3,660 research outputs found
Existence of non-exotic traversable wormholes in squared trace extended gravity theory
An extended gravity theory is used to explore the possibility of non-exotic
matter traversable wormholes. In the extended gravity theory, additional terms
linear and quadratic in the trace of the energy momentum tensor are considered
in the Einstein-Hilbert action. Obviously, such an addition leads to violation
of the energy-momentum tensor. The model parameters are constrained from the
structure of the field equations. Non-exotic matter wormholes tend to satisfy
the null energy conditions. We use two different traversable wormhole
geometries namely an exponential and a power law shape functions to model the
wormholes. From a detailed analysis of the energy conditions, it is found that,
the existence of non-exotic matter traversable wormholes is not obvious in the
model considered and its possibility may depend on the choice of the wormhole
geometry. Also, we found that, non-exotic wormholes are possible within the
given squared trace extended gravity theory for a narrow range of the chosen
equation of state parameter.Comment: 12 pages, 8 figure
Study of low energy Si and Cs implantation induced amorphization effects in Si(100)
The damage growth and surface modifications in Si(100), induced by 25 keV
Si cluster ions, as a function of fluence, , has been studied using
atomic force microscopy (AFM) and channeling Rutherford backscattering
spectrometry (CRBS). CRBS results indicate a nonlinear growth in damage from
which it has been possible to get a threshold fluence, , for
amorphization as ions-cm. For below ,
a growth in damage as well as surface roughness has been observed. At a
of ions-cm, damage saturation coupled with a much
reduced surface roughness has been found. In this case a power spectrum
analysis of AFM data showed a significant drop, in spectral density, as
compared to the same obtained for a fluence, . This drop,
together with damage saturation, can be correlated with a transition to a
stress relaxed amorphous phase. Irradiation with similar mass Cs ions, at
the same energy and fluence, has been found to result in a reduced accumulation
of defects in the near surface region leading to reduced surface features.Comment: 7 pages, 4 figure
Working Group Report: Heavy-Ion Physics and Quark-Gluon Plasma
This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09
which was part of Working Group-4. Discussion and work on some aspects of
Quark-Gluon Plasma believed to have created in heavy-ion collisions and in
early universe are reported.Comment: 20 pages, 6 eps figures, Heavy-ion physics and QGP activity report in
"IX Workshop on High Energy Physics Phenomenology (WHEPP-09)" held in
Institute of Physics, Bhubaneswar, India, during January 3-14, 2006. To be
published in PRAMANA - Journal of Physics (Indian Academy of Science
Integrated multisectoral strategy to improve girls' and women's nutrition before conception, during pregnancy and after birth in India (Swabhimaan): protocol for a prospective, non-randomised controlled evaluation
INTRODUCTION: Swabhimaan is a community-based programme to improve adolescent girls’ and women’s nutrition in the rural areas of three Indian states—Bihar, Chhattisgarh and Odisha with high prevalence of undernutrition.
METHODS AND ANALYSIS: Swabhimaan has a nested prospective, non-randomised controlled evaluation. Since 2017, five intervention sites receive community-led interventions through national government’s livelihood mission supported women’s self-help group federations and five control sites will initiate these activities 36 months later, in 2020. Community-led activities aim to improve coverage of 18 interventions including adequacy of food consumed, prevention of micronutrient deficiencies, access to basic health services and special care of nutritionally ‘at risk’ girls and women, improving hygiene and access to water and sanitation services and access to family planning services. The evaluation includes baseline (2016–2017), midline (2018–2019) and endline (2020–2021) surveys covering 6638 adolescent girls, 2992 pregnant women and 8755 mothers of children under 2. The final impact analysis will be by intention to treat, comparing primary and secondary outcomes in five intervention areas and five control areas. The primary outcomes are: (1) a 15% reduction in the proportion of adolescent girls with a body mass index (BMI) <18.5 kg/m2; (2) a 15% reduction in the proportion of mothers of children under two with a BMI <18.5 kg/m2 and (3) and a 0.4 cm improvement in mean mid-upper arm circumference among pregnant women.
