0000000001177635
AUTHOR
V. Flaminio
showing 60 related works from this author
The data acquisition system for the ANTARES neutrino telescope
2006
The ANTARES neutrino telescope is being constructed in the Mediterranean Sea. It consists of a large three-dimensional array of photo-multiplier tubes. The data acquisition system of the detector takes care of the digitisation of the photo-multiplier tube signals, data transport, data filtering, and data storage. The detector is operated using a control program interfaced with all elements. The design and the implementation of the data acquisition system are described.
Search for the exotic Θ+ resonance in the NOMAD experiment
2006
12 pages, 16 figures.-- PACS nrs.: 13.15.+g; 13.60.Le; 13.87.Fh; 14.40.Ev.-- ISI Article Identifier: 000243973100007.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ex/0612063.-- et al.
A fast algorithm for muon track reconstruction and its application to the ANTARES neutrino telescope.
2011
An algorithm is presented, that provides a fast and robust reconstruction of neutrino induced upward-going muons and a discrimination of these events from downward-going atmospheric muon background in data collected by the ANTARES neutrino telescope. The algorithm consists of a hit merging and hit selection procedure followed by fitting steps for a track hypothesis and a point-like light source. It is particularly well-suited for real time applications such as online monitoring and fast triggering of optical follow-up observations for multi-messenger studies. The performance of the algorithm is evaluated with Monte Carlo simulations and various distributions are compared with that obtained …
A more sensitive search for νμ→ντ oscillations in NOMAD
1999
With additional data and improved algorithms, we have enhanced the sensitivity of our appearance search for $\numunutau$ oscillations in the NOMAD detector in the CERN-SPS wide-band neutrino beam. The search uses kinematic criteria to identify $\nutau$ charged current interactions followed by decay of the $\tau^-$ to one of several decay modes. Our ``blind'' analyses of deep-inelastic scattering data taken in 1996 and 1997, combined with consistent reanalyses of previously reported 1995 data, yield no oscillation signal. For the two-family oscillation scenario, we present the contour outlining a 90\% C.L. confidence region in the $\sin^22\theta_{\mu \tau} - \Delta m^2$ plane. At large $\Del…
The optical instrumentation of the ATLAS Tile Calorimeter
2013
The purpose of this Note is to describe the optical assembly procedure called here Optical Instrumentation and the quality tests conducted on the assembled units. Altogether, 65 Barrel (or LB) modules were constructed - including one spare - together with 129 Extended Barrel (EB) modules (including one spare). The LB modules were mechanically assembled at JINR (Dubna, Russia) and transported to CERN, where the optical instrumentation was performed with personnel contributed by several Institutes. The modules composing one of the two Extended Barrels (known as EBA) were mechanically assembled in the USA, and instrumented in two US locations (ANL, U. of Michigan), while the modules of the oth…
Search for eV (pseudo)scalar penetrating particles in the SPS neutrino beam
2000
We carried out a model-independent search for light scalar or pseudoscalar particles $a$'s (an example of which is the axion) that couple to two photons by using a photon-regeneration method at high energies allowing a substantial increase in the sensitivity to $eV$ masses.\ The experimental set-up is based on elements of the CERN West Area Neutrino Facility (WANF) beam line and theNOMAD neutrino detector.\ The new particles, if they exist, could be produced through the Primakoff effect in interactions of high energy photons, generated by the 450 $GeV$ protons in the CERN SPS neutrino target, with virtual photons from the WANF horn magnetic field.\ The particles would penetrate the downstre…
Search for Cosmic Neutrino Point Sources with Four Year Data of the ANTARES Telescope
2012
In this paper, a time-integrated search for point sources of cosmic neutrinos is presented using the data collected from 2007 to 2010 by the ANTARES neutrino telescope. No statistically significant signal has been found and upper limits on the neutrino flux have been obtained. Assuming an E ¿2 n; spectrum, these flux limits are at 1-10 ¿10¿8 GeV cm¿2 s¿1 for declinations ranging from ¿90° to 40°. Limits for specific models of RX J1713.7¿3946 and Vela X, which include information on the source morphology and spectrum, are also given.
Search for νμ→νe oscillations in the NOMAD experiment
2003
We present the results of a search for vμ → v e oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of ve in a predominantly vμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Δm2 < 0.4 eV 2 for maximal mixing and sin2(2θ) < 1.4 × 10-3 for large Δm2. This result excludes the LSND allowed region of oscillation parameters with Δm2 ≳ 10 eV2. © 2003 Elsevier B.V. All rights reserved.
