Within dipole picture of scattering photon interaction with the target is described as a convolution of the photon wave function and the color dipole Green function which determines the interaction of dipole and the target. This Green function satisfies Balitsky-Kovchegov equation (BK). For proton scattering of the target one may also introduce wave function of the proton and the Green function of colorless three particle state. In this talk we discuss evolution equation for this Green function in the leading and next-to-leading approximations and its relation to BK equation and Bartels-Kwiecinski-Praszalowicz equation.

We work out the low energy expansion of the anomalous $f_1(1285)\to\rho\gamma$ decay amplitude by using the Nambu-Jona-Lasinio model with the broken $U(2)\times U(2)$ chiral symmetry in the one-quark-loop approximation. The related processes $f_1(1285)\to\omega\gamma$, $a_1(1260)\to\omega\gamma$, and $a_1(1260)\to\rho\gamma$, are also considered. An effective meson Lagrangian responsible for $f_1\rho\gamma$, $f_1\omega\gamma$, $a_1\rho\gamma$ and $a_1\omega\gamma$ interactions is found. The predicted radiative decay widths, $\Gamma_{f_1\to\rho^0\gamma}=311\ \mbox{keV}$, $\Gamma_{f_1\to\omega\gamma}=34.3\ \mbox{keV}$, $\Gamma_{a_1\to\rho^0\gamma}=26.8\ \mbox{keV}$, $\Gamma_{a_1\to\omega\gamma}=238\ \mbox{keV}$, allow an experimental test of the hypothesis that $f_1(1285)$ and $a_1(1260)$-mesons have a quark-antiquark nature. At present, only the $f_1(1285)\to\rho\gamma$ decay has been measured. Our result is in agreement with the recent data of CLAS Collaboration $\Gamma_{f_1\to\rho^0\gamma}=453\pm 177\ \mbox{keV}$, but is in poor agreement with the PDG-based estimate of $\Gamma_{f_1\to\rho^0\gamma}=1326\pm 313\ \mbox{keV}$. The calculations presented require a minimum of theoretical input, and are potentially very accurate.

The ensemble of almost everywhere homogeneous Abelian (anti-)self-dual fields is represented as domain wall network. The character of confined color-charged field fluctuations in the domain bulk are investigated in detail. It is shown that color charged quasiparticles can be excited inside the domain wall junctions, which indicates deconfinement. Spectra of gluon and quark quasiparticles inside the domain wall are investigated. The Nielsen-Olesen tachyonic gluon modes are shown to restrict the maximal size of deconfinement region for the cylindrical domain wall junction.

The effective meson action, which is invariant with respect to gauge transformations of vacuum field and diagonal with respect to radial quantum number of mesons, is constructed. Thus defined action allows for consistent description of spectra and interactions (weak, electromagnetic and strong) of mesons with any flavor content. Spectra, leptonic decay constants, electromagnetic transition and decay constants, strong decay constants $g_{VPP}$ were calculated.

Influence of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields on transition form factors and decay constants $g_{VPP}$ is analyzed in detail. The local gauge invariance of the nonlocal meson-quark vertices is shown to be important for successful description of the formfactors and decay constants.

Recent measurements of the semileptonic decays $\bar{B}^0 \to D^{(\ast)}\ell\bar\nu_\ell$ provide some hints of lepton universality violation in the tau mode of these decays. An excess of $4\sigma$ over the standard model (SM) prediction has been observed by the BABAR, Belle, and LHCb collaborations. In this talk, I firstly provide a detailed description of the leptonic and semileptonic decays of the $B$ meson in the framework of the Covariant Confined Quark Model (CCQM) with particular emphasis on how to isolate heavy lepton mass effects in the semileptonic decays. Secondly, I consider possible new physics (NP) effects beyond the SM in the decays $\bar{B}^0 \to D^{(\ast)} \tau^- \bar{\nu}_{\tau}$. Starting with a model-independent effective Hamiltonian including non-SM four-fermion operators, I show how to obtain experimental constraints on different NP scenarios and investigate their effects on a large set of physical observables. The polarization of the tau as probe for NP in these decays is also discussed. Finally, I briefly discuss the semileptonic decays of $J/\psi$ meson into $D_{(s)}^{(*)}$ meson, where there have been some disagreements in the theoretical predictions between different approaches.