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"Raymond, R"
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A near-minimal leptoquark model for reconciling flavour anomalies and generating radiative neutrino masses
A
bstract
We introduce two scalar leptoquarks, the SU(2)
L
isosinglet denoted
ϕ ∼
(
3
,
1
, −
1
/
3) and the isotriplet
φ ∼
(
3
,
3
, −
1
/
3), to explain observed deviations from the standard model in semi-leptonic
B
-meson decays. We explore the regions of parameter space in which this model accommodates the persistent tensions in the decay observables
R
D
(
∗
),
R
K
(
∗
) , and angular observables in
b → sμμ
transitions. Additionally, we exploit the role of these exotics in existing models for one-loop neutrino mass generation derived from ∆
L
= 2 effective operators. Introducing the vector-like quark
χ ∼
(
3
,
2
, −
5
/
6) necessary for lepton-number violation, we consider the contribution of both leptoquarks to the generation of radiative neutrino mass. We find that constraints permit simultaneously accommodating the flavour anomalies while also explaining the relative smallness of neutrino mass without the need for cancellation between leptoquark contributions. A characteristic prediction of our model is a rate of muon-electron conversion in nuclei fixed by the anoma- lies in
b → sμμ
and neutrino mass; the COMET and Mu2e experiments will thus test and potentially falsify our scenario. The model also predicts signatures that will be tested at the LHC and Belle II.
Journal Article
Detection of African Swine Fever Virus Antibodies in Serum and Oral Fluid Specimens Using a Recombinant Protein 30 (p30) Dual Matrix Indirect ELISA
In the absence of effective vaccine(s), control of African swine fever caused by African swine fever virus (ASFV) must be based on early, efficient, cost-effective detection and strict control and elimination strategies. For this purpose, we developed an indirect ELISA capable of detecting ASFV antibodies in either serum or oral fluid specimens. The recombinant protein used in the ELISA was selected by comparing the early serum antibody response of ASFV-infected pigs (NHV-p68 isolate) to three major recombinant polypeptides (p30, p54, p72) using a multiplex fluorescent microbead-based immunoassay (FMIA). Non-hazardous (non-infectious) antibody-positive serum for use as plate positive controls and for the calculation of sample-to-positive (S:P) ratios was produced by inoculating pigs with a replicon particle (RP) vaccine expressing the ASFV p30 gene. The optimized ELISA detected anti-p30 antibodies in serum and/or oral fluid samples from pigs inoculated with ASFV under experimental conditions beginning 8 to 12 days post inoculation. Tests on serum (n = 200) and oral fluid (n = 200) field samples from an ASFV-free population demonstrated that the assay was highly diagnostically specific. The convenience and diagnostic utility of oral fluid sampling combined with the flexibility to test either serum or oral fluid on the same platform suggests that this assay will be highly useful under the conditions for which OIE recommends ASFV antibody surveillance, i.e., in ASFV-endemic areas and for the detection of infections with ASFV isolates of low virulence.
Journal Article
Reconsidering the one leptoquark solution: flavor anomalies and neutrino mass
A
bstract
We reconsider a model introducing a scalar leptoquark
ϕ
∼ (
3
,
1
,
−1
/
3) to explain recent deviations from the standard model in semileptonic
B
decays. The leptoquark can accommodate the persistent tension in the decays
B
¯
→
D
∗
τ
ν
¯
as long as its mass is lower than approximately 10 TeV, and we show that a sizeable Yukawa coupling to the right-chiral tau lepton is necessary for an acceptable explanation. A characteristic prediction of this scenario is a value of
R
D
*
slightly smaller than the current world average. Agreement with the measured
B
¯
→
D
∗
τ
ν
¯
rates is mildly compromised for parameter choices addressing the tensions in
b
→
sμμ
, where the model can significantly reduce the discrepancies in angular observables, branching ratios and the lepton-flavor-universality observables
R
K
and
R
K
*
. The leptoquark can also reconcile the predicted and measured value of the anomalous magnetic moment of the muon and appears naturally in models of radiative neutrino mass derived from lepton-number violating effective operators. As a representative example, we incorporate the particle into an existing two-loop neutrino mass scenario derived from a dimension-nine operator. In this specific model, the structure of the neutrino mass matrix provides enough freedom to explain the small masses of the neutrinos in the region of parameter space dictated by agreement with the anomalies in
B
¯
→
D
∗
τ
ν
¯
, but not the
b
→
s
transition. This is achieved without excessive fine-tuning in the parameters important for neutrino mass.
Journal Article
Exploding operators for Majorana neutrino masses and beyond
A
bstract
Building UV completions of lepton-number-violating effective operators has proved to be a useful way of studying and classifying models of Majorana neutrino mass. In this paper we describe and implement an algorithm that systematises this model-building procedure. We use the algorithm to generate computational representations of all of the tree-level completions of the operators up to and including mass-dimension 11. Almost all of these correspond to models of radiative neutrino mass. Our work includes operators involving derivatives, updated estimates for the bounds on the new-physics scale associated with each operator, an analysis of various features of the models, and a look at some examples. We find that a number of operators do not admit any completions not also generating lower-dimensional operators or larger contributions to the neutrino mass, ruling them out as playing a dominant role in the neutrino-mass generation. Additionally, we show that there are at most five models containing three or fewer exotic multiplets that predict new physics that must lie below 100 TeV. Accompanying this work we also make available a searchable database containing all of our results and the code used to find the completions. We emphasise that our methods extend beyond the study of neutrino-mass models, and may be useful for generating completions of high-dimensional operators in other effective field theories. Example code: ref. [
37
].
Journal Article
Improving the Human Hazard Characterization of Chemicals: A Tox21 Update
In 2008, the National Institute of Environmental Health Sciences/National Toxicology Program, the U.S. Environmental Protection Agency's National Center for Computational Toxicology, and the National Human Genome Research Institute/National Institutes of Health Chemical Genomics Center entered into an agreement on \"high throughput screening, toxicity pathway profiling, and biological interpretation of findings.\" In 2010, the U.S. Food and Drug Administration (FDA) joined the collaboration, known informally as Tox21.
The Tox21 partners agreed to develop a vision and devise an implementation strategy to shift the assessment of chemical hazards away from traditional experimental animal toxicology studies to one based on target-specific, mechanism-based, biological observations largely obtained using in vitro assays.
Here we outline the efforts of the Tox21 partners up to the time the FDA joined the collaboration, describe the approaches taken to develop the science and technologies that are currently being used, assess the current status, and identify problems that could impede further progress as well as suggest approaches to address those problems.
Tox21 faces some very difficult issues. However, we are making progress in integrating data from diverse technologies and end points into what is effectively a systems-biology approach to toxicology. This can be accomplished only when comprehensive knowledge is obtained with broad coverage of chemical and biological/toxicological space. The efforts thus far reflect the initial stage of an exceedingly complicated program, one that will likely take decades to fully achieve its goals. However, even at this stage, the information obtained has attracted the attention of the international scientific community, and we believe these efforts foretell the future of toxicology.
Journal Article