150 nm films of Co and Ta were electron gun codeposited onto Si(100) and Si(111) substrates. The reactions of the components of the amorphous film were studied in the temperature range 873–1373 K by ...X-ray diffraction and transmission electron microscopy. The first phase to crystallize from the amorphous film was Co
2Ta which is stable in the temperature range 873–1073 K. CoSi appeared at 973 K and was stable up to 1073 K. The end products of the heat treatment were CoSi
2 close to the Si substrate and TaSi
2 as the outer layer. Complete separation of the silicides occurred, as expected from a system comprising a refractory metal and a near-noble metal on Si substrate. Reactions on Si(111) occur at a faster rate than on Si(100). These take place at higher temperatures than the formation temperatures of the respective silicides in the binary systems. No CoTaSi ternary phase was observed in the present work.
Results are presented on p + ω,ø and J/ψ production in p-W and 32S-W interactions at 200GeV/c/nucleon measured via the dimuon decay in a large kinematic region. The data are normalized to the charged ...particle multiplicity in the same rapidity interval. They have been collected using the HELIOS/3 muon spectrometer at the CERN SPS. The ratio Bσø/ (Bσρ + Bσω), where B is the relevant resonance µµ branching fraction, increases between proton and sulphur projectiles, and is somewhat enhanced going from peripheral to central S-W interactions. This results from an increase in the number of produced ø’s per charged particle. The ratio is measured in different intervals of pt and rapidity. It is not clearly dependent on pt, but is larger at higher rapidities. J/Ψ production, likewise normalized to charged multiplicity, is significantly lower in S-W compared to p-W interactions.
Ten patients with autonomic nervous system dysfunction (familial dysautonomia, juvenile diabetes, or Shy-Drager syndrome) were studied to assess the impact of their impairment on breathing during ...sleep. Several types of breathing dysfunction during sleep were identified independent of the patients' primary complaints. Obstructive sleep apnea syndrome was the most common; central sleep apnea and disturbances of te respiratory oscillator also were seen. Esophageal reflux was found to be the cause of some sleep-related problems. The observed respiratory irregularities were not associated with the usual cardiac response; a "decoupling" of heart rate from the respiratory cycle was noted during sleep in these patients.
We report a search for effects of large extra spatial dimensions in pp collisions at a center-of-mass energy of 1.8 TeV with the D0 detector, using events containing a pair of electrons or photons. ...The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% C.L. on the effective Planck scale between 1.0 and 1.4 TeV for several formalisms and numbers of extra dimensions.
The gluon momentum density
xg(
x,
Q
2) of the proton was extracted at
Q
2 = 20 GeV
2 for small values of
x between 4 × 10
−4 and 10
−2 from the scaling violations of the proton structure function
F
2 ...measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on
F
2 at low
x constrained by measurementsfrom NMC at larger
x; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small
x in comparison with the NMC result obtained at larger values of
x.
The upgraded D0 detector Abazov, V.M.; Abbott, B.; Abolins, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2006, Letnik:
565
Journal Article
Recenzirano
The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements ...to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.
Dijet production by almost real photons has been studied at HERA with the ZEUS detector. Jets have been identified using the cone algorithm. A cut on
x
γ
OBS, the fraction of the photon energy ...participating in the production of the two jets of highest transverse energy, is used to define cross sections sensitive to the parton distributions in the proton and in the photon. The dependence of the dijet cross sections on pseudorapidity has been measured for
x
γ
OBS ⩾ 0.75 and
x
γ
OBS < 0.75. The former is sensitive to the gluon momentum density in the proton. The latter is sensitive to the ginon in the photon. The cross sections are corrected for detector acceptance and compared to leading order QCD calculations.
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