Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected ...between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure in the LEP energy range by fitting an expression in which calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of () was determined to beαS(MZ) = 0.1177 ± 0.0006 (stat.) ± 0.0012 (expt.) ± 0.0010 (had.) ± 0.0032 (theo.).
Using data from
e
+
e
− annihilation into hadrons, taken with the OPAL detector at LEP at the
Z
0 pole between 1991 and 1995, we performed a simultaneous measurement of the strong coupling α
s
and ...the colour factors of the underlying gauge group of the strong interaction,
C
F
and
C
A
. The measurement was carried out by fitting next-to-leading order perturbative predictions to measured angular correlations of 4-jet events together with either a multi-jet rate or an event-shape variable. Our combined results provide a test of perturbative QCD with the assumptions only of non-abelian gauge symmetry and standard hadronization models. Our results are in agreement with SU(3) expectations for
C
F
and
C
A
and the world average of α
s
(
M
Z
0
).
Events with a final state consisting of two or more photons and large missing transverse energy have been observed in e+e− collisions at centre-of-mass energies in the range 192–209 GeV using the ...OPAL detector at LEP. Cross-section measurements are performed within the kinematic acceptance of the selection and compared with the expectations from the Standard Model process e+e−→νν¯γγ(γ). No evidence for new physics contributions to this final state is observed. Upper limits on σ(e+e−→XX)⋅BR2(X→Yγ) are derived for the case of stable and invisible Y. In the case of massive Y the combined limits obtained from all the data range from 10 to 60 fb, while for the special case of massless Y the range is 20 to 40 fb. The limits apply to pair production of excited neutrinos (X=ν*,Y=ν), to neutralino production (X=χ˜20,Y=χ˜10) and to supersymmetric models in which X=χ˜10 and Y=G˜ is a light gravitino.
SUMMARY
Objectives: The primary objective was to assess the effects of rilmenidine monotherapy and in combination with perindopril on blood pressure (BP) in patients assessed with grade 1 or 2 ...essential hypertension. The study also examined the effects of 2-year rilmenidine monotherapy on left ventricular hypertrophy (LVH) and on diastolic function of the left ventricle, along with the effects of rilmenidine on left ventricular mass index in hypertensive patients with no LVH, and the relationship between BP reduction and any change in LVH.
Research design and methods: Mild-to-moderate hypertensive patients (n = 500) were enrolled in a multicentre 2-year open study and treated with rilmenidine (1-2 mg per day) monotherapy or rilmenidine plus perindopril (2, 4 or 8 mg per day) if control of hypertension was not achieved with rilmenidine monotherapy within 12 weeks. Blood pressure was recorded at regular intervals by the investigators and LVH measured by centralised single-blind echocardiographic reading.
Results: Rilmenidine monotherapy (average dose 1.42 mg) produced a significant decrease in BPfrom the baseline of 163 ± 10/100 ± 5 mmHg to 134 ± 10/86 ± 7 mmHg at 1 year and to 136 ± 10/84 ± 7 mmHg at 2 years (p < 0.001 for both). In 188 patients with LVH, the left ventricular mass index was significantly reduced from 161.4 ± 30.5 to 131.3 ± 26.5 at 1 year and to 134.1 ± 26.0 g/m2 at 2 years (p < 0.001 for both). Addition of perindopril to those patients whose BP was not normalised by rilmenidine monotherapy after 12 weeks further decreased BP significantly from 150 ± 13/93 ± 8 mmHg to 142 ± 14/89 ± 7 mmHg at the end of the 2nd year.
Conclusions: Long-term rilmenidine monotherapy was shown to be efficient in controlling BP and in reducing LVH. The addition of perindopril to rilmenidine monotherapy proved to be effective and well tolerated in those patients who did not respond to rilmenidine alone.
Measurements of Rb, the ratio of the bb¯ cross-section to the qq¯ cross-section in e+e− collisions, are presented. The data were collected by the OPAL experiment at LEP at centre-of-mass energies ...between 182 and 209 GeV. Lepton, lifetime and event-shape information is used to tag events containing b quarks with high efficiency. The data are compatible with the Standard Model expectation. The mean ratio of the eight measurements reported here to the Standard Model prediction is 1.055±0.031±0.037, where the first error is statistical and the second systematic.
We observe Bose–Einstein correlations in π0 pairs using back-to-back two jet hadronic events from Z0 decays in the data sample collected by the OPAL detector at LEP 1 from 1991 to 1995. Using a ...static Gaussian picture for the pion emitter source, we obtain the chaoticity parameter λ=0.55±0.10±0.10 and the source radius R=(0.59±0.08±0.05) fm. According to the JETSET and HERWIG Monte Carlo models, the Bose–Einstein correlations in our data sample largely connect π0s originating from the decays of different hadrons. Prompt pions formed at string break-ups or cluster decays only form a small fraction of the sample.
This case describes a province-wide network of Community Access Internet sites that was supported during the summers of 1996 and 1997 by Wire Nova Scotia (WiNS), a government-funded program to ...provide staffing, training and technical support for these centers. Remote management enabled the efficient and low-cost operation of a program involving 67 sites.PUBLICATION ABSTRACT
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