132 research outputs found

    The primary composition beyond 10 to the 5th power GeV as deduced from high energy hadrons and muons in air showers

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    Data obtained from a large set of air shower simulation calculations with use of highly refined hadronic interaction and shower simulation model are presented, in an attempt to solve the problem of primary chemical composition beyond 100,000 GeV total energy. It is rated that high energy hadrons in air showers offer a rather unique primary mass signature and show that the interpretation of high energy muon data is much more ambiguous. Predictions are compared with experimental data

    High Energy Neutrino Flashes from Far-Ultraviolet and X-ray Flares in Gamma-Ray Bursts

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    The recent observations of bright optical and x-ray flares by the Swift satellite suggest these are produced by the late activities of the central engine. We study the neutrino emission from far-ultraviolet and x-ray flares under the late internal shock model. We show that the efficiency of pion production in the highest energy is comparable to or higher than the unity, and the contribution from such neutrino flashes to a diffuse very high energy neutrino background can be larger than that of prompt bursts if the total baryonic energy input into flares is comparable to the radiated energy of prompt bursts. These signals may be detected by IceCube and are very important because they have possibilities to probe the nature of flares (the baryon loading, the photon field, the magnetic field and so on).Comment: 4 pages, 3 figures, version published in PR

    Charged Higgs boson contribution to ντNτX\nu_{\tau} {\cal N} \to \tau^- X for very large tanβ\tan\beta in the two Higgs doublet model with UHE-neutrinos

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    We study the deep inelastic process ντ+Nτ+X\nu_{\tau} + {\cal N} \to \tau^{-} + X (with N(n+p)/2{\cal N} \equiv (n+p)/2 an isoscalar nucleon), in the context of the two Higgs doublet model {\it type two} (2HDM(II)). In particular, we discuss the contribution to the total cross section of diagrams, in which a charged Higgs boson is exchanged. We show that for large values of tanβ\tan\beta such contribution for an inclusive dispersion generated through the collision of an ultrahigh energy tau-neutrino on a target nucleon can reach up to 57% of the value of the contribution of the W+W^+ exchange diagrams (i.e. can reach up to 57% of the standard model (SM) prediction) and could permit to distinguish between the SM and the 2HDM(II) predictions at the Pierre Auger Observatory.Comment: 10 pages, 5 figure

    Neutrino Telescopes as a Direct Probe of Supersymmetry Breaking

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    We consider supersymmetric models where the scale of supersymmetry breaking lies between 5 ×106\times 10^6 GeV and 5 ×108\times 10^8 GeV. In this class of theories, which includes models of gauge mediated supersymmetry breaking, the lightest supersymmetric particle is the gravitino. The next to lightest supersymmetric particle is typically a long lived charged slepton with a lifetime between a microsecond and a second, depending on its mass. Collisions of high energy neutrinos with nucleons in the earth can result in the production of a pair of these sleptons. Their very high boost means they typically decay outside the earth. We investigate the production of these particles by the diffuse flux of high energy neutrinos, and the potential for their observation in large ice or water Cerenkov detectors. The relatively small cross-section for the production of supersymmetric particles is partially compensated for by the very long range of heavy particles. The signal in the detector consists of two parallel charged tracks emerging from the earth about 100 meters apart, with very little background. A detailed calculation using the Waxman-Bahcall limit on the neutrino flux and realistic spectra shows that km3^3 experiments could see as many as 4 events a year. We conclude that neutrino telescopes will complement collider searches in the determination of the supersymmetry breaking scale, and may even give the first evidence for supersymmetry at the weak scale.Comment: 4 pages, 3 figure

    From dense-dilute duality to self duality in high energy evolution

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    I describe recent work on inclusion of Pomeron loops in the high energy evolution. In particular I show that the complete eikonal high energy evolution kernel must be selfdual.Comment: Talk given at DIS05, April 2005, Madiso

    Phenomenology of quintessino dark matter -- Production of NLSP particles

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    In the model of quintessino as dark matter particle, the dark matter and dark energy are unified in one superfield, where the dynamics of the Quintessence drives the Universe acceleration and its superpartner, quintessino, makes up the dark matter of the Universe. This scenario predicts the existence of long lived τ~\tilde{\tau} as the next lightest supersymmetric particle. In this paper we study the possibility of detecting τ~\tilde{\tau} produced by the high energy cosmic neutrinos interacting with the earth matter. By a detailed calculation we find that the event rate is one to several hundred per year at a detector with effective area of 1km21 km^2. The study in this paper can be also applied for models of gravitino or axino dark matter particles.Comment: 16 pages, 5 figures, a new section about NLSP stau is added, references adde

    Possible High-energy neutrinos from the cosmic accelerator RXJ1713.7-3946

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    The observation of TeV-gamma rays of neutral pion origin from the supernova remnant RX J1713.7-3946 might have revealed the first specific site where protons are accelerated to energies typical of the main component of the cosmic rays. In this letter we calculate the high-energy neutrino flux associated with this source to be at least 40 muon-type neutrinos per kilometer-squared per year. We perform the same calculations for other known sources of TeV-gamma rays and show how neutrino observations can establish whether the TeV-gamma rays emitted by blazars and supernova remnants are the decay products of neutral pions and thus unequivocally establish the sources as cosmic accelerators.Comment: Replaced with version published in Astrophys.

    Muon Simulations for Super-Kamiokande, KamLAND and CHOOZ

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    Muon backgrounds at Super-Kamiokande, KamLAND and CHOOZ are calculated using MUSIC. A modified version of the Gaisser sea level muon distribution and a well-tested Monte Carlo integration method are introduced. Average muon energy, flux and rate are tabulated. Plots of average energy and angular distributions are given. Implications on muon tracker design for future experiments are discussed.Comment: Revtex4 33 pages, 16 figures and 4 table

    Radiation in Lorentz violating electrodynamics

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    Synchrotron radiation is analyzed in the classical effective Lorentz invariance violating model of Myers-Pospelov. Within the full far-field approximation we compute the electric and magnetic fields, the angular distribution of the power spectrum and the total emitted power in the m-th harmonic, as well as the polarization. We find the appearance of rather unexpected and large amplifying factors, which go together with the otherwise negligible naive expansion parameter. This opens up the possibility of further exploring Lorentz invariance violations by synchrotron radiation measurements in astrophysical sources where these amplifying factors are important.Comment: Presented at the Second Mexican Meeting on Theoretical and Experimental Physics, El Colegio Nacional, Mexico City, 6-10 September 200
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