Once more on mixing of the a_0(980) and f_0(980) mesons

We show that a recent proposal by Close and Kirk fails to describe a_0(980) and f_0(980) mixing when physical masses and widths are included.Comment: 6 pages, revtex, variant which will appear in Phys. Lett.

Transition form factors γ∗→γf2(1270)\gamma^*\to \gamma f_2(1270) and γ∗→γa2(1320)\gamma^*\to \gamma a_2(1320) in the e+e−e^+e^- collisions

The predictions for transition form factors $\gamma^*\to \gamma f_2(1270)$ and $\gamma^*\to \gamma a_2(1320)$ and corresponding $e^+e^-\to \gamma^*\to f_2\gamma$ and $e^+e^-\to \gamma^*\to a_2\gamma$ cross sections are obtained for the energy region up to $2$ GeV. These predictions are coordinated with the recent Belle data on the $\gamma^*(Q^2)\gamma\to f_2$ transition. It is shown that the QCD asymptotics of the amplitudes of the reactions $e^+e^-\to \gamma^*\to f_2\gamma$ and $e^+e^-\to \gamma^*\to a_2\gamma$ can be reached only by taking into account a compensation of contributions of $\rho(770)$, $\omega(782)$ with contributions of their radial excitations. The relation $\sigma(e^+e^-\to \gamma^*\to f_2\gamma)/\sigma(e^+e^-\to \gamma^*\to a_2\gamma)\approx 25/9$, obtained with the help of the $q\bar q$ model of $a_2$ and $f_2$ and QCD, is used to determine the $\sigma(e^+e^-\to \gamma^*\to a_2\gamma)$ at high energies. Recent BABAR measurement of the $e^+e^-\to f_2\gamma\to\pi^+\pi^-\gamma$ cross section at $10.58$ GeV gives hope for detailed investigation of the $\gamma^*(s)\to f_2\gamma$ and $\gamma^*(s)\to a_2\gamma$ transition form factors at high energy region.Comment: 10 pages, 2 figures, many changes, title change

Chiral Magnetic Skyrmions with Arbitrary Topological Charge ("skyrmionic sacks")

We show that continuous and spin-lattice models of chiral ferro- and antiferromagnets provide the existence of an infinite number of stable soliton solutions of any integer topological charge. A detailed description of the morphology of new skyrmions and the corresponding energy dependencies are provided. The considered model is general, and is expected to predict a plethora of particle-like states which may occur in various chiral magnets including atomic layers, e.g., PdFe/Ir(111), rhombohedral GaV$_4$S$_8$ semiconductor, B20-type alloys as Mn$_{1-x}$Fe$_x$Ge, Mn$_{1-x}$Fe$_x$Si, Fe$_{1-x}$Co$_x$Si, Cu$_2$OSeO$_3$, acentric tetragonal Heusler compounds

Light scalars in semi-leptonic decays of heavy quarkonia

We study the mechanism of production of the light scalar mesons in the $D_s^+\to\pi^+\pi^- e^+\nu$ decays: $D_s^+\to s\bar s e^+\nu\to [\sigma(600)+f_0(980)] e^+\nu\to\pi^+\pi^- e^+\nu$, and compare it with the mechanism of production of the light pseudoscalar mesons in the $D_s^+\to (\eta/\eta') e^+\nu$ decays: $D_s^+\to s\bar s e^+\nu\to (\eta/\eta')e^+\nu$. We show that the $s\bar s\to\sigma(600)$ transition is negligibly small in comparison with the $s\bar s\to f_0(980)$ one. As for the the $f_0(980)$ meson, the intensity of the $s\bar s\to f_0(980)$ transition makes near thirty percent from the intensity of the $s\bar s\to\eta_s$ ($\eta_s=s\bar s$) transition. So, the $D_s^+\to\pi^+\pi^- e^+\nu$ decay supports the previous conclusions about a dominant role of the four-quark components in the $\sigma(600)$ and $f_0(980)$ mesons.Comment: 8 pages, 3 figures, the variant matches the publication in Phys. Rev.