5,210 research outputs found
Interpreting Dark Matter Direct Detection Independently of the Local Velocity and Density Distribution
We demonstrate precisely what particle physics information can be extracted
from a single direct detection observation of dark matter while making
absolutely no assumptions about the local velocity distribution and local
density of dark matter. Our central conclusions follow from a very simple
observation: the velocity distribution of dark matter is positive definite,
f(v) >= 0. We demonstrate the utility of this result in several ways. First, we
show a falling deconvoluted recoil spectrum (deconvoluted of the nuclear form
factor), such as from ordinary elastic scattering, can be "mocked up" by any
mass of dark matter above a kinematic minimum. As an example, we show that dark
matter much heavier than previously considered can explain the CoGeNT excess.
Specifically, m_chi < m_Ge} can be in just as good agreement as light dark
matter, while m_\chi > m_Ge depends on understanding the sensitivity of Xenon
to dark matter at very low recoil energies, E_R ~ 6 keVnr. Second, we show that
any rise in the deconvoluted recoil spectrum represents distinct particle
physics information that cannot be faked by an arbitrary f(v). As examples of
resulting non-trivial particle physics, we show that inelastic dark matter and
dark matter with a form factor can both yield such a rise
Direct Mass Limits for Chiral Fourth-Generation Quarks in All Mixing Scenarios
Present limits on chiral fourth-generation quark masses and
are broadly generalized and strengthened by combining both and decays
and considering the full range of and flavor-mixing scenarios (with
the lighter generations). Various characteristic mass-splitting choices are
considered. With we find that CDF limits on the mass
vary by no more than 10-20% with any choice of flavor-mixing, while for the
mass, we typically find stronger bounds, in some cases up to GeV. For we find GeV, depending on
the flavor-mixing and the size of the mass splitting
Erratum: Next-to-leading order supersymmetric QCD predictions for associated production of gauginos and gluinos [Phys. Rev. D 62, 095014 (2000)]
Errors in the published version of the paper are corrected, and new figures
are provided.Comment: 3 pages, latex, 4 figure
The WIMP Forest: Indirect Detection of a Chiral Square
The spectrum of photons arising from WIMP annihilation carries a detailed
imprint of the structure of the dark sector. In particular, loop-level
annihilations into a photon and another boson can in principle lead to a series
of lines (a WIMP forest) at energies up to the WIMP mass. A specific model
which illustrates this feature nicely is a theory of two universal extra
dimensions compactified on a chiral square. Aside from the continuum emission,
which is a generic prediction of most dark matter candidates, we find a
"forest" of prominent annihilation lines that, after convolution with the
angular resolution of current experiments, leads to a distinctive (2-bump plus
continuum) spectrum, which may be visible in the near future with the Fermi
Gamma-Ray Space Telescope (formerly known as GLAST).Comment: 11 pages, 4 figure
Perceptions of service quality by clients and contact-personnel in the South African retail banking sector
A superior level of service quality is an important objective for South African retail banks. This paper investigates the levels of perceived service quality among 550 clients and 559 branch contactpersonnel in retail banks in central South Africa. The perceptions are compared, and the findings reveal that clients regard the levels of service they receive to be better than what the contact-personnel perceive them to be experiencing. The physical branch environment was also shown to be an important dimension of perceived service quality among retail clients. A cluster analysis identified three market segments to use when adopting marketing strategies, and the demographic factors of age, race and geographical location were found to be important considerations when developing these marketing strategies. An explicit micro-market marketing approach that is flexible and tailor-made to the characteristics of the location of the branch is a recommendation of the paper.Key words: service quality, central South Africa, retail bank
Highly syntenic and yet divergent: a tale of two Theilerias
The published genomic sequences of the two major host-transforming Theileria species of cattle represent a rich resource of information that has allowed novel bioinformatic and experimental studies into these important apicomplexan parasites. Since their publication in 2005, the genomes of T. annulata and T. parva have been utilised for a diverse range of applications, ranging from candidate antigen discovery to the identification of genetic markers for population analysis. This has led to advancements in the quest for a sub-unit vaccine, while providing a greater understanding of variation among parasite populations in the field. The unique ability of these Theileria species to induce host cell transformation is the subject of considerable scientific interest and the availability of full genomic sequences has provided new insights into this area of research. This article reviews the data underlying published comparative analyses, focussing on the general features of gene expression, the major Tpr/Tar multi-copy gene family and a re-examination of the predicted macroschizont secretome. Codon usage between the Theileria species is reviewed in detail, as this underpins ongoing comparative studies investigating selection at the intra- and inter-species level. The TashAT/TpshAT family of genes, conserved between T. annulata and T. parva, encodes products targeted to the host nucleus and has been implicated in contributing to the transformed bovine phenotype. Species-specific expansion and diversification at this critical locus is discussed with reference to the availability, in the near future, of genomic datasets which are based on non-transforming Theileria species
A Case of Cholangitis Glandularis Proliferans and Cholangiocarcinoma of the Common Bile Duct
A case of Cholangitis Glandularis Proliferans (CAGP) in association with a cholangiocarcinoma of the
common bile duct as described. This is the eighth case of CAGP described and the second association
with cholangiocarcinoma
Hepatic Dystychoma: A Five Year Experience
In 5 years, 64 solid hepatic lesions have been referred for diagnosis and management which have been
found unexpectedly on organ imaging in well patients. We have called this lesion a “dystychoma”
Flavor changing scalar couplings and production at hadron colliders
We calculate the contributions of the flavor changing scalar ()
couplings arised from topcolor-assisted technicolor () models at
tree-level to the and production at the Tevatron and
experiments. We find that the production cross sections are very small at the
Tevatron with , which is smaller than 5 fb in most of the
parameter space of models. However, the virtual effects of the
couplings on the production can be easily detected at the
with via the final state
().Comment: 10 pages,5 figure
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