The probability $P(c \rightarrow D^{*+})$ that a charm quark fragments into a $D^{*+}$ meson and the $c \rightarrow l^+$ semileptonic branching fraction were measured in $Z^0\ $ decay into $c\bar{c}$ ...events. \par % A double tag method based % on the detection of exclusively reconstructed $D$ mesons % accompanied by a slow pion or a lepton in the opposite hemisphere was used.\par From the analysis of 3.5 Million $Z^0\ $ events collected from 1992 to 1995, a sample of charm meson decays with $81\%$ $c\bar{c}$ purity was selected. % In this sample, a signal of $2371\pm140$ low momentum pions % originating from a $D^{*\pm}$ decay in the opposite hemisphere % was observed. The product of the $c \rightarrow D^{*+}$ fragmentation probability times the $D^{*+}\rightarrow D^0\pi^+$ branching fraction was measured to be: \begin{eqnarray*} P(c \rightarrow D^{*+})\cdot BR(D^{*+}\rightarrow D^0\pi^+) = 0.174\pm0.010(stat) \pm0.004(syst) \; . \end{eqnarray*} Using the world averaged value for $BR(D^{*+}\rightarrow D^0\pi^+)$, the fragmentation probability is inferred: \begin{eqnarray*} P(c \rightarrow D^{*+}) = 0.255\pm0.015(stat) \pm0.006(syst) \pm0.005 (syst.BR) \; . \end{eqnarray*} From the same sample, $1828\pm 51$ identified leptons in the opposite hemisphere were selected. From this sample, the charm semileptonic branching fraction was measured to be: \begin{eqnarray*} BR(c \rightarrow l^+) = 0.0958\pm0.0042(stat) \pm0.0028(syst) \; . \end{eqnarray*}
A search for the Higgs boson in final states with one, two or three isolated photons has been performed based on data taken at LEP 2 by the DELPHI detector. The data analysed correspond to a total ...integrated luminosity of 67.5 pb −1 at centre-of-mass energies of 161 GeV (9.7 pb −1 ), 172 GeV (10.1 pb −1 ) and 183 GeV (47.7 pb −1 ). No evidence for the processes e + e − → Hγ with H→b b ̄ or γγ and e + e − →Hq q ̄ with H → γγ was observed. Model-independent limits on σ(e + e − →Hγ)×BR(H→b b ̄ ) , σ(e + e − →Hq q ̄ )×BR(H→γγ) and σ ( e + e − → Hγ )× BR ( H → γγ ) are set, as well as model-dependent limits on Higgs boson anomalous couplings to vector bosons. (Elsevier)
Searches for HZ production with the Higgs boson decaying into an invisible final state have been performed with the data collected by the DELPHI experiment up to the centre-of-mass energy of 183 GeV. ...The hadronic and muon pair final states of the Z boson were analysed. From the absence of signal, upper limits on the cross-section and the corresponding Higgs boson mass limits were set at 95% confidence level. The results are interpreted as excluded parameter regions in the framework of the minimal supersymmetric standard model and in the simplest Majoron model with one Higgs doublet and one Higgs singlet field. (Elsevier)
TEX is a well-known system for the production of quality documents, offering the user a high degree of sophistication in the specification of the final format. It has companion packages (most notably ...LATEX) which allow other document processing activities, including the production of new fonts, pictures and extended production systems. It suffers from the criticism that it is now dated and does not offer WYSIWYG functionality. With the emergence of new technology and more powerful computing at the desktop, there is a high demand for a more graphics-oriented interface to which the user can relate easily and which immediately lets him see the appearance of the document being planned. However, the emerging wordprocessing and document processing packages still have faults. The project described in this paper was aimed at rescuing the full power of the TEX packages in the newly emerging X-windows technological context. We describe software which was produced to take full advantage of the facilities of both systems by translating TEX output into bit-mapped images which can then be displayed on an X-terminal and mixed with such facilities as the extra fonts available and bit-maps produced in the X-environment. An interactive environment is defined that gives the user flexibility in the creation of a document of high quality with a friendly human-computer interface, which allows the windowing environment to give a new look to an old and well-tried system. The advantages of this approach are many, and include the use of a well-understood environment, a large amount of software in the public domain to extend the package and drive printers, and the exploitation of the emerging X-window standard.
N-strip on n-bulk silicon microstrip detectors were irradiated at the CERN PS to 3×10
14
p
cm
-2 and their post-irradiation performance evaluated using fast binary readout electronics. Strip noise ...measurements demonstrate that detectors using conventional p-stop strip isolation are vulnerable to microdischarge at high bias voltages after irradiation. However, a novel isolation technique is shown to suppress microdischarge and lead to excellent post-irradiation characteristics.
The visual analysis of Chinese characters by skilled readers is investigated in an experiment designed to contrast the effect of number of strokes & that of orthographic units consisting of stroke ...patterns. Four stimulus sets consisted of characters having either two or three orthographic units arranged either vertically or horizontally; orthographic units of these sets were recombined with the lexical radical in its proper position to generate pseudo-character sets & with the lexical radical improperly placed to generate illegal noncharacter sets. Each of the 12 sets was divided into two subsets based on number of strokes. Pairs of stimuli were presented to right-handed native Chinese graduate students (N = 6 males & 6 females) having undergraduate degrees from mainland China institutions, who judged as quickly as possible whether stimulus pairs were same or different. Conditions varied number of strokes within same pairs & proportion of different units within different pairs. Mean reaction times for correct responses & mean error rates show a word superiority effect, an advantage of pseudo-characters over noncharacters, an effect of number of orthographic units, an effect of proportion of mismatching units in "different" judgments, & no effect of the number of individual strokes. 5 Figures, 39 References. Adapted from the source document
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