First search for point sources of high-energy cosmic neutrinos with the ANTARES neutrino telescope
2011
Results are presented of a search for cosmic sources of high-energy neutrinos with the ANTARES neutrino telescope. The data were collected during 2007 and 2008 using detector configurations containing between 5 and 12 detection lines. The integrated live time of the analyzed data is 304 days. Muon tracks are reconstructed using a likelihood-based algorithm. Studies of the detector timing indicate a median angular resolution of 0.5 0.1deg. The neutrino flux sensitivity is 7.5 ¿ 10 -8(E ¿/ GeV) -2 GeV -1 s -1 cm -2 for the part of the sky that is always visible (¿ < -48deg), which is better than limits obtained by previous experiments. No cosmic neutrino sources have been observed.
Testbeam studies of production modules of the ATLAS Tile Calorimeter
2009
We report test beam studies of {11\,\%} of the production ATLAS Tile Calorimeter modules. The modules were equipped with production front-end electronics and all the calibration systems planned for the final detector. The studies used muon, electron and hadron beams ranging in energy from 3~GeV to 350~GeV. Two independent studies showed that the light yield of the calorimeter was $\sim 70$~pe/GeV, exceeding the design goal by {40\,\%}. Electron beams provided a calibration of the modules at the electromagnetic energy scale. Over 200~calorimeter cells the variation of the response was {2.4\,\%}. The linearity with energy was also measured. Muon beams provided an intercalibration of the respo…
The positioning system of the ANTARES Neutrino Telescope
2012
The ANTARES neutrino telescope, located 40km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning sys…
A Search for Single Photon Events in Neutrino Interactions
2011
We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e + e - in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurr…
Production properties of $K*(892)\pm$ vector mesons and their spin alignment as measured in the NOMAD experiment
2006
First measurements of K*(892) mesons production properties and their spin alignment in nu_mu charged current (CC) and neutral current (NC) interactions are presented. The analysis of the full data sample of the NOMAD experiment is performed in different kinematic regions. For K*+ and K*- mesons produced in nu_mu CC interactions and decaying into K0 pi+/- we have found the following yields per event: (2.6 +/- 0.2 (stat.) +/- 0.2 (syst.))% and (1.6 +/- 0.1 (stat.) +/- 0.1 (syst.))% respectively, while for the K*+ and K*- mesons produced in nu NC interactions the corresponding yields per event are: (2.5 +/- 0.3 (stat.) +/- 0.3 (syst.))% and (1.0 +/- 0.3 (stat.) +/- 0.2 (syst.))%. The results o…
The ANTARES Optical Beacon System
2007
ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirabl…
Precision measurement of scaled momentum, charge multiplicity, and thrust in νμN and interactions
1999
By focusing on the notion of electronic document, we differentiate two evolutions which are useful to distinct titles: on the one hand are the documents, which have value of reference. Its administrator will take care to preserve its integrity and its context of production which is strongly significant. On the other hand are resources, evolutionary elements by nature, which the user must be able to appropriate and who must thus be placed at the disposal so that the production is erased, to focus on a logic of exploitation and service.
