723 research outputs found
Comment on "Fano Resonance for Anderson Impurity Systems"
In a recent Letter, Luo et al. (Phys. Rev. Lett. 92, 256602 (2004)) analyze
the Fano line shapes obtained from scanning tunneling spectroscopy (STS) of
transition metal impurities on a simple metal surface, in particular of the
Ti/Au(111) and Ti/Ag(100) systems. As the key point of their analysis, they
claim that there is not only a Fano interference effect between the impurity
d-orbital and the conduction electron continuum, as derived in Ujsaghy et al.
(Phys. Rev. Lett. 85, 2557 (2000)), but that the Kondo resonance in the
d-electron spectral density has by itself a second Fano line shape, leading to
the experimentally observed spectra. In the present note we point out that this
analysis is conceptually incorrect. Therefore, the quantitative agreement of
the fitted theoretical spectra with the experimental results is meaningless.Comment: 1 page, no figures. Accepted for publication in PRL; revised version
uploaded on November 18th, 200
Neutrino anomalies and future prospects in neutrino physics
I give an overview of some of the several anomalies appearing in neutrino oscillation experiments, setting particular focus to the reactor antineutrino anomaly and the Gallium anomaly. I will discuss these two anomalies in some detail and, in particular, compare their explanation due to neutrino oscillations in presence of a light sterile neutrino among each other and also with the bounds from the analyses of reactor spectral ratio data, β-decay data, and solar neutrino data
Status of neutrino oscillations 2018: first hint for normal mass ordering and improved CP sensitivity
We present a new global fit of neutrino oscillation parameters within the
simplest three-neutrino picture, including new data which appeared since our
previous analysis~\cite{Forero:2014bxa}. In this update we include new
long-baseline neutrino data involving the antineutrino channel in T2K, as well
as new data in the neutrino channel, data from NOA, as well as new reactor
data, such as the Daya Bay 1230 days electron antineutrino disappearance
spectrum data and the 1500 live days prompt spectrum from RENO, as well as new
Double Chooz data. We also include atmospheric neutrino data from the IceCube
DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we
also update our solar oscillation analysis by including the 2055-day day/night
spectrum from the fourth phase of the Super-Kamiokande experiment. With the new
data we find a preference for the atmospheric angle in the upper octant for
both neutrino mass orderings, with maximal mixing allowed at for normal (inverted) ordering. We also obtain a strong
preference for values of the CP phase in the range ,
excluding values close to at more than 4. More remarkably, our
global analysis shows for the first time hints in favour of the normal mass
ordering over the inverted one at more than 3. We discuss in detail the
origin of the mass ordering, CP violation and octant sensitivities, analyzing
the interplay among the different neutrino data samples.Comment: Updated neutrino oscillation analysis using the most recent results
from T2K, NOA, RENO and Super-Kamiokande. 17 pages, 8 figures, 1 tabl
Inspection of the detection cross section dependence of the Gallium Anomaly
We discuss in detail the dependence of the Gallium Anomaly on the detection
cross section. We provide updated values of the size of the Gallium Anomaly and
find that its significance is larger than about for all the detection
cross section models. We discuss the dependence of the Gallium Anomaly on the
assumed value of the half life of , which determines the
cross sections of the transitions from the ground state of
to the ground state of . We show that a value of the
half life which is larger than the standard one can reduce
or even solve the Gallium Anomaly. Considering the short-baseline neutrino
oscillation interpretation of the Gallium Anomaly, we show that a value of the
half life which is larger than the standard one can reduce
the tension with the results of other experiments. Since the standard value of
the half life was measured in 1985, we advocate the
importance of new measurements with modern technique and apparatus for a better
assessment of the Gallium Anomaly.Comment: v3: 11 pages, 4 figures, 3 tables, references added, typo correcte
Sterile neutrinos with altered dispersion relations revisited
In this paper we investigate neutrino oscillations with altered dispersion
relations in the presence of sterile neutrinos. Modified dispersion relations
represent an agnostic way to parameterize new physics. Models of this type have
been suggested to explain global neutrino oscillation data, including
deviations from the standard three-neutrino paradigm as observed by a few
experiments. We show that, unfortunately, in this type of models new tensions
arise turning them incompatible with global data.Comment: 22 pages, 7 figures, 2 tables. Version 2, matches published versio
Gallium Anomaly: Critical View from the Global Picture of and Disappearance
The significance of the Gallium Anomaly, from the BEST, GALLEX, and SAGE
radioactive source experiments, is quantified using different theoretical
calculations of the neutrino detection cross section, and its explanation due
to neutrino oscillations is compared with the bounds from the analyses of
reactor rate and spectral ratio data, -decay data, and solar neutrino
data. In the 3+1 active-sterile neutrino mixing scheme, the Gallium Anomaly is
in strong tension with the individual and combined bounds of these data sets.
In the combined scenario with all available data, the parameter goodness of fit
is below 0.042%, corresponding to a severe tension of 4-5, or stronger.
Therefore, we conclude that one should pursue other possible solutions beyond
short-baseline oscillations for the Gallium Anomaly. We also present a new
global fit of and disappearance data, showing that there is
a 2.6-3.3 preference in favor of short-baseline oscillations, which is
driven by an updated analysis of reactor spectral ratio data.Comment: 20 pages, 10 figures. With more discussions, version accepted for
publication at Journal of High Energy Physic
Zooming in on neutrino oscillations with DUNE
We examine the capabilities of the DUNE experiment as a probe of the neutrino mixing paradigm. Taking the current status of neutrino oscillations and the design specifications of DUNE, we determine the experiment's potential to probe the structure of neutrino mixing and CP violation. We focus on the poorly determined parameters θ23 and δCP and consider both two and seven years of run. We take various benchmarks as our true values, such as the current preferred values of θ23 and δCP, as well as several theorymotivated choices. We determine quantitatively DUNE's potential to perform a precision measurement of θ23, as well as to test the CP violation hypothesis in a model-independent way. We find that, after running for seven years, DUNE will make a substantial step in the precise determination of these parameters, bringing to quantitative test the predictions of various theories of neutrino mixing
Fate of conjugated natural and synthetic steroid estrogens in crude sewage and activated sludge batch studies
This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/es801952h.Steroids are excreted from the human body in the conjugated form but are present in sewage influent and effluent as the free steroid, the major source of estrogenic activity observed in water courses. The fate of sulfate and glucuronide conjugated steroid estrogens was investigated in batch studies using activated sludge grown on synthetic sewage in a laboratory-scale Husmann simulation and crude sewage from the field. A clear distinction between the fate of sulfate and glucuronide conjugates was observed in both matrices, with sulfated conjugates proving more recalcitrant and glucuronide deconjugation preferential in crude sewage. For each conjugate, the free steroid was observed in the biotic samples. The degree of free steroid formation was dependent on the conjugate moiety, favoring the glucuronide. Subsequent degradation of the free steroid (and sorption to the activated sludge solid phase) was evaluated. Deconjugation followed the first order reaction rate with rate constants for 17α-ethinylestradiol 3-glucuronide, estriol 16α-glucuronide, and estrone 3-glucuronide determined as 0.32, 0.24, and 0.35 h respectively. The activated sludge solid retention time over the range of 3−9 days had 74 to 94% of sulfate conjugates remaining after 8 h. In contrast, a correlation between increasing temperature and decreasing 17α-ethinylestradiol 3-glucuronide concentrations in the activated sludge observed no conjugate present in the AS following 8 h at 22 °C Based on these batch studies and literature excretion profiles, a hypothesis is presented on which steroids and what form (glucuronide, sulfate, or free) will likely enter the sewage treatment plant.EPSR
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