Related papers: Channel coupling in e+ e- annihilation into heavy …
The effects of charmed meson loops on the spectrum of charmonium are considered, with special attention paid to the levels above open-charm threshold. It is found that the coupling to charmed mesons generates a structure at the D \bar{D}*…
We look at the mass distribution of the $D_s^+ \pi^-$ in the $B^0 \to \bar{D}^0 D_s^+ \pi^-$ decay, where a peak has been observed in the region of the $D^*_s \rho$, $D^* K^*$ thresholds. By creating these two channels together with a…
The $D {\bar D}^*$ scattering amplitude and the production of the final states $\pi^+ \pi^- J/\psi$ and $\pi^+ \pi^- \pi^0 J/\psi$ near the $D^0 {\bar D}^{*0}$ threshold are discussed following the recent suggestion that the observed peaks…
We define and study the properties of channels which are analogous to unital qubit channels in several ways. A full treatment can be given only when the dimension d is a prime power, in which case each of the (d+1) mutually unbiased bases…
The recent observation of multiple near-threshold structures in $e^+e^-$ annihilation-including $\psi(3770)$, $G(3900)$, $R(3760)$, $R(3780)$, and $R(3810)$-reveals limitations in existing models of charmonium and exotic hadrons. In this…
It is suggested that the recently observed enhancement of the relative yield in $e^+e^-$ annihilation of states with hidden charm and hidden strangeness above 4.43\,GeV is associated with the $S$ wave production of the charmed strange meson…
Whether the $Y(4260)$ can couple to open charm channels has been a crucial issue for understanding its nature. The available experimental data suggest that the cross section line shapes of exclusive processes in $e^+e^-$ annihilations have…
Using recent CLEO III results for the cross section for $e^+e^- \to {\rm hadrons}$ at seven centre-of-mass energies between 6.964 and 10.538 GeV, we derive a value for the strong coupling constant…
Annihilation cross-section of ultra low-energy atomic antihydrogen ($% E\le10^{-5}$ a.u.) on atomic hydrogen are calculated within a quantum mechanical coupled channels approach. The results differ from the extrapolations of semiclassical…
Two-dimensional Eliashberg equations have been solved by use of a mixed interaction with $s$- and $d$-channels. It is discussed what kind of pairing symmetry of the superconducting state can be realized when the channel mixing parameters…
We report a new measurement of the exclusive $e^+ e^- \to D^{(*) \pm} D^{*\mp}$ cross sections as a function of the center-of-mass energy from the $D^{(*) \pm} D^{* \mp}$ threshold through $\sqrt{s}=6.0$ GeV with initial-state radiation.…
We discuss the general behavior of the near-threshold scattering amplitude with channel couplings. The signal of the exotic hadrons near the threshold may manifest as a dip structure in the cross section originated from a zero point of the…
Using the CLEO-c detector at the Cornell Electron Storage Ring, we have measured inclusive and exclusive cross sections for the production of D+, D0 and Ds+ mesons in e+e- annihilations at thirteen center-of-mass energies between 3.97 and…
We analyze the origin of the structures observed in the reactions $e^+e^-\to 3(\pi^+\pi^-)$, $2(\pi^+\pi^-\pi^0)$, $\omega\pi^+\pi^-\pi^0$, and $e^+e^-\to 2(\pi^+\pi^-)\pi^0$ around the antiproton-proton ($\bar pp$) threshold. We calculate…
A self-consistent coupled-channel approach is used to study the properties of $D$ and $\bar D$ mesons in hot dense matter. The starting point is a broken SU(4) s-wave Tomozawa-Weinberg $DN$ ($\bar DN$) interaction supplemented by an…
The cross section for vector leptoquark pair production in $e^+e^-$ annihilation is calculated for the case of finite anomalous gauge boson couplings $\kappa_{\gamma, Z}$ and $\lambda_{\gamma, Z}$. The minimal cross section is found to…
We report a study of the processes of $e^+e^-\to K^+ (D_s^- D^{*0} + D^{*-}_s D^0)$ based on $e^+e^-$ annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698…
We calculate the exclusive cross sections for e^+ e^- annihilation into two charmonium states through a virtual photon. Purely electromagnetic contributions are surprisingly large, changing the cross sections by as much as 21%. The…
The mechanism of channel coupling via decay products is used to study energy shifts, level mixing as well as the possibility of new near-threshold resonances in $c\bar c, b\bar b$ systems. The Weinberg eigenvalue method is formulated in the…
Using precise data from the BESIII collaboration, we obtained compelling evidence of a subthreshold pole in the $e^+ e^-\rightarrow D_s^+ D_s^-$ process with mass of (3896$^{+13}_{-22}$)~MeV. The latter suggests the identification of this…