10,459 research outputs found
Renormalization Group Effects on the Mass Relation Predicted by the Standard Model with Generalized Covariant Derivatives
Renormalization group analysis is made on the relation for masses of the top quark and the Higgs boson, which is
predicted by the standard model based on generalized covariant derivatives with
gauge and Higgs fields. This relation is a low energy manifestation of a tree
level constraint which holds among the quartic Higgs self-coupling constant and
the Yukawa coupling constants at a certain high energy scale . With the
renormalization group equation at one-loop level, the evolution of the
constraint is calculated from down to the low energy region around the
observed top quark mass. The result of analysis shows that the Higgs boson mass
is in for a wide range of the
energy scale and it approaches to 177 GeV ()
for large values of .Comment: 13 pages, LaTeX, no figure
Observation of Radiative B Meson Decays into Higher Kaonic Resonances
We have studied radiative B meson decays into higher kaonic resonances decaying into a two-body or three-body final state, using a data sample of 21.3 fb recorded at the resonance with the Belle detector at KEKB. For the two-body final state, we extract the component from an analysis of the helicity angle distribution, and obtain . For the three-body final state, we observe a signal that is consistent with a mixture of and . This is the first time that and have been observed separately. We find their branching fractions to be and , respectively
Approximate Sum Rules of CKM Matrix Elements from Quasi-Democratic Mass Matrices
To extract sum rules of CKM matrix elements, eigenvalue problems for
quasi-democratic mass matrices are solved in the first order perturbation
approximation with respect to small deviations from the democratic limit. Mass
spectra of up and down quark sectors and the CKM matrix are shown to have clear
and distinctive hierarchical structures. Numerical analysis shows that the
absolute values of calculated CKM matrix elements fit the experimental data
quite well. The order of the magnitude of the Jarlskog parameter is estimated
by the relation .Comment: Latex, 15 pages, no figure
Small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts. Volume 1. Aerodynamic test results
The results and analyses of aerodynamic and acoustic studies conducted on the small scale noise and wind tunnel tests of upper surface blowing nozzle flap concepts are presented. Various types of nozzle flap concepts were tested. These are an upper surface blowing concept with a multiple slot arrangement with seven slots (seven slotted nozzle), an upper surface blowing type with a large nozzle exit at approximately mid-chord location in conjunction with a powered trailing edge flap with multiple slots (split flow or partially slotted nozzle). In addition, aerodynamic tests were continued on a similar multi-slotted nozzle flap, but with 14 slots. All three types of nozzle flap concepts tested appear to be about equal in overall aerodynamic performance but with the split flow nozzle somewhat better than the other two nozzle flaps in the landing approach mode. All nozzle flaps can be deflected to a large angle to increase drag without significant loss in lift. The nozzle flap concepts appear to be viable aerodynamic drag modulation devices for landing
Phases of a bilayer Fermi gas
We investigate a two-species Fermi gas in which one species is confined in
two parallel layers and interacts with the other species in the
three-dimensional space by a tunable short-range interaction. Based on the
controlled weak coupling analysis and the exact three-body calculation, we show
that the system has a rich phase diagram in the plane of the effective
scattering length and the layer separation. Resulting phases include an
interlayer s-wave pairing, an intralayer p-wave pairing, a dimer Bose-Einstein
condensation, and a Fermi gas of stable Efimov-like trimers. Our system
provides a widely applicable scheme to induce long-range interlayer
correlations in ultracold atoms.Comment: 5 pages, 5 figures; (v2) stability of trimer is emphasized; (v3)
published versio
Marginally unstable Holmboe modes
Marginally unstable Holmboe modes for smooth density and velocity profiles
are studied. For a large family of flows and stratification that exhibit
Holmboe instability, we show that the modes with phase velocity equal to the
maximum or the minimum velocity of the shear are marginally unstable. This
allows us to determine the critical value of the control parameter R
(expressing the ratio of the velocity variation length scale to the density
variation length scale) that Holmboe instability appears R=2. We then examine
systems for which the parameter R is very close to this critical value. For
this case we derive an analytical expression for the dispersion relation of the
complex phase speed c(k) in the unstable region. The growth rate and the width
of the region of unstable wave numbers has a very strong (exponential)
dependence on the deviation of R from the critical value. Two specific examples
are examined and the implications of the results are discussed.Comment: Submitted to Physics of Fluid
Quantizing Majorana Fermions in a Superconductor
A Dirac-type matrix equation governs surface excitations in a topological
insulator in contact with an s-wave superconductor. The order parameter can be
homogenous or vortex valued. In the homogenous case a winding number can be
defined whose non-vanishing value signals topological effects. A vortex leads
to a static, isolated, zero energy solution. Its mode function is real, and has
been called "Majorana." Here we demonstrate that the reality/Majorana feature
is not confined to the zero energy mode, but characterizes the full quantum
field. In a four-component description a change of basis for the relevant
matrices renders the Hamiltonian imaginary and the full, space-time dependent
field is real, as is the case for the relativistic Majorana equation in the
Majorana matrix representation. More broadly, we show that the Majorana
quantization procedure is generic to superconductors, with or without the Dirac
structure, and follows from the constraints of fermionic statistics on the
symmetries of Bogoliubov-de Gennes Hamiltonians. The Hamiltonian can always be
brought to an imaginary form, leading to equations of motion that are real with
quantized real field solutions. Also we examine the Fock space realization of
the zero mode algebra for the Dirac-type systems. We show that a
two-dimensional representation is natural, in which fermion parity is
preserved.Comment: 26 pages, no figure
A Phenomenological Formula for KM Matrix
We propose a phenomenological formula relating the Kobayashi-Maskawa matrix
and quark masses in a form $(m_d,\ m_s,\ m_b)\propto (m_u,\ m_c,\
m_t)V_{KM}$. The formula agrees with experimental data well and has an
interesting geometric picture. The origin of such a formula is discussed in the
standard model.Comment: 9 pages, LaTeX, no figure
Influence of self-gravity on the runaway instability of black hole-torus systems
Results from the first fully general relativistic numerical simulations in
axisymmetry of a system formed by a black hole surrounded by a self-gravitating
torus in equilibrium are presented, aiming to assess the influence of the torus
self-gravity on the onset of the runaway instability. We consider several
models with varying torus-to-black hole mass ratio and angular momentum
distribution orbiting in equilibrium around a non-rotating black hole. The tori
are perturbed to induce the mass transfer towards the black hole. Our numerical
simulations show that all models exhibit a persistent phase of axisymmetric
oscillations around their equilibria for several dynamical timescales without
the appearance of the runaway instability, indicating that the self-gravity of
the torus does not play a critical role favoring the onset of the instability,
at least during the first few dynamical timescales.Comment: To appear on Phys.Rev.Let
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