29,936 research outputs found
Sensitivity to new physics: a_e vs. a_mu
At present it is generally believed that ``new physics'' effects contribute
to leptonic anomalous magnetic moment, a_l, via quantum loops only and they are
proportional to the squared lepton mass, (m_l)^2. An alternative mechanism for
a contribution by new physics is proposed. It occurs at the tree level and
exhibits a linear rather than quadratic dependence on m_l. This leads to a much
larger sensitivity of a_e to the new physics than was expected so far.Comment: 4 pages, 2 figure
New Goldstone multiplet for partially broken supersymmetry
The partial spontaneous breaking of rigid N=2 supersymmetry implies the
existence of a massless N=1 Goldstone multiplet. In this paper we show that the
spin-(1/2,1) Maxwell multiplet can play this role. We construct its full
nonlinear transformation law and find the invariant Goldstone action. The
spin-1 piece of the action turns out to be of Born-Infeld type, and the full
superfield action is duality invariant. This leads us to conclude that the
Goldstone multiplet can be associated with a D-brane solution of superstring
theory for p=3. In addition, we find that N=1 chirality is preserved in the
presence of the Goldstone-Maxwell multiplet. This allows us to couple it to N=1
chiral and gauge field multiplets. We find that arbitrary Kahler and
superpotentials are consistent with partially broken N=2 supersymmetry.Comment: Latex, 13 pages. Version to appear in Phys. Rev.
Gravitational-wave confusion background from cosmological compact binaries: Implications for future terrestrial detectors
Increasing the sensitivity of a gravitational-wave (GW) detector improves our
ability to measure the characteristics of detected sources. It also increases
the number of weak signals that contribute to the data. Because GW detectors
have nearly all-sky sensitivity, they can be subject to a confusion limit: Many
sources which cannot be distinguished may be measured simultaneously, defining
a stochastic noise floor to the sensitivity. For GW detectors operating at
present and for their planned upgrades, the projected event rate is
sufficiently low that we are far from the confusion-limited regime. However,
some detectors currently under discussion may have large enough reach to binary
inspiral that they enter the confusion-limited regime. In this paper, we
examine the binary inspiral confusion limit for terrestrial detectors. We
consider a broad range of inspiral rates in the literature, several planned
advanced gravitational-wave detectors, and the highly advanced "Einstein
Telescope" design. Though most advanced detectors will not be impacted by this
limit, the Einstein Telescope with a very low frequency "seismic wall" may be
subject to confusion noise. At a minimum, careful data analysis will be require
to separate signals which will appear confused. This result should be borne in
mind when designing highly advanced future instruments.Comment: 19 pages, 6 figures and 3 tables; accepted for publication in Phys.
Rev.
Flour for home baking: A cross‐sectional analysis of supermarket products emphasising the whole grain opportunity
Flour, typically derived from wheat, rye, corn and rice is a pantry staple, providing structure to bread and baked goods. This study aimed to provide a cross‐sectional analysis of flour for home baking, highlighting the nutrition composition of whole grain flour and identifying novel categories. An audit was undertaken in February 2020, in four major supermarkets in metropolitan Sydney (Aldi, Coles, IGA and Woolworths). Ingredient lists, Nutrition Information Panel, claims, and country of origin were collected. The median and range were calculated for energy, protein, fat, saturated fat, carbohydrate, sugars, dietary fibre and sodium. Overall, 130 products were collected, including 26 plain flour, 12 self‐raising, 17 plain wholemeal, 4 wholemeal self‐raising, 20 bread-making mixes (4 were whole grain), 20 other refined grain (including corn and rice flour), 17 gluten-free, 3 legume, 4 fruit/vegetable, 4 coconut and 3 other non‐grain (e.g., hemp seed, cricket flour) products. Plain wheat flour dominated the category, while whole grain (wholemeal) made up 19% of products, yet they contained significantly more dietary fibre (p < 0.001) and protein (p < 0.001). Self‐raising flours were significantly higher in sodium (p < 0.001) and gluten‐free products were lower in protein and dietary fibre, making legume, buckwheat and quinoa flour a better choice. Sustainability principles in fruit and vegetable production and novel insect products have driven new product development. There is a clear opportunity for further on‐pack promotion of whole grain and dietary fibre within the category via food product labelling
Optimizing the Earth-LISA "rendez-vous"
We present a general survey of heliocentric LISA orbits, hoping it might help
in the exercise of rescoping the mission. We try to semi-analytically optimize
the orbital parameters in order to minimize the disturbances coming from the
Earth-LISA interaction. In a set of numerical simulations we include
nonautonomous perturbations and provide an estimate of Doppler shift and
breathing as a function of the trailing angle.Comment: 18 pages, 16 figures. Submitted on CQ
Residual mean first-passage time for jump processes: theory and applications to L\'evy flights and fractional Brownian motion
We derive a functional equation for the mean first-passage time (MFPT) of a
generic self-similar Markovian continuous process to a target in a
one-dimensional domain and obtain its exact solution. We show that the obtained
expression of the MFPT for continuous processes is actually different from the
large system size limit of the MFPT for discrete jump processes allowing
leapovers. In the case considered here, the asymptotic MFPT admits
non-vanishing corrections, which we call residual MFPT. The case of L/'evy
flights with diverging variance of jump lengths is investigated in detail, in
particular, with respect to the associated leapover behaviour. We also show
numerically that our results apply with good accuracy to fractional Brownian
motion, despite its non-Markovian nature.Comment: 13 pages, 8 figure
Genetic distance predicts trait differentiation at the subpopulation but not the individual level in eelgrass, Zostera marina.
Ecological studies often assume that genetically similar individuals will be more similar in phenotypic traits, such that genetic diversity can serve as a proxy for trait diversity. Here, we explicitly test the relationship between genetic relatedness and trait distance using 40 eelgrass (Zostera marina) genotypes from five sites within Bodega Harbor, CA. We measured traits related to nutrient uptake, morphology, biomass and growth, photosynthesis, and chemical deterrents for all genotypes. We used these trait measurements to calculate a multivariate pairwise trait distance for all possible genotype combinations. We then estimated pairwise relatedness from 11 microsatellite markers. We found significant trait variation among genotypes for nearly every measured trait; however, there was no evidence of a significant correlation between pairwise genetic relatedness and multivariate trait distance among individuals. However, at the subpopulation level (sites within a harbor), genetic (FST) and trait differentiation were positively correlated. Our work suggests that pairwise relatedness estimated from neutral marker loci is a poor proxy for trait differentiation between individual genotypes. It remains to be seen whether genomewide measures of genetic differentiation or easily measured "master" traits (like body size) might provide good predictions of overall trait differentiation
Experimental investigation of the competing orders and quantum criticality in hole- and electron-doped cuprate superconductors
We investigate the issues of competing orders and quantum criticality in cuprate superconductors via experimental studies of the high-field thermodynamic phase diagrams and the quasiparticle tunneling spectroscopy. Substantial field-induced quantum fluctuations are found in all cuprates investigated, and the corresponding correlation with quasiparticle spectra suggest that both electron- (n-type) and hole-doped (p-type) cuprate superconductors are in close proximity to a quantum critical point that separates a pure superconducting (SC) phase from a phase consisting of coexisting SC and a competing order. We further suggests that the relevant competing order is likely a spin-density wave (SDW) or a charge density wave (CDW), which can couple efficiently to an in-plane Cu-O bond stretching longitudinal optical (LO) phonon mode in the p-type cuprates but not in the n-type cuprates. This cooperative interaction may account for the pseudogap phenomenon above T, only in the p-type cuprate superconductors
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