29,052 research outputs found
Rare -Decays and Heavy to Light Semileptonic Transitions in the Isgur and Wise Limit
From the experimental branching ratios for and
D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e one finds, in the Heavy Quark
Limit of , , larger but consistent with
the actual quoted range . In the same framework one predicts
for .Comment: 9 pages, 1 Figure avalaible on request from [email protected]
Statistical PT-symmetric lasing in an optical fiber network
PT-symmetry in optics is a condition whereby the real and imaginary parts of
the refractive index across a photonic structure are deliberately balanced.
This balance can lead to a host of novel optical phenomena, such as
unidirectional invisibility, loss-induced lasing, single-mode lasing from
multimode resonators, and non-reciprocal effects in conjunction with
nonlinearities. Because PT-symmetry has been thought of as fragile,
experimental realizations to date have been usually restricted to on-chip
micro-devices. Here, we demonstrate that certain features of PT-symmetry are
sufficiently robust to survive the statistical fluctuations associated with a
macroscopic optical cavity. We construct optical-fiber-based coupled-cavities
in excess of a kilometer in length (the free spectral range is less than 0.8
fm) with balanced gain and loss in two sub-cavities and examine the lasing
dynamics. In such a macroscopic system, fluctuations can lead to a
cavity-detuning exceeding the free spectral range. Nevertheless, by varying the
gain-loss contrast, we observe that both the lasing threshold and the growth of
the laser power follow the predicted behavior of a stable PT-symmetric
structure. Furthermore, a statistical symmetry-breaking point is observed upon
varying the cavity loss. These findings indicate that PT-symmetry is a more
robust optical phenomenon than previously expected, and points to potential
applications in optical fiber networks and fiber lasers.Comment: Submitted to Nature Communications, Pages 1-19: Main manuscript;
Pages 20-38: Supplementary material
Measuring the actual energy cost performance of green buildings: a test of the earned value management approach
Reduced energy consumption is a key aspect of the green building. Nonetheless, research indicates that there is a performance gap between the predicted and the actual energy performance once buildings are occupied, which implies a cost deviation from the anticipated energy cost performance. However, the cost deviation also might result from lower or higher energy rates than expected. As an appropriate research methodology for existing theory testing, case study research strategy was adopted to empirically examine the earned value management (EVM) approach to measure the actual life cycle cost performance of energy in green buildings. With slight methodological and terminological adaptations, it is found that the EVM approach can be applied to conduct a holistic cost performance measurement of the actual energy consumption in green buildings. The strength of the earned value approach is that it allows for detecting whether the energy cost saving or overrun results from lower or higher energy consumption, or from actual energy rate variations. The earned value approach allows for quantifying each cost variance independently, which is a significant aspect of actual energy cost performance measurement in green buildings
Corrections to Decay in the 2HDM
QCD corrections to the inclusive decay are
investigated within the two - Higgs doublet extension of the standard model
(2HDM). The analysis is performed in the so - called off-resonance region; the
dependence of the obtained results on the choice of the renormalization scale
is examined in details. It is shown that corrections can suppress
the decay width up to times (depending on the
choice of the dilepton invariant mass and the low - energy scale ). As
a result, in the experimentally allowed range of the parameters space, the
relations between the branching ratio and the new physics
parameters are strongly affected. It is found also that though the
renormalization scale dependence of the branching is
significantly reduced, higher order effects in the perturbation theory can
still be nonnegligible.Comment: 16 pages, latex, including 6 figures and 3 table
Anomalous Magnetic Properties in Ni50Mn35In15
We present here a comprehensive investigation of the magnetic ordering in
Ni50Mn35In15 composition. A concomitant first order martensitic transition and
the magnetic ordering occurring in this off-stoichiometric Heusler compound at
room temperature signifies the multifunctional character of this magnetic shape
memory alloy. Unusual features are observed in the dependence of the
magnetization on temperature that can be ascribed to a frustrated magnetic
order. It is compelling to ascribe these features to the cluster type
description that may arise due to inhomogeneity in the distribution of magnetic
atoms. However, evidences are presented from our ac susceptibility, electrical
resistivity and dc magnetization studies that there exists a competing
ferromagnetic and antiferromagnetic order within crystal structure of this
system. We show that excess Mn atoms that substitute the In atoms have a
crucial bearing on the magnetic order of this compound. These excess Mn atoms
are antiferromagnetically aligned to the other Mn, which explains the peculiar
dependence of magnetization on temperature.Comment: Accepted in J. Phys. D.:Appl. Physic
Factors associated with intimate partner violence against women in a mega city of South-Asia: multi-centre cross-sectional study
Objectives: To assess the proportion of women subjected to intimate partner violence and the associated factors, and to identify the attitudes of women towards the use of violence by their husbands. Design: Cross-sectional study. Setting: Family practice clinics at a teaching hospital in Karachi, Pakistan. Participants: A total of 520 women aged between 16 and 60 years were consecutively approached to participate in the study and interviewed by trained data collectors. Overall, 401 completed questionnaires were available for analysis. Multivariate logistic regression analysis was used to identify the association of various factors of interest. Results: In all, 35% of the women reported being physically abused by their husbands in the last 12 months. Multivariate analysis showed that experiences of violence were independently associated with women\u27s illiteracy (adjusted odds ratio=5.9; 95% confidence interval, 1.8-19.6), husband\u27s illiteracy (3.9; 1.4-10.7), smoking habit of husbands (3.3; 1.9-5.8), and substance use (3.1; 1.7-5.7). Conclusion: It is imperative that intimate partner violence be considered a major public health concern. It can be prevented through comprehensive, multifaceted, and integrated approaches. The role of education is greatly emphasised in changing the perspectives of individuals and societies against intimate partner violence
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