39,905 research outputs found
Search for a high mass SM-like Higgs boson in the H to ZZ to llqq decay channel in CMS
A search for a high mass standard-model-like Higgs boson decaying into two Z
bosons with subsequent decay into two leptons and two quarks performed at CMS
is presented. The analysis is based on 19.7 1/fb of proton-proton collisions
produced in LHC at center-of-mass energy of 8 TeV. Different categories are
exploited in order to isolate hypothetical Higgs boson-like signals in the mass
range up to 1 TeV. The data are interpreted in terms of a standard-model-like
Higgs boson as well as an electroweak singlet, visible through the interference
with the 125 GeV Higgs boson. No evidence of a signal is found and upper limits
are set on the production cross section and other model parameters.Comment: 4 pages, 5 figures, to appear in the proceedings of the 50th
Rencontres de Moriond, Electroweak session, 201
The core-cusp problem in cold dark matter halos and supernova feedback: Effects of Mass Loss
The core-cusp problem remains as one of the unsolved discrepancies between
observations and theories predicted by the standard paradigm of cold dark
matter (CDM) cosmology. To solve this problem, we perform N-body simulations to
study the nonlinear response of CDM halos to the variance of the gravitational
potential induced by gas removal from galaxy centers. In this study, we focus
on the timescale of the gas ejection, which is strongly correlated with stellar
activities, and demonstrate that it is one of the key factors in determining
the dynamical response of CDM halos. The results of simulations show that the
power-low index of the mass-density profile of the dark matter halo correlated
with the timescale of the mass loss, and it is flatter when the mass loss
occurs over a short time than when it occurs over a long time. However, it is
still larger than typical observational values; in other words, the central
cusp remains for any mass loss model in the simulations. Moreover, for the slow
mass-loss case, the final density profile of the dark matter halo recovers the
universal density profiles predicted by the CDM cosmology. Therefore, mass loss
driven by stellar feedback may not be an effective mechanism to flatten the
central cusp.Comment: 4 pages, 3 figures, 1 table, accepted for publication in
Astrophysical Journal Letter
Sea quark and gluon polarization in the nucleon at NLO accuracy
We investigate the sea quark polarization in the nucleon by means of a
combined next to leading order analysis to the recently enlarged set of
inclusive and semi-inclusive polarized deep inelastic scattering data. Using
the Lagrange multiplier method, we asses the uncertainty inherent to the
extraction of the different spin dependent parton densities in a QCD global
fit, and the impact of the increased set of semi-inclusive data now available.
We comment on future prospects at RHIC and JLAB and their potential impact in
the future determination of polarized parton densities.Comment: 15 pages, 9 figures, 3 table
Extraction of polarized parton densities from polarized DIS and SIDIS
We present results on the quark and gluon polarization in the nucleon
obtained in a combined next to leading order analysis to the available
inclusive and semi-inclusive polarized deep inelastic scattering data.Comment: Talk given at XIII International Workshop on Deep Inelastic
Scattering, April,27 - May,1, 2005, Madison, Wisconsin, USA, 4 pages, 2
figure
Building the Stellar Halo Through Feedback in Dwarf Galaxies
We present a new model for the formation of stellar halos in dwarf galaxies.
We demonstrate that the stars and star clusters that form naturally in the
inner regions of dwarfs are expected to migrate from the gas rich, star forming
centre to join the stellar spheroid. For dwarf galaxies, this process could be
the dominant source of halo stars. The effect is caused by stellar
feedback-driven bulk motions of dense gas which, by causing potential
fluctuations in the inner regions of the halo, couple to all collisionless
components. This effect has been demonstrated to generate cores in otherwise
cuspy cold dark matter profiles and is particularly effective in dwarf galaxy
haloes. It can build a stellar spheroid with larger ages and lower
metallicities at greater radii without requiring an outside-in formation model.
Globular cluster-type star clusters can be created in the galactic ISM and then
migrate to the spheroid on 100\thinspace Myr timescales. Once outside the inner
regions they are less susceptible to tidal disruption and are thus long lived;
clusters on wider orbits may be easily unbound from the dwarf to join the halo
of a larger galaxy during a merger. A simulated dwarf galaxy
( at ) is used to examine this
gravitational coupling to dark matter and stars.Comment: 12 pages, 3 figures, accepted for publication in ApJ
Attitudes of undergraduate nursing students to cultural diversity: (Portuguese-Spanish) in a transboundary context.
Our main goal was to identify the attitudes of nursing students to cultural diversity in a healthcare setting, and find the potential relationship between this and the students' national background and their knowledge of cultural diversity. A descriptive observational study comparing two culturally different populations within a cross-border area (Algarve-Huelva) was conducted. The attitudes of the participants were measured across six categories: this study will describe the most significant ones. The cultural context is essential to the development of attitudes to immigration. Nursing care is a communicative act and encountering the "other" the core of the nursing professionals' work. (C) 2017 The Authors. Published by Elsevier Ltd
Coherence of the posterior predictive p-value based on the posterior odds.
^aIt is well-known that classical p-values sometimes behave
incoherently for testing hypotheses in the sense that, when
, the support given to
is greater than or equal to the support given to
. This problem is also found for posterior
predictive p-values (a Bayesian-motivated alternative to classical
p-values). In this paper, it is proved that, under some conditions,
the posterior predictive p-value based on the posterior odds is
coherent, showing that the choice of a suitable discrepancy variable
is crucial
Weyl Invariance and Black Hole Evaporation
We consider the semiclassical dynamics of CGHS black holes with a
Weyl-invariant effective action for conformal matter. The trace anomaly of
Polyakov effective action is converted into the Virasoro anomaly thus leading
to the same flux of Hawking radiation. The covariance of semiclassical
equations can be restored through a non-local redefinition of the
metric-dilaton fields. The resulting theory turns out to be equivalent to the
RST model. This provides a mechanism to solve semiclassical equations of 2D
dilaton gravity coupled to conformal matter for classically soluble models.Comment: LaTeX, needs amssymb, 8 pages. One reference adde
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