Principal Background Research Articles

Production of aWboson and two jets with oneb-quark tag

The production of a $W$ boson and two jets, at least one of which contains a $b$ quark, is a principal background to single-top production, Higgs production, and signals of new physics at hadron colliders. We present a next-to-leading-order calculation of the cross section at the Fermilab Tevatron and the CERN Large Hadron Collider. The next-to-leading-order cross section differs substantially from that at leading order, and we provide a context in which to understand this result.

Cosmogenic activation of germanium and its reduction for low background experiments

Production of 60Co and 68Ge from stable isotopes of germanium by nuclear active component of cosmic rays is a principal background source for the new generation 76Ge double beta decay experiments like GERDA and Majorana. The biggest contribution of cosmogenic activity is expected to be produced during transportation of either enriched material or already grown crystal.In this article the properties and feasibility of a movable iron shield are discussed. An activation reduction factor of about 10 is predicted by simulations with the SHIELD code for a simple cylindrical configuration. This is sufficient for the GERDA Phase II background requirements. The possibility of further increasing the reduction factor and physical limitations are considered. The importance of activation reduction during germanium purification and detector manufacturing is emphasized.

The search for "true north" in corporate financial reporting

This contribution reviews the search for "true north" in corporate financial reporting, based on the book entitled Mark-to-Market Accounting: "True North" in Financial Reporting by Schuetze and Wolnizer. Among other reasons, this book is significant because the principal author's background is in practice rather than academia. As suggested by its title, the main argument of the book is that corporate financial reports can be improved and that the key to such improvement rests with ensuring that they depict "economic reality".

Two Peyssonnelia species (Peyssonneliaceae, Rhodophyta) from Puerto Rico including Peyssonnelia flavescens sp. nov.

D.L. Ballantine and H. Ruiz. 2005. Two Peyssonnelia species (Peyssonneliaceae, Rhodophyta) from Puerto Rico including Peyssonnelia flavescens sp. nov. Phycologia 44: 328–334.Two highly colourful encrusting red algal species from deep and shallow coral reef habitats in Puerto Rico are reported. Peyssonnelia boergesenii Weber Bosse is characterized by its multicoloured appearance, polyflabellate arrangement of hypothallial cells and multicellular holdfasts. Peyssonnelia flavescens sp. nov. is variably bi- to tri-coloured, with the principal background colour bright yellow to tan. It forms large crusts, to 30 cm in diameter, which are variably thick, measuring 310–640 μm in thickness. The new species differs from other known Peyssonnelia species by cutting off elongate, 12–17 μm long, spermatangial initials that cut off seriate chains of spermatangia distally and by its production of very large tetrasporangia, to 170 μm long.

Detection of small N 2O concentrations using a frequency doubled 12C 18O 2 laser

A reliable procedure for remote high-accuracy laser detection of N 2O as one of the principal destroyers of the protective ozone layer of the Earth has been developed. The procedure is based on using a CO 2-laser system emitting efficiently in the ∼4.5 μm range. In this case lasing from isotopic modification 12C 18O 2 of carbon dioxide with its subsequent frequency doubling by a nonlinear crystal is used. With the object of reducing the price the composition of the active medium (both for TEA laser and low-pressure longitudinal-discharge-excitation laser) has been optimized. New high-efficiency intracavity frequency doubling schemes based on nonlinear AgGaSe 2 crystals have been developed for CO 2-lasers of both types. Low concentrations of N 2O and concentrations of the principal background gases CO and H 2O have been measured under real atmosphere conditions with the aid of the lidar complex built around these lasers.

