2,241 research outputs found
Anisotropic flow of identified particles in Pb--Pb collisions at TeV
Anisotropic flow is sensitive to the shear and bulk ()
viscosity of the quark-gluon plasma created in heavy-ion collisions, as well as
the initial state of such collisions and hadronization mechanisms. In these
proceedings, elliptic () and higher harmonic () flow
coefficients of , , p and the
-meson, are presented for Pb-Pb collisions at the highest-ever
center-of-mass energy of = 5.02 TeV. Comparisons to
hydrodynamic calculations (IP-Glasma, MUSIC, UrQMD) are shown to constrain the
initial conditions and viscosity of the medium
Anisotropic flow of inclusive and identified particles in Pb--Pb collisions at TeV
Anisotropic flow measurements constrain the shear and bulk
() viscosity of the quark-gluon plasma created in heavy-ion
collisions, as well as give insight into the initial state of such collisions
and hadronization mechanisms. In these proceedings, elliptic () and higher
harmonic () flow coefficients of , ,
p and the -meson,measured in Pb--Pb collisions at
the highest-ever center-of-mass energy of = 5.02 TeV, are
presented.Comment: 4 pages, 5 figure
Experimental investigation of cloud droplet dynamics at the research station Schneefernerhaus
The collision–coalescence of droplets in turbulence is responsible for
the fast growth of cloud droplets from 15 to
40 ÎĽm in radius, but how exactly it causes this quick
growth is not understood. The growth of cloud droplets through
collision–coalescence is governed by two quantities: the radial
distribution function (RDF), which is a measure for the degree of
clustering the droplets exhibit, and the radial relative velocity (RRV),
which is a measure for the velocity difference between nearby droplets.
In this thesis an in-situ experiment is described, that is designed to
simultaneously measure all aspects relevant to turbulent
collision–coalescence of cloud droplets: droplet motions, droplet
sizes, and properties of the turbulent carrier flow. The experiment is
located in the German Alps, on top of the environmental research station
Schneefernerhaus, at an altitude of 2650 m where clouds
naturally occur. Droplet motions are measured using a particle tracking
setup; turbulence statistics are measured with a sonic anemometer that
is mounted close by.
Droplet sizes are measured using a novel technique that relies only on
the droplet intensities as recorded by the particle tracking experiment.
A complete derivation of the technique based on Lorentz-Mie scattering
theory is given. Droplet sizes measured with this approach are compared
to those obtained with a holographic instrument.
The experiment is used to measure droplet rms accelerations and the
radial distribution function conditioned on (pairs of) Stokes numbers.
Both qualitatively agree with literature values, but further research is
needed to see why there is no quantitative agreement.
This work was supported by the European Union Horizon 2020 program, in particular Marie Skłodowska-Curie actions under Grant Agreement No. 675675."2021-11-2
Numerical Methods for the Hyperbolic Monge-Ampère Equation with Applications to Optical Design
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