16,819 research outputs found
Rephasing invariance and the neutrino mu-tau symmetry
The vacuum neutrino mixing is known to exhibit an approximate
symmetry, which was shown to be preserved for neutrino propagating in matter.
This symmetry reduces the neutrino transition probabilities to very simple
forms when expressed in a rephasing invariant parametrization introduced
earlier. Applications to long baseline experiments are discussed.Comment: 12 pages, 4 figure
Density Fluctuations in the Oscillatory Phase of Nonclassical Inflaton in FRW Universe
Using coherent and squeezed state formalisms of quantum optics for a
minimally coupled non-classical inflaton in the FRW mertic is studied, in
semiclassical theory of gravity. The leading order solution for the
semiclassical Einstein equations in the coherent, squeezed and squeezed vacuum
states are obtained perturbatively and are exhibit powerlaw expansion
behaviour. The validity of the semiclassical theory is examined in the squeezed
vacuum state in the oscillatory phase of the inflaton. The semiclassical theory
in the oscillatory phase of the non-classical inflaton holds only if the
associated squeezing parameter is much less compared to unity. Quantum
fluctuations of the inflaton is also examined in coherent and squeezed state
formalisms.Comment: 14 pages, 2 figures, To appear in Int.J.Mod.Phys.
Combustion: Structural interaction in a viscoelastic material
The effect of interaction between combustion processes and structural deformation of solid propellant was considered. The combustion analysis was performed on the basis of deformed crack geometry, which was determined from the structural analysis. On the other hand, input data for the structural analysis, such as pressure distribution along the crack boundary and ablation velocity of the crack, were determined from the combustion analysis. The interaction analysis was conducted by combining two computer codes, a combustion analysis code and a general purpose finite element structural analysis code
Quark Mass Matrices with Four and Five Texture Zeroes, and the CKM Matrix, in terms of Mass Eigenvalues
Using the triangular matrix techniques of Kuo et al and Chiu et al for the
four and five texture zero cases, with vanishing (11) elements for U and D
matrices, it is shown, from the general eigenvalue equations and hierarchy
conditions, that the quark mass matrices, and the CKM matrix can be expressed
(except for the phases) entirely in terms of quark masses. The matrix
structures are then quite simple and transparent. We confirm their results for
the five texture zero case but find, upon closer examination of all the CKM
elements which our results provide, that six of their nine patterns for the
four texture zero case are not compatible with experiments. In total, only one
five-texture zero and three four-texture zero patterns are allowed.Comment: 15 pages, 3 table
Single Beam Interferometry of a Thermal Bump: IâExperiment
We present a sensitive interferometric technique which simultaneously measures the optical, elastic and thermal parameters of solids. We obtain the optical reflectivity change and the displacement due to thermal expansion (thermal bump) produced by an intensity modulated and focused laser beam
Family of Hermitian Low-Momentum Nucleon Interactions with Phase Shift Equivalence
Using a Schmidt orthogonalization transformation, a family of Hermitian
low-momentum NN interactions is derived from the non-Hermitian Lee-Suzuki (LS)
low-momentum NN interaction. As special cases, our transformation reproduces
the Hermitian interactions for Okubo and Andreozzi. Aside from their common
preservation of the deuteron binding energy, these Hermitian interactions are
shown to be phase shift equivalent, all preserving the empirical phase shifts
up to decimation scale Lambda. Employing a solvable matrix model, the Hermitian
interactions given by different orthogonalization transformations are studied;
the interactions can be very different from each other particularly when there
is a strong intruder state influence. However, because the parent LS
low-momentum NN interaction is only slightly non-Hermitian, the Hermitian
low-momentum nucleon interactions given by our transformations, including the
Okubo and Andreozzi ones, are all rather similar to each other. Shell model
matrix elements given by the LS and several Hermitian low-momentum interactions
are compared.Comment: 10 pages, 7 figure
Hermitian quark mass matrices with four texture zeros
We provide a complete and systematic analysis of hermitian, hierarchical
quark mass matrices with four texture zeros. Using triangular mass matrices,
each pattern of texture zeros is readily shown to lead to a definite relation
between the CKM parameters and the quark masses. Nineteen pairs are found to be
consistent with present data, and one other is marginally acceptable. In
particular, no parallel structure between the up and down mass matrices is
found to be favorable with data.Comment: 18 pages, no figure, references [8] and [10] adde
Approximate Treatment of Hermitian Effective Interactions and a Bound on the Error
The Hermitian effective interaction can be well-approximated by
(R+R^dagger)/2 if the eigenvalues of omega^dagger omega are small or
state-independent(degenerate), where R is the standard non-Hermitian effective
interaction and omega maps the model-space states onto the excluded space. An
error bound on this approximation is given.Comment: 13 page
Solar Neutrinos with Three Flavor Mixings
The recent 71Ga solar neutrino observation is combined with the 37Cl and
Kamiokande-II observations in an analysis for neutrino masses and mixings. The
allowed parameter region is found for matter enhanced mixings among all three
neutrino flavors. Distortions of the solar neutrino spectrum unique to three
flavors are possible and may be observed in continuing and next generation
experiments.Comment: August 1992 (Revised) PURD-TH-92-
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