327,847 research outputs found
Disorder-sensitive superconductivity in the iron silicide LuFeSi studied by the Lu-site substitutions
We studied effect of non-magnetic and magnetic impurities on
superconductivity in LuFeSi by small amount substitution of the Lu
site, which investigated structural, magnetic, and electrical properties of
non-magnetic (LuSc)FeSi,
(LuY)FeSi, and magnetic
(LuDy)FeSi. The rapid depression of by
non-magnetic impurities in accordance with the increase of residual resistivity
reveals the strong pair breaking dominated by disorder. We provide compelling
evidence for the sign reversal of the superconducting order parameter in
LuFeSi.Comment: 4 pages, 5 figure
A Sharp Liouville Theorem for Elliptic Operators
We introduce a new condition on elliptic operators which ensures the validity of the Liouville property for bounded
solutions to on . Such condition is sharp when . We extend
our Liouville theorem to more general second order operators in non-divergence
form assuming a Cordes type condition
On thermodynamics of black p-branes
Thermodynamic properties of a class of black -branes in -dimensions
considered by Duff and Lu are investigated semi-classically. For black
-brane, thermodynamic quantities depend on and only through the
combination . The behavior of the Hawking temperature
and the lifetime vary with , with a critical value . For
, there remains a remnant, in which non-zero entropy is stored.
Implications of the fact that the Bekenstein-Hawking entropy of the black
-brane depend only on is discussed from the point of
view of duality.Comment: 8 pages, LaTe
Extraction of and from experimental decay rates using lattice QCD form factors
We present a determination of the Cabibbo-Kobayashi-Maskawa matrix elements
and obtained by combining the momentum dependence of the
semileptonic vector form factors and , recently determined from lattice QCD simulations, with the
differential rates measured for the semileptonic and decays. Our analysis is based on the results for the
semileptonic form factors produced by the European Twisted Mass Collaboration
with flavors of dynamical quarks in the whole range of values
of the squared 4-momentum transfer accessible in the experiments. The
statistical and systematic correlations between the lattice data as well as
those present in the experimental data are properly taken into account. With
respect to the standard procedure based on the use of only the vector form
factor at zero 4-momentum transfer, we obtain more precise and consistent
results: and . The
second-row CKM unitarity is fulfilled within the current uncertainties:
. Moreover, using for the
first time hadronic inputs determined from first principles, we have calculated
the ratio of the semileptonic decay rates into muons and
electrons, which represent a test of lepton universality within the SM,
obtaining in the isospin-symmetric limit of QCD: and .Comment: 8 pages, 2 figures, 8 tables. Version to appear in EPJ
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