12,978 research outputs found
Oceanographic applications of the Kalman filter
The Kalman filter is a data-processing algorithm with a distinguished history in systems theory. Its application to oceanographic problems is in the embryo stage. The behavior of the filter is demonstrated in the context of an internal equatorial Rossby wave propagation problem
Role of Long-Range Correlations on the Quenching of Spectroscopic Factors
We consider the proton and neutron quasiparticle orbits around the
closed-shell 56Ni and 48Ca isotopes. It is found that large model spaces
(beyond the capability of shell-model applications) are necessary for
predicting the quenchings of spectroscopic factors.
The particle-vibration coupling is identified as the principal mechanism.
Additional correlations--due to configuration with several particle-hole
excitations--are estimated using shell-model calculations and generate an extra
reduction which is < ~4% for most quasiparticle states. The theoretical
calculations nicely agree with (e,e'p) and heavy ion knock-out experiments.
These results open a new path for a microscopic understanding of the
shell-model.Comment: Minor comments added and typos corrected. Accepted for publication on
Phys. Rev. Let
The Hosotani Mechanism in Bulk Gauge Theories with an Orbifold Extra Space S^1/Z_2
We pursue the possibility of the scenario in which the Higgs field is
identified with the extra-space component of a bulk gauge field. The space-time
we take is M S/Z. We show that a non-trivial
Z-parity assignment allows some of the extra-space component to have
radiatively induced VEV, which strongly modifies the mass spectrum and gauge
symmetry of the theory, realized by oribifolding. In particular we investigate
the dynamical mass generation of zero-mode fermion and spontaneous gauge
symmetry breaking due to the VEV. The gauge theories we adopt are a prototype
model SU(2) and SU(3) model, of special interest as the realistic minimal
scheme to incorporate the standard model SU(2) U(1).Comment: 16 pages 3 figure
The LHC (CMS) Discovery Potential for Models with Effective Supersymmetry and Nonuniversal Gaugino Masses
We investigate squark and gluino pair production at LHC (CMS) with subsequent
decays into quarks, leptons and LSP in models with effective supersymmetry
where third generation of squarks is relatively light while the first two
generations of squarks are heavy. We consider the general case of nonuniversal
gaugino masses. Visibility of signal by an excess over SM background in (n \geq
2)jets + (m \geq 0)leptons + E^{miss}_T events depends rather strongly on the
relation between LSP, second neutralino, gluino and squark masses and it
decreases with the increase of LSP mass. We find that for relatively heavy
gluino it is very difficult to detect SUSY signal even for light 3^{rd}
generation squarks (m_{\tilde q_3}\le 1 TeV) if the LSP mass is closed to the
3^{rd} generation squark mass.Comment: 1 latex (35 pages), 4 eps (figures) file
Charm and Bottom Quark Masses from Perturbative QCD
Using a new result for the first moment of the hadronic production cross
section at order , and new data on the and
resonances for the charm quark, we determine the \msb masses of the
charm and bottom quarks to be GeV and
GeV. We assume that the continuum
contribution to the sum rules is adequately described by pQCD. While we observe
a large reduction of the perturbative error, the shifts induced by the
theoretical input are very small. The main change in the central value of
is related to the experimental data. On the other hand, the value of is
not changed by our calculation to the assumed precision.Comment: 5 pages, 2 figures, final version as publishe
Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements
Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage
The Neron-Severi group of a proper seminormal complex variety
We prove a Lefschetz (1,1)-Theorem for proper seminormal varieties over the
complex numbers. The proof is a non-trivial geometric argument applied to the
isogeny class of the Lefschetz 1-motive associated to the mixed Hodge structure
on H^2.Comment: 16 pages; Mathematische Zeitschrift (2008
Electric Dipole moments of charged leptons and lepton flavor violating interactions in the general two Higgs Doublet model
We calculate the electric dipole moment of electron using the experimental
result of muon electric dipole moment and upper limit of the BR(\mu -->
e\gamma) in the framework of the general two Higgs doublet model. Our
prediction is 10^{-32} e-cm, which lies in the experimental current limits.
Further, we obtain constraints for the Yukawa couplings \bar{\xi}^{D}_{N,\tau
e} and \bar{\xi}^{D}_{N,\tau\mu}. Finally we present an expression which
connects the BR(\tau\to \mu\gamma) and the electric dipole moment of
\tau-lepton and study the relation between these physical quantities.Comment: 8 pages, 4 Figures (required epsf sty
Pre-MS depletion, accretion and primordial 7Li
We reconsider the role of pre-main sequence (pre-MS) Li depletion on the
basis of new observational and theoretical evidence: i) new observations of
Halpha emissions in young clusters show that mass accretion could be continuing
till the first stages of the MS, ii) theoretical implications from
helioseismology suggest large overshooting values below the bottom of the
convective envelopes. We argue here that a significant pre-MS 7Li destruction,
caused by efficient overshoot mixing, could be followed by a matter accretion
after 7Li depletion has ceased on MS thus restoring Li almost to the pristine
value. As a test case we show that a halo dwarf of 0.85 Msun with an extended
overshooting envelope starting with an initial abundance of A(Li) = 2.74 would
burn Li completely, but an accretion rate of the type 1e-8xe^{-t/3e6} Msun
yr would restore Li to end with an A(Li) = 2.31. A self-regulating
process is required to produce similar final values in a range of different
stellar masses to explain the PopII Spite plateau. However, this framework
could explain why open cluster stars have lower Li abundances than the
pre-solar nebula, the absence of Li in the most metal poor dwarfs and a number
of other features which lack of a satisfactory explanation.Comment: To be published in Memorie della Societ\`a Astronomica Italiana
Supplementi Vol. 22, Proceedings of Lithium in the cosmos, Iocco F.,
Bonifacio P., Vangioni E., ed
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