Ultra High Energy Neutrino-Relic Neutrino Interactions In Dark Halos to Solve Infrared-Tev And GZK Cut-Off

Ultra High Energy Neutrino scattering on Relic Light Neutrinos in Dark Galactic or Local Group lead to Z and WW,ZZ showering: the nucleon component of the shower may overcome the GZK cut-off while the electro-magnetic tail at TeVs up to EeVs energy may solve the Infrared-TeV cut-off in a natural way. Different Gamma TeV puzzles may find a solution within this scenario: new predictions on UHECR spectra in future data are derived.Comment: 4 pages, 3 figures, 2 tables ICRC 2001 HE 3.6 Dark Matter - German

Why Tau First?

Electron neutrino has been the first neutral lepton to be foreseen and discovered last century. The un-ordered muon and its neutrino arose later by cosmic rays. The tau discover, the heaviest, the most unstable charged lepton, was found surprisingly on 1975. Its neutrino was hardly revealed just on 2000. So why High Energy Neutrino Astronomy should rise first via tau neutrino, the last, the most rare one? The reasons are based on a chain of three favorable coincidences found last decade: the neutrino masses and their flavor mixing, the UHECR opacity on Cosmic Black Body (GZK cut off on BBR), the amplified tau air-shower decaying in flight. Indeed guaranteed UHE GZK tau neutrinos, feed by muon mixing, while skimming the Earth might lead to boosted UHE tau, mostly horizontal ones. These UHE lepton decay in flight are spread, amplified, noise free Air-Shower: a huge event for an unique particle. To be observed soon: within Auger sky, in present decade. Its discover may sign of the first tau appearance.Comment: 8 pages, 4 figure

Upward Tau Air Showers from Earth

We estimate the rate of observable Horizontal and Upward Tau Air-Showers (HORTAUs, UPTAUS) considering both the Earth opacity and the finite size of the terrestrial atmosphere. We calculate the effective target volumes and masses for Tau air-showers emerging from the Earth. The resulting model-independent masses for satellite experiments such as EUSO may encompass at E_nu_tau = 10^19 eV a very large volume, V= 1020 km^3. Adopting simple power law neutrino fluxes, E^-2 and E^-1, calibrated to GZK-like and Z-Burst-like models, we estimate that at E= 10^19 eV nearly half a dozen horizontal shower events should be detected by EUSO in three years of data collection by the "guaranteed" GZK neutrino flux. We also find that the equivalent mass for an Earth outer layer made of rock is dominant compared to the water, contrary to simplified all-rock/all-water Earth models and previous Montecarlo simulations. Therefore we expect an enhancement of neutrino detection along continental shelves nearby the highest mountain chains, also given the better geometrical acceptance for Earth skimming neutrinos. The Auger experiment might reveal such a signature at E_nu= 10^{18} eV (with 26 events in 3 yr) towards the Andes, if the angular resolution at the horizon (both in azimuth and zenith) would reach an accuracy of nearly one degree needed to disentangle tau air showers from common UHECR. The number of events increases at lower energies; therefore we suggest an extension of the EUSO and Auger sensitivity down to (or even below) E_nu = 10^19 eV and E_nu = 10^18 eV respectively.Comment: New version resubmitted to ApJ on the 6th April 2004; 55 Pages,20 figures, major changes following referee reques

Directional depletion interactions in shaped particles

Entropic forces in colloidal suspensions and in polymer-colloid systems are of long-standing and continuing interest. Experiments show how entropic forces can be used to control the self-assembly of colloidal particles. Significant advances in colloidal synthesis made in the past two decades have enabled the preparation of high quality nano-particles with well-controlled sizes, shapes, and compositions, indicating that such particles can be utilized as "artificial atoms" to build new materials. To elucidate the effects of the shape of particles upon the magnitude of entropic interaction, we analyse the entropic interactions of two cut-spheres. We show that the solvent induces a strong directional depletion attraction among flat faces of the cut-spheres. Such an effect highlights the possibility of using the shape of particles to control directionality and strength of interaction.Comment: 6 pages, 4 figure

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