An Acoustic Doppler Current Profiler (ADCP) was moored at the deep-sea site of the ANTARES neutrino telescope near Toulon, France, thus providing a unique opportunity to compare high-resolution ...acoustic and optical observations between 70 and 170
m above the sea bed at 2475
m. The ADCP measured downward vertical currents of magnitudes up to 0.03
m
s
−1 in late winter and early spring 2006. In the same period, observations were made of enhanced levels of acoustic reflection, interpreted as suspended particles including zooplankton, by a factor of about 10 and of horizontal currents reaching 0.35
m
s
−1. These observations coincided with high light levels detected by the telescope, interpreted as increased bioluminescence. During winter 2006 deep dense-water formation occurred in the Ligurian subbasin, thus providing a possible explanation for these observations. However, the 10–20 days quasi-periodic episodes of high levels of acoustic reflection, light and large vertical currents continuing into the summer are not direct evidence of this process. It is hypothesized that the main process allowing for suspended material to be moved vertically later in the year is local advection, linked with topographic boundary current instabilities along the rim of the ‘Northern Current’.
► We describe yearlong optical and acoustic data from the deep-Mediterranean. ► Observations are made near the continental slope foot, near dense-water formation. ► Optics (bioluminescence), acoustics (plankton) and currents show enhanced bursts. ► Bursts are related to dense-water formation and enhanced boundary current activity.
► Group velocity of light measured by the ANTARES neutrino telescope in sea water. ► LEDs emit short duration flashes of different wavelengths detected by PMTs. ► Measurements show decrease of the ...refraction index with increasing wavelength. ► Measurements are in agreement with theoretical predictions.
The group velocity of light has been measured at eight different wavelengths between 385nm and 532nm in the Mediterranean Sea at a depth of about 2.2km with the ANTARES optical beacon systems. A parametrisation of the dependence of the refractive index on wavelength based on the salinity, pressure and temperature of the sea water at the ANTARES site is in good agreement with these measurements.
A re-analysis of some $\bar{p}p$ and $\bar{p}n$ data, at rest and in flight,
obtained in bubble chamber experiments, is presented. The ($\pi ^{+}\pi ^{-}$)
and ($K_{S}K_{S}$) final states for the ...channels (2$\pi ^{-}\pi ^{+}$) and
($K_{S}K_{S}\pi$) are investigated. Evidence for a narrow meson resonance
structure, cautiously suggested as $f_{0} (1500)$, is given. In the ($\pi
^{+}\pi ^{-}$) invariant mass distribution from $\bar{p}n$ annihilations in
flight, using the method of difference spectra, a very clear evidence for $\rho
^{0}, f_{2}(1270)$ and $f_{0} (1500)$ is first time obtained from these data.
This re-analysis suggests that the old bubble chamber data can still provide
relevant information on the annihilation process in liquid hydrogen and
deuterium, and can elucidate controversial aspects of the annihilation
mechanism.
A re-analysis of some \(\bar{p}p\) and \(\bar{p}n\) data, at rest and in flight, obtained in bubble chamber experiments, is presented. The (\(\pi ^{+}\pi ^{-}\)) and (\(K_{S}K_{S}\)) final states for ...the channels (2\(\pi ^{-}\pi ^{+}\)) and (\(K_{S}K_{S}\pi\)) are investigated. Evidence for a narrow meson resonance structure, cautiously suggested as \(f_{0} (1500)\), is given. In the (\(\pi ^{+}\pi ^{-}\)) invariant mass distribution from \(\bar{p}n\) annihilations in flight, using the method of difference spectra, a very clear evidence for \(\rho ^{0}, f_{2}(1270)\) and \(f_{0} (1500)\) is first time obtained from these data. This re-analysis suggests that the old bubble chamber data can still provide relevant information on the annihilation process in liquid hydrogen and deuterium, and can elucidate controversial aspects of the annihilation mechanism.
A search for high-energy neutrinos coming from the direction of the Sun has been performed using the data recorded by the ANTARES neutrino telescope during 2007 and 2008. The neutrino selection ...criteria have been chosen to maximize the selection of possible signals produced by the self-annihilation of weakly interacting massive particles accumulated in the centre of the Sun with respect to the atmospheric background. After data unblinding, the number of neutrinos observed towards the Sun was found to be compatible with background expectations. The \(90\%\) CL upper limits in terms of spin-dependent and spin-independent WIMP-proton cross-sections are derived and compared to predictions of two supersymmetric models, CMSSM and MSSM-7. The ANTARES limits are competitive with those obtained by other neutrino observatories and are more stringent than those obtained by direct search experiments for the spin-dependent WIMP-proton cross-section.
We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by ...conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.
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