Related papers: Two-photon processes in two-nucleon systems as a t…
The cross section of the reaction $pp \to pp \gamma \gamma$ is estimated and the exploration possibilities of this reaction to probe for a possible excitation of subnuclear degrees of freedom in two-nucleon systems, in particular, the…
As a desirable supplement to the reaction $pp \to pp2\gamma$, proposed earlier (nucl-th/9712064 and references therein) to probe for the NN--decoupled dibaryon resonances we suggest to use for the same goal the radiative capture processes…
We have studied the pion^{-} capture in nuclei leading to two photons, using improved many body methods which have been tested with success in one photon pion^{-} radiative capture, muon^{-} capture and neutrino scattering. The qualitative…
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…
We compare the virtues of two options for the isospin (I=1 or 2) of the apparently exotic dibarion resonance d_1^*(1956), as it is noticed by the DIB2gamma Collaboration (JINR) in the reaction pp -> 2 gamma X below the pion threshold, and…
We performed quantum manipulations of the multi-level spin system S=5/2 of a Mn$^{2+}$ ion, by means of a two-tone pulse drive. The detuning between the excitation and readout radio frequency pulses allows one to select the number of…
The invariant mass spectra of the $pp\pi^-$ and $pp$ systems produced in the double charge exchange (DCX) of positively charged pions on photoemulsion are analysed. A pronounced peak is observed in the $pp\pi^-$ invariant mass spectrum,…
The goal of this research is to determine and study a physical system that will enable a fast and intrinsically two-photon detector, which would be of interest for quantum information and metrology applications. We consider two types of…
Two-photon absorption is theoretically analyzed within the semiclassical formalism of radiation-matter interaction. We consider an ensemble of inhomogeneously broadened three-level atoms subjected to the action of two counterpropagating…
The term two--photon processes is used for the reactions in which some system of particles is produced in collision of two photons, either real or virtual. In the study of these processes our main goal was to suggest approach, allowing to…
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 an energy below the pion production threshold, namely, at…
Two-photon processes in electron-positron collisions of the form $e^+e^-\to e^+e^-X$ are a well-established tool for probing hadronic structure and provide a direct access to non-vector states in $e^+e^-$ collisions. Collisions of quasi…
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 role of the nucleon resonances in the double polarization observables of pion photoproduction is investigated by using the resonance parameters predicted by Capstick and Roberts. As an example, we show that the not-well-determined…
We discuss processes leading to two photon final states in peripheral heavy ion collisions at RHIC. Due to the large photon luminosity we show that the continuum subprocess $\gamma \gamma \to \gamma \gamma$ can be observed with a large…
Photon absorption by a quark in one nucleon followed by its high momentum transfer interaction with a quark in the other may produce two final-state nucleons with high relative momentum. We sum the relevant quark rescattering diagrams, to…
We consider two basic nuclear reactions: Radiative capture of neutrons by protons, $n+p\to \gamma+~d$ and its time-reversed counterpart, photodisintegration of the deuteron, $\gamma +d\to n+p$. In both of these cases we assume that the…
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 an energy below the pion production threshold, namely, at…
Resonant two-photon ionization in a system consisting of two spatially well-separated atoms is studied. Due to two-center electron-electron correlations, the ionization may also proceed through photo-excitation of both atoms with subsequent…
Lattice QCD calculations of two-nucleon systems are used to isolate the short-distance two-body electromagnetic contributions to the radiative capture process $np \to d\gamma$, and the photo-disintegration processes $\gamma^{(\ast)} d \to…