Related papers: Structure of double pionic atoms
We identify a new class of three-nucleon forces that arises in the low-energy effective theory of nuclear interactions including pions. We estimate their contribution to the energy of neutron and nuclear matter and find that it can be as…
Metastable pionic helium ($\pi{\rm He}^+$) is a three-body atom composed of a helium nucleus, an electron occupying the $1s$ ground state, and a negatively charged pion $\pi^-$ in a Rydberg state with principal- and orbital angular momentum…
This is the first of a series of papers devoted to a detailed analysis of isospin-breaking effects in the $\pi \pi$ scattering amplitude and the vector form factor of the pion. Isospin breaking originates from the mass difference between up…
Strong electron correlation effects in the photophysics of quasi-one-dimensional $\pi$-conjugated organic systems such as polyenes, polyacetylenes, polydiacetylenes, etc., have been extensively studied. Far less is known on correlation…
The impact parameter dependence of \rpi ratio is examined in heavy-ion collisions at 400MeV/nucleon within a transport model. It is shown that the sensitivity of \rpi ratio on symmetry energy shows a transition from central to peripheral…
We derive from the subleading contributions to the chiral three-nucleon force (long-range terms, published in Phys.\,Rev.\,C\,77, 064004 (2008)) a density-dependent two-nucleon interaction $V_\text{med}$ in isospin-symmetric, spin-saturated…
The analysis of the $\pi\gamma$ transition form factor provides severe constraints on the pion's wave function. This information is used to examine charmonium decays into two pions critically. It will be argued that the standard…
The ABC effect - a puzzling low-mass enhancement in the $\pi\pi$ invariant mass spectrum - is well-known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on first exclusive and kinematically…
The study of the charge asymmetry of produced particles allows to investigate the interference of different production mechanisms and to determine new features of the corresponding amplitudes. In the process $e^- e^+ \to e^- e^+ \pi^+…
We present an analysis of isospin-breaking effects in threshold pion-nucleon scattering due to the light quark mass difference and the dominant virtual photon effects. We discuss the deviation from various relations, which are exact in the…
We have calculated the effect of the inclusion of final state interactions on pion production from nuclei with incident pion beams. We find that the effect of absorption, along with geometric considerations, explains much of the enhancement…
Estimation of the back-to-back pi-pi correlations arising due to evolution of the pionic field in the course of pion production process is given for central heavy nucleus collisions at moderate energies.
The proton-neutron 2 particles - 2 holes correlations in superfluid nuclei, described by an effective, Josephson-type interaction ~[(P+N-)+(P-N+)], are studied within a boson approximation. The strength of this interaction is estimated…
We study the dynamics of two types of pairs of excitations which are bound despite their strong repulsive interaction. One corresponds to doubly occupied sites in one-dimensional Bose-Hubbard systems, the so-called doublons. The other is…
The cross section for exclusive production of $\pi^+ \pi^-$ and $\pi^0 \pi^0$ meson pairs in ultrarelativistic heavy ion collisions is calculated for LHC energy $\sqrt{s_{NN}} =$ 3.5 TeV taking into account photon-photon mechanism. We…
We show that the spin-orbit interaction (SOI) arising due to the in-plane electric field of the Coulomb repulsion between electrons in a two-dimensional quantum well produces an attractive component in the pair interaction Hamiltonian that…
We investigate isospin-breaking effects in double-charm molecular pentaquarks with the $D^{(*)}\Sigma_c^{(*)}$ configuration, using the one-boson-exchange potential framework. In these systems, the isospin-breaking effects arise from two…
We investigate the spin structure of many-fermion systems with a spin-conserving two-body random interaction. We find a strong dominance of spin-0 ground states and considerable correlations between energies and wave functions of low-lying…
We report variational calculations of symmetric nuclear matter and pure neutron matter, using the new Argonne v18 two-nucleon and Urbana IX three-nucleon interactions. At the equilibrium density of 0.16 fm^-3 the two-nucleon densities in…
We report the first experimental observation of the pionic fusion of two heavy ions. The 12C(12C,24Mg)pi0 and 12C(12C,24Na)pi+ cross sections have been measured to be 208 +/- 38 and 182 +/- 84 picobarns, respectively, at E_cm = 137 MeV.…