2,367 research outputs found
Injury of Aboriginal and Torres Strait Islander people due to transport: 2005-06 to 2009-10
This report looks at death and serious injury of Aboriginal and Torres Strait Islander people in Australia due to transport accidents in the five-year period 2005-06 to 2009-10. Land transport accidents accounted for 26% of all fatal injury cases and 9% of all serious injury cases for Aboriginal and Torres Strait Islander people. The age-standardised rate for Aboriginal and Torres Strait Islander people was 2.8 times the rate for Other Australians for fatal cases, and 1.3 times the rate for Other Australians for serious injuries
Isospin-breaking two-nucleon force with explicit Delta-excitations
We study the leading isospin-breaking contributions to the two-nucleon
two-pion exchange potential due to explicit Delta degrees of freedom in chiral
effective field theory. In particular, we find important contributions due to
the delta mass splittings to the charge symmetry breaking potential that act
opposite to the effects induced by the nucleon mass splitting.Comment: 10 pages, 4 figure
Novel Properties of Frustrated Low Dimensional Magnets with Pentagonal Symmetry
In the context of magnetism, frustration arises when a group of spins cannot
find a configuration that minimizes all of their pairwise interactions
simultaneously. We consider the effects of the geometric frustration that
arises in a structure having pentagonal loops. Such five-fold loops can be
expected to occur naturally in quasicrystals, as seen for example in a number
of experimental studies of surfaces of icosahedral alloys. Our model considers
classical vector spins placed on vertices of a subtiling of the two dimensional
Penrose tiling, and interacting with nearest neighbors via antiferromagnetic
bonds. We give a set of recursion relations for this system, which consists of
an infinite set of embedded clusters with sizes that increase as a power of the
golden mean. The magnetic ground states of this fractal system are studied
analytically, and by Monte Carlo simulation.Comment: 7 pages, 7 figures, contribution to ICQ11 (Sapporo, Japan 2010)
conference proceeding
Global phase diagram of the spin-1 antiferromagnet with uniaxial anisotropy on the kagome lattice
The phase diagram of the XXZ spin-1 quantum magnet on the kagome lattice is
studied for all cases where the coupling is antiferromagnetic. In the
zero magnetic field case, the six previously introduced phases, found using
various methods, are: the nondegenerate gapped photon phase which breaks no
space symmetry or spin symmetry; the six-fold degenerate phase with plaquette
order, which breaks both time reversal symmetry and translational symmetry; the
"superfluid" (ferromagnetic) phase with an in-plane global U(1) symmetry
broken, when ; the nematic phase when and large; and a phase with resonating
dimers on each hexagon. We obtain all of these phases and partial information
about their quantum phase transitions in a single framework by studying
condensation of defects in the six-fold plaquette phases. The transition
between nematic phase and the six-fold degenerate plaquette phase is
potentially an unconventional second-order critical point. In the case of a
nonzero magnetic field along , another ordered phase with translation
symmetry broken is opened up in the nematic phase. Due to the breaking of
time-reversal symmetry by the field, a supersolid phase emerges between the
six-fold plaquette order and the superfluid phase. This phase diagram might be
accessible in nickel compounds, BF salts, or optical lattices of atoms with
three degenerate states on every site.Comment: 17 pages, 16 figure
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