21,299 research outputs found
Lepton-number violation and right-handed neutrinos in Higgs-less effective theories
Following previous work, we identify a symmetry S_nat that generalizes the
concept of custodial symmetry, keeping under control deviations from the
Standard Model (SM). To realize S_nat linearly, the space of gauge fields has
to be extended. Covariant constraints formulated in terms of spurions reduce
S_nat back to SU(2)_L x U(1)_Y. This allows for a covariant introduction of
explicit S_nat-breaking parameters. We assume that S_nat is at play in a theory
of electroweak symmetry-breaking without a light Higgs particle. We describe
some consequences of this assumption, using a non-decoupling effective theory
in which the loop expansion procedure is based on both momentum and spurion
power counting, as in Chiral Perturbation Theory. A hierarchy of lepton-number
violating effects follows. Leading corrections to the SM are non-oblique. The
effective theory includes stable light right-handed neutrinos, with an unbroken
Z_2 symmetry forbidding neutrino Dirac masses. nu_R contribution to dark matter
places bounds on their masses.Comment: Corresponds to published version: added subsection VI-D about
order-of-magnitude estimate
Strong-coupling scales and the graph structure of multi-gravity theories
In this paper we consider how the strong-coupling scale, or perturbative
cutoff, in a multi-gravity theory depends upon the presence and structure of
interactions between the different fields. This can elegantly be rephrased in
terms of the size and structure of the `theory graph' which depicts the
interactions in a given theory. We show that the question can be answered in
terms of the properties of various graph-theoretical matrices, affording an
efficient way to estimate and place bounds on the strong-coupling scale of a
given theory. In light of this we also consider the problem of relating a given
theory graph to a discretised higher dimensional theory, a la dimensional
deconstruction.Comment: 23 pages, 7 figures; v2: additional references included, and minor
typos corrected; version published in JHE
The decoupling limit of Multi-Gravity: Multi-Galileons, Dualities and More
In this paper we investigate the decoupling limit of a particular class of
multi-gravity theories, i.e. of theories of interacting spin-2 fields. We
explicitly compute the interactions of helicity-0 modes in this limit, showing
that they take on the form of multi-Galileons and dual forms. In the process we
extend the recently discovered Galileon dualities, deriving a set of new
multi-Galileon dualities. These are also intrinsically connected to healthy,
but higher-derivative, multi-scalar field theories akin to `beyond Horndeski'
models.Comment: 41 pages, 2 figure
Alat Uji Baterai 12V 60AH Secara Elektronis
This research discusses the implementation of electronic circuits for battery testing to replace the manual tester that is usually used in Switchyard. The equipment consists of constant-current controlled circuit to produce relatively constant current according to battery capacity so that it is able to be used as a battery tester based on a charge-and-discharge method with constant current. PC based data acquisition is used in order to have data that are more accurate. Experimental results in testing 12 V, 60 AH battery demonstrates the ability of the equipment to replace the manual one as a battery tester
How SU(2) Anyons are Z Parafermions
We consider the braid group representation which describes the non-abelian
braiding statistics of the spin 1/2 particle world lines of an SU(2)
Chern-Simons theory. Up to an abelian phase, this is the same as the
non-Abelian statistics of the elementary quasiparticles of the
Read-Rezayi quantum Hall state. We show that these braiding statistics are
identical to those of Z Parafermions
Effect of Dynamical Coulomb Correlations on the Fermi Surface of Na_0.3CoO_2
The t2g quasi-particle spectra of Na_0.3CoO_2 are calculated within the
dynamical mean field theory. It is shown that as a result of dynamical Coulomb
correlations charge is transfered from the nearly filled e_g' subbands to the
a_1g band, thereby reducing orbital polarization among Co t2g states. Dynamical
correlations therefore stabilize the small e_g' Fermi surface pockets, in
contrast to angle-resolved photoemission data, which do not reveal these
pockets.Comment: 4 pages, to appear in PR
Tip aerodynamics from wind tunnel test of semi-span wing
Presented are the results of a low-speed wind tunnel test on a 5.33-aspect-ratio, semi-span wing with 30- and 35 deg swept tapered tips. The test results include aerodynamic data for the tip itself and for the entire wing including the tip. The metric tip extended inboard 1.58 wing chord lengths. The aerodynamic drag data show the strong influence of tip incidence angle on tip drag for various lift levels. Pitching-moment characteristics show the effect of a moment center at 0.13 c and 0.25 c
Effects of a radially varying electrical conductivity on 3D numerical dynamos
The transition from liquid metal to silicate rock in the cores of the
terrestrial planets is likely to be accompanied by a gradient in the
composition of the outer core liquid. The electrical conductivity of a volatile
enriched liquid alloy can be substantially lower than a light-element-depleted
fluid found close to the inner core boundary. In this paper, we investigate the
effect of radially variable electrical conductivity on planetary dynamo action
using an electrical conductivity that decreases exponentially as a function of
radius. We find that numerical solutions with continuous, radially outward
decreasing electrical conductivity profiles result in strongly modified flow
and magnetic field dynamics, compared to solutions with homogeneous electrical
conductivity. The force balances at the top of the simulated fluid determine
the overall character of the flow. The relationship between Coriolis and
Lorentz forces near the outer boundary controls the flow and magnetic field
intensity and morphology of the system. Our results imply that a low
conductivity layer near the top of Mercury's liquid outer core is consistent
with its weak magnetic field.Comment: 30 pages, 11 figures, 2 tables. To be published in Physics of Earth
and Planetary Interiors (PEPI)
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