493 research outputs found
High-quality polarization entanglement state preparation and manipulation in standard telecommunication channels
We report a novel and simple approach for generating near-perfect quality
polarization entanglement in a fully guided-wave fashion. Both deterministic
pair separation into two adjacent telecommunication channels and the paired
photons' temporal walk-off compensation are achieved using standard fiber
components. Two-photon interference experiments are performed, both for
quantitatively demonstrating the relevance of our approach, and for
manipulating the produced state between bosonic and fermionic symmetries. The
compactness, versatility, and reliability of this configuration makes it a
potential candidate for quantum communication applications.Comment: 6 figure
The N=28 shell closure; from N=Z to the neutron drip line
The evolution of the N=28 neutron shell closure is studied in the N=28
isotones from neutron drip line's Mg to N=Z doubly magic Ni. It
is found that the N=28 closure vanishes at Z=12 in favor of a deformed ground
state. For Z=14 and Z=16 closed shell and intruder configurations are almost
degenerate, leading to highly mixed ground states and to very low lying excited
0 states. For Z20 the intruder states are always above the closed shell
ground states. We examine their structure and their possible existence as
collective yrare bands of well defined particle-hole character
Shells and Shapes in the N=28 isotones
International audienceNew experimental results on 43S and 44S reveal that these nuclei are located in a transitional region of shape coexistence between the spherical 48Ca and the oblate 42Si. The origin of the deformation is discussed in terms of the evolution of the single particle energy levels leading to the compression of the energy difference of the orbitals in the sd and pf shells for protons and neutrons, respectively. Therefore, due to quadrupole excitations across the Z = 14 and N = 28 gaps, the intruder configuration in the neutron rich S isotopes became the ground state
Unveiling the intruder deformed 0 state in Si
The 0 state in Si has been populated at the {\sc Ganil/Lise3}
facility through the -decay of a newly discovered 1 isomer in
Al of 26(1) ms half-life. The simultaneous detection of pairs
allowed the determination of the excitation energy E(0)=2719(3) keV and
the half-life T=19.4(7) ns, from which an electric monopole strength of
(E0)=13.0(0.9) was deduced. The 2 state is
observed to decay both to the 0 ground state and to the newly observed
0 state (via a 607(2) keV transition) with a ratio
R(2)=1380(717). Gathering all
information, a weak mixing with the 0 and a large deformation parameter
of =0.29(4) are found for the 0 state, in good agreement with
shell model calculations using a new {\sc sdpf-u-mix} interaction allowing
\textit{np-nh} excitations across the N=20 shell gap.Comment: 5 pages, 3 figures, accepted for publication in Physical Review
Letter
Shell Evolution towards Ni 78: Low-Lying States in Cu 77
The level structure of the neutron-rich Cu77 nucleus is investigated through β-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of Ni77 are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in Cu77 are identified for the first time by correlating γ rays with the β decay of Ni77, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near Ni78 and suggests a single-particle nature for both the 5/21- and 3/21- states in Cu77, leading to doubly magic Ni78. © 2017 American Physical Society
Torque: topology-free querying of protein interaction networks
Torque is a tool for cross-species querying of protein–protein interaction networks. It aims to answer the following question: given a set of proteins constituting a known complex or a pathway in one species, can a similar complex or pathway be found in the protein network of another species? To this end, Torque seeks a matching set of proteins that are sequence similar to the query proteins and span a connected region of the target network, while allowing for both insertions and deletions. Unlike existing approaches, Torque does not require knowledge of the interconnections among the query proteins. It can handle large queries of up to 25 proteins. The Torque web server is freely available for use at http://www.cs.tau.ac.il/∼bnet/torque.html
Prolate-Spherical Shape Coexistence at N=28 in S
The structure of S has been studied using delayed and
electron spectroscopy at \textsc{ganil}. The decay rates of the 0
isomeric state to the 2 and 0 states have been measured for the
first time, leading to a reduced transition probability
B(E2~:~20= 8.4(26)~efm and a monopole
strength (E0~:~00
=~8.7(7)10. Comparisons to shell model calculations point
towards prolate-spherical shape coexistence and a phenomenological two level
mixing model is used to extract a weak mixing between the two configurations.Comment: 5 pages, 3 figures, accepted for publication in Physical Review
Letter
Spectroscopy of F
The structure of the weakly-bound F odd-odd nucleus,
produced from Na nuclei, has been investigated at GANIL by means of
the in-beam -ray spectroscopy technique. A single -line is
observed at 657(7) keV in F which has been ascribed to the decay of
the excited J= state to the J=1 ground state. The possible presence of
intruder negative parity states in F is also discussed.Comment: 3 pages, 1 figure, accepted for publication in Physical Review
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