A study of strange particle production in nu(mu) charged current interactions in the NOMAD experiment
2001
A study of strange particle production in $\nu_\mu$ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles ($K^0_s, \Lambda, \bar{\Lambda}$) have been measured. Mean multiplicities are reported as a function of the event kinematic variables $E_\nu$, $W^2$ and $Q^2$ as well as of the variables describing particle behaviour within a hadronic jet: $x_F$, $z$ and $p_T^2$. Decays of resonances and heavy hyperons with identified $K^0_s$ and $\Lambda$ in the final state have been analyzed. Clear signals corresponding to $\rm {K^\star}^\pm$ $\rm {\Sigma^\star}^\pm$, $\rm \Xi^-$ and $\rm \Sigma^0$ have been observed. A study of s…
Search for heavy neutrinos mixing with tau neutrinos
2001
We report on a search for heavy neutrinos ($\nus$) produced in the decay $D_s\to \tau \nus$ at the SPS proton target followed by the decay $\nudecay$ in the NOMAD detector. Both decays are expected to occur if $\nus$ is a component of $\nu_{\tau}$.\ From the analysis of the data collected during the 1996-1998 runs with $4.1\times10^{19}$ protons on target, a single candidate event consistent with background expectations was found. This allows to derive an upper limit on the mixing strength between the heavy neutrino and the tau neutrino in the $\nus$ mass range from 10 to 190 $\rm MeV$. Windows between the SN1987a and Big Bang Nucleosynthesis lower limits and our result are still open for f…
First results of the Instrumentation Line for the deep-sea ANTARES neutrino telescope
2006
In 2005, the ANTARES Collaboration deployed and operated at a depth of 2500 m a so-called Mini Instrumentation Line equipped with Optical Modules (MILOM) at the ANTARES site. The various data acquired during the continuous operation from April to December 2005 of the MILOM confirm the satisfactory performance of the Optical Modules, their front-end electronics and readout system, as well as the calibration devices of the detector. The in-situ measurement of the Optical Module time response yields a resolution better than 0.5 ns. The performance of the acoustic positioning system, which enables the spatial reconstruction of the ANTARES detector with a precision of about 10 cm, is verified. T…
Hadron energy reconstruction for the ATLAS calorimetry in the framework of the non-parametrical method
2002
This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known $e/h$ ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within $\pm 1%$ of the true values and the fractional energy resolution is $[(58\pm3)% /\sqrt{E}+(2.5\pm0.3)%]\oplus (1.7\pm0.2)/E…
Study of Large Hemispherical Photomultiplier Tubes for the ANTARES Neutrino Telescope
2005
The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a 3 dimensional matrix of 900 large area photomultiplier tubes housed in pressure resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the PMT chosen for ANTARES.
Performance of the front-end electronics of the ANTARES neutrino telescope
2010
ANTARES is a high-energy neutrino telescope installed in the Mediterranean Sea at a depth of 2475 m. It consists of a three-dimensional array of optical modules, each containing a large photomultiplier tube. A total of 2700 front-end ASICs named Analogue Ring Samplers (ARS) process the phototube signals, measure their arrival time, amplitude and shape as well as perform monitoring and calibration tasks. The ARS chip processes the analogue signals from the optical modules and converts information into digital data. All the information is transmitted to shore through further multiplexing electronics and an optical link. This paper describes the performance of the ARS chip; results from the fu…
Updated Results from the $\nu_{\tau}$ Appearance Search in NOMAD
2000
Updated results from the appearance searches for $\numunutau$ and $\nuenutau$ oscillations in the full NOMAD data sample are reported. The increased data and the use of more refined kinematic schemes for the $\nutau$ CC selection allow a significant improvement of the overall sensitivity. The ``blind analysis" of both the deep-inelastic and the low multiplicity samples yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90\% C.L. region in the $\sin^22\theta_{\mu\tau} - \Delta m^2$ plane which includes $\sin^22\theta_{\mu\tau}\ <\ 4.4\times10^{-4}$ at large $\Delta m^2$ and $\Delta m^2 < 0.8$ eV$^2$/$c^4$ at $\sin^22\theta_{\mu \tau}=1$. The cor…
Search for a diffuse flux of high-energy ¿µ with the ANTARES neutrino telescope
2011
A search for a diffuse flux of astrophysical muon neutrinos, using data collected by the ANTARES neutrino telescope is presented. A $(0.83\times 2\pi)$ sr sky was monitored for a total of 334 days of equivalent live time. The searched signal corresponds to an excess of events, produced by astrophysical sources, over the expected atmospheric neutrino background. The observed number of events is found compatible with the background expectation. Assuming an $E^{-2}$ flux spectrum, a 90% c.l. upper limit on the diffuse $\nu_\mu$ flux of $E^2\Phi_{90%} = 5.3 \times 10^{-8} \ \mathrm{GeV\ cm^{-2}\ s^{-1}\ sr^{-1}} $ in the energy range 20 TeV - 2.5 PeV is obtained. Other signal models with differ…
SEARCH FOR A CORRELATION BETWEEN ANTARES NEUTRINOS AND PIERRE AUGER OBSERVATORY UHECRs ARRIVAL DIRECTIONS
2013
A multimessenger analysis optimized for a correlation of arrival directions of ultra-high energy cosmic rays (UHECRs) and neutrinos is presented and applied to 2190 neutrino candidate events detected in 2007-2008 by the ANTARES telescope and 69 UHECRs observed by the Pierre Auger Observatory between 2004 January 1 and 2009 December 31. No significant correlation is observed. Assuming an equal neutrino flux (E-2 energy spectrum) from all UHECR directions, a 90% CL upper limit on the neutrino flux of 5.0 x 10(-8) GeV cm(-2) s(-1) per source is derived.
