First measurement of chiral dynamics in π- γ → π- π- π+.

The COMPASS Collaboration at CERN has investigated the π- γ → π- π- π+ reaction at center-of-momentum energy below five pion masses, sqrt[s]<5m(π), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t'<0.001 GeV2/c2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3π-invariant mass m(3π)=sqrt[s] were extracted. The absolute cross section was determined in seven bins of sqrt[s] with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190   GeV/c π- into π- π- π+.

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190 GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1 GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66 GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0)) MeV/c2 and a width of (269±21(-64)(+42)) MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

[Effect of corazole on the dynamics of oxidative-reductive processes in cerebral cortical neurons]. / Vliianie korazola na dinamiku okislitel'no-vosstanovitel'nykh protsessov v neironakh kory golovnogo mozga.

By using the complex of techniques on the basis of life-time microscopy and spectrophotometry of the structures of II, III layers of the cat brain motor cortex there was studied the effect of ionophoretically delivered corazole on the dynamics of integral redox-state of pyramidal cells bodies, the surrounding neuropil as compared to the changed bioelectrical activity. The development of the convulsant activity of neurons coincided with the shift of their redox-state towards the accumulation of intracellular reducing equivalents. Both in the bodies of neurons and in the structures of neuropil a stable pronounced increase of restoration of intracellular redox-systems was preceded by the process of wave-like fluctuating changes in the content of reducing equivalents. The role of the revealed disturbances of oxidation-reduction processes in the mechanisms of corazole-induced lesions of neurons is discussed.

[Effects of corazol on the dynamics of membrane-bound calcium in the structures of the cerebral cortex]. / Vliianie korazola na dinamiku soderzhaniia membranno-sviazannogo kal'tsiia v strukturakh kory golovnogo mozga.

Using the complex methodical approach on the basis of in vivo microscopy and chlortetracycline fluorescent probe of the cat brain cortex preparation the authors studied the changes in the content of the bound calcium in the structures of II-III motor cortex layers in response to influence by metrasol. Correlation between rapid decrease of some part of the bound calcium and development of neuron seizures was discovered. Moreover process of calcium absorption by intracellular membranes in response to influence of metrasol in high doses was revealed. Apparently functional different intracellular membranes are involved in this process.