Related papers: Positron annihilation in $e^+ -$H collision above …
A model independent formalism for the electron positron annihilation reaction $e^++e^-\to a_1(1260)+\pi $ has been derived. The differential and total cross sections and the elements of the spin--density matrix of the $a_1$-meson were…
The present work reports results for: pd radiative capture observables measured at center-of-mass (c.m.) energies in the range 0--100 keV and at 2 MeV by the TUNL and Wisconsin groups, respectively; contributions to the…
The differential cross-section of the single-photon annihilation of channeled positron on the K-shell electron of one of the crystal atoms is calculated and angular distribution of emitted photons is investigated. It is shown that…
The positron-electron pair annihilation in two photons is known for its numerous applications using PET scanners. The decay of Positronium (Ps) from a standard sealed source in more than two photons is less likely but can be observed with a…
Para positronium composed by an electron-antielectron pair is an unstable system decaying into two high energetic gamma photons via self annihilation process, due to the conservation of the charge conjugation parity in electromagnetically…
The n-3H and p-3He elastic phase-shifts below the trinucleon disintegration thresholds are calculated by solving the 4-nucleon problem with three different realistic nucleon-nucleon interactions (the I-N3LO model by Entem and Machleidt, the…
We present the third-order QCD prediction for the production of top-anti-top quark pairs in electron-positron collisions close to the threshold in the dominant S-wave state. We observe a significant reduction of the theoretical uncertainty…
QED processes at electron-positron colliders are considerd. We present differential cross-sections for large-angle Bhabha scattering, annihilation into muons and photons. Radiative corrections in the first order are taken into account…
The Positron Puzzle is a half-century old conundrum about the origin of the Galactic $\gamma$-ray emission line at photon energies of 511 keV, and the shape of its morphology, showing a bulge-to-disk luminosity ratio of $\sim 1$ - unlike…
The differential and total cross sections for electron capture by positrons from helium atoms are calculated using a first-order distorted wave theory satisfying the Coulomb boundary conditions. In this formalism a parametric potential is…
Forward-backward (charge) asymmetry in the processes of $e^+e^-$ annihilation into a pair of charged pseudoscalar mesons is recalculated in the one-loop approximation. The exact dependence on the meson masses is taken into account. Results…
In this paper we study the generalized electrodynamics contribution for the electron-positron scattering process, $e^{-}e^{+}\rightarrow e^{-}e^{+}$, the Bhabha scattering. Within the framework of the standard model, for energies larger…
We show that the $\psi(2\mathrm S)$ subthreshold pole influences the cross section of the electron-positron annihilation into the $\mathrm D^+\mathrm D^-$ and $\mathrm D^0\bar\mathrm D^0$ final states. We perform a fit to the merged BES…
In halide perovskites, electrons (holes) exist as electronic (hole) polarons, excitons, free and trapped electrons (holes). Six kinds of collisions could lead to annihilation of electron and hole, three of them involve polaron(s). In the…
The projection method is used to demonstrate the existence of positron attachment to three doubly excited states of helium. The e^+He(2s^2 1Se), e^+He(3s^2 1Se), and the e^+He(2s2p 3Po) states have binding energies of 0.447eV, 0.256eV and…
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the physics capabilities of an electron-electron or…
The $\eta$-3N-interaction is studied within the four-body Faddeev-Yakubovsky theory adopting purely separable forms for the two- and three-body subamplitudes, limiting the basic two-body interactions to s-waves only. The corresponding…
Previous studies of $(d,p)$ reactions in three-body (proton, neutron, nuclear core) systems revealed a nontrivial effect of the core excitation: the transfer cross section cannot be factorized into the spectroscopic factor and the…
The precision of fixed-order calculations on the dihadron production in electron-positron annihilation is paramount for probing QCD factorization and constraining non-perturbative inputs. This paper investigates the QCD corrections to the…
Ab initio calculation of low energy scattering of electrons (muons) off hydrogen (muonic hydrogen) are performed on the basis of Faddeev-Merkuriev (FM) equations. The explicit contribution of induced dipole interaction in the asymptotic…