Search for neutrino emission from gamma-ray flaring blazars with the ANTARES telescope
2012
The ANTARES telescope observes a full hemisphere of the sky all the time with a duty cycle close to 100%. This makes it well suited for an extensive observation of neutrinos produced in astrophysical transient sources. In the surrounding medium of blazars, i.e. active galactic nuclei with their jets pointing almost directly towards the observer, neutrinos may be produced together with gamma-rays by hadronic interactions, so a strong correlation between neutrinos and gamma-rays emissions is expected. The time variability information of the studied source can be obtained by the gamma-ray light curves measured by the LAT instrument on-board the Fermi satellite. If the expected neutrino flux ob…
First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope
2013
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 sup…
Time calibration of the ANTARES neutrino telescope
2011
The ANTARES deep-sea neutrino telescope comprises a three-dimensional array of photomultipliers to detect the Cherenkov light induced by upgoing relativistic charged particles originating from neutrino interactions in the vicinity of the detector. The large scattering length of light in the deep sea facilitates an angular resolution of a few tenths of a degree for neutrino energies exceeding 10 TeV. In order to achieve this optimal performance, the time calibration procedures should ensure a relative time calibration between the photomultipliers at the level of ~1 ns. The methods developed to attain this level of precision are described.
Inclusive production of ρ0(770), f0(980) and f2(1270) mesons in νμ charged current interactions
2001
The inclusive production of the meson resonances $\rho^{0}(770)$, $f_0(980)$ and $f_2(1270)$ in neutrino-nucleus charged current interactions has been studied with the NOMAD detector exposed to the wide band neutrino beam generated by 450 GeV protons at the CERN SPS. For the first time the $f_{0}(980)$ meson is observed in neutrino interactions. The statistical significance of its observation is 6 standard deviations. The presence of $f_{2}(1270)$ in neutrino interactions is reliably established. The average multiplicity of these three resonances is measured as a function of several kinematic variables. The experimental results are compared to the multiplicities obtained from a simulation b…
Limit on νe→ντ oscillations from the NOMAD experiment
2000
Abstract In the context of a two-flavour approximation we reinterpret the published NOMAD limit on ν μ → ν τ oscillations in terms of ν e → ν τ oscillations. At 90% C.L. we obtain sin 2 2θ eτ 5.2×10 −2 for large Δm 2 , while for sin 2 2 θ eτ =1 the confidence region includes Δm 2 2 / c 4 .
New results on a search for a 33.9 MeV/c2 neutral particle from π+ decay in the NOMAD experiment
2002
We report on a direct search in NOMAD for a new 33.9 MeV/c^2 neutral particle (X) produced in pion decay in flight, pi-->mu_X followed by the decay X -->nu e^+e^-. Both decays are postulated to occur to explain the time anomaly observed by the KARMEN experiment. From the analysis of the data collected during the 1996?1998 runs with 4.1×10^19 protons on target, a single candidate event consistent with background expectations was found. The search is sensitive to a pion branching ratio BR(pi-->muX >3.7×10^-15, significantly smaller than previous experimental limits.
The ATLAS hadronic tile calorimeter: From construction toward-physics
2005
ATLAS; The Tile Calorimeter, which constitutes the central section of the ATLAS hadronic calorimeter, is a non-compensating sampling device made of iron and scintillating tiles. The construction phase of the calorimeter is nearly complete, and most of the effort now is directed toward the final assembly and commissioning in the underground experimental hall. The layout of the calorimeter and the tasks carried out during construction are described, first with a brief reminder of the requirements that drove the calorimeter design. During the last few years a comprehensive test-beam program has been followed in order to establish the calorimeter electromagnetic energy scale, to study its unifo…
Search for relativistic magnetic monopoles with the ANTARES neutrino telescope
2012
Magnetic monopoles are predicted in various unified gauge models and could be produced at intermediate mass scales. Their detection in a neutrino telescope is facilitated by the large amount of light emitted compared to that from muons. This paper reports on a search for upgoing relativistic magnetic monopoles with the ANTARES neutrino telescope using a data set of 116 days of live time taken from December 2007 to December 2008. The one observed event is consistent with the expected atmospheric neutrino and muon background, leading to a 90% C.L. upper limit on the monopole flux between 1.3 ¿ 10¿17 and 8.9 ¿ 10¿17 cm¿2 s¿1 sr¿1 for monopoles with velocity ß ¿ 0.625.
