Related papers: Resonance Structure in the $\gamma\gamma$ Invarian…
Along with $\pi^0$ and {\eta} mesons, a resonance structure in the invariant mass spectrum of two photons at M{\gamma}{\gamma} = 360 \pm 7 \pm 9 MeV is observed in the reaction d + C \rightarrow {\gamma} + {\gamma} + X at momentum 2.75…
A new resonance structure at M = 355 \pm 6 \pm 9 MeV is observed in the invariant mass spectrum of two gamma-quanta produced in the reaction d + C => gamma + gamma + x at momentum 2.75 GeV/c per nucleon. Preliminary estimates of its width…
The results of an analysis of the invariant mass spectra of photon pairs produced in dC, pC and dCu interactions at momenta of 2.75, 5.5 and 3.83 GeV/c per nucleon respectively, are presented. Signals in the form of enhanced structures at…
To investigate the interaction between the nucleon $N$ and nucleon resonance $N(1535)1/2^-$, the $\eta d$ threshold structure connected to the isoscalar $S$-wave $N$-$N(1535)1/2^-$ system has been experimentally studied in the…
The reaction $\gamma p \rightarrow p \pi^0 \eta$ has been studied with the CBELSA/TAPS detector at the electron stretcher accelerator ELSA in Bonn for incident photon energies from threshold up to 3.1 GeV. This paper has been motivated by…
We show that the resonance-like structure found by the \emph{CELSIUS-WASA Collaboration} in the two-photon invariant mass spectrum of the reaction $pp \to pp \gamma \gamma$ is rather a signature of the $NN$-decoupled dibaryon resonance…
Exclusive and kinematically complete high-statistics measurements of the double pionic fusion reaction $dd \to ^4$He$\pi^0\pi^0$ have been performed in the energy range 0.8 - 1.4 GeV covering thus the region of the ABC effect, which denotes…
We study initial-state radiation events, $e^+e^- \to \gamma_{ISR}\pi^+\pi^-J/\psi$, with data collected with the BaBar detector. We observe an accumulation of events near 4.26 GeV/$c^2$ in the invariant-mass spectrum of $\pi^+\pi^-J/\psi$.…
Born cross sections for the processes $e^+e^- \to \omega\eta$ and $e^+e^- \to \omega\pi^{0}$ have been determined for center-of-mass energies between 2.00 and 3.08 GeV with the BESIII detector at the BEPCII collider. The results obtained in…
Recently, a $\gamma\gamma$ collider based on the existing 17.5 GeV linac of the European XFEL has been proposed. High-energy photons will be generated by Compton scattering of laser photons with a wavelength of 0.5-1 $\mu$m on electrons.…
The $\gamma p \to \pi^0 \eta p$ reaction has been investigated by the CBELSA/TAPS Collaboration, revealing a narrow structure in the $\eta p$ invariant mass distributions at a mass of $1700$ MeV. In this study, we explore the possibility…
The reaction $p + d \rightarrow p + d + X$ was studied at 0.8-2.0 GeV proton beam energies with the ANKE magnetic spectrometer at the COSY synchrotron storage ring. The proton-deuteron pairs emerging with high momenta, 0.6-1.8 GeV/$c$, were…
The energy spectrum for high energy $\gamma$-rays ($E_\gamma \geq 10$ MeV) from the process $pp \to \gamma \gamma X$ emitted at $90^0$ in the laboratory frame has been measured at 216 MeV. The resulting photon energy spectrum extracted from…
The contribution of the low-lying nucleon resonances $P_{33}(1232)$, $P_{11}(1440)$ $D_{13}(1520)$ and $S_{11}(1535)$ to the invariant mass spectra of di-electrons stemming from the exclusive processes $pp\to pp e^+e^-$ and $pn\to pn…
We have observed a "$K^-pp$"-like structure in the $d(\pi^+,K^+)$ reaction at 1.69 GeV/$c$. In this reaction $\Lambda(1405)$ hyperon resonance is expected to be produced as a doorway to form the $K^-pp$ through the $\Lambda^*p\rightarrow…
The missing mass spectra for the $^{12}C(p, K^0_s)$ and $^{12}C(p,\Lambda)$ reactions have been studied by using of the propane bubble chamber(PBC) data from 700000 stereo photographs or $10^6$ inelastic interactions. The momentum spectrum…
We have measured an inclusive missing-mass spectrum of the $d(\pi^+, K^+)$ reaction at the pion incident momentum of 1.69 GeV/$c$ at the laboratory scattering angles between 2$^\circ$ and 16$^\circ$ with the missing-mass resolution of 2.7…
Charged particle and gamma decays in 24Mg* are investigated for excitation energies where quasimolecular resonances appear in 12C+12C collisions. Various theoretical predictions for the occurence of superdeformed and hyperdeformed bands…
The in-medium spectral functions of $\rho$ and $\omega$ mesons and the broadening of the nucleon resonances at finite baryon density are calculated self-consistently by combining a resonance dominance model for the vector meson production…
With the help of the linearized perturbation theory, the collective beam instability due to the space charge, modelled by the Vlasov-Poisson equation, is well studied in the former research theoretically in a general sense [Chao Li and R.…