5,054 research outputs found
Magnetothermoelectric DC conductivities from holography models with hyperscaling factor in Lifshitz spacetime
We investigate an Einstein-Maxwell-Dilaton-Axion holographic model and obtain
two branches of a charged black hole solution with a dynamic exponent and a
hyperscaling violation factor when a magnetic field presents. The
magnetothermoelectric DC conductivities are then calculated in terms of horizon
data by means of holographic principle. We find that linear temperature
dependence resistivity and quadratic temperature dependence inverse Hall angle
can be achieved in our model. The well-known anomalous temperature scaling of
the Nernst signal and the Seebeck coefficient of cuprate strange metals are
also discussed.Comment: 1+23 pages, 4 figures, references adde
Electromagnetic radiation of baryons containing two heavy quarks
The two heavy quarks in a baryon which contains two heavy quarks and a light
one, can constitute a scalar or axial vector diquark. We study electromagnetic
radiations of such baryons, (i) \Xi_{(bc)_1} -> \Xi_{(bc)_0}+\gamma, (ii)
\Xi_{(bc)_1}^* -> \Xi_{(bc)_0}+\gamma, (iii) \Xi_{(bc)_0}^{**}(1/2, l=1) ->
\Xi_{(bc)_0}+\gamma, (iv) \Xi_{(bc)_0}^{**}(3/2, l=1) -> \Xi_{(bc)_0}+\gamma
and (v) \Xi_{(bc)_0}^{**}(3/2, l=2) -> \Xi_{(bc)_0}+\gamma, where
\Xi_{(bc)_{0(1)}}, \Xi^*_{(bc)_1} are S-wave bound states of a heavy scalar or
axial vector diquark and a light quark, and \Xi_{(bc)_0}^{**}(l is bigger than
1) are P- or D-wave bound states of a heavy scalar diquark and a light quark.
Analysis indicates that these processes can be attributed into two categories
and the physical mechanisms which are responsible for them are completely
distinct. Measurements can provide a good judgment for the diquark structure
and better understanding of the physical picture.Comment: 15 pages, Late
Renormalization group improved pQCD prediction for leptonic decay
The complete next-to-next-to-next-to-leading order short-distance and
bound-state QCD corrections to leptonic decay rate
has been finished by Beneke {\it et al.}
\cite{Beneke:2014qea}. Based on those improvements, we present a
renormalization group (RG) improved pQCD prediction for by applying the principle of maximum conformality (PMC). The PMC
is based on RG-invariance and is designed to solve the pQCD renormalization
scheme and scale ambiguities. After applying the PMC, all known-type of
-terms at all orders, which are controlled by the RG-equation, are
resummed to determine optimal renormalization scale for its strong running
coupling at each order. We then achieve a more convergent pQCD series, a
scheme- independent and more accurate pQCD prediction for
leptonic decay, i.e. keV, where the uncertainty is the squared average of
the mentioned pQCD errors. This RG-improved pQCD prediction agrees with the
experimental measurement within errors.Comment: 11 pages, 4 figures. Numerical results and discussions improved,
references updated, to be published in JHE
Ethyl 1-[(4-acetyl-2-methoxyphenoxy)methyl]cyclopropane-1-carboxylate
In the title compound, C16H20O5, the dihedral angle between the planar rings, viz. benzene and cyclopropane, is 52.1 (2)°. Molecules are connected in the crystal via weak intermolecular C—H⋯O hydrogen bonds, forming chains in the [001] direction
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