364 research outputs found
Tests of the Equivalence Principle with Neutral Kaons
We test the Principle of Equivalence for particles and antiparticles, using
CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time,
we search for possible annual, monthly and diurnal modulations of the
observables |eta_{+-}| and phi_{+-}, that could be correlated with variations
in astrophysical potentials. Within the accuracy of CPLEAR, the measured values
of |eta_{+-}| and phi_{+-} are found not to be correlated with changes of the
gravitational potential. We analyze data assuming effective scalar, vector and
tensor interactions, and we conclude that the Principle of Equivalence between
particles and antiparticles holds to a level of 6.5, 4.3 and 1.8 x 10^{-9},
respectively, for scalar, vector and tensor potentials originating from the Sun
with a range much greater than the distance Earth-Sun. We also study
energy-dependent effects that might arise from vector or tensor interactions.
Finally, we compile upper limits on the gravitational coupling difference
between K0 and K0bar as a function of the scalar, vector and tensor interaction
range.Comment: 15 pages latex 2e, five figures, one style file (cernart.csl)
incorporate
Outflows of very ionized gas in the center of Seyfert galaxies: kinematics and physical conditions
Mid-resolution spectra are used to deduce the size and kinematics of the
coronal gas in a sample of Seyfert galaxies by means of observations of the
[FeXI], [FeX], [FeVII], [SiVI] and [SiVII] lines. These coronal lines (CL)
extend from the unresolved nucleus up to a few tens to a few hundreds of
parsecs. The region of the highest ionized ions studied, [FeXI] and [FeX], is
the least spatially extended, and concentrates at the center; intermediate
ionization lines extend from the nucleus up to a few tens to a few hundred
parsecs; lower [OIII]-like ions are known to extendin the kpc range. All
together indicates a stratification in the ionized gas, usually interpreted in
terms of nuclear photoionization as the driving ionization mechanism. However,
CL profiles show various peculiarities: they are broader by a factor of two
than lower ionization lines, the broadening being in terms of asymmetric blue
wings, and their centroid position at the nucleus is blueshifted by a few
hundreds of km/s. Moreover, in NGC1386 and NGC1068, a double peak [FeVII] line
is detected in the nuclear and extended coronal region, this being the first
report in of such type of profile in CL in active galactic nuclei. If
interpreted as outflow signatures, the total broadening of the lines at zero
intensity levels implies gas velocities up to 2000 km/s. Although the
stratification of ions across the coronal region means that photoionization is
the main power mechanism, the high velocities deduced from the profiles, the
relatively large spatial extension of the emission, and the results from
photoionization models indicate that an additional mechanism is at work. We
suggest that shocks generated by the outflow could provide the additional
required power for line formation.Comment: Accepted for publication in the Astrophysical Journal. 40 pages, 15
figures. Minor changes made on the affiliation of one co-autho
Estudo do efeito do ozÎnio gerado durante ensaios elétricos em equipamentos de segurança confeccionados em borracha natural
Test of CPT Symmetry and Quantum Mechanics with Experimental data from CPLEAR
We use fits to recent published CPLEAR data on neutral kaon decays to
and to constrain the CPT--violation parameters
appearing in a formulation of the neutral kaon system as an open
quantum-mechanical system. The obtained upper limits of the CPT--violation
parameters are approaching the range suggested by certain ideas concerning
quantum gravity.Comment: 9 pages of uuencoded postscript (includes 3 figures
Extraordinary exposed in early motherhood - a qualitative study exploring experiences of mothers with type 1 diabetes
<p>Abstract</p> <p>Background</p> <p>Women with type 1 diabetes face several challenges during pregnancy, childbirth and in relation to breastfeeding. It is therefore of utmost importance to consider their need for specific support, early postpartum as well as in daily life after discharge from maternity care. Few studies have investigated these aspects of healthcare. The aim of this study was to explore experiences after childbirth regarding breastfeeding, glycemic control, support and well-being in women with type 1 diabetes.</p> <p>Methods</p> <p>A hermeneutic reflective life world research approach was used in this qualitative study. Data was gathered through audio-recorded focus group discussions and individual interviews with 23 women with type 1 diabetes, 6-24 months after childbirth. After verbatim transcription, the text was analyzed in order to identify themes of meaning and a conclusive interpretation of the explored phenomenon.</p> <p>Results</p> <p>Experiences of extraordinary exposure challenged the women with type 1 diabetes in their transition to early motherhood. The exposure included a struggle with breastfeeding, although with a driving force to succeed. Everyday life was filled with uncertainty and unpredictability related to one's own unstable glycemic control and the women down-prioritized their own needs in favor of the child. A feeling of being disconnected from professional care further contributed to the experiences of extraordinary exposure.</p> <p>Conclusion</p> <p>In early motherhood women with type 1 diabetes have a great need for support in managing daily life postpartum, which requires contemporary approaches to overlap insufficient linkage between health care professionals in maternity and child health care, and diabetes care.</p
Asclepius or Hippocrates? Differing interpretations of postâcompulsory initial teacher training mentoring
The neutral kaon decays to : a detailed analysis of the CPLEAR data
A detailed analysis of neutral kaons decaying to \Pgpp \Pgpm \Pgpz\ is presented based on the complete data set containing half a million events. Time-dependent decay rate asymmetries are measured between initially tagged \PKz\ and \PaKz\ and for different regions of the phase space. These asymmetries, resulting from the interference between the CP-conserving decay amplitude of \PKzL\ and the decay amplitude of \PKzS\ -- either CP-violating or CP-conserving -- allow the determinationof the \PKzS\ parameters \etapmz\ (CP-violating) and \lampmz\ (CP-conserving), and also of the main i sospin components of the \PKzS\ decay amplitude. The branching ratio of \PKzS\ \Pgpp \Pgpm \Pgpz\ (CP-conserving) is deduced directly from \lampmz . In addition, we extract the slope parameters describing the energy dependence of the \PKzL \rightarrow \Pgpp \Pgpm \Pgpz Dalitz plot. The whole set of our results fits well within the current phenomenological picture of the neut ral-kaon system including CP violation and Chiral Perturbation Theory (ChPT)
Determination of the T- and CPT-violation parameters in the neutral-kaon system using the Bell-Steinberger relation and data from CPLEAR
Data from the CPLEAR experiment, together with the most recent world averages for some of the neutral-kaon parameters, were constrained with the Bell--Steinberger (or unitarity) relation, allowing the T-violation parameter \ree and the CPT-violation parameter \imd of the neutral-kaon mixing matrix to be determined with an increased accuracy: \ree = (164.9 \pm 2.5)\times 10^{-5}, \imd = ( 2.4 \pm 5.0)\times 10^{-5}. Moreover, the constraint allows the CPT-violation parameter for the neutral-kaon semileptonic decays, \rey, to be determined for the first time. The parameters \rexm and \imxp are given with an increased accuracy. The quantity , which enters the T-violation CPLEAR asymmetry previously published, is determined to be . The value obtained for \red is in agreement with the one resulting from a previous unconstrained fit and has a slightly smaller error
Measurement of the mass difference using semileptonic decays of tagged neutral kaons
We report on a new measurement of the \kl--\ks\ mass difference \dm\ using the CPLEAR full data sample of neutral-kaon decays to \semi. The result is \dm = (0.5295 \pm 0.0020_{\stat} \pm 0.0003_{\syst}) \times 10^{10}\ \hbs. It includes earlier data reported in Ref. \cite{deltam1}. A measurement of the \dsdq\ violating parameter \rex\ is also obtained
- âŠ