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The possibility of electrocoagulating purification of spent washing liquids (SWL) from emulsified lubricating oils was verified. Using this technology, railway car-repair depots would be able to organize the recycling systems for repeated use of refined SWL and for isolated lubricants utilization. The purification of real SWL was simulated with faint direct current (DC) exposure on the lubricant emulsions (SWL imitations).

The influence of various forms of the reflecting elements on the uniformity of the distribution of seeds over the width of the couch sown with the coulter is considered in the article, since the main drawback of the existing coulter designs for intrasoil spread is the insufficient uniformity of seed distribution over the width of the coulter's sown band. Also, the article presents the results of laboratory studies to determine the uniformity of seed distribution across widths using various forms of the reflective element.

The radiative decay Λ(1520) → Λγ was recorded in the exclusive reaction p + N → Λ(1520)K+ + N at the SPHINX facility. The branching ratio for this decay and the corresponding partial width were found to be, respectively, Br[Λ(1520) → Λγ] = (1.02 ± 0.21) × 10−2 and Γ[Λ(1520) → Λγ] = 159 ± 35 keV (the quoted errors are purely statistical, the systematic errors being within 15%).

A search for narrow Θ+(1540), a candidate for a pentaquark baryon with positive strangeness, has been performed in an exclusive proton-induced reaction \(p + C(N) \to \Theta ^ + \bar \kappa ^0 + C(N)\) on carbon nuclei or quasifree nucleons at \(E_{beam} = 70GeV(\sqrt s = 11.5GeV)\) studying nK+, pKS0, and pKL0 decay channels of Θ+(1540) in four different final states of the \(\Theta ^ + \bar K^0 \) system. In order to assess the quality of the identification of the final states with neutron or KL0, we reconstructed Λ(1520) → nKS0 and ϕ → KL0KS0 decays in the calibration reactions p + C(N) → Λ (1520)K++C(N) and p+C(N) → pϕ+C(N). We found no evidence for a narrow pentaquark peak in any of the studied final states and decay channels. Assuming that the production characteristics of the \(\Theta ^ + \bar K^0 \) system are not drastically different from those of the Λ(1520)K+ and pϕ systems, we established upper limits on the cross-section ratios \(\sigma (\Theta ^ + \bar K^0 )/\sigma (\Lambda (1520)K^ + ) < 0.02\) and \(\sigma (\Theta ^ + \bar K^0 )/\sigma (p\phi ) < 0.15\) at 90% C.L. and a preliminary upper limit for the forward-hemisphere cross section \(\sigma (\Theta ^ + \bar K^0 )\) nb/nucleon.

The radiative decay Λ ( 1520 ) → Λ γ was measured directly in the study of the exclusive diffractive-like reaction p + N → Λ ( 1520 ) K + + N , Λ ( 1520 ) → Λ γ with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR [ Λ ( 1520 ) → Λ γ ] = ( 1.02 ± 0.21 ( stat ) ± 0.15 ( syst ) ) × 10 −2 and Γ [ Λ ( 1520 ) → Λ γ ] = 159 ± 33 ( stat ) ± 26 ( syst ) keV .

The first preliminary results from the upgraded SPHINX spectrometer, working in the proton beam with the energy of 70 GeV of the IHEP accelerator, are presented. The data for the reaction p + N ⊒ [Σ0 K +] + N based on new statistics are in good agreement with our previous data and strongly support the existence of the X (2000) state (with an increase in statistics for this state by a factor of ∼5). We also observed radiative decay of Λ(1520) → Λγ. The significant increase in statistics for many diffractive-production reactions will allow us to study them in great detail.

The diffractive reaction p + N → [∑+ K 0] + N induced by 70-GeV protons is investigated at the SPHINX facility. The measured mass spectrum of the ∑+ K 0 system originating from this reaction shows a resonance structure with a mass of M=1995±18 MeV and a width of Γ=90±32 MeV. The cross section for the formation of this structure is found to be σ=182±38 nb per target nucleon. These data comply well with the results that we obtained previously in studying the reaction p + N → [∑0 K +] + N, where we observed the formation of the X(2000) → ∑0 K + state, a candidate for an exotic baryon with hidden strangeness. The measured ratio R of the two branching fractions, R = Br[X(2000) → ∑+ K 0]/Br[X(2000) → ∑0 K +] = 1.91 ± 0.38, is consistent with the value of R=2 expected for an isospin-1/2 baryon.

Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.

New data for the diffractive reaction p+N→ [Σ0 K +] +N at E p= 70 GeV were obtained with partially upgraded SPHINX setup. The data are in a good agreement with the results of our previous study of this reaction. In the mass spectrum M(Σ0 K +) a structure at the threshold region with a mass ∼1810 MeV and a distinct X(2000) peak with M= 1989 ± 6 MeV and γ= 91 ± 20 MeV are observed. Unusual features of the massive X(2000) state (narrow decay width, anomalously large branching ratio for the decay channel with strange particle emission) make it a serious candidate for cryptoexotic pentaquark baryon with hidden strangeness |qqqs¯s>. We also present new results on the narrow threshold structure X(1810) with M= 1807 ± 7 MeV and γ= 62 ± 19 MeV which is produced in the region of very small P 2 T < 0.01 GeV2. The possibility of the Coulomb production mechanism for X(1810) is discussed.

