Preliminary results of a Mesoscale Model for MARS

The Earth atmospheric circulation has been studied for long time using both GCM (General Circulation Models) and Mesoscale Models or LAM (Limited Area Models). The latter have been widely applied to study local circulation at high resolution and for weather forecasting. In the last years, the Martian atmosphere arouse the interest of the scientific community, both for supporting the landing of Beagle 2 lander and for studying and assessing similarities/differences with the Earth atmosphere. To this aim, GCM have been successfully used. Recently, also Earth LAMs have been changed to simulate the Mars atmosphere, showing good results. The scarce availability of observations did not allowed for validating these models. In this work an attempt is made to validate the newly developed MARS-MM5 against GCM. The model simulation produced using a data base on the basis of output from multi-annual integration of two CGM (see Lewis S. R. et al., J. Geophys. Res., 104 (E10) (1999) 177) is used for statistically evaluates MARS-MM5. The preliminary results suggest that MARS-MM5 is able to correctly reproduce the Mars atmosphere, indeed either the horizontal and the vertical structure of temperature produced by MARS-MM5 is in good agreement with the ones produced by GCM. A few discrepancies are found in the PBL, probably produced by a different parameterization

Shadows of Relic Neutrino Masses and Spectra on Highest Energy GZK Cosmic Rays

The Ultra High Energy (UHE) neutrino scattering onto relic cosmic neutrinos in galactic and local halos offers an unique way to overcome GZK cut-off. The UHE nu secondary of UHE photo-pion decays may escape the GZK cut-off and travel on cosmic distances hitting local light relic neutrinos clustered in dark halos. The Z resonant production and the competitive W^+W^-, ZZ pair production define a characteristic imprint on hadronic consequent UHECR spectra. This imprint keeps memory both of the primary UHE nu spectra as well as of the possible relic neutrino masses values, energy spectra and relic densities. Such an hadronic showering imprint should reflect into spectra morphology of cosmic rays near and above GZK 10^{19}-10^{21}eV cut-off energies. A possible neutrino degenerate masses at eVs or a more complex and significant neutrino mass split below or near Super-Kamiokande \triangle m_{\nu_{SK}}= 0.1 eV masses might be reflected after each corresponding Z peak showering, into new twin unexpected UHECR flux modulation behind GZK energies: E_{p} sim 3(frac{triangle m_{\nu_{SK}}}/m_{\nu}10^{21}),eV. Other shadowsof lightest, nearly massless, neutrinos m_{nu_{2K} simeq 0.001eV simeq kT_{\nu}, their lowest relic temperatures, energies and densities might be also reflected at even higher energies edges near Grand Unification: E_{p} \sim 2.2(m_{\nu_{2K}/E_{\nu}})10^{23}, eV .Comment: 14 pages, 6 Figures,Invited Talk Heidelberg DARK 200

Quark contact interactions at the LHC

Quark contact interactions are an important signal of new physics. We introduce a model in which the presence of a symmetry protects these new interactions from giving large corrections in flavor changing processes at low energies. This minimal model provides the basic set of operators which must be considered to contribute to the high-energy processes. To discuss their experimental signature in jet pairs produced in proton-proton colllisions, we simplify the number of possible operators down to two. We show (for a representative integrated luminosity of 200 pb^-1 at \surd s = 7 TeV) how the presence of two operators significantly modifies the bound on the characteristic energy scale of the contact interactions which is obtained by keeping a single operator.Comment: 8 pages, 2 figure

Electromagnetic Form Factors in the hypercentral CQM

We report on the recent results of the hypercentral Constituent Quark Model (hCQM). The model contains a spin independent three-quark interaction which is inspired by Lattice QCD calculations and reproduces the average energy values of the SU(6) multiplets. The splittings are obtained with a SU(6)-breaking interaction, which can include also an isospin dependent term. Concerning Constituent Quark models, we have shown for the first time that the decreasing of the ratio of the elastic form factors of the proton is due to relativistic effects using relativistic corrections to the e.m. current and boosts. Now the elastic nucleon form factors have been recalculated, using a relativistic version of the hCQM and a relativistic quark current showing a very detailed reproduction of all the four form factor existing data over the complete range of 0-4 $GeV^2$. Futhermore, the model has been used for predictions concerning the electromagnetic transverse and longitudinal transition form factors giving a good description of the medium $Q^2$ behaviour. We show that the discrepancies in the reproduction of the helicity amplitudes at low $Q^2$ are due to pion loops. We have calculated the helicity amplitudes for all the 3 and 4 star resonances opening the possibility of application to the evaluation of cross sections.Comment: 5 pages, 7 figures, Invited talk at the ICTP 4th International Conference on Perspectives in Hadronic Physics, Trieste, Italy, 12-16 May 2003. Accepted by Eur. Phys. J.

Hydrogen Re-Embrittlement of Aerospace grade High Strength Steels

Hydrogen Re-Embrittlement on anodically coated high strength steels is a relevant risk for aerospace structures due to the possibility of hydrogen uptake during the operative life of the components. AISI 4340 and Maraging 250 unnotched tensile specimens were subjected to SSRT in order to evaluate the influence of test environment on time to failure. Fracture surfaces were examined by SEM analysis to evaluate the degree of embrittlement and to correlate it with hydrogen diffusivity of the tested steels

Hydrogen Re-embrittlement of Aerospace Grade High Strength Steels

Hydrogen Re-Embrittlement on anodically coated high strength steels is a relevant risk for aerospace structures due to the possibility of hydrogen uptake during the operative life of the components. AISI 4340 and Maraging 250 unnotched tensile specimens were subjected to SSRT in order to evaluate the influence of test environment on time to failure. Fracture surfaces were examined by SEM analysis to evaluate the degree of embrittlement and to correlate it with hydrogen diffusivity of the tested steels

Electroproduction of nucleon resonances

The unitary isobar model MAID has been extended and used for a partial wave analysis of pion photo- and electroproduction in the resonance region W < 2 GeV. Older data from the world data base and more recent experimental results from Mainz, Bates, Bonn and JLab for Q^2 up to 4.0 (GeV/c)^2 have been analyzed and the Q^2 dependence of the helicity amplitudes have been extracted for a series of four star resonances. We compare single-Q^2 analyses with a superglobal fit in a new parametrization of Maid2003 together with predictions of the hypercentral constituent quark model. As a result we find that the helicity amplitudes and transition form factors of constituent quark models should be compared with the analysis of bare resonances, where the pion cloud contributions have been subtracted.Comment: 6 pages Latex including 5 figures, Invited talk at ICTP 4th International Conference on Perspectives in Hadronic Physics, Trieste, Italy, 12-16 May 200

Failure envelopes of pile groups under inclined and eccentric load

A novel numerical procedure for defining failure envelopes of pile groups under inclined and eccentric load is proposed. The starting point is a closed-form exact solution for interaction diagram of pile groups under combined axial-moment loading recently published in the literature. Failure envelopes in the generalised force space are then derived as an extension of this solution by means of an incremental algorithm. It is shown that the axial load at foundation level has always a beneficial effect on the lateral capacity of the pile group, even if this favourable effect is often neglected in practice. On the contrary, the amount of interaction between the horizontal and moment components of the resultant action at failure is usually very small, with the exception of piles groups with end-bearing piles. Some example applications of the proposed method are provided and a simple, yet reliable procedure for ultimate limit-state analysis of pile groups subjected to inclined and eccentric loads is suggested