiquark bound systems, is considered within the Bethe-Salpeter formalism with momentum dependent masses of the constituents. This dependence is found by solving the…
Meson-meson amplitudes are important on their own and also play key roles in analyses of heavy-meson and tau decays. In this work we propose a new phenomenological model suited to all $SU(3)$ mesonic two-body final state interactions up to…
Motivated by the recent observation of $T_{c\bar{s}0}(2900)^0$ and $T_{c\bar{s}0}(2900)^{++}$ in the $D_s \pi$ invariant mass distributions, we investigate $D^{\ast}K^{\ast}$ interactions in a coupled-channel approach. We show that the…
We report on our lattice QCD study of coupled $DD_s^* - D^*D_s$ scattering in the $J^P=1^+$ channel and elastic $DD_s$ scattering in the $J^P=0^+$ channel, aimed at investigating the possible existence of $cc\bar{u}\bar{s}$ tetraquarks near…
We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled channels unitary approach. We examine the scattering amplitudes and their poles, which can be…
We investigate the $D\bar{D}$ production in $e^+e^-$ annihilations near threshold in an effective Lagrangian approach. This shows that the lineshape of the cross section near threshold is sensitive to the contributions from $\psi^\prime$,…
We develop a novel approach to chiral meson-baryon dynamics incorporating unitarity constraints and explicit resonance fields. It is based on the most general structure of any pion-nucleon partial wave amplitude neglecting the unphysical…
We investigate the nonrelativistic reduction of the Bethe-Salpeter amplitude for the deuteron electrodisintegration near threshold energies. To this end, two assumptions have been used in the calculations: 1) the static approximation and 2)…
We present the results of a coupled-channel model for $\bar{K}N$ scattering in the resonance region. The model fulfills unitarity, has the correct analytical properties for the amplitudes and the partial waves have the right threshold…
Three-body dynamics above threshold is required for the reliable extraction of many amplitudes and resonances from experiment and lattice QCD. The S-matrix principle of unitarity can be used to construct dynamical coupled-channel approaches…
The $N/D$ method is used to study the $S_{11}$ channel low energy $\pi N$ scattering amplitude. The input of left cuts are obtained from various phenomenological models. With the aid of the production representation, the total phase shifts…
Excited hadrons are seen as resonances in the scattering of lighter stable hadrons like $\pi$, $K$ and $\eta$. Many decay into multiple final states necessitating coupled-channel analyses. Recently it has become possible to obtain…