The Thin Gap Chambers database experience in test beam and preparations for ATLAS

Thin gap chambers (TGCs) are used for the muon trigger system in the forward region of the LHC experiment ATLAS. The TGCs are expected to provide a trigger signal within 25 ns of the bunch spacing. An extensive system test of the ATLAS muon spectrometer has been performed in the H8 beam line at the CERN SPS during the last few years. A relational database was used for storing the conditions of the tests as well as the configuration of the system. This database has provided the detector control system with the information needed for configuration of the front end electronics. The database is used to assist the online operation and maintenance. The same database is used to store the non event condition and configuration parameters needed later for the offline reconstruction software. A larger scale of the database has been produced to support the whole TGC system. It integrates all the production, QA tests and assembly information. A 1/12th model of the whole TGC system is currently in use for testing the performance of this database in configuring and tracking the condition of the system. A prototype of the database was first implemented during the H8 test beams. This paper describes the database structure, its interface to other systems and its operational performance.Comment: Proceedings IEEE, Nuclear Science Symposium 2005, Stockholm, Sweeden, May 200

Neutrino flux predictions for known Galactic microquasars

It has been proposed recently that Galactic microquasars may be prodigious emitters of TeV neutrinos that can be detected by upcoming km^2 neutrino telescopes. In this paper we consider a sample of identified microquasars and microquasar candiates, for which available data enables rough determination of the jet parameters. By employing the parameters inferred from radio observations of various jet ejection events, we determine the neutrino fluxes that should have been produced during these events by photopion production in the jet. Despite the large uncertainties in our analysis, we demonstrate that in several of the sources considered, the neutrino flux at Earth, produced in events similar to those observed, would exceed the detection threshold of a km^2 neutrino detector. The class of microquasars may contain also sources with bulk Lorentz factors larger than those characteristic of the sample considered here, directed along our line of sight. Such sources, which may be very difficult to resolve at radio wavelengths and hence may be difficult to identify as microqusar candidates, may emit neutrinos with fluxes significantly larger than typically obtained in the present analysis. These sources may eventually be identified through their neutrino and gamma-ray emission.Comment: 17 pages. Submitted to Ap

Background questions for the "enter"/"exit" research

How do languages encode different kinds of movement, and what features do people pay attention to when describing motion events? This document outlines topics concerning the investigation of “enter” and “exit” events. It helps contextualise research tasks that examine this domain (see 'Motion Elicitation' and 'Enter/Exit animation') and gives some pointers about what other questions can be explored

Scatterer that leaves "footprints" but no "fingerprints"

We calculate the exact transmission coefficient of a quantum wire in the presence of a single point defect at the wire's cut-off frequencies. We show that while the conductance pattern (i.e., the scattering) is strongly affected by the presence of the defect, the pattern is totally independent of the defect's characteristics (i.e., the defect that caused the scattering cannot be identified from that pattern).Comment: 4 pages, 3 figure

Large-Amplitude, Pair-Creating Oscillations in Pulsar and Black Hole Magnetospheres

A time-dependent model for pair creation in a pulsar magnetosphere is developed. It is argued that the parallel electric field that develops in a charge-starved region (a gap) of a pulsar magnetosphere oscillates with large amplitude. Electrons and positrons are accelerated periodically and the amplitude of the oscillations is assumed large enough to cause creation of upgoing and downgoing pairs at different phases of the oscillation. With a charge-starved initial condition, we find that the oscillations result in bursts of pair creation in which the pair density rises exponentially with time. The pair density saturates at $N_\pm\simeq E_{0}^2/(8\pi m_ec^2\Gamma_{\rm thr})$, where $E_0$ is the parallel electric field in the charge-starved initial state, and $\Gamma_{\rm thr}$ is the Lorentz factor for effec tive pair creation. The frequency of oscillations following the pair creation burst is given roughly by $\omega_{\rm osc}=eE_0/(8m_ec\Gamma_{\rm thr})$. A positive feedback keeps the system stable, such that the average pair creation rate balances the loss rate due to pairs escaping the magnetosphere.Comment: 21 pages, 6 figures, ApJ submitte

Color technology is not necessary for rich and efficient color language

The evolution of basic color terms in language is claimed to be stimulated by technological development, involving technological control of color or exposure to artificially colored objects. Accordingly, technologically “simple” non-industrialized societies are expected to have poor lexicalization of color, i.e., only rudimentary lexica of 2, 3 or 4 basic color terms, with unnamed gaps in the color space. While it may indeed be the case that technology stimulates lexical growth of color terms, it is sometimes considered a sine qua non for color salience and lexicalization. We provide novel evidence that this overlooks the role of the natural environment, and people's engagement with the environment, in the evolution of color vocabulary. We introduce the Maniq—nomadic hunter-gatherers with no color technology, but who have a basic color lexicon of 6 or 7 terms, thus of the same order as large languages like Vietnamese and Hausa, and who routinely talk about color. We examine color language in Maniq and compare it to available data in other languages to demonstrate it has remarkably high consensual color term usage, on a par with English, and high coding efficiency. This shows colors can matter even for non-industrialized societies, suggesting technology is not necessary for color language. Instead, factors such as perceptual prominence of color in natural environments, its practical usefulness across communicative contexts, and symbolic importance can all stimulate elaboration of color language

Word order affects the time course of sentence formulation in Tzeltal

The scope of planning during sentence formulation is known to be flexible, as it can be influenced by speakers' communicative goals and language production pressures (among other factors). Two eye-tracked picture description experiments tested whether the time course of formulation is also modulated by grammatical structure and thus whether differences in linear word order across languages affect the breadth and order of conceptual and linguistic encoding operations. Native speakers of Tzeltal [a primarily verb–object–subject (VOS) language] and Dutch [a subject–verb–object (SVO) language] described pictures of transitive events. Analyses compared speakers' choice of sentence structure across events with more accessible and less accessible characters as well as the time course of formulation for sentences with different word orders. Character accessibility influenced subject selection in both languages in subject-initial and subject-final sentences, ruling against a radically incremental formulation process. In Tzeltal, subject-initial word orders were preferred over verb-initial orders when event characters had matching animacy features, suggesting a possible role for similarity-based interference in influencing word order choice. Time course analyses revealed a strong effect of sentence structure on formulation: In subject-initial sentences, in both Tzeltal and Dutch, event characters were largely fixated sequentially, while in verb-initial sentences in Tzeltal, relational information received priority over encoding of either character during the earliest stages of formulation. The results show a tight parallelism between grammatical structure and the order of encoding operations carried out during sentence formulation

A Strong Szego Theorem for Jacobi Matrices

We use a classical result of Gollinski and Ibragimov to prove an analog of the strong Szego theorem for Jacobi matrices on $l^2(\N)$. In particular, we consider the class of Jacobi matrices with conditionally summable parameter sequences and find necessary and sufficient conditions on the spectral measure such that $\sum_{k=n}^\infty b_k$ and $\sum_{k=n}^\infty (a_k^2 - 1)$ lie in $l^2_1$, the linearly-weighted $l^2$ space.Comment: 26 page