Zenith distribution and flux of atmospheric muons measured with the 5-line ANTARES detector
2010
The ANTARES high energy neutrino telescope is a three-dimensional array of about 900 photomultipliers distributed over 12 mooring lines installed in the Mediterranean Sea. Between February and November 2007 it acquired data in a 5-line configuration. The zenith angular distribution of the atmospheric muon flux and the associated depth-intensity relation are measured and compared with previous measurements and Monte Carlo expectations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is presented.
A search for neutrino emission from the Fermi bubbles with the ANTARES telescope
2014
Adrián-Martínez, S. et al.
The ANTARES telescope neutrino alert system
2012
The ANTARES telescope has the capability to detect neutrinos produced in astrophysical transient sources. Potential sources include gamma-ray bursts, core collapse supernovae, and flaring active galactic nuclei. To enhance the sensitivity of ANTARES to such sources, a new detection method based on coincident observations of neutrinos and optical signals has been developed. A fast online muon track reconstruction is used to trigger a network of small automatic optical telescopes. Such alerts are generated for special events, such as two or more neutrinos, coincident in time and direction, or single neutrinos of very high energy.
Search for muon neutrinos from gamma-ray bursts with the ANTARES neutrino telescope using 2008 to 2011 data
2013
Aims. We search for muon neutrinos in coincidence with GRBs with the ANTARES neutrino detector using data from the end of 2007 to 2011. Methods. Expected neutrino fluxes were calculated for each burst individually. The most recent numerical calculations of the spectra using the NeuCosmA code were employed, which include Monte Carlo simulations of the full underlying photohadronic interaction processes. The discovery probability for a selection of 296 GRBs in the given period was optimised using an extended maximum-likelihood strategy. Results. No significant excess over background is found in the data, and 90% confidence level upper limits are placed on the total expected flux according to …
Measurement of the polarization in νμ charged current interactions in the NOMAD experiment
2001
The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF 0)=−0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in…
A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment
2008
We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ($\nu_\mu n\to \mu^- p$ and $\bar{\nu}_\mu p\to \mu^+ n$) using a set of experimental data collected by the NOMAD collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly Carbon) normalizing it to the total $\nu_\mu$ ($\bar{\nu}_\mu$) charged current cross-section. The results for the flux averaged QEL cross-sections in the (anti)neutrino energy interval 3-100 GeV are $\sigma^{qel}_{\nu_\mu} = (0.92 \pm 0.02 (stat) \pm 0.06 (syst))\times 10^{-38} \cm^2$ and $\sigma{qel}_{\bar{\nu}_\mu} = (0.81 \pm 0.05 (stat) \pm 0.08 (syst))\times 10^{-38} \cm…
A first search for coincident gravitational waves and high energy neutrinos using LIGO, Virgo and ANTARES data from 2007
2013
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 sup…
Study of D*+ production in nu_mu charged current interactions in the NOMAD experiment
2002
A search was made among $\nu_\mu$ charged current events collected in the NOMAD experiment for the reaction: $\nu_\mu + N \rightarrow \mu^- + D^{\star+} + hadrons \hookrightarrow D^0 + \pi^+ \hookrightarrow K^- + \pi^+ A $D^{\star+}$ sample composed of 47 events, with 90% purity, was extracted. The $D^{\star+}$ yield in $\nu_\mu$ charged current interactions was measured to be $T = (0.99 \pm 0.15(stat.) \pm 0.11(syst.))$%. The mean fraction of the hadronic jet energy taken by the $D^{\star+}$ is $0.67 \pm 0.02(stat) \pm 0.02(syst.)$. The distributions of the fragmentation variables $z$, ${P_{T}}^2$ and $x_F$ for $D^{\star+}$ are also presented.
