7,183 research outputs found
New calculations of the PNC Matrix Element for the 0 doublet in N
A new calculation of the predominantly isoscalar PNC matrix element between
the (E 8.7 MeV) states in N has
been carried out in a (0+1+2+3+4) model space with the
Warburton-Brown interaction. The magnitude of the PNC matrix element of 0.22 to
0.34 eV obtained with the DDH PNC interaction is substantially suppressed
compared with previous calculations in smaller model spaces but shows agreement
with the preliminary Seattle experimental data. The calculated sign is opposite
to that obtained experimentally, and the implications of this are discussed.Comment: REVTEX, 28 page
Fano resonance resulting from a tunable interaction between molecular vibrational modes and a double-continuum of a plasmonic metamolecule
Coupling between tuneable broadband modes of an array of plasmonic
metamolecules and a vibrational mode of carbonyl bond of poly(methyl
methacrylate) is shown experimentally to produce a Fano resonance, which can be
tuned in situ by varying the polarization of incident light. The interaction
between the plasmon modes and the molecular resonance is investigated using
both rigorous electromagnetic calculations and a quantum mechanical model
describing the quantum interference between a discrete state and two continua.
The predictions of the quantum mechanical model are in good agreement with the
experimental data and provide an intuitive interpretation, at the quantum
level, of the plasmon-molecule coupling
Development and Characterisation of a Gas System and its Associated Slow-Control System for an ATLAS Small-Strip Thin Gap Chamber Testing Facility
A quality assurance and performance qualification laboratory was built at
McGill University for the Canadian-made small-strip Thin Gap Chamber (sTGC)
muon detectors produced for the 2019-2020 ATLAS experiment muon spectrometer
upgrade. The facility uses cosmic rays as a muon source to ionise the quenching
gas mixture of pentane and carbon dioxide flowing through the sTGC detector. A
gas system was developed and characterised for this purpose, with a simple and
efficient gas condenser design utilizing a Peltier thermoelectric cooler (TEC).
The gas system was tested to provide the desired 45 vol% pentane concentration.
For continuous operations, a state-machine system was implemented with alerting
and remote monitoring features to run all cosmic-ray data-acquisition
associated slow-control systems, such as high/low voltage, gas system and
environmental monitoring, in a safe and continuous mode, even in the absence of
an operator.Comment: 23 pages, LaTeX, 14 figures, 4 tables, proof corrections for Journal
of Instrumentation (JINST), including corrected Fig. 8b
Two neutrino double beta decay within the -approximation
We examine the contributions of odd-parity nuclear operators to the
two-neutrino double beta decay amplitude, which come from
the -wave Coulomb corrections to the electron wave functions and the recoil
corrections to the nuclear currents. Although they are formally of higher order
in or of the nucleon than the usual Fermi and Gamow-Teller
matrix elements, explicit calculations performed within the QRPA show that they
are significant when confronted with the experimental data.Comment: 9 pages, latex, no figure
Statistical properties of thermodynamically predicted RNA secondary structures in viral genomes
By performing a comprehensive study on 1832 segments of 1212 complete genomes
of viruses, we show that in viral genomes the hairpin structures of
thermodynamically predicted RNA secondary structures are more abundant than
expected under a simple random null hypothesis. The detected hairpin structures
of RNA secondary structures are present both in coding and in noncoding regions
for the four groups of viruses categorized as dsDNA, dsRNA, ssDNA and ssRNA.
For all groups hairpin structures of RNA secondary structures are detected more
frequently than expected for a random null hypothesis in noncoding rather than
in coding regions. However, potential RNA secondary structures are also present
in coding regions of dsDNA group. In fact we detect evolutionary conserved RNA
secondary structures in conserved coding and noncoding regions of a large set
of complete genomes of dsDNA herpesviruses.Comment: 9 pages, 2 figure
Optical excitations of a self assembled artificial ion
By use of magneto-photoluminescence spectroscopy we demonstrate bias
controlled single-electron charging of a single quantum dot. Neutral, single,
and double charged excitons are identified in the optical spectra. At high
magnetic fields one Zeeman component of the single charged exciton is found to
be quenched, which is attributed to the competing effects of tunneling and
spin-flip processes. Our experimental data are in good agreement with
theoretical model calculations for situations where the spatial extent of the
hole wave functions is smaller as compared to the electron wave functions.Comment: to be published in Physical Review B (rapid communication
Estimating the burden of respiratory syncytial virus (RSV) on respiratory hospital admissions in children less than five years of age in England, 2007-2012
BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of hospital admission in young children. With several RSV vaccines candidates undergoing clinical trials, recent estimates of RSV burden are required to provide a baseline for vaccine impact studies. OBJECTIVES: To estimate the number of RSV-associated hospital admissions in children aged <5Â years in England over a 5-year period from 2007 using ecological time series modelling of national hospital administrative data. PATIENTS/METHODS: Multiple linear regression modelling of weekly time series of laboratory surveillance data and Hospital Episode Statistics (HES) data was used to estimate the number of hospital admissions due to major respiratory pathogens including RSV in children <5Â years of age in England from mid-2007 to mid-2012, stratified by age group (<6Â months, 6-11Â months, 1-4Â years) and primary diagnosis: bronchiolitis, pneumonia, unspecified lower respiratory tract infection (LRTI), bronchitis and upper respiratory tract infection (URTI). RESULTS: On average, 33Â 561 (95% confidence interval 30Â 429-38Â 489) RSV-associated hospital admissions in children <5Â years of age occurred annually from 2007 to 2012. Average annual admission rates were 35.1 (95% CI: 32.9-38.9) per 1000 children aged <1Â year and 5.31 (95% CI: 4.5-6.6) per 1000 children aged 1-4Â years. About 84% (95% CI: 81-91%) of RSV-associated admissions were for LRTI. The diagnosis-specific burden of RSV-associated admissions differed significantly by age group. CONCLUSIONS: RSV remains a significant cause of hospital admissions in young children in England. Individual-level analysis of RSV-associated admissions is required to fully describe the burden by age and risk group and identify optimal prevention strategies
First-forbidden mirror beta-decays in A=17 mass region
The first-forbidden beta-decay of 17Ne into the 'halo' state J=1/2+ of 17F
presents one of the largest measured asymmetries for mirror beta-decay feeding
bound final states. This asymmetry is studied in the framework of the Shell
Model Embedded in the Continuum (SMEC). The spatial extent of single particle
orbits is constrained by the proton capture cross-section 16O(p,gamma)17F
calculated in SMEC . This allows to estimate the mirror symmetry breaking in
17F/17O and 17Ne/17N nuclei.Comment: 23 pages, 7 figures Misprints correcte
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