In the experiments at the SPHINX facility in 70 GeV proton beam of the IHEP accelerator the coherent diffractive production reactions on carbon nucleip+C→ [∑(1385)0K++C andp+C→[Σ0K+]+C were investigated. The evidences for new baryon states were obtained in the study of hyperon-kaon effective mass spectra in these two reactions:X (2050) with massM=(2052±6) MeV and width Γ=(35−35+22) MeV inM[∑(1385)0K+] andX(2000) withM=1999±6 MeV and Γ=91±17 MeV inM[Σ0K+]. The unusual features of these massive states (small enough decay widths, anomalously large branching ratios for decays with strange particles emission) make them very serious candidates for cryptoexotic pentaquark baryons with hidden strangeness.

In the experiments at the SPHINX facility in the 70 GeV proton beam of the IHEP accelerator the diffractive production reactionsp+N→[Σ(1385)0K+] +N andp+N→[Σ(1385)0K+]+N+ (neutral particles) were studied. In the effective mass spectra of the [Σ(1385)0K+] system in these processes there were no signals from the anomalously narrow baryon stateNϕ (1960) which had been observed earlier in the measurement at the BIS-2 setup.

The reactions of baryon diffractive productionp+N→(pK + K −)+N, p+N→(pϕ)+N, p+N→[Λ(1520)K +]+N p+N→[Σ(1385) o K +]+N in the 70 GeV proton beam were studied. Very sensitive upper limits for the production cross sections of heavy narrow cryptoexotic baryon resonances with hidden strangeness were obtained.

The radiative decayη′→π+π−γ has been studied with the statistics of ≃2000 events. Different ways of describingmππ distribution are considered. It is shown that if the dominating contribution to this process is made by the decay channel η′→ργ, then the generally accepted ways of describing the ρ peak do not agree with experimental data.

In the experiments with LEPTON-F and SPHINX spectrometers the pion-induced charged exchange reactions π- + p → ϕ + n and π- + p → ω + n at Pπ-=32.5 GeV, as well as proton-induced diffractive reactions p + N → [pϕ] + N and p + N → [pω] + N at E p =70 GeV were studied. The comparison of the cross-sections for ϕ and ω-production in these reactions is used for testing the OZI selection rule in hadronic processes. It has been demonstrated that in pion reactions the ratio of the yields of ϕ and ω-mesons R(ϕ/ω) = (3 ± 1) · 10−3 is in a good agreement with naive quark model prediction based on the mixing in vector meson nonet and on the OZI rule (R(ϕ/ω)ozi = tg 2Δθ V − 4 · 10−3). At the same time in proton reactions the effective ratio of ϕ and ω yields is ∼ (4 ÷ 7) · 10-2, i.e. a strong violation of the OZI rule is observed in proton-nucleon interactions. This violation can be in favor of possible existence of some exotic ss component in the quark structure of protons.

A special mode of muonic beam with an average momentum of 21 GeV/c and opposite helicity from 40 GeV/c π-meson decay (the soft part of muonic spectrum corresponding to backward emission of muons in the pion rest-frame; negative polarization of muonic beam) and from 28 GeV/c μ-meson decay (the hard part of the muonic spectrum, positive polarization of muonic beam) has been realized at the IHEP muon beam channel with the view of search for parity-nonconservation effects in deep inelastic μN-interactions. The beam channel is automatically retuned from the operational mode with one helicity to that with the opposite one in each five accelerator cycles during the time intervals between the cycles. Muonic polarization was measured with the help of the energy spectrum of electrons from μ→eνν decay in-flight. In the momentum range 19–23 GeV/c the difference in polarization of two muonic beams was λ = 0.80±0.15.

The results on studying J/ψ particle production in the inclusive process π − + (Cu nucleus) → ( J / ψ ) + … obtained on the spectrometer “Lepton” are presented for momenta of 27 and 40 GeV/ c . The total cross sections for J/ψ production have been determined: σ [ π − + (Cu nucleus) → J / ψ + …] | x >0 = 410 ± 80 nb/Cu nucleus ( P π = 27 GeV/ c ), 980 ± 120 nb/Cu nucleus ( P π = 40 GeV/ c ). Differential distributions for this process in the kinematic variables X and P ⊥ are presented. There is a maximum in X -distribution in the range X ≈ 0.3.

