Search results for "gase"
showing 10 items of 1216 documents
"Table 25" of "Studies of W boson plus jets production in p\bar{p} collisions at sqrt(s)=1.96 TeV"
2013
Differential production cross-section, normalized to the measured inclusive W boson cross-section, as a function of W boson pT for events with four or more jets produced in association with a W boson. First uncertainty is statistical, second uncertainty is systematic.
"Table 11" of "Studies of W boson plus jets production in p\bar{p} collisions at sqrt(s)=1.96 TeV"
2013
Differential production cross-section, normalized to the measured inclusive W boson cross-section, as a function of lepton pseudorapidity for events with three or more jets produced in association with a W boson. First uncertainty is statistical, second uncertainty is systematic.
"Table 9" of "Studies of W boson plus jets production in p\bar{p} collisions at sqrt(s)=1.96 TeV"
2013
Differential production cross-section, normalized to the measured inclusive W boson cross-section, as a function of lepton pseudorapidity for events with one or more jets produced in association with a W boson. First uncertainty is statistical, second uncertainty is systematic.
"Table 12" of "Studies of W boson plus jets production in p\bar{p} collisions at sqrt(s)=1.96 TeV"
2013
Differential production cross-section, normalized to the measured inclusive W boson cross-section, as a function of lepton pseudorapidity for events with four or more jets produced in association with a W boson. First uncertainty is statistical, second uncertainty is systematic.
"Table 2" of "Measurement of the shape of the boson transverse momentum distribution in p anti-p ---> Z / gamma* ---> e+ e- + X events produced…
2008
Correlation matrix for all rapidity Z bosons for the 12 bins used for PT < 30.
FTICR analysis of the magnetic trapping mode of the electron beam ion trap
1996
Abstract An electron beam ion trap is used to produce and confine highly-charged atomic ions in an energetic electron beam (electron trapping mode). After switching off the electron beam the ions remain trapped due to the external magnetic and electric fields. We have investigated the properties of this magnetic trapping mode by use of Fourier transform ion cyclotron resonance mass spectrometry. We found that the number of highly charged ions and the relative species abundance is nearly the same just before and just after turning off the electron beam. The electron trapping mode thus represents an ideal method for filling the trap in situ without the losses associated with transferring the …
Direct observation of second-order atom tunnelling
2007
Tunnelling of material particles through a classically impenetrable barrier constitutes one of the hallmark effects of quantum physics. When interactions between the particles compete with their mobility through a tunnel junction, intriguing novel dynamical behaviour can arise where particles do not tunnel independently. In single-electron or Bloch transistors, for example, the tunnelling of an electron or Cooper pair can be enabled or suppressed by the presence of a second charge carrier due to Coulomb blockade. Here we report on the first direct and time-resolved observation of correlated tunnelling of two interacting atoms through a barrier in a double well potential. We show that for we…
Observation of the Kibble-Zurek scaling law for defect formation in ion crystals
2013
Traversal of a symmetry-breaking phase transition at finite rates can lead to causally separated regions with incompatible symmetries and the formation of defects at their boundaries, which has a crucial role in quantum and statistical mechanics, cosmology and condensed matter physics. This mechanism is conjectured to follow universal scaling laws prescribed by the Kibble-Zurek mechanism. Here we determine the scaling law for defect formation in a crystal of 16 laser-cooled trapped ions, which are conducive to the precise control of structural phases and the detection of defects. The experiment reveals an exponential scaling of defect formation γ(β), where γ is the rate of traversal of the …
Trapping of laser-vaporized alkali metal atoms in rare-gas matrices
1999
Abstract Alkali metal atoms prepared by laser ablation of solid Li and Na are trapped in Ar, Kr, and Xe matrices and studied by electron paramagnetic resonance spectroscopy (EPR) at 15 K. Evidence for tight trapping sites, not observed for atoms generated by conventional Knudsen oven techniques, is presented. The novel tight trapping sites are characterized by a large increase in the isotropic hyperfine coupling constant and a simultaneous decrease in the isotropic g -value. Based on the EPR data, it is suggested that the observed tight trapping corresponds to single substitution of lattice atoms in Ar, Kr, and Xe matrices.
Microscopic study of He2-SF6 trimers
2003
The He2-SF6 trimers, in their different He isotopic combinations, are studied in the framework of both the correlated Jastrow approach and the correlated hyperspherical harmonics (CHH) expansion method. The energetics and structure of the He-SF6 dimers are analyzed, and the existence of a characteristic rotational band in the excitation spectrum is discussed, as well as the isotopic differences. The binding energies and the spatial properties of the trimers, in their ground and lowest lying excited states, obtained by the Jastrow ansatz are in excellent agreement with the results of the converged CHH expansion. The introduction of the He-He correlation makes all trimers bound by largely sup…