The Public Becomes Personal: From Ernaux's Passion simple to Journal du dehors

The Public Becomes Personal: From Ernaux's Passion simple to Journal du dehors

BACKGROUNDS TO SENSITIVE EXPERIMENTS UNDERGROUND

▪ Abstract We summarize residual background sources encountered in experiments conducted deep underground. Physical mechanisms of production and methods of estimation for the dominant sources are considered, and comparisons of the calculations with underground measurements are discussed. Principal background sources discussed include primary interactions of cosmic rays, mechanisms of neutron production by cosmic rays and low energy backgrounds from neutrons, primordial and anthropogenic radionuclides, and secondary radioactivity from spallation.

Early Release for Seriously Ill and Elderly Prisoners: Should French Practice be Followed?

In 2002 a formal system for dealing with the early release of prisoners on grounds of ill health was introduced in France. One year following its enactment the new legislation has already been applied successfully in cases of seriously ill and elderly prisoners. This article describes the principal features and background to this new system and examines the arguments at issue on this question, more particularly the human rights argument in light of the Strasbourg case law under article 3 of the European Convention on Human Rights. In a comparative perspective the article questions whether, given the prison situation in England and Wales, a similar reform should not also be considered in this jurisdiction.

DistinguishingWHandWbb¯production at the Fermilab Tevatron

The production of a Higgs boson in association with a W-boson is the most likely process for the discovery of a light Higgs at the Fermilab Tevatron. Since it decays primarily to b-quark pairs, the principal background for this associated Higgs production process is WBBbar, where the BBbar pair comes from the splitting of an off mass shell gluon. In this paper we investigate whether the spin angular correlations of the final state particles can be used to separate the Higgs signal from the WBBbar background. We develop a general numerical technique which allows one to find a spin basis optimized according to a given criterion, and also give a new algorithm for reconstructing the W longitudinal momentum which is suitable for the WH and WBBbar processes.

The DØ run II luminosity monitor

The DØ Run II Luminosity Monitor consists of plastic scintillation detectors with fine-mesh photomultiplier readout that cover the range 2.7 < |η| < 4.4 in pseudorapidity. The detector is designed to provide a precise measurement of the rate for non-diffractive inelastic collisions that is used to calculate the Tevatron luminosity at DØ. Excellent time-of-flight resolution allows a clean separation between beam-beam interactions and the principal background from beam halo. In addition, timing is used to measure the position of the primary interaction vertex and to detect multiple interactions. Accurate correction for multiple proton-antiproton interactions in a single beam crossing is essential for an accurate luminosity determination. Associated electronics provide a single-interaction trigger term for the DØ Level 1 trigger, and readout of the photomultiplier timing and pulse-height measurements.

The Principal Background of &quot;The Third Afforestration Boom&quot; in New Zealand : Sharp Declining Sheep Farming after 1984

The Principal Background of &quot;The Third Afforestration Boom&quot; in New Zealand : Sharp Declining Sheep Farming after 1984

Adaptive multilevel classification and detection in multispectral images

MTL Systems, Inc.Imaging Technologies Division3481 Dayton-Xenia RoadDayton, Ohio 45432-2796Abstract. A novel multilevel adaptive pixel classification and detection(AMLCD) method for detecting pixel and subpixel-size targets for multi-spectral images is presented. The AMLCD method takes into accountboth spectral and spatial characteristics of the data. In the first level ofprocessing, the principal background end members are obtained usingthe K-means clustering method. Each pixel is examined next for classi-fication using a minimum-distance classifier with the principal end mem-bers obtained in the previous level. In the second level, the neighbor-hood of each unclassified pixel is analyzed for inclusion of candidate endmembers in an unmixing procedure. If the list of candidate backgroundclasses is empty, the conditions for their inclusion are relaxed. The frac-tions of neighborhood and target signatures for the unclassified pixelsare determined by means of a linear least-squares method in the thirdlevel. If the results of unmixing are not satisfactory, the list of candidateclusters is renewed. Target detection within each pixel is performed next.The last processing level determines the size and location of detectedtargets with a clustering analysis methodology. Target size and locationare estimated on the basis of the sum and weighted vector mean, re-spectively, of the mixing fractions of the neighboring pixels. The AMLCDmethod was successfully applied to both synthetic and Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) hyperspectral imagery datasets.

