617 research outputs found
Probing the states through radiative decays
In this work, we have adopted the spin rearrangement scheme in the heavy
quark limit and extensively investigated three classes of the radiative decays:
, , , corresponding to the
electromagnetic transitions between one molecular state and bottomonium, one
bottomonium and molecular state, and two molecular states respectively. We also
extend the same formalism to study the radiative decays of the molecular states
with hidden charm. We have derived some model independent ratios when the
initial or final states belong to the same spin flavor multiplet. Future
experimental measurement of these ratios will test the molecular picture and
explore the underlying structures of the states.Comment: 21 pages, 10 tables Accepted by Phys.Rev.
Effect of source tampering in the security of quantum cryptography
The security of source has become an increasingly important issue in quantum
cryptography. Based on the framework of measurement-device-independent
quantum-key-distribution (MDI-QKD), the source becomes the only region
exploitable by a potential eavesdropper (Eve). Phase randomization is a
cornerstone assumption in most discrete-variable (DV-) quantum communication
protocols (e.g., QKD, quantum coin tossing, weak coherent state blind quantum
computing, and so on), and the violation of such an assumption is thus fatal to
the security of those protocols. In this paper, we show a simple quantum
hacking strategy, with commercial and homemade pulsed lasers, by Eve that
allows her to actively tamper with the source and violate such an assumption,
without leaving a trace afterwards. Furthermore, our attack may also be valid
for continuous-variable (CV-) QKD, which is another main class of QKD protocol,
since, excepting the phase random assumption, other parameters (e.g.,
intensity) could also be changed, which directly determine the security of
CV-QKD.Comment: 9 pages, 6 figure
Association between ACE gene I/D polymorphisms and hyperandrogenism in women with Polycystic Ovary Syndrome (PCOS) and controls
2-[1-(4-Chlorobenzoyl)pyrrolidin-2-yl]-4,4,5,5-tetramethyl-4,5-dihydroimidazole-1-oxyl-3-oxide
In the title compound, C18H23ClN3O3, the imidazole ring system has an envelope conformation, whereas the nitronyl nitroxide unit displays a half-chair or twisted conformation. In the crystal, C—H⋯O hydrogen bonds build up a three-dimensional network
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