419,881 research outputs found
Amplitude equations for a linear wave equation in a weakly curved pipe
We study boundary effects in a linear wave equation with Dirichlet type
conditions in a weakly curved pipe. The coordinates in our pipe are prescribed
by a given small curvature with finite range, while the pipe's cross section
being circular. Based on the straight pipe case a perturbative analysis by
which the boundary value conditions are exactly satisfied is employed. As such
an analysis we decompose the wave equation into a set of ordinary differential
equations perturbatively. We show the conditions when secular terms due to the
curbed boundary appear in the naive peturbative analysis. In eliminating such a
secularity with a singular perturbation method, we derive amplitude equations
and show that the eigenfrequencies in time are shifted due to the curved
boundary.Comment: To appear in J Phys A: Math. Theo
Generation Mixing of Sneutrinos in Heavier Chargino Decay
The heavier chargino decay could yield two charged leptons of different
generations, owing to generation mixing of sneutrinos. We discuss the
possibility of producing and through this process in near future
collider experiments. The analyses are made systematically in the
supersymmetric extension of the standard model without assuming a specific
scenario for the mixing. Production of the heavier chargino is evaluated in
collisions. In the parameter region consistent with nonobservation of
the radiative decay, sizable parts lead to a detectable branching ratio
for the generation-changing decay of the heavier chargino.Comment: 22 pages, Revtex, 7 figures. v2: For the total width of the heavier
chargino, the contribution from the decay into a charged slepton and a
neutirno has been included. The figures (Figs. 2, 3, 4, 5), the equations and
the related descriptions in sections II and III have been revised. Several
references and equations added. v3: Several sentences of section I and V have
been rewritten, conclusions unchange
Centre for Metropolitan History Annual Report 2003-4
The Centre produces a short report each year covering its activities. This is the report for 1 August 2003 - 31 July 2004
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