An automated setup for measuring single-spin asymmetry in inclusive neutral-meson production at the 14th channel of the IFVE accelerator (IHEP) is described. The experiments were conducted using both the secondary pion beam with 40-GeV/c momentum and the primary proton beam with 70-GeV energy, brought to the setup zone by means of a bent single crystal. The main characteristics of the detectors and data-acquisition system are presented.

The results of measuring the spin asymmetry (the analyzing power) of protons from the reactions pi- (K -) +d(up) --> p(90-degrees) + X at the initial particle momentum 40 GeV/c are described. No significant asymmetries are found for emission of protons in the studied range of momenta (0.3-0.7 GeV/c) and angles (85-95-degrees in the laboratory system). The spin asymmetries averaged over the indicated intervals are found to be A(y)pi = (1 +/- 2) % and A(y)k = (9.4 +/- 9.8) % for the reactions with pions and kaons, respectively. The results are compared with theoretical predictions for these reactions (the model of hard parton collisions, the spectator mechanism of cumulative nucleon production, and so forth), and also with experimental data obtained in analogous studies.

The like-spin up-down asymmetry in production of {pi}{sup 0} and {eta} mesons has been measured in the central region on polarized protons and deuterons bombarded by negative pions and kaons at initial momentum 40 GeV/{ital c}. A significant asymmetry is observed in production of {pi}{sup 0} mesons, reaching 40--50% in the region {ital p}{sub {ital t}} {gt}2.4 GeV/{ital c}. An indication is obtained of the same behavior of the asymmetry in the production of {eta} mesons.

The inclusive production of π0’s in the interaction of unpolarized π−, k−, and antiproton beams with polarized proton and deuteron targets has been studied at IHEP. The absolute value of the asymmetry for π0 production in the polarized proton and deuteron targets is between zero and fiften percent for large x=P*/P* max and small Pt and independent on the quark flavor. Results are presented and compared with theoretical calculations. (AIP)

A 40%‐asymmetry has been revealed in the hard scattering region at 40 GeV. Systematic errors in the experiment are noticeable. The observed effect requires detailed discussion of the production mechanisms.

The total cross section for the process {pi}{sup +}{pi{minus}}{r arrow}{pi0}{pi0} in the dipion mass region 0.55{lt}{ital M}{lt}2.0 GeV is determined from the peripheral transitions {pi}{sup {minus}}{r arrow}{pi0}{pi0} in carbon and propanediol targets at an initial {pi}{sup {minus}}-meson momentum 39.1 GeV/{ital c}.