91,873 research outputs found
Two-Photon Pathway to Ultracold Ground State Molecules of NaK
We report on high-resolution spectroscopy of ultracold fermionic
\nak~Feshbach molecules, and identify a two-photon pathway to the rovibrational
singlet ground state via a resonantly mixed \Bcres intermediate state.
Photoassociation in a Na-K atomic mixture and one-photon
spectroscopy on \nak~Feshbach molecules reveal about 20 vibrational levels of
the electronically excited \ctrip state. Two of these levels are found to be
strongly perturbed by nearby \Bsing states via spin-orbit coupling, resulting
in additional lines of dominant singlet character in the perturbed complex
{}, or of
resonantly mixed character in {}. The dominantly singlet level is used to locate
the absolute rovibrational singlet ground state via Autler-Townes spectroscopy. We demonstrate coherent
two-photon coupling via dark state spectroscopy between the predominantly
triplet Feshbach molecular state and the singlet ground state. Its binding
energy is measured to be 5212.0447(1) \cm, a thousand-fold improvement in
accuracy compared to previous determinations. In their absolute singlet ground
state, \nak~molecules are chemically stable under binary collisions and possess
a large electric dipole moment of Debye. Our work thus paves the way
towards the creation of strongly dipolar Fermi gases of NaK molecules.Comment: 23 pages, 8 figure
Ultracold Dipolar Gas of Fermionic NaK Molecules in their Absolute Ground State
We report on the creation of an ultracold dipolar gas of fermionic
NaK molecules in their absolute rovibrational and hyperfine
ground state. Starting from weakly bound Feshbach molecules, we demonstrate
hyperfine resolved two-photon transfer into the singlet ground state, coherently bridging a binding energy
difference of 0.65 eV via stimulated rapid adiabatic passage. The
spin-polarized, nearly quantum degenerate molecular gas displays a lifetime
longer than 2.5 s, highlighting NaK's stability against two-body chemical
reactions. A homogeneous electric field is applied to induce a dipole moment of
up to 0.8 Debye. With these advances, the exploration of many-body physics with
strongly dipolar Fermi gases of NaK molecules is in experimental
reach.Comment: 5 pages, 5 figure
16 x 25 Ge:Ga Detector Arrays for FIFI LS
We are developing two-dimensional 16 x 25 pixel detector arrays of both
unstressed and stressed Ge:Ga photoconductive detectors for far-infrared
astronomy from SOFIA. The arrays, based on earlier 5 x 5 detector arrays used
on the KAO, will be for our new instrument, the Far Infrared Field Imaging Line
Spectrometer (FIFI LS). The unstressed Ge:Ga detector array will cover the
wavelength range from 40 to 120 microns, and the stressed Ge:Ga detector array
from 120 to 210 microns. The detector arrays will be operated with multiplexed
integrating amplifiers with cryogenic readout electronics located close to the
detector arrays. The design of the stressed detector array and results of
current measurements on several prototype 16 pixel linear arrays are reported.
They demonstrate the feasibility of the current concept. ***This paper does not
include Figures due to astro-ph size limitations. Please download entire file
at http://fifi-ls.mpe-garching.mpg.de/spie.det.ps.gz ***Comment: 8 pages, SPIE Proceedings, Astronomical Telescopes and
Instrumentation 200
The quantization of the chiral Schwinger model based on the BFT-BFV formalism II
We apply an improved version of Batalin-Fradkin-Tyutin (BFT) Hamiltonian
method to the a=1 chiral Schwinger Model, which is much more nontrivial than
the a>1.\delta\xi$ in the measure. As a result, we explicitly
obtain the fully gauge invariant partition function, which includes a new type
of Wess-Zumino (WZ) term irrelevant to the gauge symmetry as well as usual WZ
action.Comment: 17 pages, To be published in J. Phys.
Protein transduction: A novel tool for tissue regeneration
Tissue regeneration in humans is limited and excludes vitals organs like heart and brain. Transformation experiments with oncogenes like T antigen have shown that retrodifferentiation of the respective cells is possible but hard to control. To bypass the risk of cancer formation a protein therapy approach has been developed. The transient delivery of proteins rather than genes could still induce terminallydifferentiated cells to reenter the cell cycle. This approach takes advantage of proteintransducing domains that mediate the transfer of cargo proteins into cells. The goal of this brief review is to outline the basics of protein transduction and to discuss potential applications for tissue regeneration
Generalized BFT Formalism of Electroweak Theory in the Unitary Gauge
We systematically embed the SU(2)U(1) Higgs model in the unitary
gauge into a fully gauge-invariant theory by following the generalized BFT
formalism. We also suggest a novel path to get a first-class Lagrangian
directly from the original second-class one using the BFT fields.Comment: 14 pages, Latex, no figure
Observation of b symmetry vibrational levels of the SO \tilde{\mbox{C}} B state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants
The B state of SO has a double-minimum
potential in the antisymmetric stretch coordinate, such that the minimum energy
geometry has nonequivalent SO bond lengths. However, low-lying levels with odd
quanta of antisymmetric stretch (b vibrational symmetry) have not
previously been observed because transitions into these levels from the
zero-point level of the state are vibronically forbidden.
We use IR-UV double resonance to observe the b vibrational levels of the
state below 1600 cm of vibrational excitation. This
enables a direct characterization of the vibrational level staggering that
results from the double-minimum potential. In addition, it allows us to
deperturb the strong -axis Coriolis interactions between levels of a and
b vibrational symmetry, and to determine accurately the vibrational
dependence of the rotational constants in the distorted
electronic state
Does three-tangle properly quantify the three-party entanglement for Greenberger-Horne-Zeilinger-type states?
Some mixed states composed of only GHZ states can be expressed in terms of
only W-states. This fact implies that such states have vanishing three-tangle.
One of such rank-3 states, , is explicitly presented in this paper.
These results are used to compute analytically the three-tangle of a rank-4
mixed state composed of four GHZ states. This analysis with
considering Bloch sphere of qudit system allows us to derive the
hyper-polyhedron. It is shown that the states in this hyper-polyhedron have
vanishing three-tangle. Computing the one-tangles for and ,
we prove the monogamy inequality explicitly. Making use of the fact that the
three-tangle of is zero, we try to explain why the W-class in the
whole mixed states is not of measure zero contrary to the case of pure states.Comment: 10 pages, no figure V2: new calculational results are included. 11
pages: V3 accepted in the Rapid Communication of PRA, 4 pages (two column
Rotating Black Holes at Future Colliders. III. Determination of Black Hole Evolution
TeV scale gravity scenario predicts that the black hole production dominates
over all other interactions above the scale and that the Large Hadron Collider
will be a black hole factory. Such higher dimensional black holes mainly decay
into the standard model fields via the Hawking radiation whose spectrum can be
computed from the greybody factor. Here we complete the series of our work by
showing the greybody factors and the resultant spectra for the brane localized
spinor and vector field emissions for arbitrary frequencies. Combining these
results with the previous works, we determine the complete radiation spectra
and the subsequent time evolution of the black hole. We find that, for a
typical event, well more than half a black hole mass is emitted when the hole
is still highly rotating, confirming our previous claim that it is important to
take into account the angular momentum of black holes.Comment: typoes in eqs(82)-(84) corrected; version to appear in Phys. Rev. D;
references and a footnote added; same manuscript with high resolution
embedded figures available on
http://www.gakushuin.ac.jp/univ/sci/phys/ida/paper
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