Extraction of the neutron charge form factor from the charge form factor of deuteron

We extract the neutron charge form factor from the charge form factor of deuteron obtained from $T_{20}(Q^2)$ data at $0\le Q^2\le$ 1.717 (GeV$^2$). The extraction is based on the relativistic impulse approximation in the instant form of the relativistic Hamiltonian dynamics. Our results (12 new points) are compatible with existing values of the neutron charge form factor of other authors. We propose a fit for the whole set (35 points) taking into account the data for the slope of the form factor at $Q^2 = 0$.Comment: LaTeX2e, 12 pages, 2 figures, tabl

Nonperturbative relativistic approach to pion form factor: predictions for future JLab experiments

Some predictions concerning possible results of the future JLab experiments on the pion form factor F_pi(Q^2) are made. The calculations exploit the method proposed previously by the authors and based on the instant-form Poincare invariant approach to pion considered as a quark-antiquark system. Long ago, this model has predicted with surprising accuracy the values of F_pi(Q^2) measured later in JLab experiment. The results are almost independent from the form of wave function. The pion mean square radius and the decay constant f_pi also agree with experimental values. The model gives power-like asymptotic behavior of F_pi(Q^2) at high momentum transfer in agreement with QCD predictions.Comment: 6 pages, 2 figures, revte

Analytical Form of the Deuteron Wave Function Calculated within the Dispersion Approach

We present a convenient analytical parametrization of the deuteron wave function calculated within dispersion approach as a discrete superposition of Yukawa-type functions, in both configuration and momentum spaces.Comment: 3 pages, 2 figure; several minor corrections adde

Pólya–Carlson dichotomy for dynamical zeta functions and a twisted Burnside–Frobenius theorem

For the unitary dual mapping of an automorphism of a torsion-free, finite rank nilpotent group, we prove the Pólya–Carlson dichotomy between rationality and the natural boundary for the analytic behavior of its Artin–Mazur dynamical zeta function. We also establish Gauss congruences for the Reidemeister numbers of the iterations of endomorphisms of groups in this class. Our method is the twisted Burnside–Frobenius theorem proven in the paper for automorphisms of this class of groups, and a calculation of the Reidemeister numbers via a product formula and profinite completions