The Invisible Higgs Decay Width in the Add Model at the LHC

Assuming flat universal extra dimensions, we demonstrate that for a light Higgs boson the process $pp\to W^*W^* +X \to Higgs,graviscalars +X \to invisible+X$ will be observable at the $5 \sigma$ level at the LHC for the portion of the Higgs-graviscalar mixing ($\xi$) and effective Planck mass ($M_D$) parameter space where channels relying on visible Higgs decays fail to achieve a $5 \sigma$ signal. Further, we show that even for very modest values of $\xi$ the invisible decay signal probes to higher $M_D$ than does the ($\xi$-independent) jets/\gam + missing energy signal from graviton radiation. We also discuss various effects, such as Higgs decay to two graviscalars, that could become important when $m_h/M_D$ is of order 1.Comment: 6 pages, 2 figures, To appear in the Proceedings of the Les Houches Workshop 2003: ``Physics at TeV Colliders'', ed. F. Boudjem

Playing with fermion couplings in Higgsless models

We discuss the fermion couplings in a four dimensional SU(2) linear moose model by allowing for direct couplings between the left-handed fermions on the boundary and the gauge fields in the internal sites. This is realized by means of a product of non linear $\sigma$-model scalar fields which, in the continuum limit, is equivalent to a Wilson line. The effect of these new non local couplings is a contribution to the $\epsilon_3$ parameter which can be of opposite sign with respect to the one coming from the gauge fields along the string. Therefore, with some fine tuning, it is possible to satisfy the constraints from the electroweak data.Comment: Latex file, 20 pages, 4 eps figure

Comparing electroweak data with a decoupling model

Present data, both from direct Higgs search and from analysis of electroweak data, are starting to become rather restrictive on the possible values for the mass of the standard model Higgs. We discuss a new physics scenario based on a model with decoupling (both in a linear and in a non linear version) showing how it allows for an excellent fit to the present values of the $\epsilon$ parameters and how it widens the allowed ranges for the Higgs mass (thought as elementary in the linear version, or as composite in the non linear one).Comment: 10 pages, 3 Figures Late

An Extension of the Electroweak Model with Decoupling at Low Energy

We present a renormalizable model of electroweak interactions containing an extra $SU(2)'_L\otimes SU(2)'_R$ symmetry. The masses of the corresponding gauge bosons and of the associated Higgs particles can be made heavy by tuning a convenient vacuum expectation value. According to the way in which the heavy mass limit is taken we obtain a previously considered non-linear model (degenerate BESS) which, in this limit, decouples giving rise to the Higgsless Standard Model (SM). Otherwise we can get a model which decouples giving the full SM. In this paper we argue that in the second limit the decoupling holds true also at the level of radiative corrections. Therefore the model discussed here is not distinguishable from the SM at low energy. Of course the two models differ deeply at higher energies.Comment: 13+2 pages, LaTe

MULTISCALE DOCUMENTATION AND MONITORING OF L'AQUILA HISTORICALCENTRE USING UAV PHOTOGRAMMETRY

Nowadays geomatic techniques can guarantee not only a precise and accurate survey for the documentation of our historical heritage but also a solution to monitor its behaviour over time after, for example, a catastrophic event (earthquakes, landslides, ecc). Europe is trying to move towards harmonized actions to store information on cultural heritage (MIBAC with the ICCS forms, English heritage with the MIDAS scheme, etc) but it would be important to provide standardized methods in order to perform measuring operations to collect certified metric data. The final result could be a database to support the entire management of the cultural heritage and also a checklist of "what to do" and "when to do it". The wide range of geomatic techniques provides many solutions to acquire, to organize and to manage data at a multiscale level: high resolution satellite images can provide information in a short time during the "early emergency" while UAV photogrammetry and laser scanning can provide digital high resolution 3D models of buildings, ortophotos of roofs and facades and so on. This paper presents some multiscale survey case studies using UAV photogrammetry: from a minor historical village (Aielli) to the centre of L'Aquila (Santa Maria di Collemaggio Church) from the post-emergency to now. This choice has been taken not only to present how geomatics is an effective science for modelling but also to present a complete and reliable way to perform conservation and/or restoration through precise monitoring techniques, as shown in the third case study

Vortex and half-vortex dynamics in a spinor quantum fluid of interacting polaritons

Spinorial or multi-component Bose-Einstein condensates may sustain fractional quanta of circulation, vorticant topological excitations with half integer windings of phase and polarization. Matter-light quantum fluids, such as microcavity polaritons, represent a unique test bed for realising strongly interacting and out-of-equilibrium condensates. The direct access to the phase of their wavefunction enables us to pursue the quest of whether half vortices ---rather than full integer vortices--- are the fundamental topological excitations of a spinor polariton fluid. Here, we are able to directly generate by resonant pulsed excitations, a polariton fluid carrying either the half or full vortex states as initial condition, and to follow their coherent evolution using ultrafast holography. Surprisingly we observe a rich phenomenology that shows a stable evolution of a phase singularity in a single component as well as in the full vortex state, spiraling, splitting and branching of the initial cores under different regimes and the proliferation of many vortex anti-vortex pairs in self generated circular ripples. This allows us to devise the interplay of nonlinearity and sample disorder in shaping the fluid and driving the phase singularities dynamicsComment: New version complete with revised modelization, discussion and added material. 8 pages, 7 figures. Supplementary videos: https://drive.google.com/folderview?id=0B0QCllnLqdyBfmc2ai0yVF9fa2g2VnZodGUwemVkLThBb3BoOVRKRDJMS2dUdjlZdkRTQk