[en] Using Brillouin scattering, we have determined the complete set of elastic constants of the technologically important β-Si₃N₄. Availability of single crystals has allowed us to measure all five independent c_ij, which (in units of GPa) are: c₁₁=433(3), c₃₃=574(3), c₁₃=127(5), c₄₄=108(2), c₆₆=119(4), and c₁₂=c₁₁-2c₆₆=195(8), giving a bulk modulus of 259. Our values are compared with existing calculations and c_ij determined from nano-indentation results combined with empirical relations and trends in related materials. (c) 2000 American Institute of Physics

[en] The equation of state for cold nuclear matter is determined by the effective, density-dependent interaction between bound nucleons at temperature T=0. This interaction can be probed in elastic nucleus-nucleus collisions at various density overlaps which may extend to several times the normal matter density. For this purpose the elastic scattering of ¹⁶O ions on ¹⁶O has been measured at incident energies from 250 to 1120 MeV with high accuracy. From these data, which sample both diffractive and refractive scattering processes, was extracted the underlying scattering potentials utilizing model-unrestricted analysis methods. These potentials fit very well into the systematics found in light-ion scattering and compare very favorably with microscopic calculations, if these are based on a weak density dependence of the effective NN interaction, resulting in a soft equation of state for cold nuclear matter

[en] The reaction νp → νp has been observed in an experiment conducted at the Brookhaven AGS. Experimental details and a comparison with quasi-elastic neutrino scattering are presented

[en] The symbolic conventions for spin paramters in high energy scattering experiments are set forth for elastic and pseudo-elastic scattering, one-particle inclusive reactions, and for total cross section measurements

[en] A study is made of deuteron-nucleus elastic and quasi-elastic scattering and the connection between the opaque nucleus model and the Glauber model is pointed out. The contributions to different cross-sections of the collisions in which the nucleus, excited by one of the nucleons of the deuteron, is brought back to the ground state by the other nucleon is analysed. Coherent deuteron disintegration is found to be highly improbable when the target nucleus is heavy and incoherent disintegration accounts for nearly all the deuteron disintegration. Thus a correct comparison between theoretical and experimental data on proton stripping must take the incoherent deuteron disintegration into consideration

[en] Quasielastic neutron scattering from droplet microemulsions is considered. Independent spherical fluid droplets are immersed in another fluid, the bulk fluids being separated by a surface layer fluctuating in shape. As distinct from the previous theories, the intermediate scattering function is calculated assuming small but nonzero thickness of the interface. The three components of the system are characterized by different scattering length densities. Consequently, the theory is applicable also for the scattering on emulsions containing large droplets with negligible thickness of the layer. With the aim to determine the Helfrich's elasticity characteristics of the surface layer, we apply the obtained formulas to describe the neutron spin-echo scattering experiments on microemulsions in which the droplet shape fluctuations have been detected. A quantitative agreement with the experiments can be reached only if the values of bending elasticity coefficient κ are smaller (in some cases significantly) than those determined in previous works. We conclude that the coefficients κ extracted so far from the neutron scattering experiments are not reliable and the theoretical description of these experiments should be essentially improved. (author)

[en] The multipole scattering coefficients for elastic wave scattering from a spherical inhomogeneity in a fluid-saturated porous medium have been calculated. These coefficients may be used to obtain estimates of the effective macroscopic constants for long-wavelength propagation of elastic waves through partially saturated media. If the volume average of the single scattering from spherical bubbles of gas and liquid is required to vanish, the resulting equations determine the effective bulk modulus, density, and viscosity of the multiphase fluid filling the pores. The formula for the effective viscosity during compressional wave excitation is apparently new

[en] We propose to construct and deploy a fine-grained detector in the Fermilab NOvA 2 GeV narrow-band neutrino beam. In this beam, the detector can make unique contributions to the measurement of quasi-elastic scattering, neutral-current elastic scattering, neutral-current π⁰ production, and enhance the NOvA measurements of electron neutrino appearance. To minimize cost and risks, the proposed detector is a copy of the SciBar detector originally built for the K2K long baseline experiment and used recently in the SciBooNE experiment.

[en] The detection of multinucleon transfer channels populated with very low cross-sections allow to study into detail phenomena that are important for a wide class of experiments. Some of the results recently obtained at LNL with the time-of-flight magnetic spectrometer PISOLO are discussed. A comparison between the data and the microscopic calculations performed with the new theoretical model developed by the Copenhagen group are presented

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