2,283 research outputs found
Possible trace of neutrino nonstandard interactions in the supernova
Neutrino non-standard interactions (NSI), previously introduced for the sun,
are studied in the supernova context. For normal hierarchy the probability for
electron neutrinos and antineutrinos at low energy () is
substantially increased with respect to the non-NSI case and joins its value
for inverse hierarchy which is constant with energy. Also for inverse hierarchy
the NSI and non-NSI probabilities are the same for each neutrino and
antineutrino species. These are the possible visible effects of NSI in the
supernova. The decay into antineutrinos, which has been previously shown to be
implied by dense matter, cannot be seen experimentally, owing to the smallness
of the antineutrino production probability.Comment: 5 pages, 3 eps figures. Acknowledgements include
Non-equilibrium correlations and entanglement in a semiconductor hybrid circuit-QED system
We present a theoretical study of a hybrid circuit-QED system composed of two
semiconducting charge-qubits confined in a microwave resonator. The qubits are
defined in terms of the charge states of two spatially separated double quantum
dots (DQDs) which are coupled to the same photon mode in the microwave
resonator. We analyze a transport setup where each DQD is attached to
electronic reservoirs and biased out-of-equilibrium by a large voltage, and
study how electron transport across each DQD is modified by the coupling to the
common resonator. In particular, we show that the inelastic current through
each DQD reflects an indirect qubit-qubit interaction mediated by off-resonant
photons in the microwave resonator. As a result of this interaction, both
charge qubits stay entangled in the steady (dissipative) state. Finite shot
noise cross-correlations between currents across distant DQDs are another
manifestation of this nontrivial steady-state entanglement.Comment: Final versio
Baseline and other effects for a sterile neutrino at DUNE
We analyse the sensitivity of the Deep Underground Neutrino Experiment (DUNE)
to a sterile neutrino, combining information from both near and far detectors.
We quantify often-neglected effects which may impact the event rate estimation
in a 3+1 oscillation scenario. In particular, we find that taking into account
the information on the neutrino production point, in contrast to assuming a
point-like neutrino source, affects DUNE's sterile exclusion reach. Visible
differences remain after the inclusion of energy bin-to-bin uncorrelated
systematics. Instead, implementing exact oscillation formulae for near detector
events, including a two slab density profile, does not result in any visible
change in the sensitivity.Comment: 27 pages, 6 figures, 1 tabl
The outburst of the eruptive young star OO Serpentis between 1995 and 2006
OO Serpentis is a deeply embedded pre-main sequence star that went into
outburst in 1995 and gradually faded afterwards. Its eruption resembled the
well-known FU Orionis-type or EX Lupi-type outbursts. Since very few such
events have ever been documented at infrared wavelengths, our aim is to study
the temporal evolution of OO Ser in the infrared. OO Ser was monitored with the
Infrared Space Observatory starting 4 months after peak brightness and covering
20 months. In 2004-2006 we again observed OO Ser from the ground and
complemented this dataset with archival Spitzer obsevations also from 2004. We
analysed these data with special attention to source confusion and constructed
light curves at 10 different wavelengths as well as spectral energy
distributions. The outburst caused brightening in the whole infrared regime.
According to the infrared light curves, OO Ser started a wavelength-independent
fading after peak brightness. Later the flux decay became slower but stayed
wavelength-independent. The fading is still ongoing, and current fading rates
indicate that OO Ser will not return to quiescent state before 2011. The
outburst timescale of OO Ser seems to be shorter than that of FUors, but longer
than that of EXors. The outburst timescale and the moderate luminosity suggest
that OO Ser is different from both FUors and EXors, and shows similarities to
the recently erupted young star V1647 Ori. Based on its spectral energy
distribution and bolometric temperature, OO Ser seems to be an early class I
object, with an age of < 10^5 yr. The object is probably surrounded by an
accretion disc and a dense envelope. Due to the shorter outburst timescales,
the viscosity in the circumstellar disc of OO Ser is probably an order of
magnitude higher than usual for FUors.Comment: 12 pages, 7 figures, accepted for publication in A&
Remaining inconsistencies with solar neutrinos: can spin flavour precession provide a clue?
A few inconsistencies remain after it has been ascertained that LMA is the
dominant solution to the solar neutrino problem: why is the SuperKamiokande
spectrum flat and why is the Chlorine rate prediction over two standard
deviations above the data. There also remains the ananswered and important
question of whether the active neutrino flux is constant or time varying. We
propose a scenario involving spin flavour precession to sterile neutrinos with
three active flavours that predicts a flat SuperK spectrum and a Chlorine rate
prediction more consistent with data. We also argue that running the Borexino
experiment during the next few years may provide a very important clue as to
the possible variability of the solar neutrino flux.Comment: 3 pages, 2 figures, contribution to TAUP 2009 (Rome
How Patients Die in Internal Medicine Wards: a Retrospective Study
Os doentes com doença crónica avançada são uma presença diária nas enfermarias de Medicina Interna, não existindo um protocolo de intervenção universal e uniforme. Este estudo pretende ser uma primeira abordagem para avaliar a forma como tratamos e cuidamos destes doentes, quer de etiologia neoplásica, quer de outras doenças crónicas, igualmente consumptivas, como demência, insuficiência cardíaca, VIH/SIDA, doença pulmonar crónica obstrutiva (DPCO). Foram recolhidas informações retrospectivas dos processos clínicos acerca das atitudes e tratamentos prestados a 285 doentes falecidos em 16 meses num hospital de agudos em Lisboa. A caracterização epidemiológica da população foi a esperada, com predomínio de população idosa, dependente, com prevalência de doenças cardíacas e acidentes vasculares cerebrais (AVC), como diagnósticos principais, seguidas de demência e doenças respiratórias. Do total de falecimentos, 73% foram esperados, mas destes apenas 44% dos doentes estavam integrados em cuidados paliativos. A dor foi avaliada principalmente em doentes de foro neoplásico, sendo a analgesia administrada em 77% dos casos. A decisão de receberem cuidados paliativos foi discutida com a família em 26% dos doentes, mas não foi em nenhum caso discutido com o próprio doente. Consideramos que é necessário formação e informação para uma abordagem mais sistematizada do doente com doença crónica avançada e das suas necessidades. A definição explícita das expectativas de vida e uma abordagem sistemática da pesquisa de dor em todos estes, é necessária para garantir melhor qualidade dos cuidados prestados em fim de vida
Genomic data reveal a protracted window of introgression during the diversification of a neotropical woodcreeper radiation
The incidence of introgression during the diversification process and the timespan following divergence when introgression is possible are poorly understood in the neotropics where high species richness could provide extensive opportunities for genetic exchange. We used thousands of genome-wide SNPs to infer phylogenetic relationships, calculate ages of splitting, and to estimate the timing of introgression in a widespread avian neotropical genus of woodcreepers. Five distinct introgression events were reconstructed involving taxa classified both as subspecies and species including lineages descending from the basal-most split, dated to 7.3 million years ago. Introgression occurred between just a few hundred thousand to about 2.5 million years following divergence, suggesting substantial portions of the genome are capable of introgressing across taxa boundaries during a protracted time window of a few million years following divergence. Despite this protracted time window, we found that the proportion of the genome introgressing (6-11%) declines with the time of introgression following divergence, suggesting that the genome becomes progressively more immune to introgression as reproductive isolation increases.Peer reviewe
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