240,946 research outputs found
The Observation of Up-going Charged Particles Produced by High Energy Muons in Underground Detectors
An experimental study of the production of up-going charged particles in
inelastic interactions of down-going underground muons is reported, using data
obtained from the MACRO detector at the Gran Sasso Laboratory. In a sample of
12.2 10^6 single muons, corresponding to a detector livetime of 1.55 y, 243
events are observed having an up-going particle associated with a down-going
muon. These events are analysed to determine the range and emission angle
distributions of the up-going particle, corrected for detection and
reconstruction efficiency. Measurements of the muon neutrino flux by
underground detectors are often based on the observation of through-going and
stopping muons produced in interactions in the rock below the
detector. Up-going particles produced by an undetected down-going muon are a
potential background source in these measurements. The implications of this
background for neutrino studies using MACRO are discussed.Comment: 18 pages, 9 figures. Accepted by Astrop. Physic
First 10 kg of Naked Germanium Detectors in Liquid Nitrogen installed in the GENIUS-Test-Facility
The first four naked high purity Germanium detectors were installed
successfully in liquid nitrogen in the GENIUS-Test-Facility (GENIUS-TF) in the
GRAN SASSO Underground Laboratory on May 5, 2003. This is the first time ever
that this novel technique aiming at extreme background reduction in search for
rare decays is going to be tested underground. First operational parameters are
presented.Comment: 10 pages, latex2e, 8 figures, Was presented (first presentation) at
4th International Conference on Particle Physics Beyond the Standard Model
BEYOND'2003, Castle Ringberg, Germany, 9-14 June, 2003, Springer, Heidelberg,
Germany, 2003, edited by H.V. Klapdor-Kleingrothau
Low-Background gamma counting at the Kimballton Underground Research Facility
The next generation of low-background physics experiments will require the
use of materials with unprecedented radio-purity. A gamma-counting facility at
the Kimballton Underground Research Facility (KURF) has been commissioned to
perform initial screening of materials for radioactivity primarily from
nuclides in the 238U and 232Th decay chains, 40K and cosmic-ray induced
isotopes. The facility consists of two commercial low-background high purity
germanium (HPGe) detectors. A continuum background reduction better than a
factor of 10 was achieved by going underground. This paper describes the
facility, detector systems, analysis techniques and selected assay results.Comment: 7 pages, 7 figures. Submitted to NIM
Ultra-stable performance of an underground-based laser interferometer observatory for gravitational waves
In order to detect the rare astrophysical events that generate gravitational
wave (GW) radiation, sufficient stability is required for GW antennas to allow
long-term observation. In practice, seismic excitation is one of the most
common disturbances effecting stable operation of suspended-mirror laser
interferometers. A straightforward means to allow more stable operation is
therefore to locate the antenna, the ``observatory'', at a ``quiet'' site. A
laser interferometer gravitational wave antenna with a baseline length of 20m
(LISM) was developed at a site 1000m underground, near Kamioka, Japan. This
project was a unique demonstration of a prototype laser interferometer for
gravitational wave observation located underground. The extremely stable
environment is the prime motivation for going underground. In this paper, the
demonstrated ultra-stable operation of the interferometer and a well-maintained
antenna sensitivity are reported.Comment: 8 pages, to appear on PR
Multiple Muons From Neutrino-Initiated Multi-W(Z) Production
Current underground detectors can search for multiple muons from multi-W(Z)
production initiated by ultrahigh energy neutrinos from active galactic nuclei.
O(b) cross sections give rise to downward going muon bundles whose
features differ from those of atmospheric muon bundles.Comment: (presented at 23rd Int. Cosmic Ray Conf., July 21-30 1993, Calgary,
Canada), 5 pages (LaTeX) + 2 uuencoded PostScript figures, UCLA/93/TEP/3
Signatures of cosmic tau-neutrinos
The importance and signatures of cosmic tau--(anti)neutrinos have been
studied for upward-- and downward--going and hadronic shower
event rates relevant for present and future underground water or ice detectors,
utilizing the unique and reliable ultrasmall-- predictions of the dynamical
(radiative) parton model. The upward--going event rates
calculated just from cosmic fluxes are sizeably
enhanced by taking into account cosmic fluxes
and their associated fluxes as well. The coupled transport
equations for the upward--going flux traversing
the Earth imply an enhancement of the attenuated and regenerated
flux typically around GeV with respect
to the initial cosmic flux. This enhancement turns out to be smaller than
obtained so far, in particular for flatter initial cosmic fluxes behaving like
. Downward--going events and in particular the
background--free and unique hadronic `double bang' and `lollipop' events allow
to test downward--going cosmic fluxes up to
about GeV.Comment: 32 pages, 6 figures; Added reference
Exploring Justice
Head up the underground. Are you all familiar with that? The night of persecutions simulations, things they do that\u27s underground. That\u27s the young adult division of Open Doors ministry. Open Doors has been serving the persecuted church for 50 years with Brother Andrew and they just recently, I think, in 2000, started up the underground to kind of get people in our age brackets a little more aware of what\u27s going on and more involved. That\u27s my focus. What I\u27m going to talk about today is indirectly related to the persecuted church
Matter Effects in Atmospheric Neutrino Oscillations
The Kamiokande II and IMB data on contained events induced by atmospheric
neutrinos exhibit too low a ratio of muons to electrons, which has been
interpreted as a possible indication of neutrino oscillations. At the same
time, the recent data on upward--going muons in underground detectors have
shown no evidence for neutrino oscillations, strongly limiting the allowed
region of oscillation parameter space. In this paper we confront different
types of neutrino oscillation hypotheses with the experimental results. The
matter effects in and in oscillations are discussed and shown to affect
significantly the upward--going muons.Comment: LaTeX, 13 pages, 4 figures (appended as postscript file in the end of
the paper, one should cut them and process separately), Roma n. 91
Going Underground: Merging Collaboration with Micro-Resistance
This article connects insights about the dynamics of resistance from sociology of critique with critical management research. This connection will highlight that silent and hardly visible forms of protest need more attention from social research. Taking an interview sequence as a source, aspects of analyzing micro-resistance are developed. Explanations and justifications of how to deal with management practices show a coexistence of both, resistance and collaboration. The ensuing kind of identity regulation obviously makes management systems work together with individuals who try to stay capable of action. These insights challenge established concepts of critique in social research
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