Multihadronic decays and partial widths of the J/Ψ (3100) resonance produced in e+e− annihilation at adone

The reactions e⁺e^?→ hadrons and e⁺e⁺e^?→e⁺e^? have been studied at the J/gY (3100) resonance). The relative weights of the topological cross sections for fixed charged multiplicity are σ₂=(32±5)%, σ₄=(49±8)%, σ₆=(18±3)%, and σ₈=(1±0.6)%. The average pion multiplicities are 〈n_ch〉=3.8±0.3 and 〈n_{π^o〉=3.1±0.8}. The decay widths are Γ_e=(4.6±0.8) keV, Γ_h=(59±24) keV, and Γ=(68±26) keV.     

Dissipative terms of thermal nature in the theory of an ideal monoatomic superfluid

A dissipative model of helium II was built up in previous works, using a 13-field extended thermodynamic theory formulated by Liu and Müller. In this work a generalization of such model is presented, where an extended thermodynamics with 14 fields due to Kremer is used. It is shown that the fourteenth field is able to account for the experimental data concerning the second sound attenuation. Further, the proposed theory is able to explain the Osborne experiment. Finally, a comparison with the two-fluid model is performed, emphasizing the different ways in which the dissipative phenomena are explained by the two theories.     

Effect of a CO2 laser beam (λ0 = 10.59 μ) on the Hδ line emitted by a low pressure hydrogen discharge

We study the shift of H_δ line when hydrogen atoms are irradiated by a continuous CO₂ laser beam (λ₀ = 10.59 μ).     

Stark profiles of some ion lines of alkaline earth elements

The widths and shifts of Mg⁺, Ca⁺, Sr⁺ and Ba⁺ lines broadened by electron and ion Stark effects have been measured in an argon welding type plasma. The electron density is about 1.3×10¹⁷ cm^-3 and the temperature is about 13,000°K. Special care was taken to avoid self-absorption of resonance lines. Injection of alkaline earth elements into the cold region of the plasma edge permitted reliable measurements of the signs of line-shifts. Experimental results are compared with semi-classical theories and a new-classical computation of Sahal-Bréchot in which resonances of elastic cross sections are taken into account. Good agreement is observed between experiment and the later calculations.     

A network formulation of market equilibrium problems and variational inequalities

This paper shows that market equilibrium problems of production may generally be modelled as equilibrium flow problems in networks and that their equilibrium conditions can be visualized as a variational inequality. This connection would allow us to transplant directly elements of the well-developed theory of equilibrium flow in networks to the theory of market equilibrium.     

Schematicity and ground state correlations in the lead isotopes

The relationship between collectivity and ground state correlations is analyzed for the single closed shell lead isotopes. The effects of the schematic approximation are discussed, within the framework of both the quasiparticle Random Phase Approximation and the quasiparticle Tamm-Dancoff approach. The consistency of the RPA is investigated.     

Stark broadening and displacement of isolated He I lines

Experimental results for Stark broadened He I lines emitted by a helium plasma jet (N_e≈3×10¹⁶ cm^-3) are compared with theory; agreement is well enough for widths whereas shifts calculations present generally large discrepancies with experimental data.     

Distribution of amines in water/AOT/n-hexane reverse micelles: influence of the amine chemical structure

The distribution of different aliphatic and aromatic amines: n-butylamine (n-BA), isobutylamine (i-BA), tert-butylamine (t-BA), piperidine (PIP), N,N-dimethylaniline (DMA) and N-methylaniline (MA) in water/sodium 1,4-bis(2-ethylhexyl)sulfosuccinate(AOT)/n-hexane reverse micelles was investigated by steady-state fluorescence measurements. The partition constants were measured by an indirect method based on the effect that amine partitioning exert on the bimolecular rate of the reaction between a microphase incorporated fluorophore (Ru(bpy)2+(3)) and the quencher, (Fe(CN)3-(6)). For MA, that can act as a quencher of the fluorophore a direct method was used. The results show that primary amines have larger partition constants than the secondary ones. For tertiary amines the distribution constants were practically negligible. Laser flash photolysis experiments confirmed that tertiary amines, both aliphatic and aromatic, are not incorporated to the micellar pseudophase. The effect of the amine structure on the partition constant was analyzed through linear solvation free energy relationships (LSER) using solute parameters and compared with those obtained for alcohols. Hydrogen bond interactions with the AOT polar heads appear to be the main driving force for the distribution of amines between the organic and micellar pseudophases, whereas the size of the alkyl or aromatic group tends to hinder it.     

Reflexions sur sol dur,interferences et effet d'ecran

The interference effects of the sound energy from a source and that from a reflected wave on the ground are investigated in the particular case of measurements of noise reduction due to the use of a barrier.The influence of these effects on model experiments are also investigated.     

New results in the study of Brillouin scattering in thiourea

Below T₂ = 202 K, in the incommensurate phase, a Debye relaxation appears for c₃₃; it can be attributed to a linear coupling between an acoustical mode and a phason. The relaxation time is τ = τ₀/(T₀?T) with τ₀ = 6.2 x 10^?12 sec deg and T₀ = 200.9 K. The same phenomenon appears more weakly for c₁₁. The c₆₆ elastic constant has a double discontinuity around T₁ = 169 K; this shows that in the vicinity of T₁ there are two transitions, separated by a temperature interval of 3°.