19,643 research outputs found
Full QCD on APE100 Machines
We present the first tests and results from a study of QCD with two flavours
of dynamical Wilson fermions using the Hybrid Monte Carlo Algorithm (HMCA) on
APE100 machines.Comment: 23 pages, LaTeX, 13 PS figures not include
Scattering for nonlinear Schrodinger equation under partial harmonic confinement
We consider the nonlinear Schrodinger equation under a partial quadratic
confinement. We show that the global dispersion corresponding to the
direction(s) with no potential is enough to prove global in time Strichartz
estimates, from which we infer the existence of wave operators thanks to
suitable vector-fields. Conversely, given an initial Cauchy datum, the solution
is global in time and asymptotically free, provided that confinement affects
one spatial direction only. This stems from anisotropic Morawetz estimates,
involving a marginal of the position density.Comment: 26 pages. Some typos fixed, especially in Section
Solving the solar neutrino problem with kamLAND and BOREXINO
We analyze the expected signals of two future neutrino experiments, kamLAND
and BOREXINO. We show that with just these experiments, we will hopefully be
able to determine which of the existing solutions to the solar neutrino problem
is the real solution. We also analyze existing solar neutrino data and
determine the best-fit points in the oscillation-parameter space finding that
with the inclusion of SNO-charged current, the global-rates analysis gives a
favored LMA solution with a goodness of fit (g.o.f) of just 32.63%, whereas the
g.o.f of the SMA solution is 9.83%. Nonetheless, maximal and quasi-maximal
mixing is not favored. If we include the Superkamiokande spectrum in our \chi^2
analysis, we obtain a LMA solution with a g.o.f. of 84.38%.Comment: 4 pages, 5 figures, Talk given at 37th Rencontres de Moriond on
Electroweak Interactions and Unified Theories, Les Arcs, France, 9-16 Mar
200
After Sno and Before Kamland: Present and Future of Solar and Reactor Neutrino Physics
We present a short review of the existing evidence in favor of neutrino mass
and neutrino oscillations which come from different kinds of experiments. We
focus our attention in particular on solar neutrinos, presenting a review of
some recent analysis of all available neutrino oscillation evidence in Solar
experiments including the recent and data. We present in detail
the power of the reactor experiment KamLAND for discriminating existing
solutions to the SNP and giving accurate information on neutrino masses and
mixing angles.Comment: Expanded version of the contribution to appear in the Proceedings of
''Third Tropical Workshop on Particle Physics and Cosmology: Neutrinos,
Branes and Cosmology (Puerto Rico, August 2002)'
The solar neutrino puzzle: present situation and future scenarios
We present a short review of the existing evidence in favor of neutrino mass
and neutrino oscillations which come from different kinds of experiments. We
focus our attention in particular on solar neutrinos, presenting a global
updated phenomenological analysis of all the available data and we comment on
different possible future scenarios.Comment: 22 pp. Expanded version of the contribution to appear in the
Proceedings of ``Les Rencontres de Physique de la Vallee d'Aoste'', February
200
Managing standards compliance
Software engineering standards determine practices that `compliant' software processes shall follow. standards generally define practices in terms of constraints that must hold for documents. The document types identified by standards include typical development products, such as user requirements, and also process-oriented documents, such as progress reviews and management reports. The degree of standards compliance can be established by checking these documents against the constraints. It is neither practical nor desirable to enforce compliance at all points in the development process. Thus compliance must be managed rather than imposed.
We outline a model of standards and compliance and illustrate it with some examples. We give a brief account of the notations we have developed tosupport the use of the model and describe a support environment we have constructed. We contrast our approach to related work and discuss the broader implications of our findings for process modelling and the management of inconsistent information
Extinction properties of the X-ray bright/optically faint afterglow of GRB 020405
We present an optical-to-X-ray spectral analysis of the afterglow of GRB
020405. The optical spectral energy distribution not corrected for the
extragalactic extinction is significantly below the X-ray extrapolation of the
single powerlaw spectral model suggested by multiwavelength studies. We
investigate whether considerable extinction could explain the observed spectral
``mismatch'' by testing several types of extinction curves. For the first time
we test extinction curves computed with time-dependent numerical simulations of
dust grains destruction by the burst radiation. We find that an extinction law
weakly depen dent on wavelength can reconcile the unabsorbed optical and X-ray
data with the expected synchrotron spectrum. A gray extinction law can be
provided by a dust grain size distribution biased toward large grains.Comment: 6 pages, 5 figures, accepted for publication on A&
Organizational Change, Skill Formation, Human Capital Measurement: Evidence From Italian Manufacturing Firms
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