Acoustic and optical variations during rapid downward motion episodes in the deep north-western Mediterranean Sea
2011
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 …
Neutrino production of opposite sign dimuons in the NOMAD experiment
2000
The NOMAD Collaboration presents a study of opposite sign dimuon events in the framework of Leading Order QCD. A total of 2714 neutrino- and 115 antineutrino-induced opposite sign dimuon events with $E_{\mu 1}, E_{\mu 2} > 4.5$ GeV, $15 1\;(\mbox{GeV}/\mbox{c})^{2}$ are observed %in the data from the 1995 and 1996 runs. in the Front-Calorimeter of NOMAD during the 1995 and 1996 runs. The analysis yields a value for the charm quark mass of $m_{c} = 1.3^{+0.3\;+0.3}_{-0.3\;-0.3}\;\mbox{GeV}/\m box{c}^{2}$ and for the average semileptonic branching ratio of $B_{c} = 0.095^{+0.007\;+0.014}_{-0.007\;-0.013}$. The ratio of the strange to non-strange sea in the nucleon is measured to be $\kappa = …
AMADEUS-The acoustic neutrino detection test system of the ANTARES deep-sea neutrino telescope
2011
The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around - 145 dB re 1 V/mu Pa (including preamplifier). Completed in May 2008, AMADEUS consists of six "acoustic clusters", each comprising six acoustic sensors that are arranged at distanc…
Prediction of neutrino fluxes in the NOMAD experiment
2003
The method developed for the calculation of the flux and composition of the West Area Neutrino Beam used by NOMAD in its search for neutrino oscillations is described. The calculation is based on particle production rates computed using a recent version of FLUKA and modified to take into account the cross sections measured by the SPY and NA20 experiments. These particles are propagated through the beam line taking into account the material and magnetic fields they traverse. The neutrinos produced through their decays are tracked to the NOMAD detector. The fluxes of the four neutrino flavours at NOMAD are predicted with an uncertainty of about 8% for nu(mu) and nu(e), 10% for antinu(mu), and…
Search for a new gauge boson in $\pi^{0}$ decays
1998
A search was made for a new light gauge boson $X$ which might be produced in $\pi^{0}\to\gamma + X$ decay from neutral pions generated by 450-GeV protons in the CERN SPS neutrino target. The X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Primakoff effect, in the process of $X \to\pi^{0}$ conversion in the external Coulomb field of a nucleus. With $1.45\times10^{18}$ protons on target, 20 candidate events with energy between 8 and 140 GeV were found from the analysis of neutrino data. This number is in agreement with the expectation of 18.1$\pm$2.8 background events from standard neutrino processes. A new 90% C.L. upper limit on the branching ratio…
Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope
2012
The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass …
Bose-Einstein correlations in charged current muon-neutrino interactions in the NOMAD experiment at CERN
2004
Bose-Einstein Correlations in one and two dimensions have been studied, with high statistics, in charged current muon-neutrino interaction events collected with the NOMAD detector at CERN. In one dimension the Bose-Einstein effect has been analyzed with the Goldhaber and the Kopylov-Podgoretskii phenomenological parametrizations. The Goldhaber parametrization gives the radius of the pion emission region R_G = 1.01+/-0.05(stat)+0.09-0.06(sys) fm and for the chaoticity parameter the value lambda = 0.40+/-0.03(stat)+0.01-0.06(sys). Using the Kopylov-Podgoretskii parametrization yields R_KP = 2.07+/-0.04(stat)+0.01-0.14(sys) fm and lambda_KP = 0.29+/-0.06(stat)+0.01-0.04(sys). Different paramet…
First search for neutrinos in correlation with gamma-ray bursts with the ANTARES neutrino telescope
2013
A search for neutrino-induced muons in correlation with a selection of 40 gamma-ray bursts that occurred in 2007 has been performed with the ANTARES neutrino telescope. During that period, the detector consisted of 5 detection lines. The ANTARES neutrino telescope is sensitive to TeV-PeV neutrinos that are predicted from gamma-ray bursts. No events were found in correlation with the prompt photon emission of the gamma-ray bursts and upper limits have been placed on the flux and fluence of neutrinos for different models.
