We measure the relative cross sections for ital D mesons produced in interactions of pisup minus and pisup + beams with targets of Be, Cu, Al, and W. The measurement is based on 1400 fully ...reconstructed decays of the types ital Dsup 0r arrowital Ksup minuspisup +, ital Dsup +r arrowital Ksup minuspisup +pisup +, and charge conjugates. We find that the cross section for the production of both neutral and charged ital D's by either pisup minus or pisup + is well fitted by the form ital Asup alpha where ital A is the atomic mass and alpha=1.00plus minus0.05plus minus0.02, where the errors are statistical and systematic, respectively. There is no significant dependence of alpha on the transverse or longitudinal momentum of the ital D meson or on the charge of either the incident pion or the produced ital D mesons.
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We measure the differential cross section with respect to Feynman-{ital x} ({ital x}{sub {ital F}}) and transverse momentum ({ital P}{sub {ital T}}) for charm meson production using targets of Be, ...Al, Cu, and W. In the range 0.1{lt}{ital x}{sub {ital F}}{lt}0.7, {ital d}{sigma}/{ital dx}{sub {ital F}} is well fit by the form (1{minus}{ital x}{sub {ital F}}){sup {ital n}} with {ital n}=3.9{plus minus}0.3. The difference between {ital n} values for {ital D}{sup {minus}} and {ital D}{sup +} is 1.1{plus minus}0.7. However, we find an asymmetry of 0.18{plus minus}0.06 favoring the production of {ital D}{sup {minus}} compared to {ital D}{sup +}. In the lower {ital P}{sub {ital T}} range, {lt}2 GeV, {ital d}{sigma}/{ital dP}{sub {ital T}}{sup 2} is well fit by the form exp({minus}{ital b}{times}{ital P}{sub {ital T}}{sup 2}) with {ital b}=1.03{plus minus}0.06 GeV{sup {minus}2}, while in the higher {ital P}{sub {ital T}} range, 0.8 to 3.6 GeV, it is well fit by the form exp({minus}{ital b}{prime}{times}{ital P}{sub {ital T}}) with {ital b}{prime}=2.76{plus minus}0.08 GeV{sup {minus}1}. The shape of the differential cross section has no significant dependence on atomic mass of the target material.
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PVD allows the deposition of thin films with outstanding properties. One of the excellent properties is the combination of high wear and corrosion resistance. The coatings, however often lack of ...sufficient density caused by pores, pinholes and transient grains and grain boundaries starting from the substrate and ending at the outer film surface. An aggressive environment can then easily corrode the underlying less noble substrate. The purpose of the present study is to create dense films with respect to corrosive media using the Cr-N system as an example. Two sets of samples were prepared: i) multiple layer deposition of chromium and chromium nitride and ii) additional intermediate etching (IE) of single and multiple layers. High speed steel (1.3207 and 1.3247) was used as substrate material and magnetron sputtering for the film deposition. The characterization was performed by potentiodynamic and potentiostatic corrosion tests and by structural and compositional investigations.
Current judgment models underlying multidimensional scaling assume that perceived interstimulus proximity is determined solely by intradimensional differences between stimuli, independent of context ...effects. Class structure represents a context effect, with class centroids constituting multidimensional anchors within a configuration. The dependence of proximity judgments on class structure was examined in 3 experiments to test the appropriateness of the multidimensional scaling (MDS) judgment model for configurations containing element clusters. A total of 76 undergraduates served as Ss. Stimuli were multidimensional patterns generated to form 2 classes. Feature usage in judgments of intraclass similarity differed markedly from that in interclass similarity judgments. Moreover, the perceived similarities of 90 between-class pairs were in part determined by the distances of the pair members from class centroids, as well as by intradimensional differences. The partial context dependence of subjective proximity estimates suggests a source of incompleteness of the current MDS judgment model as applied to class structured events. (24 ref)
We report results from Fermilab experiment E769 on the differential cross sections of ital Dsup *plus minus charm vector mesons with respect to Feynman-ital x (ital xsub ital F) and transverse ...momentum (ital Psub ital T), and on the atomic mass dependence of the production. The ital Dsup * mesons were produced by a 250 GeV pi beam on a target of Be, Al, Cu, and W foils. The ital dsigma/ital dxsub ital F distribution is fit by the form (1minusital xsub ital F)sup ital n with ital n=3.5plus minus0.3plus minus0.1, the ital dsigma/ital dPsub ital Tsup 2 distribution by exp(minusital btimesital Psub ital Tsup 2) with ital b=0.70plus minus0.07plus minus0.04 GeVsup minus2, and the cross section ital A dependence by ital Asup alpha with alpha=1.00plus minus0.07plus minus0.02. These results are compared to the equivalent parameters for the production of pseudoscalar ital Dsup 0 and ital Dsup plus minus charm mesons.
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