New data have been obtained on a resonance in the ϕπ 0 system, the C meson, which is formed in the π − p → ϕπ 0 n charge-exchange reaction. The experiment has been performed at the Serpukhov 70 GeV accelerator. The mass and the width of the resonance are measured to be M =1480±40 MeV , Γ =130±60 MeV . The production cross section is determined at a π − momentum of 32.5 GeV / c : σ ( π − p → Cn )· BR ( C → ϕπ 0 )=40±15 nb . The C(1480) meson has an isospin I =1 and spin-parity J PC =1 − − . It is strongly coupled to the ϕπ 0 channel and is considered as a possible exotic meson.

Experimental results on the investigation of inclusive production of muon pairs and vector mesons (J/ψ, ϱ0(ω)) in π−N collisions at 27 and 40 GeV/c momenta are presented.

The difference of the cross sections for deep inelastic scattering of muons with average momenta 21 GeV/c with right and left helicity at large angles, i.e., with large momentum transfer, has been measured. No statistically-significant dependence of cross sections on the longitudinal polarization of muons has been found, i.e. no parity-nonconservation effects in deep inelastic μN interaction have been observed. The magnitude of the cross-section asymmetry R = [〈σ R 〉 − 〈σ L 〉] [〈σ R 〉+ + 〈σ L 〉] may be represented as R = β〈Q2〉 = (− 4 ± 6) × 10−3 〈Q2, (GeV/c)2〉. The limitations Go(μ) = (+ 6 ± 10)G have been obtained for the constant Go(μ) of vector-axial interaction ( G o (μ) 2 ) [ μ γα(1 + γ 5 )μ] J α o (hadron, V-A).

The D(1285) radiative decay has been observed, 19±5 events of this type have been detected. The branching ratio Br[D(1285)→ φγ ] = (0.9±0.2±0.4) × 10 −3 and the partial width γ [D(1285)→ φγ ] = 23 ±5±10) keV have been determined. The conclusion has been made that, most probably, the E(1420) meson does not belong to the axial nonet.

Coherent pi^+pi^-pi^- production in the interactions of a beam of 600 GeV pi^- mesons with C, Cu and Pb nuclei has been studied with the SELEX facility (Experiment E781 at Fermilab). The a2(1320) meson signal has been detected in the Coulomb (low q^2) region. The Primakoff formalism used to extract radiative decay width of this meson yields Gamma=284+/-25+/-25 keV, which is the most precise measurement to date., Comment: 16 pages, 5 figures, LaTeX, elsart, added reference and minor corrections, submitted to Phys.Lett.B

Results on the study of D(1285)→K+K− π0-decay are presented. The K+K− effective mass spectrum is measured with statistics which are by an order of magnitude higher than in the previous data. From the analysis of the differential spectrum d N d M KK (in the framework of the δ-dominance model) the δ-meson effective width is Γδ>180MeV/c2 at √s=1 GeV/c2, which means a strong coupling of the δ-meson with hadrons.

The results of studying the mass spectrum of μ+μ−γ systems produced in πp collisions at 25 GeVc are presented. A wide-aperture magnetic spectrometer with a hodoscope γ-detector was used to identify muon pairs and photons. There is a clear peak in the mass spectrum which corresponds to the decay η→μ+μ−γ previously not observed. The branching ratio for the decay is estimated to be 1.5 × 10−4.

The upper limits for the branching ratios of rare η, η′ decays have been obtained: BR( η → π 0 μ + − ) −6 , BR( η ′→ ημ + μ − ) −5 , BR( η ′→ π 0 μ + μ − ) −5 and BR( η → π 0 μ + μ − γ ) −6 (90% c.l.). These are several orders of magnitude lower than the previous limits. The analysis of the decay η ′→ ημ + μ − excludes the existence of light Higgs particles with a mass lower than 409 MeV/ c 2 .

The muon pair mass spectrum in the reactionπ − p→μ + μ − n has been investigated at 25 and 33 GeV/ c . A peak corresponding to the rareη→μ + μ − decay is observed. The measured branching ratio for this decay is (6.5 ± 2.1) × 10 −6 in agreement with theoretical estimates.

The mass spectrum for μ + μ − γ systems produced in π − p interactions at 25 and 33 GeV/ c has been studied. To detect muon pairs and photons a wide-aperture magnetic spectrometer and a hodoscope γ-detector were used. In the mass spectrum a clear peak is seen corresponding to the decay η ′ → μ + μ − γ not previously observed. The branching ratio for this decay, 8 × 10 −5 , is in agreement with the η′ form-factor model, based on vector dominance.

The results of studying the mass spectrum of μ + μ − γγ systems produced in π − p collisions at 25 and 33 GeV/c presented. The wide-aperture magnetic spectrometer with a hodoscope γ-detector was used to identify muon pairs and photons. There is a clear peak in the mass spectrum which corresponds to the decay ω → π 0 μ + μ − previously not observed. The branching ratio for the decay is estimated to be 9 × 10 −5 with a systematic error of 50%.