New Generation of Large Scale Scintillation Counters for Detection of EAS and Use in Guard Systems of Experimental Physics Setups

The work is dedicated to the discussion of four new types of large-area scintillation counters design intended for detection of EAS and the use in the guard systems of experimental physics setups with low-cost production. The solid counters based on scintillating polystyrene plates are produced by melting clear polystyrene granules with additives in a mirror mold. Other counters are based on lentil-like polystyrene scintillation granules which are a new kind of plastic scintillators produced at IHEP. WLS fibers and SiPM as a photo sensor are used for a light detection. The dimensions of the tested detectors were 500 × 500 and to 1000 × 1000 mm2, their measured light output was up to 180 ph.e.     

The Coherent Production of the (K +π0) System by K + Beam on Copper Nuclei at the OKA Setup

Journal of Experimental and Theoretical Physics - On the statistics of ~1.7 × 108 interactions of positively charged kaons on copper nuclei, coherent events of the K+π0 system production...     

<Emphasis Type="Italic">K</Emphasis><Subscript><Emphasis Type="Italic">e</Emphasis>3</Subscript> Decay Studies in the OKA Experiment

Recent results from OKA setup concerning form factor studies in K_e3 decay are presented. About 5.25 M events obtained for decays of 17.7 GeV/cK⁺ are selected for the analysis. The linear and quadratic slopes for the decay form factor f₊(t) are measured: λ'₊ = 2.95 ± 0.022 ± 0.018 × 10 ^-2 for the linear slope fit and λ₊ = 2.611 ± 0.035 ± 0.028 × 10 ^-2, λ"₊ = 1.91 ± 0.19 ± 0.14 × 10 ^-3 for the quadratic one. The scalar and tensor contributions are compatible with zero. Several alternative parametrizations are tried: the Pole fit parameter is found to be M _V = 891 ± 3 MeV; the parameter of the dispersive parametrization is measured to be Λ₊ = 2.458 ± 0.018 × 10^-2.