445 research outputs found
Electroweak Supersymmetry with an Approximate U(1)_PQ
A predictive framework for supersymmetry at the TeV scale is presented, which
incorporates the Ciafaloni-Pomarol mechanism for the dynamical determination of
the \mu parameter of the MSSM. It is replaced by (\lambda S), where S is a
singlet field, and the axion becomes a heavy pseudoscalar, G, by adding a mass,
m_G, by hand. The explicit breaking of Peccei-Quinn (PQ) symmetry is assumed to
be sufficiently weak at the TeV scale that the only observable consequence is
the mass m_G. Three models for the explicit PQ breaking are given; but the
utility of this framework is that the predictions for all physics at the
electroweak scale are independent of the particular model for PQ breaking. Our
framework leads to a theory similar to the MSSM, except that \mu is predicted
by the Ciafaloni-Pomarol relation, and there are light, weakly-coupled states
in the spectrum. The production and cascade decay of superpartners at colliders
occurs as in the MSSM, except that there is one extra stage of the cascade
chain, with the next-to-LSP decaying to its "superpartner" and \tilde{s},
dramatically altering the collider signatures for supersymmetry. The framework
is compatible with terrestrial experiments and astrophysical observations for a
wide range of m_G and . If G is as light as possible, 300 keV < m_G < 3 MeV,
it can have interesting effects on the radiation energy density during the
cosmological eras of nucleosynthesis and acoustic oscillation, leading to
predictions for N_{\nu BBN} and N_{\nu CMB} different from 3.Comment: 45 pages, 2 colour figures, a reference added, minor correction
Intersectionality as a tool for clinical ethics consultation in mental healthcare.
Bioethics increasingly recognizes the impact of discriminatory practices based on social categories such as race, gender, sexual orientation or ability on clinical practice. Accordingly, major bioethics associations have stressed that identifying and countering structural discrimination in clinical ethics consultations is a professional obligation of clinical ethics consultants. Yet, it is still unclear how clinical ethics consultants can fulfill this obligation. More specifically, clinical ethics needs both theoretical tools to analyze and practical strategies to address structural discrimination within clinical ethics consultations. Intersectionality, a concept developed in Black feminist scholarship, is increasingly considered in bioethical theory. It stresses how social structures and practices determine social positions of privilege and disadvantage in multiple, mutually co-constitutive systems of oppression. This article aims to investigate how intersectionality can contribute to addressing structural discrimination in clinical ethics consultations with a particular focus on mental healthcare. To this end, we critically review existing approaches for clinical ethics consultants to address structural racism in clinical ethics consultations and extend them by intersectional considerations. We argue that intersectionality is a suitable tool to address structural discrimination within clinical ethics consultations and show that it can be practically implemented in two complementary ways: 1) as an analytic approach and 2) as a critical practice
Tenascin promotes cerebellar granule cell migration and neurite outgrowth by different domains in the fibronectin type III repeats.
J1/tenascin in substrate-bound and soluble form displays contrary effects on neurite outgrowth.
Shadowing in neutrino deep inelastic scattering and the determination of the strange quark distribution
We discuss shadowing corrections to the structure function in neutrino
deep-inelastic scattering on heavy nuclear targets. In particular, we examine
the role played by shadowing in the comparison of the structure functions
measured in neutrino and muon deep inelastic scattering. The importance of
shadowing corrections in the determination of the strange quark distributions
is explained.Comment: 22 pages, 7 figure
Tenascin-C contains distinct adhesive, anti-adhesive, and neurite outgrowth promoting sites for neurons.
A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD
We present a study of exclusive neutral pion production in neutrino-nucleus
Neutral Current interactions using data from the NOMAD experiment at the CERN
SPS. The data correspond to muon-neutrino Charged Current
interactions in the energy range GeV. Neutrino
events with only one visible in the final state are expected to result
from two Neutral Current processes: coherent production, {\boldmath
} and single production in
neutrino-nucleon scattering. The signature of coherent production is an
emergent almost collinear with the incident neutrino while 's
produced in neutrino-nucleon deep inelastic scattering have larger transverse
momenta. In this analysis all relevant backgrounds to the coherent
production signal are measured using data themselves. Having determined the
backgrounds, and using the Rein-Sehgal model for the coherent
production to compute the detection efficiency, we obtain {\boldmath } corrected coherent- events with GeV. We measure {\boldmath }.
This is the most precise measurement of the coherent production to
date.Comment: 23 pages, 9 figures, accepted for publication in Phys. Lett.
Modified Quark-Meson Coupling Model for Nuclear Matter
The quark-meson coupling model for nuclear matter, which describes nuclear
matter as non-overlapping MIT bags bound by the self-consistent exchange of
scalar and vector mesons, is modified by introducing medium modification of the
bag constant. We model the density dependence of the bag constant in two
different ways: one invokes a direct coupling of the bag constant to the scalar
meson field, and the other relates the bag constant to the in-medium nucleon
mass. Both models feature a decreasing bag constant with increasing density. We
find that when the bag constant is significantly reduced in nuclear medium with
respect to its free-space value, large canceling isoscalar Lorentz scalar and
vector potentials for the nucleon in nuclear matter emerge naturally. Such
potentials are comparable to those suggested by relativistic nuclear
phenomenology and finite-density QCD sum rules. This suggests that the
reduction of bag constant in nuclear medium may play an important role in low-
and medium-energy nuclear physics.Comment: Part of the text is reordered, revised version to appear in Phys.
Rev. C. 19 pages, ReVTeX, 4 figures embedde
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