ETHICS AND DISSEMINATION: All procedures involving human subjects were approved by the Institutional Ethics Committee of the All India Institute of Medical Sciences, Bihar, Chhattisgarh and Odisha and in compliance with guidelines laid down in the Declaration of Helsinki. Evidence will inform maternal and preconception nutrition policy at national and state level.
TRIAL REGISTRATION NUMBER: 58261b2f46876 and CTRI/2016/11/007482; Pre-results
Observation of charge asymmetry dependence of pion elliptic flow and the possible chiral magnetic wave in heavy-ion collisions
We present measurements of and elliptic flow, , at
midrapidity in Au+Au collisions at 200, 62.4, 39, 27,
19.6, 11.5 and 7.7 GeV, as a function of event-by-event charge asymmetry,
, based on data from the STAR experiment at RHIC. We find that
() elliptic flow linearly increases (decreases) with charge asymmetry
for most centrality bins at and higher.
At , the slope of the difference of
between and as a function of exhibits a
centrality dependence, which is qualitatively similar to calculations that
incorporate a chiral magnetic wave effect. Similar centrality dependence is
also observed at lower energies.Comment: 6 pages, 4 figure
Azimuthal anisotropy in U+U and Au+Au collisions at RHIC
Collisions between prolate uranium nuclei are used to study how particle
production and azimuthal anisotropies depend on initial geometry in heavy-ion
collisions. We report the two- and four-particle cumulants, and
, for charged hadrons from U+U collisions at =
193 GeV and Au+Au collisions at = 200 GeV. Nearly fully
overlapping collisions are selected based on the amount of energy deposited by
spectators in the STAR Zero Degree Calorimeters (ZDCs). Within this sample, the
observed dependence of on multiplicity demonstrates that ZDC
information combined with multiplicity can preferentially select different
overlap configurations in U+U collisions. An initial-state model with gluon
saturation describes the slope of as a function of multiplicity in
central collisions better than one based on Glauber with a two-component
multiplicity model.Comment: Final paper version accepted for publication in Phys. Rev. Lett. New
version includes comparisons to a constituent quark glauber mode
Centrality and transverse momentum dependence of elliptic flow of multi-strange hadrons and meson in Au+Au collisions at = 200 GeV
We present high precision measurements of elliptic flow near midrapidity
() for multi-strange hadrons and meson as a function of
centrality and transverse momentum in Au+Au collisions at center of mass energy
200 GeV. We observe that the transverse momentum dependence of
and is similar to that of and , respectively,
which may indicate that the heavier strange quark flows as strongly as the
lighter up and down quarks. This observation constitutes a clear piece of
evidence for the development of partonic collectivity in heavy-ion collisions
at the top RHIC energy. Number of constituent quark scaling is found to hold
within statistical uncertainty for both 0-30 and 30-80 collision
centrality. There is an indication of the breakdown of previously observed mass
ordering between and proton at low transverse momentum in the
0-30 centrality range, possibly indicating late hadronic interactions
affecting the proton .Comment: 7 pages and 4 figures, Accepted for publication in Physical Review
Letter
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Elliptic flow of electrons from heavy-flavor hadron decays in Au+Au collisions at 200, 62.4, and 39 GeV
We present measurements of elliptic flow () of electrons from the decays
of heavy-flavor hadrons () by the STAR experiment. For Au+Au collisions
at 200 GeV we report , for transverse momentum
() between 0.2 and 7 GeV/c using three methods: the event plane method
({EP}), two-particle correlations ({2}), and four-particle
correlations ({4}). For Au+Au collisions at = 62.4 and
39 GeV we report {2} for GeV/c. {2} and {4} are
non-zero at low and intermediate at 200 GeV, and {2} is consistent
with zero at low at other energies. The {2} at the two lower beam
energies is systematically lower than at 200 GeV for
GeV/c. This difference may suggest that charm quarks interact less
strongly with the surrounding nuclear matter at those two lower energies
compared to GeV.Comment: Version accepted by PR
- …