2,648 research outputs found
Magnetic monopoles at the LHC and in the Cosmos
The magnetic monopole was postulated in 1931 by Dirac to explain electric
charge quantisation. Searches for pair-produced monopoles are performed at
accelerator facilities whenever a new energy regime is made available. In
addition, monopoles with masses too high to be accessible at colliders would
still have been produced in the early Universe and such relics can be searched
for either in flight or trapped in matter. Here we discuss recent results and
future prospects for direct monopole detection at the LHC and in bulk matter
searches, with emphasis on the complementarity between the various techniques.
Significant improvements of the results from the ATLAS experiment are expected
with the development of new triggers. Dedicated LHC experiments will allow to
probe wider ranges of monopole charges and masses: the MoEDAL experiment using
both nuclear-track detectors and absorbing arrays, and searches for trapped
monopoles in accelerator material. Finally, it is highlighted how the first
search for monopoles trapped in polar volcanic rocks allows to set new
constraints on the abundance of monopoles bound to matter in the Earth's
interior and by extension in the primary material that formed the Solar System.Comment: 4 pages, 48th Rencontres de Moriond on Very High Energy Phenomena in
the Universe, 9-16 March 2013, La Tuile, Italy, proceedings to appear in 201
Searching for magnetic monopoles trapped in accelerator material at the Large Hadron Collider
If produced in high energy particle collisions at the LHC, magnetic monopoles
could stop in material surrounding the interaction points. Obsolete parts of
the beam pipe near the CMS interaction region, which were exposed to the
products of pp and heavy ion collisions, were analysed using a SQUID-based
magnetometer. The purpose of this work is to quantify the performance of the
magnetometer in the context of a monopole search using a small set of samples
of accelerator material ahead of the 2013 shutdown.Comment: 11 page
Effects of ATLAS Tile calorimeter failures on jets and missing transverse energy measurements
Failures of the ATLAS Tile calorimeter would affect the jet energy resolution and would fake tails of missing transverse energy. Significant effects are expected in processes involving high transverse momentum jets ( GeV). These effects, their consequences, as well as methods to minimize them, are studied using simulated data for various degradation topologies and for different physics processes
Application of large area SiPMs for the readout of a plastic scintillator based timing detector
In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end
of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon
beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6
cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM
anode readout ASIC (MUSIC R1) based on a novel low input impedance current
conveyor has been used to read out and amplify SiPMs independently and sum the
signals at the end. Prospects for applications in large-scale particle physics
detectors with timing resolution below 100 ps are provided in light of the
results
Application of large area SiPMs for the readout of a plastic scintillator based timing detector
In this study an array of eight 6 mm x 6 mm area SiPMs was coupled to the end
of a long plastic scintillator counter which was exposed to a 2.5 GeV/c muon
beam at the CERN PS. Timing characteristics of bars with dimensions 150 cm x 6
cm x 1 cm and 120 cm x 11 cm x 2.5 cm have been studied. An 8-channel SiPM
anode readout ASIC (MUSIC R1) based on a novel low input impedance current
conveyor has been used to read out and amplify SiPMs independently and sum the
signals at the end. Prospects for applications in large-scale particle physics
detectors with timing resolution below 100 ps are provided in light of the
results
Study of timing characteristics of a 3 m long plastic scintillator counter using waveform digitizers
A plastic scintillator bar with dimensions 300 cm x 2.5 cm x 11 cm was
exposed to a focused muon beam to study its light yield and timing
characteristics as a function of position and angle of incidence. The
scintillating light was read out at both ends by photomultiplier tubes whose
pulse shapes were recorded by waveform digitizers. Results obtained with the
WAVECATCHER and SAMPIC digitizers are analyzed and compared. A discussion of
the various factors affecting the timing resolution is presented. Prospects for
applications of plastic scintillator technology in large-scale particle physics
detectors with timing resolution around 100 ps are provided in light of the
results
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