15,396 research outputs found
Effects of Resonant Cavity on Macroscopic Quantum Tunneling of Fluxon in Long Josephson Junctions
We investigate the effects of high-Q_c resonant cavity on macroscopic quantum
tunneling (MQT) of fluxon both from a metastable state to continuum and from
one degenerate ground-state of a double-well potential to the other. By using a
set of two coupled perturbed sine-Gordon equations, we describe the tunneling
processes in linear long Josephson junctions (LJJs) and find that MQT in the
resonant cavity increases due to potential renomalization, induced by the
interaction between the fluxon and cavity.Enhancement of the MQT rate in the
weak-coupling regime is estimated by using the experimantally accessible range
of the model parameters. The tunneling rate from the metastable state is found
to increase weakly with increasing junction-cavity interaction strength.
However, the energy splitting between the two degenerate ground-states of the
double-well potential increases significantly with increasing both the
interaction strength and frequency of the resonant cavity mode. Finally, we
discuss how the resonant cavity may be used to tune the property of Josephson
vortex quantum bits.Comment: Accepted for publication in Phy. Rev.
Does Antarctic Krill Employ Body Shrinkage as an Overwintering Strategy?
To determine if Antarctic krill employ body shrinkage as one of its overwintering mechanisms in the field, Euphausia superba and Euphausia crystallorophias were collected during fall and winter in and around Marguerite Bay through US Southern Ocean GLOBEC field programs during fall and winter 2001 and 2002. The relationships between the body length and weight of both krill species were exponentially correlated with no significant differences between the two species (p\u3e0.05). The ratio between eye diameter and body length of individual krill was examined in an expectation that it could be used as an indicator of the body shrinkage as previously suggested by Shin and Nicol (2002). These ratios were significantly different between the two krill species. Especially, E. crystallorophias had bigger eyes than E. superba. In both krill species, eye diameters were highly correlated with body lengths (regression coefficients ≥ 0.70). For E. crystallorophias, no significant differences of the ratio of eye diameter/body length were detected between fall and winter. Even though the ratios for E. superba were seasonally varied, it was not clear whether body shrinkage was an actual and critical overwintering mechanism for the krill population found in this study area. These results suggest that some individuals of E. superba might experience the body shrinkage during a part of their life, but this morphological index alone (eye diameter/body length) may be insufficient to unambiguously separate the shrunk krill from the non-shrunk ones in the field-collected animals
Rayleigh scattering in fused silica samples for gravitational wave detectors
Laser interferometer gravitational wave detectors require very high optical quality test masses. We report the bulk Rayleigh scattering in high quality fused silica samples. Results show that the scattering of the high quality fused silica is similar for various grades of fused silica from Heraeus. The total integrated scattering is about 0.7 ppm cm− 1at 1064 nm wavelength, which agrees with the theoretical value calculated using known fused silica parameters. All samples show Rayleigh scattering ratio inhomogeneity of ~ 4%
The polymorphisms of κ-casein gene and their associations with milk production traits and expression analysis in Chinese Holstein cattle
The polymorphisms of exon 4 and 5 of κ-casein (CSN3) gene and their associations with milk production traits and expression pattern in Chinese Holstein cattle were investigated. Nine mutational sites, of which seven were novel mutational sites, were identified and genotyped by polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP), created restriction site-PCR (CRS-RFLP) and sequencing methods in 398 cows. Linkage disequilibrium analysis showed that SNP-1 (g.10891 T > C rs 43703015, g.10927 C > A rs 43703016, g.10988 G > A ss 256302464 and g.10966 A > T ss 256302465) and SNP-2 (g.12907 A > G ss 256302466, g.12950 G > A ss 256302468, g.12989 C > T ss 256302469 and g.13028 A > G ss 256302470) were completely linked, respectively. Correlation analysis showed that SNP-1, SNP-2 and SNP-3 (g.12980 T > C ss 256302467) markers were closely correlated to the fat content. The SNP-3 marker had a remarkable effect on the protein content (P < 0.05). 16 combined genotypes of the three SNPs were found. Fat and protein content in combinations of genotypes were varied significantly (P < 0.05). Genotypes BBCCEE and ABTCDD individuals had the highest fat and protein content, respectively, which may be useful for marker assisted selection program in dairy cattle. The expression of CSN3 mRNA in the mammary tissue was higher than that of in the liver tissue (P < 0.05) and the expression in the spleen of BB genotype was higher than that of AA genotype in the SNP-1 (P < 0.05) by fluorescent quantitation real-time PCR (Q-PCR) assay.Key words: SNPs, CSN3 gene, combined genotype, Q-PCR, milk production traits
EM Decay of X(3872) as the charmonium
The recently BaBar results raise the possibility that X(3872) has negative
parity. This makes people reconsider assigning X(3872) to the state. In this paper we give a general form of the wave function of
mesons. By solving the instantaneous Bethe-Salpeter equation, we get
the mass spectrum and corresponding wave functions. We calculate
electromagnetic decay widths of the first state which we assume to be
the X(3872) particle. The results are keV, eV and keV. The ratio of branch fractions
of the second and first channel is about 0.002, which is inconsistent with the
experimental value . So X(3872) is unlikely to be a
charmonium state. In addition, we obtain a relatively large decay width for
channel which is keV.Comment: Revised versio
Production and optical properties of liquid scintillator for the JSNS experiment
The JSNS (J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron
Source) experiment will search for neutrino oscillations over a 24 m short
baseline at J-PARC. The JSNS inner detector will be filled with 17 tons
of gadolinium-loaded liquid scintillator (LS) with an additional 31 tons of
unloaded LS in the intermediate -catcher and outer veto volumes.
JSNS has chosen Linear Alkyl Benzene (LAB) as an organic solvent because
of its chemical properties. The unloaded LS was produced at a refurbished
facility, originally used for scintillator production by the RENO experiment.
JSNS plans to use ISO tanks for the storage and transportation of the LS.
In this paper, we describe the LS production, and present measurements of its
optical properties and long term stability. Our measurements show that storing
the LS in ISO tanks does not result in degradation of its optical properties.Comment: 7 pages, 4 figures
- …