61,521 research outputs found
Heavy Quarkonium
I review heavy quarkonium physics in view of recent experimental results. In
particular, I discuss new results on spin singlet states, photon and hadronic
transitions, D-states and discovery of yet unexplained narrow X(3872) state.Comment: 15 pages, 16 figures. 2nd version: minor changes in references and
text. Invited talk presented at the 21st International Symposium On Lepton
And Photon Interactions At High Energies (LP03) 11-16 August 2003, Batavia,
Illinoi
Dimerization-induced enhancement of the spin gap in the quarter-filled two-leg rectangular ladder
We report density-matrix renormalization group calculations of spin gaps in
the quarter-filled correlated two-leg rectangular ladder with bond-dimerization
along the legs of the ladder. In the small rung-coupling region, dimerization
along the leg bonds can lead to large enhancement of the spin gap.
Electron-electron interactions further enhance the spin gap, which is nonzero
for all values of the rung electron hopping and for arbitrarily small
bond-dimerization. Very large spin gaps, as are found experimentally in
quarter-filled band organic charge-transfer solids with coupled pairs of
quasi-one-dimensional stacks, however, occur within the model only for large
dimerization and rung electron hopping that are nearly equal to the hopping
along the legs. Coexistence of charge order and spin gap is also possible
within the model for not too large intersite Coulomb interaction
Notes on highest weight modules of the elliptic algebra
We discuss a construction of highest weight modules for the recently defined
elliptic algebra , and make several conjectures
concerning them. The modules are generated by the action of the components of
the operator on the highest weight vectors. We introduce the vertex
operators and through their commutation relations with the
-operator. We present ordering rules for the - and -operators and
find an upper bound for the number of linearly independent vectors generated by
them, which agrees with the known characters of -modules.Comment: Nonstandard macro package eliminate
A two component jet model for the X-ray afterglow flat segment in short GRB 051221A
In the double neutron star merger or neutron star-black hole merger model for
short GRBs, the outflow launched might be mildly magnetized and neutron rich.
The magnetized neutron-rich outflow will be accelerated by the magnetic and
thermal pressure and may form a two component jet finally, as suggested by
Vlahakis, Peng & K\"{o}nigl (2003). We show in this work that such a two
component jet model could well reproduce the multi-wavelength afterglow
lightcurves, in particular the X-ray flat segment, of short GRB 051221A. In
this model, the central engine need not to be active much longer than the
prompt ray emission.Comment: 11 pages, 2 figure; Accepted for publication by ApJ
Probabilistic teleportation of unknown two-particle state via POVM
We propose a scheme for probabilistic teleportation of unknown two-particle
state with partly entangled four-particle state via POVM. In this scheme the
teleportation of unknown two-particle state can be realized with certain
probability by performing two Bell state measurements, a proper POVM and a
unitary transformation.Comment: 5 pages, no figur
Metallic Triple Beam Resonator with Thick-film Printed Drive and Pickup
A triple beam resonator fabricated in 430S17 stainless steel with thick-film piezoelectric elements to drive and detect the vibrations is presented. The resonator substrate was fabricated by a simultaneous, double-sided photochemical etching technique and the thick-film piezoelectric elements were deposited by a standard screen-printing process. The combination of these two batch-fabrication processes provides the opportunity for mass production of the device at low cost. The resonator, a dynamically balanced triple beam tuning fork (TBTF) structure 23.5 mm long and 6.5 mm wide, has a favoured mode at 4.96 kHz with a Q-factor of 3630 operating in air
Optimal Controlled Teleportation
We give the analytic expressions of maximal probabilities of successfully
controlled teleportating an unknown qubit via every kind of tripartite states.
Besides, another kind of localizable entanglement is also determined.
Furthermore, we give the sufficient and necessary condition that a three-qubit
state can be collapsed to an EPR pair by a measurement on one qubit, and
characterize the three-qubit states that can be used as quantum channel for
controlled teleporting a qubit of unknown information with unit probability and
with unit fidelity.Comment: 4 page
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