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
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
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 for very large in the two Higgs doublet model with UHE-neutrinos
We study the deep inelastic process
(with 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 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 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
We consider supersymmetric models where the scale of supersymmetry breaking
lies between 5 GeV and 5 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
km 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
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
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 as the next lightest supersymmetric particle. In this
paper we study the possibility of detecting 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 . 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
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
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
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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