Light quark mass ratio from Dalitz plot of η→π+π−π0\eta \to \pi^+\pi^-\pi^0 decay

High statistics Dalitz-plot distribution of $\eta \to \pi^+\pi^-\pi^0$ decay obtained recently by KLOE collaboration \cite{kloe} is fitted to the results of corresponding theoretical calculations in Chiral Perturbation Theory (ChPT) with unitarity corrections taken into account. The quark mass ratio $Q = \sqrt{(m^2_s - (m_d + m_u)^2/4)/(m^2_d - m^2_u)}$ can be otained from this analysis. We get $Q= 22.8\pm 0.4$ which differs from the value $Q_{DT} = 24.2$ that follows from Dashen's theorem and agrees with recently calculated electromagnetic kaon mass difference.Comment: 2 pages, no figure

Temporal characterization of rock dynamic destruction

Dynamic strength tests published in literature have been analysed by structuraltemporal damage criteria. Parameter τ - incubation time - describing material stability behaviour under high-rate influences have been estimated for Kimachi sandstone, Inada granite and Tage tuff. Two types of dynamic tensile experiments have been used: split Hopkinson pressure bar and spalling. Purely dynamic effect of fracture delay have been observed in the case of Kimachi sandstone and discussed

Once more on electromagnetic form factors of nucleons in extended vector meson dominance model

Extended vector meson dominance model, that allows to describe the electromagnetic form factors of nucleons obeying the asymptotic quark counting rule prescriptions and contains the minimal number of free parameters, is presented. We get a reasonable fit of form factors over experimentally available space-like region of momentum transfer and get also reasonable results in the time-like region.Comment: 7 pages, 2 figure