3,948 research outputs found
Using a neural network approach for muon reconstruction and triggering
The extremely high rate of events that will be produced in the future Large
Hadron Collider requires the triggering mechanism to take precise decisions in
a few nano-seconds. We present a study which used an artificial neural network
triggering algorithm and compared it to the performance of a dedicated
electronic muon triggering system. Relatively simple architecture was used to
solve a complicated inverse problem. A comparison with a realistic example of
the ATLAS first level trigger simulation was in favour of the neural network. A
similar architecture trained after the simulation of the electronics first
trigger stage showed a further background rejection.Comment: A talk given at ACAT03, KEK, Japan, November 2003. Submitted to
Nuclear Instruments and Methods in Physics Research, Section
Managing Uncertain Complex Events in Web of Things Applications
A critical issue in the Web of Things (WoT) is the need to process and analyze the interactions of Web-interconnected real-world
objects. Complex Event Processing (CEP) is a powerful technology for analyzing streams of information about real-time distributed events, coming from different sources, and for extracting conclusions from them. However, in many situations these events are not free from uncertainty, due to either unreliable data sources and networks, measurement uncertainty, or to the inability to determine whether an event has actually happened or not. This short research paper discusses how CEP systems
can incorporate different kinds of uncertainty, both in the events and in the rules. A case study is used to validate the proposal, and we discuss the benefits and limitations of this CEP extension.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Asymptotic bounds for the sizes of constant dimension codes and an improved lower bound
We study asymptotic lower and upper bounds for the sizes of constant
dimension codes with respect to the subspace or injection distance, which is
used in random linear network coding. In this context we review known upper
bounds and show relations between them. A slightly improved version of the
so-called linkage construction is presented which is e.g. used to construct
constant dimension codes with subspace distance , dimension of the
codewords for all field sizes , and sufficiently large dimensions of the
ambient space, that exceed the MRD bound, for codes containing a lifted MRD
code, by Etzion and Silberstein.Comment: 30 pages, 3 table
Plasma Panel Sensors for Particle and Beam Detection
The plasma panel sensor (PPS) is an inherently digital, high gain, novel
variant of micropattern gas detectors inspired by many operational and
fabrication principles common to plasma display panels (PDPs). The PPS is
comprised of a dense array of small, plasma discharge, gas cells within a
hermetically-sealed glass panel, and is assembled from non-reactive,
intrinsically radiation-hard materials such as glass substrates, metal
electrodes and mostly inert gas mixtures. We are developing the technology to
fabricate these devices with very low mass and small thickness, using gas gaps
of at least a few hundred micrometers. Our tests with these devices demonstrate
a spatial resolution of about 1 mm. We intend to make PPS devices with much
smaller cells and the potential for much finer position resolutions. Our PPS
tests also show response times of several nanoseconds. We report here our
results in detecting betas, cosmic-ray muons, and our first proton beam tests.Comment: 2012 IEEE NS
The MATHUSLA Test Stand
The rate of muons from LHC collisions reaching the surface above the
ATLAS interaction point is measured and compared with expected rates from
decays of and bosons and - and -quark jets. In addition, data
collected during periods without beams circulating in the LHC provide a
measurement of the background from cosmic ray inelastic backscattering that is
compared to simulation predictions. Data were recorded during 2018 in a 2.5
2.5 6.5~ active volume MATHUSLA test stand detector
unit consisting of two scintillator planes, one at the top and one at the
bottom, which defined the trigger, and six layers of RPCs between them, grouped
into three -measuring layers separated by 1.74 m from each other.
Triggers selecting both upward-going tracks and downward-going tracks were
used.Comment: 18 pages, 11 figures, 1 tabl
An Algebraic Approach for Decoding Spread Codes
In this paper we study spread codes: a family of constant-dimension codes for
random linear network coding. In other words, the codewords are full-rank
matrices of size (k x n) with entries in a finite field F_q. Spread codes are a
family of optimal codes with maximal minimum distance. We give a
minimum-distance decoding algorithm which requires O((n-k)k^3) operations over
an extension field F_{q^k}. Our algorithm is more efficient than the previous
ones in the literature, when the dimension k of the codewords is small with
respect to n. The decoding algorithm takes advantage of the algebraic structure
of the code, and it uses original results on minors of a matrix and on the
factorization of polynomials over finite fields
The Cosmic Ray Hodoscopes for Testing Thin Gap Chambers at the Technion and Tel Aviv University
Thin gap chambers (TGCs) are built for the muon trigger chambers in the
endcap region of the LHC experiment ATLAS. More than 2500 ATLAS TGCs are being
produced at the Weizmann institute in Israel, and in Shandong University in
China. Detailed testing of these chambers is performed at the Technion and at
the Tel-Aviv University. Two cosmic ray hodoscopes for testing the operation of
these detectors were built in Israel. In these hodoscopes the response of the
chambers to energetic cosmic ray muons is recorded and analyzed. The hodoscopes
measure the exact time and space location of the cosmic ray hit and read out
the chambers which are being tested to verify that they produce a corresponding
signal within the required time interval. The cosmic ray hodoscopes built at
the Technion and at the Tel Aviv University for the test of ATLAS TGCs are
described. The mechanical structure, readout electronics, data acquisition and
operating scheme are presented. Typical TGC test results are presented and
discussed
Measurement of the branching ratios of the Z0 into heavy quarks
We measure the hadronic branching ratios of the Z0 boson into heavy quarks:
Rb=Gamma(Z0->bb)/Gamma(Z0->hadrons) and Rc=Gamma(Z0->cc/Gamma(Z0->hadrons)
using a multi-tag technique. The measurement was performed using about 400,000
hadronic Z0 events recorded in the SLD experiment at SLAC between 1996 and
1998. The small and stable SLC beam spot and the CCD-based vertex detector were
used to reconstruct bottom and charm hadron decay vertices with high efficiency
and purity, which enables us to measure most efficiencies from data. We obtain,
Rb=0.21604 +- 0.00098(stat.) +- 0.00073(syst.) -+ 0.00012(Rc) and, Rc= 0.1744
+- 0.0031(stat.) +- 0.0020(syst.) -+ 0.0006(Rb)Comment: 37 pages, 8 figures, to be submitted to Phys. Rev. D version 2:
changed title to ratios, used common D production fractions for Rb and Rc and
corrected Zgamma interference. Identical to PRD submissio
Direct Measurements of A_b and A_c using Vertex/Kaon Charge Tags at SLD
Exploiting the manipulation of the SLC electron-beam polarization, we present
precise direct measurements of the parity violation parameters A_c and A_b in
the Z boson - c quark and Z boson - b quark coupling. Quark/antiquark
discrimination is accomplished via a unique algorithm that takes advantage of
the precise SLD CCD vertex detector, employing the net charge of displaced
vertices as well as the charge of kaons that emanate from those vertices. From
the 1996-98 sample of 400,000 Z decays, produced with an average beam
polarization of 73.4%, we find A_c = 0.673 +/- 0.029 (stat.) +/- 0.023 (syst.)
and A_b = 0.919 +/- 0.018 (stat.) +/- 0.017 (syst.).Comment: 11 pages, 2 figures, 2 tables, to be submitted to Physical Review
Letters; version 2 reflects changes suggested by the refere
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