A precision measurement of charm dimuon production in neutrino interactions from the NOMAD experiment
2013
We present our new measurement of the cross-section for charm dimuon production in neutrino iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15 344 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample - about 9 x 10(6) events after all analysis cuts - and the high resolution NOMAD detector to constrain the total systematic uncertainty on the ratio of charm dimuon to inclusive Charged Current (CC) cross-sections to similar to 2%. We also perform a fit to the NOMAD data to extract the charm production parameters and the strange quark sea…
Measurement of pion and proton response and longitudinal shower profiles up to 20 nuclear interaction lengths with the ATLAS Tile calorimeter
2010
The response of pions and protons in the energy range of 20–180 GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron–scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion-to-proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion-indu…
Measurement of the group velocity of light in sea water at the ANTARES site
2012
The group velocity of light has been measured at eight different wavelengths between 385 nm and 532 nm in the Mediterranean Sea at a depth of about 2.2 km 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 precise measurement of the muon neutrino nucleon inclusive charged current cross section off an isoscalar target in the energy range 2.5
2008
Abstract We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5 ⩽ E ν ⩽ 40 GeV . The significance of this measurement is its precision, ±4% in 2.5 ⩽ E ν ⩽ 10 GeV , and ±2.6% in 10 ⩽ E ν ⩽ 40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.
A study of strange particles produced in neutrino neutral current interactions in the NOMAD experiment
2004
Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.
A measurement of coherent neutral pion production in neutrino neutral current interactions in the NOMAD experiment
2009
We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \leq E_{\nu} \leq 300$ GeV. Neutrino events with only one visible $\pi^0$ in the final state are expected to result from two Neutral Current processes: coherent $\pi^0$ production, {\boldmath $\nu + {\cal A} \to \nu + {\cal A} + \pi^0$} and single $\pi^0$ production in neutrino-nucleon scattering. The signature of coherent $\pi^0$ production is an emergent $\pi^0$ almost collinear with the incident neutrino while $\pi^0$'s pro…
ANTARES: The first undersea neutrino telescope
2011
The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given. © 2011 Elsevier B.V. All rights reserved.
Mechanical construction and installation of the ATLAS tile calorimeter
2013
This paper summarises the mechanical construction andinstallation of the Tile Calorimeter for the ATLASexperiment at the Large Hadron Collider in CERN, Switzerland. The TileCalorimeter is a sampling calorimeter using scintillator as the sensitivedetector and steel as the absorber and covers the central region of the ATLASexperiment up to pseudorapidities ±1.7. The mechanical construction ofthe Tile Calorimeter occurred over a periodof about 10 years beginning in 1995 with the completionof the Technical Design Report and ending in 2006 with the installationof the final module in the ATLAS cavern. Duringthis period approximately 2600 metric tons of steel were transformedinto a laminated struc…
A method for detection of muon induced electromagnetic showers with the ANTARES detector
2012
The primary aim of ANTARES is neutrino astronomy with upward going muons created in charged current muon neutrino interactions in the detector and its surroundings. Downward going muons are background for neutrino searches. These muons are the decay products of cosmic-ray collisions in the Earths atmosphere far above the detector. This paper presents a method to identify and count electromagnetic showers induced along atmospheric muon tracks with the ANTARES detector. The method is applied to both cosmic muon data and simulations and its applicability to the reconstruction of muon event energies is demonstrated. © 2012 Elsevier B.V. All rights reserved.
Measurement of the atmospheric muon flux with a 4 GeV threshold in the ANTARES neutrino telescope
2010
A new method for the measurement of the muon flux in the deep-sea ANTARES neutrino telescope and its dependence on the depth is presented. The method is based on the observation of coincidence signals in adjacent storeys of the detector. This yields an energy threshold of about 4 GeV. The main sources of optical background are the decay of 40K and the bioluminescence in the sea water. The 40K background is used to calibrate the efficiency of the photo-multiplier tubes.
Measurement of the atmospheric ?µ energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope
2013
Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is similar to 25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index gamma (meas)=3.58 +/- 0.12. With the present statistics the contribution of prompt neutrinos cannot be established.
Performance of the First ANTARES Detector Line
2009
In this paper we report on the data recorded with the first Antares detector line. The line was deployed on the 14th of February 2006 and was connected to the readout two weeks later. Environmental data for one and a half years of running are shown. Measurements of atmospheric muons from data taken from selected runs during the first six months of operation are presented. Performance figures in terms of time residuals and angular resolution are given. Finally the angular distribution of atmospheric muons is presented and from this the depth profile of the muon intensity is derived.