22,626 research outputs found
Speculations on Isolated Lepton Events at HERA
Speculations on mechanisms which might be responsible for events with an
isolated high p_T lepton, a hadron jet and missing energy, as observed in the
H1 experiment at HERA, are discussed.Comment: LaTeX, 6 pages, 2 figures, presented at the XXXI Conference of
Theoretical Physics "Matter to the Deepest", Ustron, Poland, September 5-11,
200
Inflation with blowing-up solution of cosmological constant problem
The cosmological constant problem is how one chooses, without fine-tuning,
one singular point for the 4D cosmological constant. We argue
that some recently discovered {\it weak self-tuning} solutions can be viewed as
blowing-up this one point into a band of some parameter. These weak self-tuning
solutions may have a virtue that only de Sitter space solutions are allowed
outside this band, allowing an inflationary period. We adopt the hybrid
inflation at the brane to exit from this inflationary phase and to enter into
the standard Big Bang cosmology.Comment: LaTeX file of 20 pages including 2 eps figure
Magnetic Excitations and Continuum of a Field-Induced Quantum Spin Liquid in -RuCl
We report on terahertz spectroscopy of quantum spin dynamics in
-RuCl, a system proximate to the Kitaev honeycomb model, as a
function of temperature and magnetic field. An extended magnetic continuum
develops below the structural phase transition at K. With the onset
of a long-range magnetic order at K, spectral weight is transferred to
a well-defined magnetic excitation at meV, which is
accompanied by a higher-energy band at meV. Both
excitations soften in magnetic field, signaling a quantum phase transition at
T where we find a broad continuum dominating the dynamical response.
Above , the long-range order is suppressed, and on top of the continuum,
various emergent magnetic excitations evolve. These excitations follow clear
selection rules and exhibit distinct field dependencies, characterizing the
dynamical properties of the field-induced quantum spin liquid
A Characterization of Visibility Graphs for Pseudo-Polygons
In this paper, we give a characterization of the visibility graphs of
pseudo-polygons. We first identify some key combinatorial properties of
pseudo-polygons, and we then give a set of five necessary conditions based off
our identified properties. We then prove that these necessary conditions are
also sufficient via a reduction to a characterization of vertex-edge visibility
graphs given by O'Rourke and Streinu
Reconstruction of Fundamental SUSY Parameters
We summarize methods and expected accuracies in determining the basic
low-energy SUSY parameters from experiments at future ee linear
colliders in the TeV energy range, combined with results from LHC. In a second
step we demonstrate how, based on this set of parameters, the fundamental
supersymmetric theory can be reconstructed at high scales near the grand
unification or Planck scale. These analyses have been carried out for minimal
supergravity [confronted with GMSB for comparison], and for a string effective
theory.Comment: 8 pages, latex, 7 figures, expanded version of contributions to the
proceedings of ICHEP.2002 (Amstersdam) and LCWS.2002 (Jeju Island
Charge and current fluctuations in a superconducting single electron transistor near a Cooper pair resonance
We analyze charge tunneling statistics and current noise in a superconducting
single-electron transistor in a regime where the Josephson-quasiparticle cycle
is the dominant mechanism of transport. Due to the interplay between Coulomb
blockade and Josephson coherence, the probability distribution for tunneling
events strongly deviates from a Poissonian and displays a pronounced even--odd
asymmetry in the number of transmitted charges. The interplay between charging
and coherence is reflected also in the zero-frequency current noise which is
significantly quenched when the quasi-particle tunneling rates are comparable
to the coherent Cooper-pair oscillation frequency. Furthermore the finite
frequency spectrum shows a strong enhancement near the resonant transition
frequency for Josephson tunneling.Comment: 10 pages, 11 figure
Shot Noise and Full Counting Statistics from Non-equilibrium Plasmons in Luttinger-Liquid Junctions
We consider a quantum wire double junction system with each wire segment
described by a spinless Luttinger model, and study theoretically shot noise in
this system in the sequential tunneling regime. We find that the
non-equilibrium plasmonic excitations in the central wire segment give rise to
qualitatively different behavior compared to the case with equilibrium
plasmons. In particular, shot noise is greatly enhanced by them, and exceeds
the Poisson limit. We show that the enhancement can be explained by the
emergence of several current-carrying processes, and that the effect disappears
if the channels effectively collapse to one due to, {\em e.g.}, fast plasmon
relaxation processes.Comment: 9 pages; IOP Journal style; several changes in the tex
Valuable rubidium extraction from potassium reduced seawater brine
© 2017 Elsevier Ltd Extraction of rubidium (Rb) which is an economically valuable metal from seawater reverse osmosis (SWRO) brine is beneficial. However, potassium (K) in SWRO brine hinders Rb extraction. Natural clinoptilolite zeolite in powder form was able to selectively remove K from SWRO brine (Langmuir maximum sorption, Qmax (cal.) = 57.47 ± 0.09 mg/g). An integrated submerged membrane sorption reactor (SMSR) containing zeolite powder achieved 65% K removal from SWRO brine. Periodic replacement of zeolite in SMSR, coupled with membrane backwashing was effective in maintaining a high K removal efficiency and a stable transmembrane pressure. Less than 5% Rb losses occurred along with K sorption, establishing the high K selectivity by zeolite in SWRO brine. Utilization of K loaded zeolite as a slow release fertilizer would be beneficial for agriculture. In SWRO brine with reduced K contents, the Rb sorption efficiency of polymer encapsulated potassium copper hexacyanoferrate (KCuFC(PAN)) sorbent, increased significantly from 18% to 83%
- âŠ