相关论文: Quadrupole Contribution to Two Neutron Removal in …
We analyze the one-photon mechanism of $e^+e^-$ pair production in the collision of nonrelativistic nuclei. The contribution of electric quadrupole radiation of virtual photon to the corresponding cross section is found. The effect of the…
A series expansion of the interaction between a nucleus and its surrounding electron distribution provides terms that are well-known in the study of hyperfine interactions: the familiar quadrupole interaction and the less familiar…
We report on a kinematically complete measurement of double ionization of helium by a single 1100 eV circularly polarized photon. By exploiting dipole selection rules in the two-electron continuum state, we observed the angular emission…
We evaluate the two-photon exchange contribution to the $e N \to e \Delta(1232) \to e \pi N$ process at large momentum transfer with the aim of a precision study of the ratios of electric quadrupole (E2) and Coulomb quadrupole (C2) to the…
A recently proposed method, based on quadrupole and multiplicity fluctuations in heavy ion collisions, is modified in order to take into account distortions due to the Coulomb field. This is particularly interesting for bosons produced in…
We study the convergence of bound-state quadrupole moments in finite harmonic oscillator spaces. We derive an expression for the infrared extrapolation for the quadrupole moment of a nucleus and benchmark our results using different model…
We present a complete three-loop calculation of the electric dipole moment of the $u$ and $d$ quarks in the Standard Model. For the $d$ quark, more relevant for the experimentally important neutron electric dipole moment, we find…
We perform detailed calculations of two-photon-exchange QED corrections to the cross section of pion electroproduction. The results are obtained with and without the soft-photon approximation; analytic expressions for the radiative…
A realistic shell-model study is performed for neutron-deficient tin isotopes up to mass A=108. All shell-model ingredients, namely two-body matrix elements, single-particle energies, and effective charges for electric quadrupole transition…
We present an accurate method of treating the one-neutron removal reaction at intermediate incident energies induced by both nuclear and Coulomb interactions. In the method, the nuclear and Coulomb breakup processes are consistently treated…
The first direct experimental observation of an electric quadrupole ($\textit{E}$2) transition between bound states of an atomic negative ion has been made. The transition was observed in the negative ion of bismuth by resonant (1+1)…
A computer program is presented by which one may calculate the multiple electric dipole, electric quadrupole and magnetic dipole Coulomb excitation with relativistic heavy ions. The program applies to an arbitrary nucleus, specified by the…
We point out that the proton-neutron energy contribution, for low multipoles (in particular for the quadrupole component), effectively renormalizes the strength of the pairing interaction acting amongst identical nucleons filling up a…
The largest radiative corrections to the cross section of electron-proton scattering at high energies are associated with emission of photons, real and virtual, by electron. They contain large logarithms coming from soft and collinear…
The systematic shifts of the transition frequencies in the molecular hydrogen ions are of relevance to ultra-high-resolution radio-frequency, microwave and optical spectroscopy of these systems, performed in ion traps. We develop the…
Electric quadrupole (E2) matrix elements provide a measure of nuclear deformation and related collective structure. Ground-state quadrupole moments in particular are known to high precision in many p-shell nuclei. While the experimental…
The eikonal reaction theory (ERT) proposed lately is a method of calculating one-neutron removal reactions at intermediate incident energies in which Coulomb breakup is treated accurately with the continuum discretized coupled-channels…
Although the study of collisions of heavy ions resulting in formation of dinuclear systems has a long history this process still is a subject of experimental and scientific activities, partly because nowadays the heavy-ion fusion process is…
A method for precise calculation of the energy corrections due to second order electric quadrupole interactions, as well as mixed electric quadrupole-vacuum polarization in the framework of the dynamic hyperfine structure in heavy muonic…
Radiative corrections to processes that involve the production and subsequent decay of unstable particles are complex due to various theoretical and practical problems. The so-called double-pole approximation offers a way out of these…