We give a precision analysis of the correlation coefficients of the electron-energy spectrum and angular distribution of the β − -decay and radiative β − -decay of the neutron with polarized neutron and electron to order 10 −3 . The calculation of correlation coefficients is carried out within the Standard model with contributions of order 10 −3 , caused by the weak magnetism and proton recoil, taken to next-to-leading order in the large proton mass expansion, and with radiative corrections of order α/π ∼ 10 −3 , calculated to leading order in the large proton mass expansion. The obtained results can be used for the planning of experiments on the search for contributions of order 10 −4 of interactions beyond the Standard model.

We calculate the correlation coefficients of the electron-energy and electron-antineutrino angular distribution of the neutron β −-decay with polarized electron and unpolarised neutron and proton. The calculation is carried out within the standard model (SM) with the contributions, caused by the weak magnetism, proton recoil and radiative corrections of order of 10 −3 , Wilkinson's corrections of order 10 −5 [Wilkinson, Nucl. Phys. A377, 474 (1982) and Ivanov et al., Phys. Rev. C 95, 055502 (2017)] and the contributions of interactions beyond the SM. The obtained results can be used for the analysis of experimental data on searches of interactions beyond the SM at the level of 10 −4 [Abele, Hyperfine Interact. 237, 155 (2016)]. The contributions of G-odd correlations are calculated and found at the level of 10 −5 in agreement with the results obtained by Gardner and Plaster [

We present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant β is less than 1.9 ×10 7 for n = 1 at 95% confidence level, where n is an input parameter of the self-interaction of the chameleon field ϕ inversely proportional to ϕ n .

No abstract

We suggest an effective quark model for low-lying baryon octet and decuplet motivated by QCD with a linearly rising confinement potential incorporating the extended Nambu-Jona-Lasinio (ENJL) model with linear realization of chiral U (3) × U (3) symmetry. Baryons are considered as external heavy states coupled to local three-quark currents with fixed spinorial structure and to low-lying mesons through quark-meson interactions defined in the ENJL-model. In the constituent quark loop representation we have calculated the coupling constants of the πNN, πN∆ and γN∆ interactions and the σ πN -term. The obtained results are in reasonable agreement with experimental data and other effective field theory approaches.

We calculate the chameleon field potential for ultracold neutrons, bouncing on top of one or between two neutron mirrors in the gravitational field of the Earth. For the resulting non-linear equations of motion we give approximate analytical solutions and compare them with exact numerical ones for which we propose the analytical fit. The obtained solutions may be used for the quantitative analysis of contributions of a chameleon field to the transition frequencies of quantum states of ultra-cold neutrons bound in the gravitational field of the Earth.

Magnetic monopoles are considered as massless fermion elds interacting via local four{monopole interaction of the Nambu{Jona{Lasinio kind leading to monopole condesation. Condensation of magnetic monopole currents and any derivative of them are obtained. It is shown that the bosonized version of this Monopole{Nambu{ Jona{Lasinio (MNJL) model is reducing to London 0 s theory of dual superconductivity within Dirac 0 s extension of Maxwell 0 s Electrodynamics. The a nity of the MNJL{model with Compact Quantum Electrodynamics is discussed.

We discuss the derivation of the path integral representation over gauge degrees of freedom for Wilson loops in SU (N ) gauge theory and 4-dimensional Euclidean space-time by using well-known properties of group characters. A discretized form of the path integral is naturally provided by the properties of group characters and does not need any artificial regularization. We show that the path integral over gauge degrees of freedom for Wilson loops derived by Diakonov and Petrov (Phys. Lett. B224 (1989) 131) by using a special regularization is erroneous and predicts zero for the Wilson loop. This property is obtained by direct evaluation of path integrals for Wilson loops defined for pure SU (2) gauge fields and Z(2) center vortices with spatial azimuthal symmetry. Further we show that both derivations given by Diakonov and Petrov for their regularized path integral, if done correctly, predict also zero for Wilson loops. Therefore, the application of their path integral representation of Wilson loops cannot give a new way to check confinement in lattice as has been declared by Diakonov and Petrov (Phys. Lett. B242 (1990) 425). From the path integral representation which we consider we conclude that no new non-Abelian Stokes theorem can exist for Wilson loops except the old-fashioned one derived by means of the path-ordering procedure.