Pleyel as Music Publisher:A documentary sourcebook of early 19th-century music

Abstract In Australia the history of the music trades is an underdeveloped area of research, one that is almost completely ignored by musicologists.1 Because of the way Australia was settled, the principal historical background derives chiefly, but not solely, from the British Isles, where, in 1859, Bennet Woodcroft, an engineer and patent agent, produced a series of abridgments of patent specifications that included one on printing 1617-1857 and another on music inventions of various kinds, including some relating to the music trades. These abridgments are invaluable reference tools, even today.

Islamization of Knowledge

This well-written book comprehensively outlines the basic precepts onwhich a concept and a program of Islamization of knowledge must, accordingto the author, rest. In his attempt to outline these directions, the author firstdefines the concept of Islamization as " ... practising (i.e., discovering, compiling,piecing together, communicating and publishing) intellectual activitybased on the Islamic concept of the universe" (p. 5). He further states that"'Islamization' covers everything within the realm of the true belief in theexistence of Allah (SWT)" (p. 5). This definition is enhanced by Khalil's unequivocalreference to the Shari'ah and fiqh, the derivative of the Qur'an andthe Sunnah, as being the principal background for the Islamization process.Another important aspect of Islamization, according to the author, is theabsence of dualism in this framework. He says that in the quest for establishingthe Islamic dimensions of belief in the diversity of human acquisitions,all "that might lead to dualism between the Divine orientation and its absoluteknowledge and the conflicting relativism of human efforts" (p. 6) must beavoided.The author correctly points out that Islamization must be carried out onboth the theoretical (normative) and the practical (positive) aspects of the sciences.It is here, however, that a series of questions arise and which, in turn,lead to a critical analysis that seemingly does not support the author's thesison the modus operandi and worldview of Islamization. Internal inconsistencieswithin the arguments presented also lead to several difficulties. In my analysisof some of these problematic points, I will use the tawhidi precept that tentersthe Islamization process.Islamizing the Natural and the Social SciencesKhalil says that the natutal and the social sciences are not amenable tothe same degtee of Islamization. In his view, the social sciences will be Islamizedbefore the natural sciences: "... sciences such as civil engineering, algebra,trigonometry or mathematics in general, as well as other disciplineslike statistics, chemistry and possibly geology, may not be related to the process"(p. 7) ...

Burgerlike Ongehoorsaamheid

Civil Disobedience For a twofold reason civil disobedience is currently a well known phenomenon not only in South Africa but also in different countries in the rest of the world. Firstly because it is practised by more people more frequently as a means of solving political problems, and secondly because more people are justifying it on theological grounds. After an attempt at a satisfactory definition an analysis is made of civil disobedience from a social ethical perspective. Certain fundamental aspects then come under scrutiny and the principal background for civil disobedience is supplied. Having given a short critical evaluation the article ends with some positive guideliness.

W-boson-plus-two-jet production at the Fermilab Tevatron

In this paper we present a detailed study of rates and distributions for the production of a $W$ boson plus two jets at the Fermilab 1.8-TeV Collider, assuming that the top quark does not contribute to these events. This process is the principal background to the discovery of a top quark in the 80-110-GeV range with 5 ${\mathrm{pb}}^{\ensuremath{-}1}$ of data at the Fermilab Tevatron.

