3,882 research outputs found
Search for magnetic monopoles with nuclear track detectors
This paper describes an experimental search for GUT magnetic monopoles in the
MACRO experiment using the nuclear track subdetector CR39. After discussing the
working principle, the charge resolution and the calibration of the detector,
the experimental procedure for searching for magnetic monopoles is described.
Since no candidates were found, the upper flux limits obtained by the MACRO
CR39 used as a "stand alone detector" for magnetic monopoles of different
magnetic charges are presented.Comment: 4 pages, 7 EPS figures included with epsfig, uses espcrc2.sty Talk
given at the Sixth Topical Seminar on Neutrino and Astroparticle Physics, San
Miniato, Italy, 17-21 May 199
Charge Determination of High Energy Electrons and Nuclei by Synchrotron Radiation with AMS
We investigate the possibilities to identify the charge of TeV electrons and
PeV nuclei using their synchrotron radiation in the earth's magnetic field.
Characteristics of synchrotron radiation photons are evaluated and methods of
detection are discussed.Comment: 9 pages, 6 figure
Underground Muon Physics with the MACRO experiment
Underground muon events detected by the MACRO experiment at Gran Sasso have
been studied for different purposes. The studies include the vertical muon
intensity measurement, multiplicity distribution, lateral and angular muon
distribution and searches for substructures inside muon bundles. These analyses
have contributed to bring new insights in cosmic ray physics, in particular in
the framework of primary cosmic ray composition studies. Moreover, this
activity allows the testing and tuning of Monte Carlo simulations, in
particular for aspects associated with models of hadronic interactions and muon
propagation through the rock.Comment: 6 pages, 4 EPS figures included with epsfig, uses espcrc2.sty Talk
given at the Sixth Topical Seminar on Neutrino and Astroparticle Physics, San
Miniato, Italy, 17-21 May 199
Search for a Lorentz invariance violation in atmospheric neutrino oscillations using MACRO data
The energy spectrum of neutrino-induced upward-going muons in MACRO was
analysed in terms of special relativity principles violating effects, keeping
standard mass-induced atmospheric neutrino oscillations as the dominant source
of nu_mu nu_tau transitions. The data disfavour these exotic possibilities
even at a sub-dominant level, and stringent 90% C.L. limits are placed on the
Lorentz invariance violation parameters. These limits can also be
re-interpreted as upper bounds on the parameters describing violation of the
Equivalence Principle.Comment: 8 pages, 5 EPS figures, uses article.sty. Invited talk at C2CR 2005,
From Colliders to Cosmic Rays, Prague, Czech Republic, 7-13 September 200
Search for exotic contributions to atmospheric neutrino oscillations
The energy spectrum of neutrino-induced upward-going muons in MACRO was
analysed in terms of relativity principles violating effects, keeping standard
mass-induced atmospheric neutrino oscillations as the dominant effect. The data
disfavor these possibilities even at a sub-dominant level; stringent 90% C.L.
limits are placed on the Lorentz invariance violation parameter at = 0 and at = 1. The limits can be re-interpreted as
bounds on the Equivalence Principle violation parameters.Comment: Presented at the 29th I.C.R.C., Pune, India (2005
An experiment to measure the energy spectrum of cosmic ray antiprotons from 100 to 1000 MeV
Production models were developed and the confirmation of each one had significant astrophysical impact. These include radical modifications of propagation models, cosmic ray antiprotons injection from neighboring domains of antimatter, p production by evaporating primordial black holes, and cosmic ray p's as annihilation products of supersymmetry particles that might make up the dark dynamical mass of the Galaxy. It is that p's originating from supersymmetric parents might have distinct spectral features that would survive solar modulation; in one model, higgsino annihilation proceeds through the bb quark-antiquark channel, producing a spectral bump at approx. 0.3 GeV in the p spectrum
Performance of a large limited streamer tube cell in drift mode
The performance of a large (3x3 ) streamer tube cell in drift mode is
shown. The detector space resolution has been studied using cosmic muons
crossing an high precision silicon telescope. The experimental results are
compared with a GARFIELD simulation.Comment: 18 pages, 7 figures. Accepted by Nucl. Instr. and Methods
Dark Matter Time Projection Chamber: Recent R&D Results
The Dark Matter Time Projection Chamber collaboration recently reported a dark matter limit obtained with a 10 liter time projection chamber filled with CF4 gas. The 10 liter detector was capable of 2D tracking (perpendicular to the drift direction) and 2D fiducialization, and only used information from two CCD cameras when identifying tracks and rejecting backgrounds. Since that time, the collaboration has explored the potential benefits of photomultiplier tube and electronic charge readout to achieve 3D tracking, and particle identification for background rejection. The latest results of this effort is described here
Cerenkov angle and charge reconstruction with the RICH detector of the AMS experiment
The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the
International Space Station (ISS) will be equipped with a proximity focusing
Ring Imaging Cerenkov (RICH) detector, for measurements of particle electric
charge and velocity. In this note, two possible methods for reconstructing the
Cerenkov angle and the electric charge with the RICH, are discussed. A
Likelihood method for the Cerenkov angle reconstruction was applied leading to
a velocity determination for protons with a resolution of around 0.1%. The
existence of a large fraction of background photons which can vary from event
to event, implied a charge reconstruction method based on an overall efficiency
estimation on an event-by-event basis.Comment: Proceedings submitted to RICH 2002 (Pylos-Greece
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