[en] The MPD spectrometer at the NICA collider complex is currently under construction in Dubna. The main goal of the experiment is to obtain fundamental knowledge about the properties of hot and dense baryonic matter formed in heavy-ion collisions in the energy range of (4-11) A*GeV. Crucial detector of the MPD experiment is a large-sized barrel electromagnetic calorimeter (ECal), which (together with the tracking system) will provide unique opportunities for the measurement and identification of a wide variety of charged and neutral particles carrying information about early stages of the interactions. Important tasks related to the construction of the Shashlyk-type MPD ECal are the development, production and study of the calorimeter modules with projective geometry. To improve performance of ECal, the light collection in the modules should be optimized. We present the methods and technologies developed to increase the light yield with different types and configurations of reflectors on the end of wavelengths shifting fibers. Expected characteristics of the calorimeter in detection of photons and electrons are presented and discussed

[en] An amplitude analysis of an exclusive sample of 5765 events from the reaction π^- p → η(prime)π^- p at 18 GeV/c is described. The η(prime)π^- production is dominated by natural parity exchange and by three partial waves: those with J^PC = 1^-+, 2⁺⁺, and 4⁺⁺. A mass-dependent analysis of the partial-wave amplitudes indicates the production of the a₂(1320) meson as well as the a₄(2040) meson, observed for the first time decaying to η(prime)π^-. The dominant, exotic (non-q(bar q)) 1^-+ partial wave is shown to be resonant with a mass of 1.597 ± 0.010_-0.010^+0.045 GeV/c² and a width of 0.340 ± 0.040 ± 0.050 GeV/c². This exotic state, the π₁(1600), is produced with a t dependence which is different from that of the a₂(1320) meson, indicating differences between the production mechanisms for the two states