54,825 research outputs found
Dissipation in a superconducting artificial atom due to a single non-equilibrium quasiparticle
We study a superconducting artificial atom which is represented by a single
Josephson junction or a Josephson junction chain, capacitively coupled to a
coherently driven transmission line, and which contains exactly one residual
quasiparticle (or up to one quasiparticle per island in a chain). We study the
dissipation in the atom induced by the quasiparticle tunneling, taking into
account the quasiparticle heating by the drive. We calculate the transmission
coefficient in the transmission line for drive frequencies near resonance and
show that, when the artificial atom spectrum is nearly harmonic, the intrinsic
quality factor of the resonance increases with the drive power. This
counterintuitive behavior is due to the energy dependence of the quasiparticle
density of states
A new root-knot nematode, Meloidogyne moensi n. sp. (Nematoda : Meloidogynidae), parasitizing Robusta coffee from Western Highlands, Vietnam
A new root-knot nematode, parasitizing Robusta coffee in Dak Lak Province, Western Highlands of Vietnam, is described as Meloidogyne moensi n. sp. Morphological and molecular analyses demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by a swollen body of females with a small posterior protuberance that elongated from ovoid to saccate; perineal patterns with smooth striae, continuous and low dorsal arch; lateral lines marked as a faint space or linear depression at junction of the dorsal and ventral striate; distinct phasmids; perivulval region free of striae; visible and wide tail terminus surrounding by concentric circles of striae; medial lips of females in dumbbell-shaped and slightly raised above lateral lips; female stylet is normally straight with posteriorly sloping stylet knobs; lip region of second stage juvenile (J2) is not annulated; medial lips and labial disc of J2 formed dumbbell shape; lateral lips are large and triangular; tail of J2 is conoid with rounded unstriated tail tip; distinct phasmids and hyaline; dilated rectum. Meloidogyne moensi n. sp. is most similar to M. africana, M. ottersoni by prominent posterior protuberance. Results of molecular analysis of rDNA sequences including the D2-D3 expansion regions of 28S rDNA, COI, and partial COII/16S rRNA of mitochondrial DNA support for the new species status
Jet measurements by the CMS experiment in pp and PbPb collisions
The energy loss of fast partons traversing the strongly interacting matter
produced in high-energy nuclear collisions is one of the most interesting
observables to probe the nature of the produced medium. The multipurpose
Compact Muon Solenoid (CMS) detector is well designed to measure these hard
scattering processes with its high resolution calorimeters and high precision
silicon tracker. Analyzing data from pp and PbPb collisions at a center-of-mass
energy of 2.76 TeV parton energy loss is observed as a significant imbalance of
dijet transverse momentum. To gain further understanding of the parton energy
loss mechanism the redistribution of the quenched jet energy was studied using
the transverse momentum balance of charged tracks projected onto the direction
of the leading jet. In contrast to pp collisions, a large fraction the momentum
balance for asymmetric jets is found to be carried by low momentum particles at
large angular distance to the jet axis. Further, the fragmentation functions
for leading and subleading jets were reconstructed and were found to be
unmodified compared to measurements in pp collisions. The results yield a
detailed picture of parton propagation in the hot QCD medium.Comment: 7 pages, 5 figures, Quark Matter 2011 conference proceeding
Irreducible representations of Upq[gl(2/2)]
The two-parametric quantum superalgebra and its
representations are considered. All finite-dimensional irreducible
representations of this quantum superalgebra can be constructed and classified
into typical and nontypical ones according to a proposition proved in the
present paper. This proposition is a nontrivial deformation from the one for
the classical superalgebra gl(2/2), unlike the case of one-parametric
deformations.Comment: Latex, 8 pages. A reference added in v.
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