58 research outputs found
Doubly-charged scalars in the type II seesaw mechanism: Fundamental symmetry tests and high-energy searches
We analyze the sensitivity of low-energy fundamental symmetry tests to interactions mediated by doubly-charged scalars that arise in type II seesaw models of neutrino mass and their left-right symmetric extensions. We focus on the next generation measurement of the parity-violating asymmetry in Møller scattering planned by the MOLLER collaboration at Jefferson Laboratory. We compare the MOLLER sensitivity to that of searches for charged lepton flavor violation (CLFV) and neutrinoless double beta-decay (0νββ-decay) as well as present and possible future high-energy collider probes. We show that for the simplest type-II seesaw scenario, CLFV searches have the greatest sensitivity. However, in a left-right symmetric extension where the scale of parity-breaking is decoupled from the SU(2)R-breaking scale, the MOLLER experiment will provide a unique probe of scalar triplet interactions in the right-handed sector for a doubly-charged scalar mass up to ∼10 TeV and help elucidate the mechanism of 0νββ-decay
Coherent manipulation of atomic qubits in optical micropotentials
We experimentally demonstrate the coherent manipulation of atomic states in
far-detuned dipole traps and registers of dipole traps based on two-dimensional
arrays of microlenses. By applying Rabi, Ramsey, and spin-echo techniques, we
systematically investigate the dephasing mechanisms and determine the coherence
time. Simultaneous Ramsey measurements in up to 16 dipole traps are performed
and proves the scalability of our approach. This represents an important step
in the application of scalable registers of atomic qubits for quantum
information processing. In addition, this system can serve as the basis for
novel atomic clocks making use of the parallel operation of a large number of
individual clocks each remaining separately addressable.Comment: to be published in Appl. Phys.
Transversality Conditions for Infinite Horizon Variational Problems on Time Scales
We consider problems of the calculus of variations on unbounded time scales.
We prove the validity of the Euler-Lagrange equation on time scales for
infinite horizon problems, and a new transversality condition.Comment: Submitted 6-October-2009; Accepted 19-March-2010 in revised form; for
publication in "Optimization Letters"
AR and MA representation of partial autocorrelation functions, with applications
We prove a representation of the partial autocorrelation function (PACF), or
the Verblunsky coefficients, of a stationary process in terms of the AR and MA
coefficients. We apply it to show the asymptotic behaviour of the PACF. We also
propose a new definition of short and long memory in terms of the PACF.Comment: Published in Probability Theory and Related Field
Prominence seismology using small amplitude oscillations
Quiescent prominences are thin slabs of cold, dense plasma embedded in the
much hotter and rarer solar corona. Although their global shape is rather
irregular, they are often characterised by an internal structure consisting of
a large number of thin, parallel threads piled together. Prominences often
display periodic disturbances mostly observed in the Doppler displacement of
spectral lines and with an amplitude typically of the order of or smaller than
2--3 km s, a value which seems to be much smaller than the
characteristic speeds of the prominence plasma (namely the Alfv\'en and sound
velocities). Two particular features of these small amplitude prominence
oscillations is that they seem to damp in a few periods and that they seem not
to affect the whole prominence structure. In addition, in high spatial
resolution observations, in which threads can be discerned, small amplitude
oscillations appear to be clearly associated to these fine structure
constituents. Prominence seismology tries to bring together the results from
these observations (e.g. periods, wavelengths, damping times) and their
theoretical modeling (by means of the magnetohydrodynamic theory) to gain
insight into physical properties of prominences that cannot be derived from
direct observation. In this paper we discuss works that have not been described
in previous reviews, namely the first seismological application to solar
prominences and theoretical advances on the attenuation of prominence
oscillations
Physics of Solar Prominences: II - Magnetic Structure and Dynamics
Observations and models of solar prominences are reviewed. We focus on
non-eruptive prominences, and describe recent progress in four areas of
prominence research: (1) magnetic structure deduced from observations and
models, (2) the dynamics of prominence plasmas (formation and flows), (3)
Magneto-hydrodynamic (MHD) waves in prominences and (4) the formation and
large-scale patterns of the filament channels in which prominences are located.
Finally, several outstanding issues in prominence research are discussed, along
with observations and models required to resolve them.Comment: 75 pages, 31 pictures, review pape
History of clinical transplantation
How transplantation came to be a clinical discipline can be pieced together by perusing two volumes of reminiscences collected by Paul I. Terasaki in 1991-1992 from many of the persons who were directly involved. One volume was devoted to the discovery of the major histocompatibility complex (MHC), with particular reference to the human leukocyte antigens (HLAs) that are widely used today for tissue matching.1 The other focused on milestones in the development of clinical transplantation.2 All the contributions described in both volumes can be traced back in one way or other to the demonstration in the mid-1940s by Peter Brian Medawar that the rejection of allografts is an immunological phenomenon.3,4 © 2008 Springer New York
The Preterm Prediction Study: Elevated cervical ferritin levels at 22-24 weeks gestation are associated with spontaneous preterm delivery in asymptomatic women
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