A measurement of the K+ → e+v)(K+ → μ+v) branching ratio

The branching ratio $\text{R =}\text{Γ(}\text{K}{}^{\mathrm{+}}\text{→}\text{e}{}^{\mathrm{+}}\text{v)}\text{Γ(}\text{K}{}^{\mathrm{+}}\text{→ μ}{}^{\mathrm{+}}\text{v)}$ has been measured on the basis of 534 observed K⁺ → e⁺v decays. The K⁺ decay at rest; the momenta of the e⁺ and μ⁺ are measured in a magnetic spectrometer using multiwire driftchambers, and the electrons are identified in a gas Cerenkov counter. The result is R = (2.37 ± 0.17_× 10^?5. The value predicted for pure axial-vector interaction and μ-e-universality is R = 2.57 × 10^?5.     

Effects of molecular water models on Molecular Dynamic simulation of nanoflows

We study an influence of the effect of water molecular models and thermostats on approaching equilibrium in Molecular Dynamics simulation of the nanoflows of water. Out of large number of existing models of water we present the results for four selected ones, i.e.: TIP4P, PPC, TIP4P-2005, TIP5P, and for two thermostats - Gaussian and Nosé-Hoover. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spectroscopy of Ly-α Lines at Storage Rings by Crystal Spectrometry and Absorption Edge Technique

Crystal spectrometry and absorption edge technique have the capability to overcome the gap in accuracy between experiment and theory in the strong field domain of QED. New results are presented which indicate the capacity of these methods to measure the energies of X-rays emitted by highly charged heavy ions at modern storage rings with a precision sensitive to second order corrections to the Lambshift in H-like very heavy ions. This revised version was published online in July 2006 with corrections to the Cover Date.     

Measurement of the branching ratios for the decays J/ψ → ϱπ and J/ψ → γη′

Decays of the J/ψ (3.1) resonance into final states with two charged hadrons and two photons are investigated. Branching ratios for the decays J/ψ → ?π and J/ψ → γη′ are determined to be

$\text{Г(J/ψ → pφ)}\text{Г(J/ψ → all)}\text{= (1.0± 0.2) ·10}{}^{\mathrm{?2}}\text{,}\text{Г(J/ψ → γη′)}\text{ГJ/ψ → all)}\text{= (2.0± 0.7) ·}{}^{\mathrm{?3}}$

Upper limits for the same decay modes of ψ′ (3.7) are also determined.