2,167 research outputs found
Canonical Constraints on Leptonic Cp Violation using UHCR neutrino fluxes
It is shown that one can in principle constrain the CP-violating parameter
delta from measurements of four independant |V_{ij}|^2, or three of them and a
ratio, in the leptonic sector. To quantify our approach, using unitarity, we
derive simple expressions in terms of four independant |V_{ij}|^2 for
cos(delta) and an expression for sin^2(delta) from J^2. Thus, depending on the
values of |V_{ij}| and their accuracy, we can set meaningful limits on |delta|.
To illustrate numerically, if |V_{u1}|^2 is close to 0.1 with a 10% precision,
and if |V_{e3}^2 is larger than 0.005 and for values of |V_{e2}|^2 and
|V_{u3}|^2 that stay within +-0.1 of the current experimental data leads to a
bound pi/2 < |delta| < pi. Alternatively, a certain combination of parameters
with values of |V_{e3}|^2 larger than 0.01 leads to a closed bound of 73 <
|delta| < 103. In general, we find that it is better to use |V_{u1}|^2 or
|V_{t1}|^2 as the fourth independant |V_{ij}|^2 and that over most of the
parameter space, delta is least sensitive to |V_{e3}|^2. With just three
independant measurements (solar, atmospheric and reactor) it is impossible to
set limits on the CP phase. In this respect, we study the use of ultra high
energy cosmic (UHCR) neutrino fluxes as the additional fourth information. We
find that within the SM, neutrino fluxes of all three flavours will be very
similar but that pushing current neutrino data to their extreme values still
allowed, ratios of cosmic neutrino fluxes can differ by up to 20%; such large
discrepancies could imply negligibly small CP-violation. We also study a non
radiative neutrino decay model and find that the neutrino fluxes can differ by
a factor of up to 3 within this model and that an accuracy of 10% on the
neutrino fluxes is sufficient to set interestin limits on delta.Comment: 8 pages, 2 figures, 5 table
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EducationDoctor of Education (Ed.D.
Extracting W Boson Couplings from the Production of Four Leptons
We consider the processes , including all possible charged lepton combinations, with
regard to measuring parameters characterizing the boson. We calculate at
what level these processes can be used to measure anamolous triple-boson
vertice coupling parameters for the cases of colliders at 500
and 1 center of mass energies.Comment: 13 pages,OCIP/C-93-
Website Barriers to Employment for People with Disabilities
This study involves an analysis of the web content of 30 award winning companies regarding diversity and perceived company openness to employing people with disabilities. The results are mixed: some websites appear designed with disabilities in mind while others reveal constraints to website job access which in turn can result in underemployment and talent underutilization of people with disabilities. Based upon these findings, the authors discuss and make recommendations to optimize website designs that welcome people with disabilities
Applying dissipative dynamical systems to pseudorandom number generation: Equidistribution property and statistical independence of bits at distances up to logarithm of mesh size
The behavior of a family of dissipative dynamical systems representing
transformations of two-dimensional torus is studied on a discrete lattice and
compared with that of conservative hyperbolic automorphisms of the torus.
Applying dissipative dynamical systems to generation of pseudorandom numbers is
shown to be advantageous and equidistribution of probabilities for the
sequences of bits can be achieved. A new algorithm for generating uniform
pseudorandom numbers is proposed. The theory of the generator, which includes
proofs of periodic properties and of statistical independence of bits at
distances up to logarithm of mesh size, is presented. Extensive statistical
testing using available test packages demonstrates excellent results, while the
speed of the generator is comparable to other modern generators.Comment: 6 pages, 3 figures, 3 table
The Yang-Baxter equation for PT invariant nineteen vertex models
We study the solutions of the Yang-Baxter equation associated to nineteen
vertex models invariant by the parity-time symmetry from the perspective of
algebraic geometry. We determine the form of the algebraic curves constraining
the respective Boltzmann weights and found that they possess a universal
structure. This allows us to classify the integrable manifolds in four
different families reproducing three known models besides uncovering a novel
nineteen vertex model in a unified way. The introduction of the spectral
parameter on the weights is made via the parameterization of the fundamental
algebraic curve which is a conic. The diagonalization of the transfer matrix of
the new vertex model and its thermodynamic limit properties are discussed. We
point out a connection between the form of the main curve and the nature of the
excitations of the corresponding spin-1 chains.Comment: 43 pages, 6 figures and 5 table
Direct measurements of neutron capture on radioactive isotopes
We simulated the response of a 4p calorimetric g-detector array to decays of
radioactive isotopes on the s-process path. The GEANT 3.21 simulation package
was used. The main table contains estimates on the maximum sample size and
required neutron flux based on the latest available neutron capture cross
section at 30 keV. The results are intended to be used to estimate the
feasibility of neutron capture measurements with 4p arrays using the time of
flight technique
Generating-function method for tensor products
This is the first of two articles devoted to a exposition of the
generating-function method for computing fusion rules in affine Lie algebras.
The present paper is entirely devoted to the study of the tensor-product
(infinite-level) limit of fusions rules.
We start by reviewing Sharp's character method. An alternative approach to
the construction of tensor-product generating functions is then presented which
overcomes most of the technical difficulties associated with the character
method. It is based on the reformulation of the problem of calculating tensor
products in terms of the solution of a set of linear and homogeneous
Diophantine equations whose elementary solutions represent ``elementary
couplings''. Grobner bases provide a tool for generating the complete set of
relations between elementary couplings and, most importantly, as an algorithm
for specifying a complete, compatible set of ``forbidden couplings''.Comment: Harvmac (b mode : 39 p) and Pictex; this is a substantially reduced
version of hep-th/9811113 (with new title); to appear in J. Math. Phy
Measuring Movement and Social Contact with Smartphone Data: A Real-time Application to COVID-19
Tracking human activity in real time and at ïŹne spatial scale is particularly valuable during episodes such as the COVID-19 pandemic. In this paper, we discuss the suitability of smartphone data for quantifying movement and social contact. We show that these data cover broad sections of the US population and exhibit movement patterns similar to conventional survey data. We develop and make publicly available a location exposure index that summarizes county-to-county movements and a device exposure index that quantiïŹes social contact within venues. We use these indices to document how pandemic-induced reductions in activity vary across people and places
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