The flux of very high-energy neutrinos produced in our Galaxy by the interaction of accelerated cosmic rays with the interstellar medium is not yet determined. The characterization of this flux will ...shed light on Galactic accelerator features, gas distribution morphology and Galactic cosmic ray transport. The central Galactic plane can be the site of an enhanced neutrino production, thus leading to anisotropies in the extraterrestrial neutrino signal as measured by the IceCube Collaboration. The ANTARES neutrino telescope, located in the Mediterranean Sea, offers a favorable view of this part of the sky, thereby allowing for a contribution to the determination of this flux. The expected diffuse Galactic neutrino emission can be obtained, linking a model of generation and propagation of cosmic rays with the morphology of the gas distribution in the Milky Way. In this paper, the so-called “gamma model” introduced recently to explain the high-energy gamma-ray diffuse Galactic emission is assumed as reference. The neutrino flux predicted by the “gamma model” depends on the assumed primary cosmic ray spectrum cutoff. Considering a radially dependent diffusion coefficient, this proposed scenario is able to account for the local cosmic ray measurements, as well as for the Galactic gamma-ray observations. Nine years of ANTARES data are used in this work to search for a possible Galactic contribution according to this scenario. All flavor neutrino interactions are considered. No excess of events is observed, and an upper limit is set on the neutrino flux of 1.1 (1.2) times the prediction of the “gamma model,” assuming the primary cosmic ray spectrum cutoff at 5 (50) PeV. This limit excludes the diffuse Galactic neutrino emission as the major cause of the “spectral anomaly” between the two hemispheres measured by IceCube.
We consider a particular effect which can be expected in scenarios of deviations from special relativity induced by Planckian physics: the loss of additivity in the total energy of a system of ...particles. We argue about the necessity to introduce a length scale to control the effects of non-additivity for macroscopic objects and consider white dwarfs as an appropriate laboratory to test this kind of new physics. We study the sensitivity of the mass-radius relation of the Chandrasekhar model to these corrections by comparing the output of a simple phenomenological model to observational data of white dwarfs.
One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context ...and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with
3.5
σ
statistical significance. The detector angular resolution for downward-going muons is
0
.
73
∘
±
0
.
14
∘
.
The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.
The data of four growth studies involving populations from Andalusia, Barcelona, Bilbao and Zaragoza have recently been reported as part of the Spanish Cross-sectional Growth Study 2008 (SCGS). With ...the aim of detecting possible differences between the population of the Madrid region and those of the SCGS, and by so-doing assess the applicability of the conclusions of this reference work to the Madrid region, a cross-sectional study of the latter was undertaken, recording the weight, height and body mass index (BMI).
We have analyzed 6463 subjects (3055 females and 3408 males) aged 3-24 years. All subjects were healthy, Caucasian, and of Spanish origin. Differences between the results of the Madrid and SCGS studies were sought by multiple linear regression analysis of the log of the height, weight and BMI data adjusted for age and geographical area. The Tukey multiple comparisons test was used to analyse differences in age ranges. All calculations were performed using SAS v. 8.2 software.
Means and standard deviations are provided for the weight, height and BMI of women and men; distributions by percentiles are also provided. No differences of clinical importance were seen in the weight, height or BMI between the subjects of the Madrid region and those of the SCGS. However, comparisons with the results of other studies performed more than 20 years ago revealed an increase in the weight and height values in all percentiles.
In summary, the official Spanish SCGS reference data for 2008 are similar to those recorded for the Madrid region. Bearing in mind that recent cross-sectional studies undertaken in Andalusia, Aragon, Catalonia, the Basque Country and the present work show no significant differences in mean weights, heights or BMIs in any age group, nor in the final height attained by adults, the Spanish population would appear to be anthropometrically homogeneous. The conclusions of the SCGS may therefore be applicable to the entire country.
Cherenkov light induced by radioactive decay products is one of the major sources of background light for deep-sea neutrino telescopes such as ANTARES. These decays are at the same time a powerful ...calibration source. Using data collected by the ANTARES neutrino telescope from mid 2008 to 2017, the time evolution of the photon detection efficiency of optical modules is studied. A modest loss of only 20% in 9 years is observed. The relative time calibration between adjacent modules is derived as well.
Abstract Cherenkov light induced by radioactive decay products is one of the major sources of background light for deep-sea neutrino telescopes such as ANTARES. These decays are at the same time a ...powerful calibration source. Using data collected by the ANTARES neutrino telescope from mid 2008 to 2017, the time evolution of the photon detection efficiency of optical modules is studied. A modest loss of only 20% in 9 years is observed. The relative time calibration between adjacent modules is derived as well.
A
bstract
Non-standard interactions of neutrinos arising in many theories beyond the Standard Model can significantly alter matter effects in atmospheric neutrino propagation through the Earth. In ...this paper, a search for deviations from the prediction of the standard 3-flavour atmospheric neutrino oscillations using the data taken by the ANTARES neutrino telescope is presented. Ten years of atmospheric neutrino data collected from 2007 to 2016, with reconstructed energies in the range from ∼16 GeV to 100 GeV, have been analysed. A log-likelihood ratio test of the dimensionless coefficients
ε
μτ
and
ε
ττ
−
ε
μμ
does not provide clear evidence of deviations from standard interactions. For normal neutrino mass ordering, the combined fit of both coefficients yields a value 1.7
σ
away from the null result. However, the 68% and 95% confidence level intervals for
ε
μτ
and
ε
ττ
−
ε
μμ
, respectively, contain the null value. Best fit values, one standard deviation errors and bounds at the 90% confidence level for these coefficients are given for both normal and inverted mass orderings. The constraint on
ε
μτ
is among the most stringent to date and it further restrains the strength of possible non-standard interactions in the
μ − τ
sector.
An offline search for a neutrino counterpart to gravitational-wave (GW) events detected during the second observation run (O2) of Advanced-LIGO and Advanced-Virgo performed with ANTARES data is ...presented. In addition to the search for long tracks induced by
ν
μ
(
ν
¯
μ
) charged current interactions, a search for showering events induced by interactions of neutrinos of any flavour is conducted. The severe spatial and time coincidence provided by the gravitational-wave alert allows regions above the detector horizon to be probed, extending the ANTARES sensitivity over the entire sky. The results of this all-neutrino-flavour and all-sky time dependent analysis are presented. The search for prompt neutrino emission within ±500 s around the time of six GW events yields no neutrino counterparts. Upper limits on the neutrino spectral fluence and constraints on the isotropic energy radiated via high-energy neutrinos (from a few TeV to a few tens of PeV) are set for each GW event analysed.
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