2,204 research outputs found
Search for magnetic monopoles using proportional counters filled with helium gas
Slow magnetic monopoles in cosmic rays have been searched at sea level with the detector which consists of seven layers of proportional counters filled with a mixture of He + 20% CH4. The velocities and the energy losses of the incident particles are measured. The upper limit of flux for the monopoles in the velocity range of 1 x 0.001 Beta 4 x 0.001 is 2.78 x 10 to the minus 12th power square centimeters sr sec of 90% confidence level
Anomalous Angular Dependence of the Dynamic Structure Factor near Bragg Reflections: Graphite
The electron energy-loss function of graphite is studied for momentum
transfers q beyond the first Brillouin zone. We find that near Bragg
reflections the spectra can change drastically for very small variations in q.
The effect is investigated by means of first principle calculations in the
random phase approximation and confirmed by inelastic x-ray scattering
measurements of the dynamic structure factor S(q,\omega). We demonstrate that
this effect is governed by crystal local field effects and the stacking of
graphite. It is traced back to a strong coupling between excitations at small
and large momentum transfers
Noncommutative U(1) Instantons in Eight Dimensional Yang-Mills Theory
We study the noncommutative version of the extended ADHM construction in the
eight dimensional U(1) Yang-Mills theory. This construction gives rise to the
solutions of the BPS equations in the Yang-Mills theory, and these solutions
preserve at least 3/16 of supersymmetries. In a wide subspace of the extended
ADHM data, we show that the integer which appears in the extended ADHM
construction should be interpreted as the -brane charge rather than the
-brane charge by explicitly calculating the topological charges in the case
that the noncommutativity parameter is anti-self-dual. We also find the
relationship with the solution generating technique and show that the integer
can be interpreted as the charge of the -brane bound to the -brane
with the -field in the case that the noncommutativity parameter is
self-dual.Comment: 22 page
Thermochemical stabilities and structures of the cluster ions OCS+, S2+, H+(OCS), and C2H5+ with OCS molecules in the gas phase
Resonant inelastic x-ray scattering in single-crystal superconducting PrFeAsO0.7
Resonant inelastic x-ray scattering (RIXS) spectra at the Fe K-edge were
measured for a single crystal of the iron oxypnictide superconductor PrFeAsO0.7
(Tc=42 K). They disclose a weak, broad feature centered around 4.5 eV energy
loss, which is slightly resonantly enhanced when the incident energy is tuned
in the vicinity of the 4p white line. We tentatively ascribe it to the
charge-transfer excitation between As 4p and Fe 3d.Comment: 2 pages, 2 figure
Simultaneous Measurement of Regional Cerebral Blood Flow Changes Using [15O]H2O-PET and Functional Near-Infrared Spectroscopy (fNIRS): A Pilot Study
Donepezil Binding to Acetylcholinesterase and Response to Donepezil Therapy in Parkinson\u27s Disease Dementia: [5-11C-methoxy]Donepezil-PET Study
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