1,177 research outputs found
A Simple Realization of the Inverse Seesaw Mechanism
Differently from the canonical seesaw mechanism, which is grounded in grand
unified theories, the inverse seesaw mechanism lacks a special framework that
realizes it naturally. In this work we advocate that the 3-3-1 model with
right-handed neutrinos has such an appropriate framework to accommodate the
inverse seesaw mechanism. We also provide an explanation for the smallness of
the parameter and estimate the branching ratio for the rare lepton flavor
violation process .Comment: About 14pages, no figures, basis corrected, to appear at the PR
Asymptotic Analysis of Plausible Tree Hash Modes for SHA-3
Discussions about the choice of a tree hash mode of operation for a
standardization have recently been undertaken. It appears that a single tree
mode cannot address adequately all possible uses and specifications of a
system. In this paper, we review the tree modes which have been proposed, we
discuss their problems and propose remedies. We make the reasonable assumption
that communicating systems have different specifications and that software
applications are of different types (securing stored content or live-streamed
content). Finally, we propose new modes of operation that address the resource
usage problem for the three most representative categories of devices and we
analyse their asymptotic behavior
Light colored scalars from grand unification and the forward-backward asymmetry in top quark pair production
The experimental results on the t bar t production cross section at the
Tevatron are well described by the QCD contributions within the standard model,
while the recent measurement of the forward-backward asymmetry cannot be
accounted for within this framework. We consider light colored scalars
appearing in a particular SU(5) GUT model within the 45-dimensional Higgs
representation. A virtue of the model is that it connects the presence of a
light colored SU(2) singlet (Delta_6) and a color octet weak doublet (Delta_1)
with bounds on the proton lifetime, which constrain the parameter space of both
scalars. We find that both the t bar t production cross section and the
forward-backward asymmetry can be accommodated simultaneously within this
model. The experimental results prefer a region for the mass of Delta_6 around
400 GeV, while Delta_1 is then constrained to have a mass around the TeV scale
as well. We analyze possible experimental signatures and find that Delta_6
associated top production could be probed in the t bar t + jets final states at
Tevatron and the LHC.Comment: 12 pages, 13 figures, version as publishe
Serious Bacterial Infections Acquired During Treatment of Patients Given a Diagnosis of Chronic Lyme Disease - United States.
The term "chronic Lyme disease" is used by some health care providers as a diagnosis for various constitutional, musculoskeletal, and neuropsychiatric symptoms (1,2). Patients with a diagnosis of chronic Lyme disease have been provided a wide range of medications as treatment, including long courses of intravenous (IV) antibiotics (3,4). Studies have not shown that such treatments lead to substantial long-term improvement for patients, and they can be harmful (1,5). This report describes cases of septic shock, osteomyelitis, Clostridium difficile colitis, and paraspinal abscess resulting from treatments for chronic Lyme disease. Patients, clinicians, and public health practitioners should be aware that treatments for chronic Lyme disease can carry serious risks
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