12,060 research outputs found
Non-magnetic Stern-Gerlach Experiment from Electron Diffraction
Using the wave nature of the electrons, we demonstrate that a transverse spin
current can be generated simply by the diffraction through a single slit in the
spin-orbital coupling system of the two-dimensional electron gas. The
diffracted electron picks up the transverse momentum. The up spin electron goes
one way and the down spin electron goes the other, producing the coherent spin
current. In the system of spin-orbital coupling eVm, the
\emph{out-of-plane} component of the spin of the electron can be generated up
to 0.42 . Based on this effect, a novel device of grating to distill
spin is designed. Two first diffraction peaks of electron carry different
spins, duplicating the non-magnetic version of Stern-Gerlach experiment. The
direction of the spin current can be controlled by the gate voltage with low
energy cost.Comment: 4 pages, 4 figure
Existence of translating solutions to the flow by powers of mean curvature on unbounded domains
In this paper, we prove the existence of classical solutions of the Dirichlet
problem for a class of quasi-linear elliptic equations on unbounded domains
like a cone or a U-type domain. This problem comes from the study of mean
curvature flow and its generalization, the flow by powers of mean curvature.
Our approach is a modified version of the classical Perron method, where the
solutions to the minimal surface equation are used as sub-solutions and a
family auxiliary functions are constructed as super-solutions.Comment: 30 page
Hidden charm pentaquark and in the reaction
We have performed a study of the and
reactions based on the dominant Cabibbo
favored weak decay mechanism. We show that the produced only couples to
states, not and that the state is only
generated from final state interaction of and
channels which are produced in a primary stage. This guarantees that the state is generated in isospin and we see that the invariant mass
produces a clean signal for the of higher mass at MeV.
We also study the final state interaction, which is driven by the
excitation of a hidden charm resonance predicted before. We relate the strength
of the different invariant mass distributions and find similar strengths that
should be clearly visible in an ongoing LHCb experiment. In particular we
predict that a clean peak should be seen for a hidden charm resonance that
couples to the channel in the invariant mass
distribution.Comment: 8 pages, 7 figure
, and decays into and or
We study the , ,
, and decays and compare their mass distributions with those obtained for
the and .
The approach followed consist in a factorization of the weak part and the
hadronization part into a factor which is common to all the processes. Then
what makes the reactions different are some trivial Cabibbo-Kobayashi-Maskawa
matrix elements and the weight by which the different pairs of mesons appear in
a primary step plus their final state interaction. These elements are part of
the theory and thus, up to a global normalization factor, all the invariant
mass distributions are predicted with no free parameters. Comparison is made
with the limited experimental information available. Further comparison of
these results with coming LHCb measurements will be very valuable to make
progress in our understanding of the meson-meson interaction and the nature of
the low lying scalar meson resonances, and .Comment: 12 pages, 6 figures; v2: discussion added, references added, final
version published in EPJ
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