相关论文: The relation between the photonuclear E1 sum rule …
The $f$ sum rule is derived in a non-relativistic frame and connected, via Ward Identities, to the low energy Thomson scattering. A generalisation to isospin symmetry in the nuclear case is discussed and linked to the Meson Exchange…
The radiative self-energy correction to the bound-electron g factor of 2P_1/2 and 2P_3/2 states in one-electron ions is evaluated to order alpha (Z alpha)^2. The contribution of high-energy virtual photons is treated by means of an…
We improve the description of pion-photon interactions in the radiative return process $e^+e^-\to \pi^+\pi^-\gamma$ at the next-to-leading order by including the pion form factor in the Feynman rules. We present a general calculation of the…
Motivated by the normal state of the cuprates in which the f-sum rule increases faster than a linear function of the particle density, we derive a conductivity sum rule for a system in which the kinetic energy operator in the Hamiltonian is…
We extend the standard second order effective chiral Lagrangian of pions and nucleons by considering the coupling to an external gravitational field. As an application we calculate one-loop corrections to the one-nucleon matrix element of…
Photons as well as quarks and gluons are constituents of the infinite momentum frame (IMF) wave function of an energetic particle. They are mostly equivalent photons whose amplitude follows from the Lorentz transformation of the particle…
The contribution of the light-by-light diagram to the g factor of electron and muon bound in Coulomb field is obtained. For electron in a ground state, our results are in good agreement with the results of other authors obtained numerically…
The photoproduction p(gamma, K+)Lambda process is studied within a field-theoretic approach. It is shown that the background contributions constitute an important part of the reaction dynamics. We compare predictions obtained with three…
The finite nuclear size corrections to the ground state energies and g-factors in muonic atoms are investigated for several elements. Both approximative and exact solutions of the one-particle Dirac equation with both the homogeneous sphere…
In this work we introduce and study the unimodular-mimetic $f(\mathcal{G})$ gravity, where unimodular and mimetic constraints are incorporated through corresponding Lagrange multipliers. We present field equations governing this theory and…
We derive the effective interaction between two quasiparticles in symmetric nuclear matter resulting from the leading-order chiral three-nucleon force. We restrict our study to the L=0,1 Landau parameters of the central quasiparticle…
The problem of calculation of the enhancement factor due to the strong pion final state interaction is reexamined in the light of recent interest in understanding of the origine of the $\Delta I=1/2$ rule and calculations of the CP…
We review the present data on high-energy, spin-dependent photoabsorption. We find a strong isotriplet term in $(\sigma_A - \sigma_P)$ which persists from $Q^2 \sim 0.25$GeV$^2$ to high $Q^2$ polarised deep inelastic scattering. For $Q^2…
The use of high-precision measurements of the $g$ factor of single-electron ions is considered as a detailed probe for physics beyond the Standard Model. The contribution of the exchange of a hypothetical force-carrying scalar boson to the…
The sum rule for the first moment of the polarised (virtual) photon structure function $g_1^\gamma(x,Q^2;K^2)$ is revisited in the light of proposals for future $e^+ e^-$ colliders. The sum rule exhibits an array of phenomena characteristic…
This paper analyses the cosmological consequences of a modified theory of gravity whose action integral is built from a linear combination of the Ricci scalar $R$ and a quadratic term in the covariant derivative of $R$. The resulting…
A means to extract the fine-structure constant $\alpha$ from precision spectroscopic data on one-electron ions is presented. We show that in an appropriately weighted difference of the bound-electron $g$ factor and the ground state energy,…
We investigate several spin-related phenomena in a confined two-dimensional electron gas (2DEG) using the Hartree-Fock approximation for the mutual Coulomb interaction of the electrons. The exchange term of the interaction causes a large…
We have studied the $P\to\gamma^\star\gamma^\star$ transition form-factors ($P=\pi^0,\eta,\eta'$) within a chiral invariant framework that allows us to relate the three form-factors and evaluate the corresponding contributions to the muon…
General O(alpha) radiative corrections to lattice actions may be interpreted as counterterms that give additive contributions to the one-loop renormalisation of the anisotropy. The effect of changing the radiative coefficients is thus…