相关论文: Hidden dibaryons in one- and two-pion production i…
It is demonstrated that many important features of single-pion production in $pp$ collisions at intermediate energies ($T_p \simeq 400$-$800$ MeV) can naturally be explained by supposing excitation of intermediate diproton resonances in…
The two-pion production in nucleon-nucleon collisions has been studied by exclusive and kinematically complete experiments from threshold up to $T_p$ = 1.36 GeV at CELSIUS-WASA. At near-threshold energies the total and differential…
Exclusive measurements of the quasi-free $pp \to pp\pi^+\pi^-$ reaction 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 been obtained…
Exclusive measurements of the quasi-free $pp \to pp\pi^+\pi^-$ reaction have been carried out at WASA@COSY by means of $pd$ collisions at $T_p$ = 1.2 GeV. Total and differential cross sections have been extracted covering the energy region…
It is demonstrated within the dibaryon-induced model for $NN$ interaction that $pp$ scattering in $P$ waves is governed mainly by the production of the intermediate dibaryon resonances. Two dibaryon resonances with a mass of about 2200 MeV…
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…
In many reactions leading to excitations of the nucleon the Roper resonance $N^*(1440)$ can be sensed only by complex partial-wave analyses. In nucleon-nucleon collisions the isoscalar single-pion production as well as specific two-pion…
We report on baryon resonance production and decay in proton-proton collisions at a kinetic energy of $3.5$ GeV based on data measured with HADES. The exclusive channels $pp \rightarrow np\pi^{+}$ and $pp \rightarrow pp\pi^{0}$ as well as…
The production of d' dibaryons in heavy ion collisions due to the elementary process NN -> d' + pion is considered. The cross section NN -> d' + pion is estimated using the vacuum d' width = 0.5 MeV extracted from data on the double charge…
Recently a two-step process has been proposed for the double-pionic fusion to deuterium $pn (I=0) \to d\pi^+\pi^-$. Its calculation is solely based on total cross section data for the two sequential single-pion production steps $pn (I=0)\to…
The two-pion production in pp-collisions has been investigated at CELSIUS in exclusive measurements from threshold up to $T_p$ = 1.36 GeV. Total and differential cross sections have been obtained for the channels $pn\pi^+\pi^0$,…
Using the high-quality beam of storage rings in combination with a pellet target and the hermetic WASA detector covering practically the full solid angle the two-pion production in nucleon-nucleon collisions has been systematically studied…
The isoscalar dibaryon resonance $D_{03}(2380)$, discovered at WASA@COSY in the total cross section of the reaction $pn\to d\pi^0\pi^0$ and in the elastic pn scattering in the energy range corresponding to the invariant mass of the pn…
Within an effective Lagrangian model, we present calculations for cross sections of the dilepton production in proton-proton and proton-neutron collisions at laboratory kinetic energies in 1-5 GeV range. Production amplitudes include…
Dielectron production in the $\pi N$ interaction at not large energies is studied. The dominant contribution of the $\Delta$-isobar creation in the intermediate state at incident pion momenta of about 0.3-0.4 GeV$/$c is shown. The…
A resonance model for two-pion production in the pion-nucleon reaction is developed that includes information obtained in the analysis of pion-nucleon scattering in a meson-exchange model. The baryonic resonances Delta(1232), N*(1440),…
The ABC effect -- an intriguing low-mass enhancement in the $\pi\pi$ invariant mass spectrum -- is known from inclusive measurements of two-pion production in nuclear fusion reactions. First exclusive measurements carried out at…
Motivated by the renewed interest in studying the pion production on nuclei with protons at few GeV incident energies, we investigate the pion production in proton-proton collisions over an energy range of 300 $MeV$ to 2 $GeV$. Starting…
Phase shifts and inelasticity parameters for $NN$ scattering in the partial-wave channels ${}^3S_1$--${}^3D_1$ and ${}^1S_0$ at energies $T_{\rm lab}$ from zero to about 1 GeV are described within a unified $NN$ potential model assuming the…
A model for the gamma p ----> pion+ pion- p reaction developed earlier is extended to account for all isospin channels. The model includes N, Delta(1232), N^*(1440) and N^*(1520) as intermediate baryonic states and the rho-meson as an…