14,445 research outputs found
A facility to Search for Hidden Particles (SHiP) at the CERN SPS
A new general purpose fixed target facility is proposed at the CERN SPS
accelerator which is aimed at exploring the domain of hidden particles and make
measurements with tau neutrinos. Hidden particles are predicted by a large
number of models beyond the Standard Model. The high intensity of the SPS
400~GeV beam allows probing a wide variety of models containing light
long-lived exotic particles with masses below (10)~GeV/c,
including very weakly interacting low-energy SUSY states. The experimental
programme of the proposed facility is capable of being extended in the future,
e.g. to include direct searches for Dark Matter and Lepton Flavour Violation.Comment: Technical Proposa
The Straw Tube Trackers of the PANDA Experiment
The PANDA experiment will be built at the FAIR facility at Darmstadt
(Germany) to perform accurate tests of the strong interaction through bar pp
and bar pA annihilation's studies. To track charged particles, two systems
consisting of a set of planar, closed-packed, self-supporting straw tube layers
are under construction. The PANDA straw tubes will have also unique
characteristics in term of material budget and performance. They consist of
very thin mylar-aluminized cathodes which are made self-supporting by means of
the operation gas-mixture over-pressure. This solution allows to reduce at
maximum the weight of the mechanical support frame and hence the detector
material budget. The PANDA straw tube central tracker will not only reconstruct
charged particle trajectories, but also will help in low momentum (< 1 GeV)
particle identification via dE/dx measurements. This is a quite new approach
that PANDA tracking group has first tested with detailed Monte Carlo
simulations, and then with experimental tests of detector prototypes. This
paper addresses the design issues of the PANDA straw tube trackers and the
performance obtained in prototype tests.Comment: 7 pages,16 figure
MEG Upgrade Proposal
We propose the continuation of the MEG experiment to search for the charged
lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of
the experiment, which aims for a sensitivity enhancement of one order of
magnitude compared to the final MEG result, down to the
level. The key features of this new MEG upgrade are an increased rate
capability of all detectors to enable running at the intensity frontier and
improved energy, angular and timing resolutions, for both the positron and
photon arms of the detector. On the positron-side a new low-mass, single
volume, high granularity tracker is envisaged, in combination with a new highly
segmented, fast timing counter array, to track positron from a thinner stopping
target. The photon-arm, with the largest liquid xenon (LXe) detector in the
world, totalling 900 l, will also be improved by increasing the granularity at
the incident face, by replacing the current photomultiplier tubes (PMTs) with a
larger number of smaller photosensors and optimizing the photosensor layout
also on the lateral faces. A new DAQ scheme involving the implementation of a
new combined readout board capable of integrating the diverse functions of
digitization, trigger capability and splitter functionality into one condensed
unit, is also under development. We describe here the status of the MEG
experiment, the scientific merits of the upgrade and the experimental methods
we plan to use.Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted
to the Paul Scherrer Institute Research Committee for Particle Physics at the
Ring Cyclotron. 131 Page
Summary and Outlook of the International Workshop on Aging Phenomena in Gaseous Detectors (DESY, Hamburg, October, 2001)
High Energy Physics experiments are currently entering a new era which
requires the operation of gaseous particle detectors at unprecedented high
rates and integrated particle fluxes. Full functionality of such detectors over
the lifetime of an experiment in a harsh radiation environment is of prime
concern to the involved experimenters. New classes of gaseous detectors such as
large-scale straw-type detectors, Micro-pattern Gas Detectors and related
detector types with their own specific aging effects have evolved since the
first workshop on wire chamber aging was held at LBL, Berkeley in 1986. In
light of these developments and as detector aging is a notoriously complex
field, the goal of the workshop was to provide a forum for interested
experimentalists to review the progress in understanding of aging effects and
to exchange recent experiences. A brief summary of the main results and
experiences reported at the 2001 workshop is presented, with the goal of
providing a systematic review of aging effects in state-of-the-art and future
gaseous detectors.Comment: 14 pages, 2 pictures. Presented at the IEEE Nuclear Science Symposium
and Medical Imaging Conference, November 4-10, 2001, San Diego, USA.
Submitted to IEEE Trans. Nucl. Sci (IEEE-TNS
Enabling Technologies for Silicon Microstrip Tracking Detectors at the HL-LHC
While the tracking detectors of the ATLAS and CMS experiments have shown
excellent performance in Run 1 of LHC data taking, and are expected to continue
to do so during LHC operation at design luminosity, both experiments will have
to exchange their tracking systems when the LHC is upgraded to the
high-luminosity LHC (HL-LHC) around the year 2024. The new tracking systems
need to operate in an environment in which both the hit densities and the
radiation damage will be about an order of magnitude higher than today. In
addition, the new trackers need to contribute to the first level trigger in
order to maintain a high data-taking efficiency for the interesting processes.
