645 research outputs found
Songs of a hidden orchid: Yuefu and Gexing by Li He (791-817)
LEI Universiteit LeidenAsian Studie
High-dimensional unitary transformations and boson sampling on temporal modes using dispersive optics
A major challenge for postclassical boson sampling experiments is the need for a large number of coupled optical modes, detectors, and single-photon sources. Here we show that these requirements can be greatly eased by time-bin encoding and dispersive optics-based unitary transformations. Detecting consecutively heralded photons after time-independent dispersion performs boson sampling from unitaries for which an efficient classical algorithm is lacking. We also show that time-dependent dispersion can implement general single-particle unitary operations. More generally, this scheme promises an efficient architecture for a range of other linear optics experiments.United States. Air Force Office of Scientific Research. Multidisciplinary University Research Initiative (Grant FA9550-14-1-0052
Suspended liquid particle disturbance on laser-induced blast wave and low density distribution
The impurity effect of suspended liquid particles on the laser-induced gas breakdown was experimentally investigated in quiescent gas. The focus of this study is the investigation of the influence of the impurities on the shock wave structure as well as the low density distribution. A 532 nm Nd:YAG laser beam with an 188 mJ/pulse was focused on the chamber filled with suspended liquid particles 0.9 ± 0.63 μm in diameter. Several shock waves are generated by multiple gas breakdowns along the beam path in the breakdown with particles. Four types of shock wave structures can be observed: (1) the dual blast waves with a similar shock radius, (2) the dual blast waves with a large shock radius at the lower breakdown, (3) the dual blast waves with a large shock radius at the upper breakdown, and (4) the triple blast waves. The independent blast waves interact with each other and enhance the shock strength behind the shock front in the lateral direction. The triple blast waves lead to the strongest shock wave in all cases. The shock wave front that propagates toward the opposite laser focal spot impinges on one another, and thereafter a transmitted shock wave (TSW) appears. The TSW interacts with the low density core called a kernel; the kernel then longitudinally expands quickly due to a Richtmyer-Meshkov-like instability. The laser-particle interaction causes an increase in the kernel volume which is approximately five times as large as that in the gas breakdown without particles. In addition, the laser-particle interaction can improve the laser energy efficiency
Photo-production of neutral kaons on 12C in the threshold region
Kaon photo-production process on C has been studied by measuring
neutral kaons in a photon energy range of 0.81.1 GeV. Neutral kaons were
identified by the invariant mass constructed from two charged pions emitted in
the decay channel. The differential cross sections
as well as the integrated ones in the threshold photon energy region were
obtained. The obtained momentum spectra were compared with a Spectator model
calculation using elementary amplitudes of kaon photo-production given by
recent isobar models. Present result provides, for the first time, the
information on reaction which is expected to play an
important role to construct models for strangeness production by the
electromagnetic interaction. Experimental results show that cross section of
is of the same order to that of and suggest that slightly backward angular distribution
is favored in the process.Comment: 6 pages, 8 figure
Gamma-Ray Spectroscopy of O and N Hypernuclei via the O reaction
he bound-state level structures of the O and
N hypernuclei were studied by -ray spectroscopy using
a germanium detector array (Hyperball) via the O ()
reaction. A level scheme for O was determined from the
observation of three -ray transitions from the doublet of states
(,) at MeV to the ground-state doublet (,). The
N hypernuclei were produced via proton emission from unbound
states in O . Three -rays were observed and the
lifetime of the state in N was measured by the
Doppler shift attenuation method. By comparing the experimental results with
shell-model calculations, the spin-dependence of the interaction is
discussed. In particular, the measured O ground-state doublet
spacing of 26.4 1.6 0.5 keV determines a small but nonzero strength
of the tensor interaction.Comment: 22 pages, 17 figure
Search for H hypernucleus by the Li reaction at = 1.2 GeV/
We have carried out an experiment to search for a neutron-rich hypernucleus,
H, by the Li() reaction at =1.2
GeV/. The obtained missing mass spectrum with an estimated energy resolution
of 3.2 MeV (FWHM) showed no peak structure corresponding to the H
hypernucleus neither below nor above the H particle decay
threshold. An upper limit of the production cross section for the bound
H hypernucleus was estimated to be 1.2 nb/sr at 90% confidence
level.Comment: 6 pages, 5 figures, published versio
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