  An experiment EPECUR, aimed at the search of the cryptoexotic non-strange
member of the pentaquark antidecuplet, started its operation at a pion beam
line of the ITEP 10 GeV proton synchrotron. The invariant mass range of the
interest (1610-1770) MeV will be scanned for a narrow state in the pion-proton
and kaon-lambda systems in the formation-type experiment. The scan in the
s-channel is supposed to be done by the variation of the incident pi- momentum
and its measurement with the accuracy of up to 0.1% with a set of 1 mm pitch
proportional chambers located in the first focus of the beam line. The
reactions under the study will be identified by a magnetless spectrometer based
on wire drift chambers with a hexagonal structure. Because the background
suppression in this experiment depends on the angular resolution, the amount of
matter in the chambers and setup is minimized to reduce multiple scattering.
The differential cross section of the elastic pi-p-scattering on a liquid
hydrogen target in the region of the diffractive minimum will be measured with
statistical accuracy 0.5% in 1 MeV steps in terms of the invariant mass. For
KLambda-production the total cross section will be measured with 1% statistical
accuracy in the same steps. An important byproduct of this experiment will be a
very accurate study of Lambda polarization. The setup was assembled and tested
in December 2008 and in April 2009 we had the very first physics run. About
0.5x10^9 triggers were written to disk covering pion beam momentum range
940-1135 MeV/c.