Novel detector technologies have to be developed to meet these very challenging
goals. The German groups active in the upgrades of the ATLAS and CMS tracking
systems have formed a collaborative "Project on Enabling Technologies for
Silicon Microstrip Tracking Detectors at the HL-LHC" (PETTL), which was
supported by the Helmholtz Alliance "Physics at the Terascale" during the years
2013 and 2014. The aim of the project was to share experience and to work
together on key areas of mutual interest during the R&D phase of these
upgrades. The project concentrated on five areas, namely exchange of
experience, radiation hardness of silicon sensors, low mass system design,
automated precision assembly procedures, and irradiations. This report
summarizes the main achievements
Three-Dimensional Triplet Tracking for LHC and Future High Rate Experiments
The hit combinatorial problem is a main challenge for track reconstruction
and triggering at high rate experiments. At hadron colliders the dominant
fraction of hits is due to low momentum tracks for which multiple scattering
(MS) effects dominate the hit resolution. MS is also the dominating source for
hit confusion and track uncertainties in low energy precision experiments. In
all such environments, where MS dominates, track reconstruction and fitting can
be largely simplified by using three-dimensional (3D) hit-triplets as provided
by pixel detectors. This simplification is possible since track uncertainties
are solely determined by MS if high precision spatial information is provided.
Fitting of hit-triplets is especially simple for tracking detectors in
solenoidal magnetic fields. The over-constrained 3D-triplet method provides a
complete set of track parameters and is robust against fake hit combinations.
The triplet method is ideally suited for pixel detectors where hits can be
treated as 3D-space points. With the advent of relatively cheap and
industrially available CMOS-sensors the construction of highly granular full
scale pixel tracking detectors seems to be possible also for experiments at LHC
or future high energy (hadron) colliders. In this paper tracking performance
studies for full-scale pixel detectors, including their optimisation for
3D-triplet tracking, are presented. The results obtained for different types of
tracker geometries and different reconstruction methods are compared. The
potential of reducing the number of tracking layers and -- along with that --
the material budget using this new tracking concept is discussed. The
possibility of using 3D-triplet tracking for triggering and fast online
reconstruction is highlighted.Comment: Proceedings of the WIT2014 Workshop on Intelligent Tracking. 10
Pages, 8 figures. Submitted to JINS
Mapping the depleted area of silicon diodes using a micro-focused X-ray beam
For the Phase-II Upgrade of the ATLAS detector at CERN, the current ATLAS
Inner Detector will be replaced with the ATLAS Inner Tracker. The ATLAS Inner
Tracker will be an all-silicon detector, consisting of a pixel tracker and a
strip tracker. Sensors for the ITk strip tracker are required to have a low
leakage current up to bias voltages of -700 V to maintain a low noise and power
dissipation. In order to minimise sensor leakage currents, particularly in the
high-radiation environment inside the ATLAS detector, sensors are foreseen to
be operated at low temperatures and to be manufactured from wafers with a high
bulk resistivity of several k{\Omega} cm. Simulations showed the electric field
inside sensors with high bulk resistivity to extend towards the sensor edge,
which could lead to increased surface currents for narrow dicing edges. In
order to map the electric field inside biased silicon sensors with high bulk
resistivity, three diodes from ATLAS silicon strip sensor prototype wafers were
studied with a monochromatic, micro-focused X-ray beam at the Diamond Light
Source. For all devices under investigation, the electric field inside the
diode was mapped and its dependence on the applied bias voltage was studied.
The findings showed that the electric field in each diode under investigation
extended beyond its bias ring and reached the dicing edge
Progress Report on an Ultra-compact LumiCal
A new design of a detector module of submillimeter thickness for an
electromagnetic calorimeter is presented. It is aimed to be used in the
luminometers LumiCal and BeamCal in future linear ee collider
experiments. The module prototypes were produced utilizing novel connectivity
schemes technologies. They are installed in a compact prototype of the
calorimeter and tested at DESY with an electron beam of 1 GeV 6 GeV. The
performance of eight detector modules and the possibility of electron and
photon identification is studied.Comment: 10 pages, 13 figures, Talk presented at the International Workshop on
Future Linear Colliders (LCWS2016), Morioka, Japa
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