26,835 research outputs found
Inclusive Breakup Theory of Three-Body Halos
We present a recently developed theory for the inclusive breakup of
three-fragment projectiles within a four-body spectator model
\cite{CarPLB2017}, for the treatment of the elastic and inclusive non-elastic
break up reactions involving weakly bound three-cluster nuclei in
/ collisions. The four-body theory is an extension of the
three-body approaches developed in the 80's by Ichimura, Autern and Vincent
(IAV) \cite{IAV1985}, Udagawa and Tamura (UT) \cite{UT1981} and Hussein and
McVoy (HM) \cite{HM1985}. We expect that experimentalists shall be encouraged
to search for more information about the system in the elastic
breakup cross section and that also further developments and extensions of the
surrogate method will be pursued, based on the inclusive non-elastic breakup
part of the spectrum.Comment: 8 pages, 3 figures, Contribution to the Proceedings of Fusion17:
"International Conference on Heavy-Ion Collisions at Near-Barrier Energies",
20-24 February 2017 Hobart, Tasmania, Australi
Active Galactic Nuclei with Starbursts: Sources for Ultra High Energy Cosmic Rays
Ultra high energy cosmic ray events presently show a spectrum, which we
interpret here as galactic cosmic rays due to a starburst in the radio galaxy
Cen A pushed up in energy by the shock of a relativistic jet. The knee feature
and the particles with energy immediately higher in galactic cosmic rays then
turn into the bulk of ultra high energy cosmic rays. This entails that all
ultra high energy cosmic rays are heavy nuclei. This picture is viable if the
majority of the observed ultra high energy events come from the radio galaxy
Cen A, and are scattered by intergalactic magnetic fields across most of the
sky.Comment: 4 pages, 1 figure, proceedings of "High-Energy Gamma-rays and
Neutrinos from Extra-Galactic Sources", Heidelber
Averaging out magnetic forces with fast rf-sweeps in an optical trap for metastable chromium atoms
We introduce a novel type of time-averaged trap, in which the internal state
of the atoms is rapidly modulated to modify magnetic trapping potentials. In
our experiment, fast radiofrequency (rf) linear sweeps flip the spin of atoms
at a fast rate, which averages out magnetic forces. We use this procedure to
optimize the accumulation of metastable chomium atoms into an optical dipole
trap from a magneto-optical trap. The potential experienced by the metastable
atoms is identical to the bare optical dipole potential, so that this procedure
allows for trapping all magnetic sublevels, hence increasing by up to 80
percent the final number of accumulated atoms.Comment: 4 pages, 4 figure
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