100,545 research outputs found
Eta-Mesic Nucleus and COSY-GEM Data
The experimental data of the COSY-GEM Collaboration for the recoil-free
transfer reaction p (27Al, 3He) \pi - p' X, leading to the formation of bound
state of eta (\eta) meson in 25Mg nucleus, is reanalyzed in this paper. In
particular, predicted values of binding energy and half-width of the \eta
-mesic nucleus 25Mg\eta, given by different theoretical approaches, are
compared with the ones obtained from the experimental missing mass spectrum. It
is found that the spectrum can be explained reasonably well if interference
effect of another process, where \eta is not bound in 25Mg but is scattered by
the nucleus and emerge as a pion, is taken into account. The data also indicate
that the interaction between N*(1535) and a nucleus is attractive in nature.Comment: Invited talk at the International Symposium on Mesic Nuclei, Krakow,
16 June 201
Microwave method for high-frequency properties of graphene
Graphene is a remarkable material, which is yet to make the transition from unique laboratory phenomenon to useful industrial material. One missing element in the development process is a quick method of quality control of the electrical properties of graphene which may be applied in, or close to, the graphene growth process on an industrial scale. In this study, the authors describe a non-contact method using microwave resonance which potentially solves this problem. They describe the technique, consider its limitations and accuracy and suggest how the method may have future take up.UK NMS Programme, the EU EMRP project ‘GraphOhm’ and ‘MetNEMS’. The EMRP (European Metrology Research Programme
Heisenberg equation for a nonrelativistic particle on a hypersurface: from the centripetal force to a curvature induced force
In classical mechanics, a nonrelativistic particle constrained on an
curved hypersurface embedded in flat space experiences the centripetal
force only. In quantum mechanics, the situation is totally different for the
presence of the geometric potential. We demonstrate that the motion of the
quantum particle is "driven" by not only the the centripetal force, but also a
curvature induced force proportional to the Laplacian of the mean curvature,
which is fundamental in the interface physics, causing curvature driven
interface evolution.Comment: 4 page
The centripetal force law and the equation of motion for a particle on a curved hypersurface
It is pointed out that the current form of extrinsic equation of motion for a
particle constrained to remain on a hypersurface is in fact a half-finished
version for it is established without regard to the fact that the particle can
never depart from the geodesics on the surface. Once the fact be taken into
consideration, the equation takes that same form as that for centripetal force
law, provided that the symbols are re-interpreted so that the law is applicable
for higher dimensions. The controversial issue of constructing operator forms
of these equations is addressed, and our studies show the quantization of
constrained system based on the extrinsic equation of motion is favorable.Comment: 5 pages, major revisio
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