8789191
Study of the acoustic signature of UHE neutrino interactions in water and ice
The production of acoustic signals from the interactions of ultra-high energy (UHE) cosmic ray neutrinos in water and ice has been studied. A new computationally fast and efficient method of deriving the signal is presented. This method allows the implementation of up to date parameterisations of acoustic attenuation in seawater and ice that now includes the effects of complex attenuation, where appropriate. The methods presented here have been used to compute and study the properties of the acoustic signals which would be expected from such interactions. A matrix method of parameterising the signals, which includes the expected fluctuations, is also presented. These methods are used to generate the expected signals that would be detected in acoustic UHE neutrino telescopes.
13361149
Recent results from the ANTARES deep-sea neutrino telescope
Abstract The ANTARES collaboration is currently constructing a large area neutrino telescope for deployment in the Mediterranean Sea. The ANTARES detector will be located 30 km off the southern French coast. After introducing the detection principle, the details of the detector design are considered. In describing the ANTARES site, emphasis is placed on results from more than 25 deployments of autonomous mooring lines instrumented with various measuring devices. These deployments have led to an understanding of the water and environmental parameters at the site. A neutrino telescope can address a wide-ranging scientific programme which covers topics in particle physics and astrophysics, a brief summary of this programme is made, following which, aspects of the expected detector performance, specifically the angular and energy resolutions, are discussed. Finally, the results from a “demonstrator string” are presented. This is a full-scale, part-instrumented string which was deployed in the Mediterranean Sea in late 1999. The string has provided the first recorded down-going muons which have been subsequently reconstructed and analysed, examples of these events and their properties are given. The demonstrator was also equipped with the instrumentation required for determining the position, inclination and orientation of the string as a function of time. The performance of these systems is also discussed.
5995908
Probing quantum decoherence in atmospheric neutrino oscillations with a neutrino telescope
Quantum decoherence, the evolution of pure states into mixed states, may be a feature of quantum gravity. In this paper, we show how these effects can be modelled for atmospheric neutrinos and illustrate how the standard oscillation picture is modified. We examine how neutrino telescopes, such as ANTARES, are able to place upper bounds on these quantum decoherence effects.
123448556
The Acoustic Detection of Ultra-High Energy Neutrinos - a Status Report
An overview is presented of current worldwide activities in the field of the acoustic detection of ultra-high energy neutrinos. Emphasis is placed on recent results from test experimental setups, simulation work, sensitivity calculations and on data taken at deep-water deployments.
116619220
Dark Matter Searches with ANTARES
15848028
PRECISION TESTS OF THE STANDARD MODEL AT LEP AND RESULTS FROM THE 4-JET FINAL STATE AT LEP 1.5
First a short review is made of current limits on the Standard Model as derived from the electroweak sector concerning the Z boson at LEP. The second part of the paper presents an analysis of the four jet nal state at ALEPH, this analysis was performed on LEP data taken at centre of mass energies of 130 and 136 GeV. The results presented here are from approximate totals 1 of 12.3 millionhadronic Z decays and 1.3 million leptonic decays recorded by the four LEP experiments during the years 1990 to 1995 inclusive. These statistics permit a precise study of the Standard Model though the coupling of the Z boson to fermion pairs. This reaction is modiied by vacuum polarization corrections in the propogator such as t-quark and Higgs boson loops thus allowing a determination of m top and m Higgs to be made via indirect measurements. It should be noted that results for 1993 onwards are regarded as preliminary for all 4 LEP experiments. In order to combine electroweak results a common reference point is required. Each of the LEP experiments measures the leptonic and hadronic total cross-sections and the leptonic forward-backward asymmetries from angular distributions in cos. These results are tted 1 according to the Z 0 lineshape to give 9 parameters, namely the Z boson mass and width, (m Z , ? Z), the pole hadronic cross-section, (0 h), the ratios of the hadronic to leptonic partial widths, (R e , R , R) and the leptonic pole asymmetries (A 0; e FB ,A 0; FB ,A 0; FB). These 9 parameters are then combined 1 , along with the individual experimental covariance matices and common systematic errors to give the results in Table 1. The nal two entries in Table 1 represent the values of the partial width ratio and the pole asymmetry under the assumption of lepton universality. This assumption is further explored in Figure 1 where R ` is plotted against A 0;` FB individually for the 3 lepton species and also under the assumption of lepton universality. The accuracy of these results is remarkable, with the Z boson mass being measured to 24 parts per million.
55352795
INTERACTION REGION DESIGN FOR A RING-RING LHeC
The Large Hadron Electron Collider project is a proposal to study e-p and e-A interactions at the LHC. Using one of the LHC’s proton beams, an electron beam of relatively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-β focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discussed.
96445234
Optics and lattice optimizations for the LHC upgrade project
The luminosity upgrade of the LHC collider at CERN is based on a strong focusing scheme to reach lowest values of the beta function at the collision points. Several issues have to be addressed in this context, that are considered as mid term goals for the optimisation of the lattice and beam optics: Firstly a number of beam optics have been developed to establish a baseline for the hardware R&D, and that will define the specifications for the new magnets that will be needed, in Nb3Sn as well as in NbTi technology. Secondly, the need for sufficient flexibility of the beam optics especially for smallest ! * values, the need for a smooth transition between the injection and the collision optics, the comparison of the optics performance between flat and round beams and finally different ways to optimise the chromatic correction, including the study of local correction schemes. This paper presents the status of this work, which is a result of an international collaboration, and summarises the main parameters that are foreseen to reach the HL-LHC luminosity goal.