113 research outputs found

    KNO Scaling in the Neutral Pion Multiplicity Distributions for pi^{-}-proton interactions at 40 and 250 GeV/c

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    We analysed the binomial multiplicity moments of the neutral pions, using an extension of the generating functional technique for detection losses. We applied this model-independent method to the individual gamma-weights of 10000 events of pi^{-}-proton interactions at 40 GeV/c. We compared the obtained results to those of 250 GeV/c. We used the FRITIOF and a shifted KW distribution to describe the data.Comment: 8pp LaTeX, 1 Postscript Figur

    Direct characterization of photo-induced lattice dynamics in BaFe₂As₂

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    Ultrafast light pulses can modify electronic properties of quantum materials by perturbing the underlying, intertwined degrees of freedom. In particular, iron-based superconductors exhibit a strong coupling among electronic nematic fluctuations, spins and the lattice, serving as a playground for ultrafast manipulation. Here we use time-resolved X-ray scattering to measure the lattice dynamics of photoexcited BaFe2_{2}As2_{2}. On optical excitation, no signature of an ultrafast change of the crystal symmetry is observed, but the lattice oscillates rapidly in time due to the coherent excitation of an A1g_{1g} mode that modulates the Fe–As–Fe bond angle. We directly quantify the coherent lattice dynamics and show that even a small photoinduced lattice distortion can induce notable changes in the electronic and magnetic properties. Our analysis implies that transient structural modification can be an effective tool for manipulating the electronic properties of multi-orbital systems, where electronic instabilities are sensitive to the orbital character of bands

    Observations on three-dimensional measurement of confined fission track lengths in apatite using digital imagery

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    We report the results of a comparative study to explore the usefulness of 3D measurements of confined fission track lengths (TINTs) relative to horizontal confined track length measurements (dips ≀10°), and evaluate their suitability for thermal history modeling. Confined fission track lengths were measured in 10 annealed Fish Canyon Tuff apatites containing synthetic mixtures of different length components, and two Durango apatites containing spontaneous fission tracks. Measurements were primarily carried out using a digital image-based microscope system, and they were compared to those from a regular optical drawing tube-digitizing tablet setup, and a confocal laser scanning microscope. The results indicate that 3D measurements of confined track lengths are closely comparable to conventional horizontal track measurements, and the mean track lengths of inclined (dips >10°) and horizontal (dips ≀10°) confined tracks from the one sample are equivalent within the measurement uncertainty. A strong dip-bias was observed, so that almost all the confined tracks measured were dipping at <30°, and the great majority (~70%) were dipping at ≀10°, thereby qualifying as “horizontal” confined tracks. Our results suggest that a useful increase of more than 40% in sample size can be achieved from including dip- and refraction-corrected 3D track length measurements. Some evidence was seen for a small bias in favor of shorter tracks at higher dip angles but this has very little influence on the mean lengths or length distributions up to the practical limit of dips (~30°) observed in these measurements. Results obtained using the same measurement system by a single analyst over time and between six different observers in the one laboratory show good reproducibility. These results also agree well with conventional horizontal confined track length measurements in the same samples in the second laboratory involved. We conclude that 3D measurements of confined track lengths, including both horizontal and inclined tracks, are suitable for use in current fission track annealing models derived from experiments using horizontal confined tracks

    Role of the protein cellular prion ( PRPC) in the neural differentiation : prions infection( PRPC) and molecular base of the neurodegenerescence

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    Survey of ethnobiology databases

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