10,052 research outputs found
Optomechanics with molecules in a strongly pumped ring cavity
Cavity cooling of an atom works best on a cyclic optical transition in the
strong coupling regime near resonance, where small cavity photon numbers
suffice for trapping and cooling. Due to the absence of closed transitions a
straightforward application to molecules fails: optical pumping can lead the
particle into uncoupled states. An alternative operation in the far
off-resonant regime generates only very slow cooling due to the reduced
field-molecule coupling. We predict to overcome this by using a strongly driven
ring-cavity operated in the sideband cooling regime. As in the optomechanical
setups one takes advantage of a collectively enhanced field-molecule coupling
strength using a large photon number. A linearized analytical treatment
confirmed by full numerical quantum simulations predicts fast cooling despite
the off-resonant small single molecule - single photon coupling. Even ground
state cooling can be obtained by tuning the cavity field close to the
Anti-stokes sideband for sufficiently high trapping frequency. Numerical
simulations show quantum jumps of the molecules between the lowest two trapping
levels, which can be be directly and continuously monitored via scattered light
intensity detection
Strange hadronic stellar matter within the Brueckner-Bethe-Goldstone theory
In the framework of the non-relativistic Brueckner-Bethe-Goldstone theory, we
derive a microscopic equation of state for asymmetric and -stable matter
containing and hyperons. We mainly study the effects of
three-body forces (TBFs) among nucleons on the hyperon formation and the
equation of state (EoS). We find that, when TBFs are included, the stellar core
is almost equally populated by nucleons and hyperons. The resulting EoS, which
turns out to be extremely soft, has been used in order to calculate the static
structure of neutron stars. We obtain a value of the maximum mass of 1.26 solar
masses (1 solar mass ). Stellar rotations
increase this value by about 12%.Comment: 4 pages, Latex, 2 figures included. To appear in the Proceedings of
'' Bologna 2000 - Structure of the Nucleus at the Dawn of the Century'', May
29- June 3, 2000, Bologna, Ital
Structure of the hadron-quark mixed phase in protoneutron stars
We study the hadron-quark phase transition in the interior of hot
protoneutron stars, combining the Brueckner-Hartree-Fock approach for hadronic
matter with the MIT bag model or the Dyson-Schwinger model for quark matter. We
examine the structure of the mixed phase constructed according to different
prescriptions for the phase transition, and the resulting consequences for
stellar properties. We find important effects for the internal composition, but
only very small influence on the global stellar properties.Comment: 6 pages, 4 figure
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