2,512 research outputs found
The cosmic ray primary composition in the ?knee? region through the EAS electromagnetic and muon measurements at EAS-TOP
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Generalized CMB initial conditions with pre-equality magnetic fields
The most general initial conditions of CMB anisotropies, compatible with the
presence of pre-equality magnetic fields, are derived. When the plasma is
composed by photons, baryons, electrons, CDM particles and neutrinos, the
initial data of the truncated Einstein-Boltzmann hierarchy contemplate one
magnetized adiabatic mode and four (magnetized) non-adiabatic modes. After
obtaining the analytical form of the various solutions, the Einstein-Boltzmann
hierarchy is numerically integrated for the corresponding sets of initial data.
The TT, TE and EE angular power spectra are illustrated and discussed for the
magnetized generalization of the CDM-radiation mode, of the baryon-radiation
mode and of the non-adiabatic mode of the neutrino sector. Mixtures of initial
conditions are examined by requiring that the magnetized adiabatic mode
dominates over the remaining non-adiabatic contributions. In the latter case,
possible degeneracies between complementary sets of initial data might be
avoided through the combined analysis of the TT, TE and EE angular power
spectra at high multipoles (i.e. ).Comment: 28 pages, 24 included figures in eps styl
Cosmic rays measurements around the knee of the primary spectrum
In this contribution I will summarize and discuss some recent results about the study of the knee of the cosmic rays energy spectrum, indicating that this spectral feature is originated by astrophysical processes. I will then discuss the current experimental efforts that are giving further insights. Latest all particle spectrum measurements have shown that, between 1016eV and 1018eV, the spectrum cannot be described by a single slope power law: an hardening around 1016eV and a steepeningaround 1017eV have been observed. This last feature has been attributed, by the KASCADE-Grande experiment, to the heavy primary component, confirming that the energy of the elemental spectra change of slope increase with the mass of the primary particle
Ultra-Transparent Antarctic Ice as a Supernova Detector
We have simulated the response of a high energy neutrino telescope in deep
Antarctic ice to the stream of low energy neutrinos produced by a supernova.
The passage of a large flux of MeV-energy neutrinos during a period of seconds
will be detected as an excess of single counting rates in all individual
optical modules. We update here a previous estimate of the performance of such
an instrument taking into account the recent discovery of absorption lengths of
several hundred meters for near-UV photons in natural deep ice. The existing
AMANDA detector can, even by the most conservative estimates, act as a galactic
supernova watch.Comment: 9 pages, Revtex file, no figures. Postscript file also available from
http://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-888.ps.Z or from
ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-888.ps.
Study of the effect of neutrino oscillation on the supernova neutrino signal with the LVD detector
We present an update of our previous study (astro-ph/0112312) on how
oscillations affect the signal from a supernova core collapse observed in the
LVD detector at LNGS. In this paper we use a recent, more precise determination
of the cross section (astro-ph/0302055) to calculate the expected number of
inverse beta decay events, we introduce in the simulation also the -{\rm
Fe} interactions, we include the Earth matter effects and, finally, we study
also the inverted mass hierarchy case.Comment: 4 pages, 4 figures, to appear in the Proceedings of ICRC 200
Ten-year results of a three arms prospective cohort study on implants in periodontally compromised patients. Part 2: clinical results
Predicting Proton-Air Cross Sections at sqrt s ~30 TeV, using Accelerator and Cosmic Ray Data
We use the high energy predictions of a QCD-inspired parameterization of all
accelerator data on forward proton-proton and antiproton-proton scattering
amplitudes, along with Glauber theory, to predict proton-air cross sections at
energies near \sqrt s \approx 30 TeV. The parameterization of the proton-proton
cross section incorporates analyticity and unitarity, and demands that the
asymptotic proton is a black disk of soft partons. By comparing with the p-air
cosmic ray measurements, our analysis results in a constraint on the inclusive
particle production cross section.Comment: 9 pages, Revtex, uses epsfig.sty, 5 postscript figures. Minor text
revisions. Systematic errors in k included, procedure for extracting k
clarified. Previously undefined symbols now define
Long-term results of a three arms prospective cohort study on implants in periodontally compromised patients: 10-year data around sandblasted and acid-etched (SLA) surface
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