99,980 research outputs found
The Capabilities of Monochromatic EC Neutrino Beams with the SPS Upgrade
The goal for future neutrino facilities is the determination of the U(e3)
mixing and CP violation in neutrino oscillations. This will require precision
experiments with a very intense neutrino source and energy control. With this
objective in mind, the creation of monochromatic neutrino beams from the
electron capture decay of boosted ions by the SPS of CERN has been proposed. We
discuss the capabilities of such a facility as a function of the energy of the
boost and the baseline for the detector. We conclude that the SPS upgrade to
1000 GeV is crucial to reach a better sensitivity to CP violation iff it is
accompanied by a longer baseline. We compare the physics potential for two
different configurations: I) and (maximum achievable
at present SPS) to Frejus; II) and (maximum
achievable at upgraded SPS) to Canfranc. The main conclusion is that, whereas
the gain in the determination of U(e3) is rather modest, setup II provides much
better sensitivity to CP violation.Comment: 4 pages, 5 figures, To appear in the proceedings of International
Europhysics Conference on High Energy Physics (EPS-HEP2007), Manchester,
England, 19-25 July 200
A large displacement structural analysis of a pipeline subjected to gravity and bouyancy forces
p. 489-508A nonlinear analysis of an elastic tube subjected to gravity forces and buoyancy pressure is carried out. An update lagrangian formulation is used. The structural analysis efficiency in terms of computer time and accuracy, has been improved when load stiffness matrices have been introduced. In this way the follower forces characteristics such as their intensity and direction changes can be well represented. A sensitivity study of different involved variables on the final deformed pipeline shape is carried out.Mosquera, JC.; Garcia-Palacios, J.; Samartin, A. (2009). A large displacement structural analysis of a pipeline subjected to gravity and bouyancy forces. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/654
Optimal boundary geometry in an elasticity problem: a systematic adjoint approach
p. 509-524In different problems of Elasticity the definition of the optimal geometry of the boundary, according to a given objective function, is an issue of great interest. Finding the shape of a hole in the middle of a plate subjected to an arbitrary loading such that the stresses along the hole minimizes some functional or the optimal middle curved concrete vault for a tunnel along which a uniform minimum compression are two typical examples. In these two examples the objective functional depends on the geometry of the boundary that can be either a curve (in case of 2D problems) or a surface boundary (in 3D problems). Typically, optimization is achieved by means of an iterative process which requires the computation of gradients of the objective function with respect to design variables.
Gradients can by computed in a variety of ways, although adjoint methods either continuous or discrete ones are the more efficient ones when they are applied in different technical branches. In this paper the adjoint continuous method is introduced in a systematic way to this type of problems and an illustrative simple example, namely the finding of an optimal shape tunnel vault immersed in a linearly elastic terrain, is presented.Garcia-Palacios, J.; Castro, C.; Samartin, A. (2009). Optimal boundary geometry in an elasticity problem: a systematic adjoint approach. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/654
Higher-order supersymmetric quantum mechanics
We review the higher-order supersymmetric quantum mechanics (H-SUSY QM),
which involves differential intertwining operators of order greater than one.
The iterations of first-order SUSY transformations are used to derive in a
simple way the higher-order case. The second order technique is addressed
directly, and through this approach unexpected possibilities for designing
spectra are uncovered. The formalism is applied to the harmonic oscillator: the
corresponding H-SUSY partner Hamiltonians are ruled by polynomial Heisenberg
algebras which allow a straight construction of the coherent states.Comment: 42 pages, 12 eps figure
Fe I line shifts in the optical spectrum of the Sun
New improvements in the measurement of both the optical solar spectrum and
laboratory wavelengths for lines of neutral iron are combined to extract
central wavelength shifts for 1446 lines observed in the Sun. This provides the
largest available database of accurate solar wavelengths useful as a reference
for comparison with other solar-type stars. It is shown how the velocity shifts
correlate with line strength, approaching a constant value, close to zero, for
lines with equivalent widths larger than 200 mA.Comment: Latex file (5 pages), uses l-aa.sty and epsfig.sty (included); 3
Postscript figures, 1 ASCII table, accepted for publication in Astronomy and
Astrophysics Supplement Serie
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