4,745 research outputs found
New results on collectivity with ATLAS
The collective phenomena are observed not only in heavy ion collisions, but
also in the proton-nucleus and in high-multiplicity collisions. The latest
results from this area obtained in ATLAS are presented. In +Pb collisions
the emission source of particles is measured using the HBT method. The analysis
of +Pb data collected in 2016 provides information on the elliptic flow of
charged hadrons and muons. Low multiplicity events from , +Pb and
peripheral Pb+Pb collisions are studied with the cumulant methods. A deeper
understanding of Pb+Pb collisions is provided by the analysis of longitudinal
fluctuations of the collective flow parameters.Comment: 6 pages, 8 figure
Measurements of minimum bias events, underlying event and particle production properties in ATLAS
The measurements of the minimum bias events provide valuable information on
the basic properties of the interactions. The results at the new highest
energy of collisions, = 13 TeV, obtained using the ATLAS
detector, are shown. They include distributions of charged particle
pseudorapidity density, transverse momentum and multiplicity. The properties of
the underlying event, determined with respect to a leading high-
particle, are also presented. In both cases the new results are compared with
those from earlier studies of the collisions at = 7 TeV.Comment: Proceedings of the 23rd Low-x Meeting, Sandomierz, Poland, September
1-5, 2015, 11 pages, 11 figure
Phonon-assisted relaxation between hole states in quantum dot molecules
We study theoretically phonon-assisted relaxation and inelastic tunneling of
holes in a double quantum dot. We derive hole states and relaxation rates from
kp Hamiltonians and show that there is a finite distance between the dots where
lifetimes of hole states are very long which is related to vanishing tunnel
coupling. We show also that the light hole admixture to hole states can
considerably affect the hole relaxation rates even though its magnitude is very
small
High-precision Orbital and Physical Parameters of Double-lined Spectroscopic Binary Stars—HD78418, HD123999, HD160922, HD200077, and HD210027
We present high-precision radial velocities (RVs) of double-lined spectroscopic binary stars HD78418, HD123999, HD160922, HD200077, and HD210027. They were obtained based on the high-resolution echelle spectra collected with the Keck I/HIRES, Shane/CAT/Hamspec, and TNG/Sarge telescopes/spectrographs over the years 2003-2008 as part of the TATOOINE search for circumbinary planets. The RVs were computed using our novel iodine cell technique for double-line binary stars, which relies on tomographically disentangled spectra of the components of the binaries. The precision of the RVs is of the order of 1-10 m s^(–1), and to properly model such measurements one needs to account for the light-time effect within the binary's orbit, relativistic effects, and RV variations due to tidal distortions of the components of the binaries. With such proper modeling, our RVs combined with the archival visibility measurements from the Palomar Testbed Interferometer (PTI) allow us to derive very precise spectroscopic/astrometric orbital and physical parameters of the binaries. In particular, we derive the masses, the absolute K- and H-band magnitudes, and the parallaxes. The masses together with the absolute magnitudes in the K and H bands enable us to estimate the ages of the binaries. These RVs allow us to obtain some of the most accurate mass determinations of binary stars. The fractional accuracy in msin i only, and hence based on the RVs alone, ranges from 0.02% to 0.42%. When combined with the PTI astrometry, the fractional accuracy in the masses in the three best cases ranges from 0.06% to 0.5%. Among them, the masses of HD210027 components rival in precision the mass determination of the components of the relativistic double pulsar system PSR J0737 – 3039. In the near future, for double-lined eclipsing binary stars we expect to derive masses with a fractional accuracy of the order of up to ~0.001% with our technique. This level of precision is an order of magnitude higher than of the most accurate mass determination for a body outside the solar system—the double neutron star system PSR B1913+16
Improvement of speech recognition by nonlinear noise reduction
The success of nonlinear noise reduction applied to a single channel
recording of human voice is measured in terms of the recognition rate of a
commercial speech recognition program in comparison to the optimal linear
filter. The overall performance of the nonlinear method is shown to be
superior. We hence demonstrate that an algorithm which has its roots in the
theory of nonlinear deterministic dynamics possesses a large potential in a
realistic application.Comment: see urbanowicz.org.p
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