801 research outputs found
Detailed study of the ac susceptibility of Sr2RuO4 in oriented magnetic fields
We have investigated the ac susceptibility of the spin triplet superconductor
SrRuO as a function of magnetic field in various directions at
temperatures down to 60 mK. We have focused on the in-plane field configuration
(polar angle ), which is a prerequisite for inducing
multiple superconducting phases in SrRuO. We have found that the
previous attribution of a pronounced feature in the ac susceptibility to the
second superconducting transition itself is not in accord with recent
measurements of the thermal conductivity or of the specific heat. We propose
that the pronounced feature is a consequence of additional involvement of
vortex pinning originating from the second superconducting transition.Comment: Accepted for publication in Phys. Rev.
Interface superconductivity in the eutectic Sr2RuO4-Ru: 3-K phase of Sr2RuO4
The eutectic system Sr2RuO4-Ru is referred to as the 3-K phase of the
spin-triplet supeconductor Sr2RuO4 because of its enhanced superconducting
transition temperature Tc of ~3 K. We have investigated the field-temperature
(H-T) phase diagram of the 3-K phase for fields parallel and perpendicular to
the ab-plane of Sr2RuO4, using out-of-plane resistivity measurements. We have
found an upturn curvature in the Hc2(T) curve for H // c, and a rather gradual
temperature dependence of Hc2 close to Tc for both H // ab and H // c. We have
also investigated the dependence of Hc2 on the angle between the field and the
ab-plane at several temperatures. Fitting the Ginzburg-Landau effective-mass
model apparently fails to reproduce the angle dependence, particularly near H
// c and at low temperatures. We propose that all of these charecteric features
can be explained, at least in a qualitative fashion, on the basis of a theory
by Sigrist and Monien that assumes surface superconductivity with a
two-component order parameter occurring at the interface between Sr2RuO4 and Ru
inclusions. This provides evidence of the chiral state postulated for the 1.5-K
phase by several experiments.Comment: 7 pages and 5 figs; accepted for publication in Phys. Rev.
Religious Values, Practices and Pregnancy Outcomes: A Comparison of the Impact of Sect and Mainstream Christian Affiliation
In this report 6566 women enrolled in the Mater-University of Queensland Study of Pregnancy (MUSP) were separated into three groups; members of religious sects, Christians who attend church frequently and Christians who are infrequent attenders. These three groups, respectively labelled Christian sects, Christian attenders and lukewarm Christians were compared on a number of social background, lifestyle and pregnancy outcome variables. The sect members appeared to have the most favourable health, lifestyles and healthy babies at delivery, though this latter finding appears attributable to specific characteristics of the mother and her lifestyle. On most measures the children of lukewarm Christians appear to manifest the worst health while Christian attenders form a group whose children's health is between that of sect members and lukewarm Christians
Tri-meson-mixing of -- and -- in the light-cone quark model
The radiative transition form factors of the pseudoscalar mesons {,
, } and the vector mesons {, , } are restudied
with -- and -- in tri-meson-mixing
pattern, which is described by tri-mixing matrices in the light-cone
constituent quark model. The experimental transition decay widths are better
reproduced with tri-meson-mixing than previous results in a two-mixing-angle
scenario of only two-meson - mixing and - mixing.Comment: 8 pages, 6 figures, final version to appear in EPJ
Genome-based study of a spatio-temporal cluster of invasive meningococcal disease due to Neisseria meningitidis serogroup C, clonal complex 11
SummaryObjectivesTo describe a spatio-temporal cluster of invasive meningococcal disease (IMD) due to serogroup C meningococci, occurred in a restricted area of Tuscany between January and October 2015, and the results of whole genome sequencing (WGS).MethodsSurveillance activities and public health measures were implemented in the Region. Bacterial isolates from IMD cases were characterized by the National Reference Laboratory of the Istituto Superiore di Sanità (ISS), and WGS was performed on available strains. The kSNP software was used to identify core genome SNPs.ResultsOverall, 28 IMD cases due to meningococcus C were identified up to 31st October, 2015. Of them, 26 were due to meningococcus C:P1.5-1,10-8: F3-6:ST-11 (cc11) and 2 to C:P1.5-1,10-8: F3-6:ST-2780 (cc11). WGS of 13 meningococci isolated during the outbreak occurred in Tuscany in 2015 showed higher similarity when compared with those of 47 C: P1.5-1,10-8: F3-6:ST-11 (cc11) invasive strains from sporadic cases previously detected in Italy.ConclusionsA highly aggressive meningococcal C strain was involved in the cluster of severe IMD occurred in Tuscany, a Region with high vaccine coverage among children. Whether this was due to low herd immunity related to the short duration of vaccine protection needs further investigation
Young and Intermediate-age Distance Indicators
Distance measurements beyond geometrical and semi-geometrical methods, rely
mainly on standard candles. As the name suggests, these objects have known
luminosities by virtue of their intrinsic proprieties and play a major role in
our understanding of modern cosmology. The main caveats associated with
standard candles are their absolute calibration, contamination of the sample
from other sources and systematic uncertainties. The absolute calibration
mainly depends on their chemical composition and age. To understand the impact
of these effects on the distance scale, it is essential to develop methods
based on different sample of standard candles. Here we review the fundamental
properties of young and intermediate-age distance indicators such as Cepheids,
Mira variables and Red Clump stars and the recent developments in their
application as distance indicators.Comment: Review article, 63 pages (28 figures), Accepted for publication in
Space Science Reviews (Chapter 3 of a special collection resulting from the
May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space
Age
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
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