1,493 research outputs found
Novel Studies on the \eta' Effective Lagrangian
The effective Lagrangian for \eta' incorporating the effect of the QCD
\theta-angle has been developed previously. We revisit this Lagrangian and
carry out its canonical quantization with particular attention to the test
function spaces of constraints and the topology of the \eta'-field. In this
way, we discover a new chirally symmetric coupling of this field to chiral
multiplets which involves in particular fermions. This coupling violates P and
T symmetries. In a subsequent paper, we will evaluate its contribution to the
electric dipole moment (EDM) of fermions. Our motivation is to test whether the
use of mixed states restores P and T invariance, so that EDM vanishes. This
calculation will be shown to have striking new physical consequences.Comment: 14 pages, 1 figure; V2: NEW TITLE; revised version to be published in
JHEP; references adde
Controllability of nonlocal impulsive stochastic quasilinear integrodifferential systems
Sufficient conditions for controllability of nonlocal impulsive stochastic quasilinear integrodifferential systems in Hilbert spaces are established. The results are obtained by using evolution operator, semigroup theory and fixed point technique. As an application, an example is provided to illustrate the obtained result
Controllability of Sobolev-type semilinear integrodifferential systems in Banach spaces
AbstractSufficient conditions for controllability of Sobolev-type semilinear integrodifferential systems in a Banach space are established. The results are obtained by using the Schaefer fixed-point theorem
Topology in Physics - A Perspective
This article, written in honor of Fritz Rohrlich, briefly surveys the role of
topology in physics.Comment: 16pp, 2 figures included (encapsulated postscript
Interacting Relativistic Particle: Time-Space Noncommutativity And Symmetries
We discuss the symmetry properties of the reparametrization invariant model
of an interacting relativistic particle where the electromagnetic field is
taken as the constant background field. The direct coupling between the
relativistic particle and the electromagnetic {\it gauge} field is a special
case of the above with a specific set of subtleties involved in it. For the
above model, we demonstrate the existence of a time-space noncommutativity (NC)
in the spacetime structure from the symmetry considerations alone. We further
show that the NC and commutativity properties of this model are different
aspects of a unique continuous {\it gauge} symmetry that is derived from the
non-standard gauge-type symmetry transformations by requiring their consistency
with (i) the equations of motion, and (ii) the expressions for the canonical
momenta, derived from the Lagrangians. We provide a detailed discussion on the
noncommutative deformation of the Poincar{\'e} algebra.Comment: LaTeX file, 23 pages, journal reference is give
Emergent Chiral Symmetry: Parity and Time Reversal Doubles
There are numerous examples of approximately degenerate states of opposite
parity in molecular physics. Theory indicates that these doubles can occur in
molecules that are reflection-asymmetric. Such parity doubles occur in nuclear
physics as well, among nuclei with odd A 219-229. We have also suggested
elsewhere that such doubles occur in particle physics for baryons made up of
`cbu' and `cbd' quarks. In this article, we discuss the theoretical foundations
of these doubles in detail, demonstrating their emergence as a surprisingly
subtle consequence of the Born-Oppenheimer approximation, and emphasizing their
bundle-theoretic and topological underpinnings. Starting with certain ``low
energy'' effective theories in which classical symmetries like parity and time
reversal are anomalously broken on quantization, we show how these symmetries
can be restored by judicious inclusion of ``high-energy'' degrees of freedom.
This mechanism of restoring the symmetry naturally leads to the aforementioned
doublet structure. A novel by-product of this mechanism is the emergence of an
approximate symmetry (corresponding to the approximate degeneracy of the
doubles) at low energies which is not evident in the full Hamiltonian. We also
discuss the implications of this mechanism for Skyrmion physics, monopoles,
anomalies and quantum gravity.Comment: 32 pages, latex. minor changes in presentation and reference
A comparative study of night-time enhancement of TEC at a low latitude station on storm and quiet nights including the local time, seasonal and solar activity dependence
International audienceThe main characteristics of night-time enhancements in TEC during magnetic storms are compared with those during quiet nights for different seasons and solar activity conditions at Palehua, a low latitude station during the period 1980?1989. We find that the mean amplitude has both a seasonal and solar activity dependence: in winter, the values are higher for weak storms as compared to those during quiet nights and increase with an increase in solar activity. In summer, the mean amplitude values during weak storms and quiet nights are almost equal. But during equinox, the mean amplitude values for quiet nights are greater than those during weak storms. The mean half-amplitude duration is higher during weak storms as compared to that during quiet nights in summer. However, during winter and equinox, the durations are almost equal for both quiet and weak storm nights. For the mean half-amplitude duration, the quiet night values for all the seasons and equinoctial weak storm values increase with an increase in solar activity. The occurrence frequency (in percent) of TEC enhancement during weak storms is greater than during quiet nights for all seasons. The mean amplitude, the mean half-amplitude duration and the occurrence frequency (in percent) of TEC enhancement values are higher during major storms as compared to those during quiet nights. The above parameters have their highest values during pre-midnight hours. From the data analysed, this behaviour is true in the case of major storms also
Processing and utilization of tuna
Tuna, fresh or processed in different styles, is a very important
commodity in the world trade for fish and fishery products
Recommended from our members
Insoluble electrospun membranes for analyte pre-concentration in saliva
Insoluble electrospun membrane based on poly acrylic acid (PAA) crosslinked with ethylene glycol (EG) was prepared. The surface of the crosslinked PAA fibers was then grafted with polyethylenimine (PEI), octyl amine (OA) and EG using carbodiimide or thermal crosslinking to obtain insoluble membranes having anionic, cationic, hydrophobic and neutral characteristics for filtration of biomolecules from saliva. The resulting surface chemistries were confirmed by their respective ATR-FTIR spectra. Differences in fiber morphology and diameters were observed between the membranes. All the membrane variants were tested for their efficacy as solid phase extraction (SPE) matrices in the pre-concentration of ethanol in synthetic saliva, using a microfluidic chip. Gas chromatography assays showed no statistical difference for ethanol in eluents through each of the tested insoluble electrospun membrane variants versus their corresponding controls. Further studies would include the testing of these membranes in the pre-concentration of clinical biomolecules, including drugs of abuse (e.g., cocaine, THC), nutrients (e.g., glucose), proteins (e.g., albumin, HbA1C) and nucleic acids for sample preparation within point of care devices
- …