7,437 research outputs found
Evaluation of ADAM/1 model for advanced coal extraction concepts
Several existing computer programs for estimating life cycle cost of mining systems were evaluated. A commercially available program, ADAM/1 was found to be satisfactory in relation to the needs of the advanced coal extraction project. Two test cases were run to confirm the ability of the program to handle nonconventional mining equipment and procedures. The results were satisfactory. The model, therefore, is recommended to the project team for evaluation of their conceptual designs
Characteristic impedance of microstrip lines
The dyadic Green's function for a current embedded in a grounded dielectric slab is used to analyze microstrip lines at millimeter wave frequencies. The dyadic Green's function accounts accurately for fringing fields and dielectric cover over the microstrip line. Using Rumsey's reaction concept, an expression for the characteristic impedance is obtained. The numerical results are compared with other reported results
Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays
We study effects of new physics beyond the Standard Model on SU(3) symmetry
in charmless hadronic two body B decays. It is found that several equalities
for some of the decay amplitudes, such as , , , predicted by SU(3) symmetry in the SM are not affected by new
physics. These relations provide important electroweak model independent tests
for SU(3) symmetry in B decays.Comment: 4 pages, revte
A method for determining CP violating phase
A new way of determining the phases of weak amplitudes in charged decays
based on SU(3) symmetry is proposed. The CP violating phase can now be
determined without the previous difficulty associated with electroweak
penguins.Comment: 9 pages plus one figure, Revte
Spin Effects in the Local Density of States of GaAs
We present spin-resolved measurements of the local density of states in Si
doped GaAs. Both spin components exhibit strong mesoscopic fluctuations. In the
magnetic quantum limit, the main features of the spin-up and spin-down
components of the local density of states are found to be identical apart from
Zeeman splitting. Based on this observation, we introduce a mesoscopic method
to measure the -factor in a material where macroscopic methods are severely
restricted by disorder. Differences between the spin-up and spin-down
components are discussed in terms of spin relaxation due to spin-orbit
coupling.Comment: 4 pages and 5 figure
in the Standard Model
In this paper we investigate the possibility of studying form
factor using the semi-inclusive decays . In general
semi-inclusive decays involve several hadronic parameters. But for
decays we find that in the factorization
approximation, the only unknown hadronic parameters are the form factors
. Therefore these form factors can be studied in decays. Using theoretical model calculations for the form
factors the branching ratios for and
, with the cut GeV, are
estimated to be in the ranges of and ,
respectively, depending on the value of . The combined branching ratio
for is about and is insensitive to . We also discuss CP
asymmetries in these decay modes.Comment: RevTex 8 pages and two figure
Constraints on the phase and new physics from Decays
Recent results from CLEO on indicate that the phase may
be substantially different from that obtained from other fit to the KM matrix
elements in the Standard Model. We show that extracted using is sensitive to new physics occurring at loop level. It provides
a powerful method to probe new physics in electroweak penguin interactions.
Using effects due to anomalous gauge couplings as an example, we show that
within the allowed ranges for these couplings information about
obtained from can be very different from the Standard
Model prediction.Comment: Revised version with analysis done using new data from CLEO. RevTex,
11 Pages with two figure
The CP violating phase from global fit of rare charmless hadronic B decays
We study constraints on the CP violating phase in the
Kobayashi-Maskawa model using available experimental data. We first follow the
conventional method to up date the constraint on by performing a
analysis using data from , and
. We also include the recent information on in
the analysis. We obtain the best fit for to be and the 95%
C.L. allowed range to be . We then develop a method to
carry out a analysis based on SU(3) symmetry using data from and . We also discuss SU(3) breaking effects from model
estimate. We find that present data on can also give some
constraint on although weaker than the earlier method limited by the
present experimental errors. Future improved data will provide more stringent
constraint. Finally we perform a combined fit using data from ,
, , and rare charmless
hadronic B decays. The combined analysis gives for the best
fit value and as the 95% C.L. allowed range. Several
comments on other methods to determine based on SU(3) symmetry are
also provided.Comment: Revised verion with the new experimental data from Belle and Babar
included in the analysis to obtain the global fit for the CP violating phase
gamma. RevTex, 32 pages and 8 figure
Effects of R-parity violation on direct CP violation in B decays and extraction of
In the standard model, direct CP-violating asymmetries for are roughly 2% based on perturbative calculation. Rescattering effects might
enhance it to at most (20-25)%. We show that lepton-number-violating couplings
in supersymmetric models without R-parity are capable of inducing as large as
100% CP asymmetry in this channel. Such effects drastically modify the allowed
range of the CKM parameter arising from the combinations of the
observed charged and neutral B decays in the modes. With a multichannel
analysis in B decays, one can either discover this exciting new physics, or
significantly improve the existing constraints on it.Comment: Latex, 5 pages; minor changes, to appear in Phys Rev Let
Implications of LEP Results for SO(10) Grandunification with Two Intermediate Stages
We consider the breaking of the grand unification group to the
standard model gauge group through several chains containing two intermediate
stages. Using the values of the gauge coupling constants at scale derived
from recent LEP data, we determine the range of their intermediate and
unification scales. In particular, we identify those chains that permit new
gauge structure at relatively low energy .Comment: (LATEX, 9 pages + 3 pages of figures not included) OITS-48
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