Related papers: ``Electromagnetic'' Contributrion to the Nucleon S…
We determine within lattice QCD, the nucleon spin carried by valence and sea quarks, and gluons. The calculation is performed using an ensemble of gauge configurations with two degenerate light quarks with mass fixed to approximately…
We summarize three alternative extensions of the quark-valence picture of nucleon strangeness and spin, including (1) gluon spin in QCD, (2) Bjorken sum rule and QCD, (3) D--E meson mixing and tadpole leakage. All three approaches suggest…
I review what is known about the quark and gluon spin distributions in the nucleon. I discuss in some detail (a) the existence of sum rules for angular momentum; (b) the interpretation and possible measurement of the nucleon's transversity…
It is shown that the amplitude for the scattering of a heavy quarkonium system from a nucleon near threshold is completely determined by the fraction of angular momentum, as well as linear momentum, carried by gluons in the nucleon. A form…
The flux of angular momentum of electromagnetic field of an arbitrarily moving point charge is investigated. General equations are obtained for the transfer of angular momentum at arbitrary distance from the charge, and corresponding…
In a series of papers, we have established the existence of two gauge-invariant decompositions of the nucleon spin, which are physically nonequivalent. The orbital angular momenta of quarks and gluons appearing in these two decompositions…
Both electron and its neutrino possess not only the anomalous magnetic moment but also each of the existing types of electric charges and their dipole moments. Any of them can interact with field of emission leading to the elastic…
We investigate the correlations between the quark spin and orbital angular momentum inside the nucleon. Similarly to the Ji relation, we show that these correlations can be expressed in terms of specific moments of measurable parton…
The electric dipole form factor of the nucleon stemming from the QCD $\bar{\theta}$ term is calculated in chiral perturbation theory in leading order. To this order, the form factor originates from the pion cloud. Its momentum-dependence is…
We study the nucleon contribution to the electromagnetic vertex function of neutrinos that propagate in a matter background in the presence of a magnetic field. Starting from the one-loop expression for the corresponding terms of the vertex…
We discuss the shortfalls of existing resolutions of the long-standing gauge invariance problem of the canonical decomposition of the nucleon spin to the spin and angular momentum of quarks and gluons. We provide two logically flawless…
Oscillations of neutrinos $\nu_L \leftrightarrow \nu_R$ in presence of an arbitrary electromagnetic field are considered. We introduce the Hamiltonian for the neutrino spin evolution equation that accounts for possible effects of…
The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon constituents, combined with QCD final-state…
We estimate in the QCD sum rule approach the amount of the nucleon spin carried by the gluon angular momentum: the sum of the gluon spin and orbital angular momenta. The result indicates that gluons contribute at least one half of the…
The idea has been spoken that any of Dirac and Pauli form factors of leptonic current includes both normal and anomalous components. From this point of view, the dependence of independent parts of charge and magnetic moment is established…
Quantum fluctuations in the QED vacuum generate non-linear effects, such as peculiar induced electromagnetic fields. In particular, we show here that an electrically neutral particle, possessing a magnetic dipole moment, develops an induced…
We have studied the electron spin coherence in an ensemble of positively charged InAs/GaAs quantum dots. In a transverse magnetic field, we show that two main contributions must be taken into account to explain the damping of the circular…
We describe a generic mechanism by which a system of Dirac fermions in thermal equilibrium acquires electric charge in an external magnetic field. To this end the fermions should have an additional quantum number, isospin or color, and…
It is demonstrated, owing to the nonlinearity of QED, that a static charge placed in a strong magnetic field\ $B$\ is a magnetic dipole (besides remaining an electric monopole, as well). Its magnetic moment grows linearly with $B$ as long…
The neutron, in addition to possibly having a permanent electric dipole moment as a consequence of violation of time-reversal invariance, develops an induced electric dipole moment in the presence of an external electric field. We present…