667 research outputs found
Direct Detection of Non-Chiral Dark Matter
Direct detection experiments rule out fermion dark matter that is a chiral
representation of the electroweak gauge group. Non-chiral real, complex and
singlet representations, however, provide viable fermion dark matter
candidates. Although any one of these candidates will be virtually impossible
to detect at the LHC, it is shown that they may be detected at future planned
direct detection experiments. For the real case, an irreducible radiative
coupling to quarks may allow a detection. The complex case in general has an
experimentally ruled out tree-level coupling to quarks via Z-boson exchange.
However, in the case of two SU(2)_L doublets, a higher dimensional coupling to
the Higgs can suppress this coupling, and a remaining irreducible radiative
coupling may allow a detection. Singlet dark matter could be detected through a
coupling to quarks via Higgs exchange. Since all non-chiral dark matter can
have a coupling to the Higgs, at least some of its mass can be obtained from
electroweak symmetry breaking, and this mass is a useful characterization of
its direct detection cross-section.Comment: 22 pages, 3 figures. References added. Minor corrections to match
published versio
Light dark forces at flavor factories
SuperB experiment could represent an ideal environment to test a new U (1)
symmetry related to light dark forces candidates. A promising discovery channel
is represented by the resonant production of a boson U, followed by its decay
into lepton pairs. Beyond approximations adopted in the literature, an exact
tree level calculation of the radiative processes and corresponding QED
backgrounds is performed, including also the most important higher-order
corrections. The calculation is implemented in a release of the generator
BabaYaga@NLO useful for data analysis and interpretation. The distinct features
of U boson production are shown and the statistical significance is analysed
Notes on SUSY and R-Symmetry Breaking in Wess-Zumino Models
We study aspects of Wess-Zumino models related to SUSY and R-symmetry
breaking at tree-level. We present a recipe for constructing a wide class of
tree-level SUSY and R-breaking models. We also deduce a general property shared
by all tree-level SUSY breaking models that has broad application to model
building. In particular, it explains why many models of direct gauge mediation
have anomalously light gauginos (even if the R-symmetry is broken spontaneously
by an order one amount). This suggests new approaches to dynamical SUSY
breaking which can generate large enough gaugino masses.Comment: 23 pages. v2: references added, minor changes. v3: comment on
non-renormalizable case adde
Two Loop R-Symmetry Breaking
We analyze two loop quantum corrections for pseudomoduli in O'Raifeartaigh
like models. We argue that R-symmetry can be spontaneously broken at two loop
in non supersymmetric vacua. We provide a basic example with this property. We
discuss on phenomenological applications.Comment: 13 pages, 5 figures, JHEP3.cls, reference adde
A Hybrid Higgs
We construct composite Higgs models admitting a weakly coupled Seiberg dual
description. We focus on the possibility that only the up-type Higgs is an
elementary field, while the down-type Higgs arises as a composite hadron. The
model, based on a confining SQCD theory, breaks supersymmetry and electroweak
symmetry dynamically and calculably. This simultaneously solves the \mu/B_\mu
problem and explains the smallness of the bottom and tau masses compared to the
top mass. The proposal is then applied to a class of models where the same
confining dynamics is used to generate the Standard Model flavor hierarchy by
quark and lepton compositeness. This provides a unified framework for flavor,
supersymmetry breaking and electroweak physics. The weakly coupled dual is used
to explicitly compute the MSSM parameters in terms of a few microscopic
couplings, giving interesting relations between the electroweak and soft
parameters. The RG evolution down to the TeV scale is obtained and salient
phenomenological predictions of this class of "single-sector" models are
discussed.Comment: 56 pages, 7 figures, v2: discussion on FCNCs and references added,
v3: JHEP versio
Examining the Relevancy and Utility of the American Fisheries Society Certification Program to Prepare Future Fisheries Professionals
Fisheries science is a diverse field that requires individuals to be knowledgeable in many disciplines in addition to fisheries (e.g., economics, sociology, political science, chemistry; Kelso and Murphy 1988). This challenges students attempting to enter a career in fisheries, as well as academic institutions and eventual employers, to develop both depth and breadth of knowledge needed to succeed in the profession (Oglesby and Krueger 1989). The preparedness and competency of young professionals entering the workforce has long been a problem (Stauffer and McMullin 2009). Several constraints and ongoing challenges facing the profession have continued to magnify these issues over time (McMullin et al., this issue). These issues stem from the diversity of skills required or expected across employer groups (e.g., government agencies, private sectors, nongovernment organizations) and degree levels sought (B.Sc., M.Sc., Ph.D.), complexity of fisheries-related problems, and balancing a broad academic focus with specific training. Additionally, employers perceive that students lack welldeveloped critical thinking, communication, and statistical skills that are highly desired in any area of fisheries. The American Fisheries Societyâs (AFS) mission of preparing and promoting the development of fisheries professionals has been addressed in many ways, including development of the AFS Professional Certification Program in 1963. This program provides minimum standards for which fisheries professionals are recognized across government, academic, and nongovernment entities. The certification program fosters greater recognition that fisheries professionals are well equipped and prepared to act on the publicâs behalf concerning fisheries-related issues. Two tiers of certification exist, with first-tier certification (Associate Fisheries Professional) contingent upon the completion of higher education courses in six broad subject areas. In this article, we focus on the first tier of certification, the basic education determined by AFS to be critical in preparing young professionals for a career in fisheries
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