670 research outputs found
Charged Current Neutrino Cross Section and Tau Energy Loss at Ultra-High Energies
We evaluate both the tau lepton energy loss produced by photonuclear
interactions and the neutrino charged current cross section at ultra-high
energies, relevant to neutrino bounds with Earth-skimming tau neutrinos, using
different theoretical and phenomenological models for nucleon and nucleus
structure functions. The theoretical uncertainty is estimated by taking
different extrapolations of the structure function F2 to very low values of x,
in the low and moderate Q2 range for the tau lepton interaction and at high Q2
for the neutrino-nucleus inelastic cross section. It is at these extremely low
values of x where nuclear shadowing and parton saturation effects are unknown
and could be stronger than usually considered. For tau and neutrino energies
E=10^9 GeV we find uncertainties of a factor 4 for the tau energy loss and of a
factor 2 for the charged current neutrino-nucleus cross section.Comment: 20 pages and 11 figure
Charged lepton-nucleus inelastic scattering at high energies
The composite model is constructed to describe inelastic high-energy
scattering of muons and taus in standard rock. It involves photonuclear
interactions at low as well as moderate processes and the deep
inelastic scattering (DIS). In the DIS region the neutral current contribution
is taken into consideration. Approximation formulas both for the muons and tau
energy loss in standard rock are presented for wide energy range.Comment: 5 pages, 4 figures. Presented at 19th European Cosmic Ray Symposium
(ECRS 2004), Florence, Italy, 30 Aug - 3 Sep 2004. Submitted to
Int.J.Mod.Phys.
The indication for K geo-antineutrino flux with Borexino phase-III data
We provide the indication of high flux of K geo-antineutrino and
geo-neutrino (K-geo-()) with Borexino Phase III data.
This result was obtained by introducing a new source of single events, namely
K-geo-() scattering on electrons, in multivariate fit
analysis of Borexino Phase III data. Simultaneously we obtained the count rates
of events from Be, and CNO solar neutrinos. These count rates are
consistent with the prediction of the Low metallicity Sun model SSM B16-AGSS09.
MC pseudo-experiments showed that the case of High metallicity Sun and absence
of K-geo-() can not imitate the result of multivariate
fit analysis of Borexino Phase III data with introducing
K-geo-() events. We also provide arguments for the high
abundance of potassium in the Earth.Comment: 17 pages, 7 figures. arXiv admin note: substantial text overlap with
arXiv:2202.08531 We have corrected and expanded the section on radiogenic
heat of the Earth. Improved the quality of drawings. The results of the study
are partially described in L. B. Bezrukov, I. S. Karpikov, A. K. Mezhokh, S.
V. Silaeva and V. V. Sinev, Bulletin of the Russian Federation. 87 (7), 972
(2023
Relativistic Magnetic Monopole Flux Constraints from RICE
We report an upper limit on the flux of relativistic monopoles based on the
non-observation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE)
at the South Pole. We obtain a 95% C.L. limit of order 10^{-18}/(cm^2-s-sr) for
intermediate mass monopoles of 10^7<gamma<10^{12} at the anticipated energy
E=10^{16} GeV. This bound is over an order of magnitude stronger than all
previously published experimental limits for this range of boost parameters
gamma, and exceeds two orders of magnitude improvement over most of the range.
We review the physics of radio detection, describe a Monte Carlo simulation
including continuous and stochastic energy losses, and compare to previous
experimental limits.Comment: 16 pages, 6 figures. Accepted for publication in Phys. Rev. D. Minor
revisions, including expanded discussion of monopole energy uncertaint
Use of singular classical solutions for calculation of multiparticle cross sections in field theory
A method of reducing the problem of the calculation of tree multiparticle
cross sections in theory to the solution of a singular classical
Euclidean boundary value problem is introduced. The solutions are obtained
numerically in terms of the decomposition in spherical harmonics, and the
corresponding estimates of the tree cross sections at arbitrary energies are
found. Numerical analysis agrees with analytical results obtained earlier in
the limiting cases of large and small energies.Comment: LaTeX, 18 pages, 3 postscript figure
Neutron production by cosmic-ray muons at shallow depth
The yield of neutrons produced by cosmic ray muons at a shallow depth of 32
meters of water equivalent has been measured. The Palo Verde neutrino detector,
containing 11.3 tons of Gd loaded liquid scintillator and 3.5 tons of acrylic
served as a target. The rate of one and two neutron captures was determined.
Modeling the neutron capture efficiency allowed us to deduce the total yield of
neutrons neutrons per muon
and g/cm. This yield is consistent with previous measurements at similar
depths.Comment: 12 pages, 3 figure
Muon-Induced Background Study for Underground Laboratories
We provide a comprehensive study of the cosmic-ray muon flux and induced
activity as a function of overburden along with a convenient parameterization
of the salient fluxes and differential distributions for a suite of underground
laboratories ranging in depth from 1 to 8 km.w.e.. Particular attention
is given to the muon-induced fast neutron activity for the underground sites
and we develop a Depth-Sensitivity-Relation to characterize the effect of such
background in experiments searching for WIMP dark matter and neutrinoless
double beta decay.Comment: 18 pages, 28 figure
Graph Partitioning Induced Phase Transitions
We study the percolation properties of graph partitioning on random regular
graphs with N vertices of degree . Optimal graph partitioning is directly
related to optimal attack and immunization of complex networks. We find that
for any partitioning process (even if non-optimal) that partitions the graph
into equal sized connected components (clusters), the system undergoes a
percolation phase transition at where is the fraction of
edges removed to partition the graph. For optimal partitioning, at the
percolation threshold, we find where is the size of the
clusters and where is their diameter. Additionally,
we find that undergoes multiple non-percolation transitions for
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