A. N. Krinitsyn

Production asymmetry measurement of high xT hadrons in p ↑ p collisions at 40 GeV

Abstract Single-spin asymmetries for hadrons have been measured in collisions of a transversely polarized 40 GeV / c proton beam with an unpolarized liquid hydrogen target. The asymmetries were measured for π ± , K ± , protons and antiprotons, produced in the central region (0.02 ⩽ x F ⩽ 0.10 and 0.7 ⩽ p T ⩽ 3.4 GeV / c ). Asymmetries for π ± , K ± and p show, within measurement errors, a linear dependence on x T and change sign near 0.37. For protons, a negative asymmetry, independent of x T , has been found. The results are compared with those of other experiments and SU(6) model predictions.

Production of charged hadron pairs with large symmetric transverse momenta in pp collisions at 70 GeV

We measured the cross sections of hadron pair production (π, K, p) with symmetric momenta produced back-to-back in the c.m.s. in pp collisions in the range 0.45 ⩽ PT ⩽ 1.99 GeV/c. Particle correlations showing dependence on quantum numbers and transverse momentum are presented. The data are discussed in the framework of parton models.

Observation of a puzzlingA-dependence of symmetric hadron pairs at highP⊥

Symmetric hadron pair production cross section (π+ π+, π+K+, π+p,K+p, andpp) were measured in the range 0.48≦P⊥≦2.29 GeV/c from Be, Cu, and Pb targets bombarded by 70 GeV protons. TheA-dependence exponent as a function ofP⊥ differs for varios pairs.A steep drop of α for meson pairs atP⊥>1.5 GeV/c is observed.

Pair production of pions with symmetric momenta in the range 0.5⩽pT⩽2.0 GeV/c In 70 GeV p-p collisions

Abstract The invariant cross-section slope of the pp→π+π−+X process as a function of pT is found to have a break near 1 GeV/c. Fitting the cross section by a sum of two exponents gives the values of powers (12.3±0.9)(GeV/c)−1 and (8.7±0.6)(GeV/c)−1. The experimental points at pT⩾1 GeV/c are significantly higher than predictions based on hard scattering models such as QCD and CIM.

A hadron calorimeter with scintillators parallel to the beam

Abstract A hadron calorimeter in which scintillators are arranged nearly parallel to the incident particle direction and light is collected by optical fibres with WLS, has been built. The iron absorber plates are of the tapered shape to fit a barrel structure of the collider geometry. The performance of the calorimeter studied with hadron beam is presented as a function of tilt angle without and with electromagnetic calorimeter in front of the hadron one.

Prototype of barrel electromagnetic calorimeter

Abstract A prototype of the barrel electromagnetic calorimeter for a collider is described. The calorimeter is longitudinally segmented into two parts to measure particle trajectory angle. The prototype has been tested in electron and muon beams.