Search for top-quark decays to realWbosons at the Fermilab Tevatron collider

We propose ways in which eventual signals from heavy-top-quark decays into on-shell or nearly-on-shell /ital W/ bosons may be discriminated more sharply from background at the Fermilab Tevatron /ital p/bar /p/ collider. For single-lepton /ital t/bar /t/ signals, the principal background from direct /ital W/ production cannot be eliminated by acceptance cuts alone, but the signal/background ratio can be greatly increased by requiring a high jet multiplicity /ital n/. Top-quark signals can be detected and /ital m//sub /ital t// can be measured via enhancements in the single-lepton event rates at high /ital n/, or via a peak in the invariant mass of the three hardest jets at high /ital n/. A /ital t/bar /t/ signal can be extracted up to /ital m//sub /ital t//=150 GeV (180 GeV) from selected data with /ital n/greater than or equal to3 (/ital n/greater than or equal to4) jets. For two-lepton /ital t/bar /t/ signals, the principal standard-model backgrounds from /ital b/bar /b/,/ital c/bar /c/ and Drell-Yan dilepton production can all be removed by cuts. The remaining backgrounds from direct /ital W//sup +/W/sup /minus// and Drell-Yan /tau/bar ///tau/ production can be suppressed to a level well below the /ital t/bar /t/ signals, for the wholemore » of the mass range up to /ital m//sub /ital t//=200 GeV allowed for the standard model. Eventual /ital t/bar /t/ signals can be confirmed by characteristic dynamical distributions. An integrated luminosity of 10 pb/sup /minus/1/ (100 pb/sup /minus/1/) would be enough to detect top quarks up to /ital m//sub /ital t//=120 GeV (200 GeV).« less

An Approach to an Automatic Pattern Recognition of the Electroencephalogram: Background Rhythm and Paroxysmal Elements

The automatic analysis program for one derivation of E.E.G. described here is made up of two parts:1.) The first part consists of the study of background rhythm. A temporal analysis is made of the signal to identify the waves of which it is composed. Bursts of rhythms are recognised. Then the principal background rhythms are determined by the analysis of histograms of amplitude and frequency. The results are given as the percentage of the total waves, the mean frequency and amplitude and the coefficient of variation of these quantities.2.) The second part is the recognition of paroxysmal patterns. By successive applications of a set of criteria the parts of the E.E.G. which may contain spikes or spike-and-waves are extracted. The criteria are:— existence of large amplitude or slow waves,— comparison of the frequency of these suspect patterns with the background frequency,— comparison of the amplitude of these waves with the mean amplitude of the E.E.G.,— study of the rapid rhythms which, are superimposed on the show waves.This analysis is concluded by the printing of the number of isolated spikes or spike-and-waves that were observed.This program, orientated towards pattern recognition, is suitable for the study of the background patterns as well as the pattern recognition of paroxysmal bursts.

Effect of an Ice Layer on Arctic SOFAR Propagation

The effect of an ice layer on Arctic SOFAR propagation is investigated from the normal-mode solution of the sound field in multilayered media. For an ice layer 3 m thick, typical of the central Arctic Ocean, the effect on pressure amplitudes at depth and dispersion is small, but even this thin ice sheet causes a large change in particle motions near the surface. Waves are elliptically polarized in the ice in the plane of propagation. Particle motion is retrograde elliptical at the surface and prograde elliptical at the bottom of the ice. This orbital motion is similar to that of flexural waves in the ice. Flexural waves generated by large-scale ice movements at the boundaries of floes are the principal background noise in the ice. It is significant that a node of horizontal particle motion often does not occur at the same depth in the ice for both hydroacoustic waves and flexural waves. This effect may be useful to improve the signal-to-noise ratio when horizontal component geophones are used as listening devices.

Test of Time-Reversal Invariance in the Decay ProcessK+→μ++ν+e++e−

$\mathrm{CP}$ violation occurring in the ${K}_{L}\ensuremath{\rightarrow}2\ensuremath{\pi}$ decay is assumed to take place when the electromagnetic and weak interactions occur simultaneously. An analysis of the ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}+\ensuremath{\nu}+{e}^{+}+{e}^{\ensuremath{-}}$ decay is presented which shows that the measurement of the muon polarization in this decay is a practical way of determining this effect. The reduction of the principal background from ${K}_{\ensuremath{\mu}3}$ is discussed. Such an experiment would also provide valuable information on structure radiation.