String Theory and Quark Confinement

This article is based on a talk given at the ``Strings'97'' conference. It discusses the search for the universality class of confining strings. The key ingredients include the loop equations, the zigzag symmetry, the non-linear renormalization group. Some new tests for the equivalence between gauge fields and strings are proposed.Comment: 13 pages, latex; talk at STRINGS'9

Monopoles, confinement and deconfinement of (2+1)D compact lattice QED in external fields

The compact Abelian model in three space--time dimensions is studied in the presence of external electromagnetic fields at finite temperatures. We show that the deconfinement phase transition is independent on the strength of the external fields. This result is in agreement with our observation that the external fields create small--size magnetic dipoles from the vacuum which do not influence the confining properties of the model. Contrary to the deconfinement phase, the internal field in the direction of the applied external field is attenuated in the confinement phase, this screening becomes stronger with decreasing temperature.Comment: 22 pages, 24 EPS figures, LaTeX uses epsfig.st

Structures of complexes of octahaem cytochrome c nitrite reductase from Thioalkalivibrio nitratireducens with sulfite and cyanide.

The structures of complexes of octahaem cytochrome c nitrite reductase from the bacterium Thioalkalivibrio nitratireducens (TvNiR) with the substrate sulfite (1.4 Å resolution; R(cryst) = 0.126) and the inhibitor cyanide (1.55 Å resolution; R(cryst) = 0.148) have been established. The complex with sulfite was prepared by the reduction of the protein crystal with sodium dithionite. The sulfite ion is bound to the iron ion of the catalytic haem through the S atom. The Fe-S distance is 2.24 Å. The structure of the cyanide complex with full occupancy of the ligand site was established for the first time for cytochrome c nitrite reductases. The cyanide ion is bound to the catalytic haem iron through the C atom. The Fe-C distance is 1.91 Å and the Fe-C-N angle is 171°. The sulfite reductase activity of TvNiR was measured at different pH values. The activity is 0.02 µmol of HS(-) per minute per milligram at pH 7.0; it decreases with increasing pH and is absent at pH 9.0

Measurement of the ω→ηγ decay rate

The branching ratio of the rare radiative decay ω→ηγ has been measured: BR(ω→ηγ)=(8.3±2.1)·10-4. The experiment was performed at the IHEP (Serpukhov) accelerator with 38 GeV/c incident pions in the chargeexchange reaction π-p→ωn the photons from the ω→ηγ→3γ decay being detected with the multiphoton spectrometer GAMS-2000. The influence of ω-ρ mixing, which was a source of ambiguity in the interpretation of previous experiments, has been much reduced by measuring the ω produced at large momentum transfer. © 1994 Società Italiana di Fisica.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Observation of the ω → π0π0 γ decay

The rare radiative decay ω→ π0π0γ has been detected with the GAMS-2000 multiphoton spectrometer at the IHEP 70 GeV accelerator. The ω → π0γ decay events have been used for normalization. The measured branching ratio is BR(ω → π0π0γ) = (7.2 ± 2.6) × 10-5.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Model-independent measurement of ω→ηγ decay branching ratio

The rare ηγ decay width of the ω-meson has been measured in a model-independent way, with ω produced in 38 GeV/c π-p charge-exchange. Large momentum transfer events have been selected in order to eliminate ω-ρ interference contribution. BR (ω→ηγ) =(8.3±2.1)·10-4. The gammas from ω→ηγ→3γ decay have been detected with the multiphoton spectrometer GAMS-2000 at the IHEP 70 GeV proton accelerator. © 1994 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Study of fo (995) resonance in the π0π0 decay channel

A high-statistics study of the π0π0-system produced in the π-p→π0π0n reaction at 38GeV/c has been carried out at the IHEP accelerator using the GAMS-2000 multiphoton spectrometer. A partial-wave analysis which includes S, D0, D- and D+ waves has been performed in theSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Study of the reaction π-p → ηπ0n at 32, 38, and 100 GeV/c

The reaction π-p → ηπ0n at primary π- meson momenta of 32, 38, and 100 GeV/c has been studied by using the GAMS facilities. A partial-wave analysis has been performed in the effective-mass range 0.77 ≤ Mηπ0 < 182 GeV/c2. A peak associated with the a2 meson is clearly seen in the D+-wave. The difference of the D+-and P+-wave phases changes abruptly in the region of the a2 mass. A significant contribution of the P+ wave is observed at the a2-mass value and above, but this wave does not show a clear-cut resonance behavior. No significant contribution from exchanges of unnatural spin-parity are observed with the exception of the S-wave contribution in the region of the a0 mass and the D0-wave contribution in the region of the a2 mass.SCOPUS: ar.jinfo:eu-repo/semantics/publishe