125441894
A deep sea telescope for high-energy neutrinos
The ANTARES Collaboration proposes to construct a large area water Cherenkov detector in the deep Mediterranean Sea, optimised for the detection of muons from high-energy astrophysical neutrinos. This paper presents the scientific motivation for building such a device, along with a review of the technical issues involved in its design and construction. The observation of high energy neutrinos will open a new window on the universe. The primary aim is to study particle acceleration mechanisms in energetic astrophysical objects such as AGN's and GRB's, which may also shed light on the origin of ultra-high-energy cosmic rays. At lower energies, non-baryonic dark matter may be detected through the neutrinos produced when gravitationally captured WIMPs annihilate in the cores of the Earth and the Sun. Neutrino oscillations can be measured by studying distortions in the energy spectrum of upward-going atmospheric nu's. The characteristics of the proposed site are an important consideration in detector design. Water properties and detector environment parameters were measured. These tests have shown that the proposed site provides a good-quality environment for the detector, and have also demonstrated the feasibility of the deployment technique. The present proposal concerns the construction and deployment of a detector with surface area 0.1 km^2. The conceptual design for such a detector is discussed, and the physics performance evaluated. An overview of costs and schedules is presented. It is concluded that a 0.1 km^2 detector is technically feasible at realistic cost, and offers an exciting and varied physics and astrophysics programme. Such a detector will also provide practical experience which will be invaluable in the design and operation of future detectors on the astrophysically desirable 1 km^2 scale.
12347950
The ZEPLIN-III dark matter detector: Performance study using an end-to-end simulation tool
We present results from a GEANT4-based Monte Carlo tool for end-to-end simulations of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase detector which measures both the scintillation light and the ionisation charge generated in liquid xenon by interacting particles and radiation. The software models the instrument response to radioactive backgrounds and calibration sources, including the generation, ray-tracing and detection of the primary and secondary scintillations in liquid and gaseous xenon, and subsequent processing by data acquisition electronics. A flexible user interface allows easy modification of detector parameters at run time. Realistic datasets can be produced to help with data analysis, an example of which is the position reconstruction algorithm developed from simulated data. We present a range of simulation results confirming the original design sensitivity of a few times 10−8 pb to the WIMP-nucleon cross-section.
121667127
The potential of liquid xenon for WIMP search: the ZEPLIN diagnostic array
Abstract A Liquid Xenon based WIMP detector diagnostic array is currently developed by the UKDMC with the help of international collaborators. After a brief reminder on the detection principle in Liquid Xenon, the individual detectors will be described. ZEPLIN I, a detector with a 4 kg fiducial mass with a background discrimination based on Pulse Shape Analysis, is already underground and starting operation. Two setups with improved background discrimination tools (as the ionisation is also recorded) are designed and scheduled to move underground in the second half of 2001. Both of them, ZEPLIN II and ZEPLIN III, are predicted to be sensitive to rate of 0.1–0.01 events/kg/day within 2 years of data taking. Furthermore, new ideas for lower background readout devices are studied, in order to avoid the use of PhotoMultiplier Tubes (PMTs).
119286983
Muon-induced background in the EDELWEISS dark matter search
Abstract A dedicated analysis of the muon-induced background in the EDELWEISS dark matter search has been performed on a data set acquired in 2009 and 2010. The total muon flux underground in the Laboratoire Souterrain de Modane (LSM) was measured to be Φ μ = ( 5.4 ± 0.2 - 0.9 + 0.5 )  muons/m 2 /d. The modular design of the μ -veto system allows the reconstruction of the muon trajectory and hence the determination of the angular dependent muon flux in LSM. The results are in good agreement with both MC simulations and earlier measurements. Synchronization of the μ -veto system with the phonon and ionization signals of the Ge detector array allowed identification of muon-induced events. Rates for all muon-induced events Γ μ = ( 0.172 ± 0.012 ) evts / ( kg d ) and of WIMP-like events Γ μ – n = 0.008 - 0.004 + 0.005 evts / ( kg d ) were extracted. After vetoing, the remaining rate of accepted muon-induced neutrons in the EDELWEISS-II dark matter search was determined to be Γ irred μ – n 6 · 10 - 4 evts / ( kg d ) at 90% C.L. Based on these results, the muon-induced background expectation for an anticipated exposure of 3000 kg d for EDELWEISS-III is N 3000 kg d μ – n 0.6 events.
120314532
Progress report from the UK Dark Matter search at Boulby Mine
Abstract The UK Dark Matter Collaboration is currently running a series of scintillation devices at the Boulby mine in North Yorkshire to search for the neutralino, the hypothetical WIMP solution to the dark matter problem. Results of the current NaI(T1) detector array will be discussed, illustrating a population of events of unknown origin. Diagnostic tests performed to investigate the origin of these anomalous events will be outlined, including alpha, beta and neutron calibrations.
115887438
Particle polarization in inclusive reactions
123087039
Composite superstring model for hadron amplitudes
Hadron dynamics is formulated in terms of interacting composite strings. These composite string amplitudes give other possible solution of duality equations for crossing channels in addition to classical string amplitudes. The composite strings carry quark flavour and spin degrees of freedom on edging two-dimensional surfaces. Consistent composite string models with extended N = 3 Virasoro superconformal symmetry are found. Simple amplitudes for interaction of π and K-mesons in this model are represented.
115452072
Production of high-energy muons in extensive air showers from primary el rays
The primary mechanism for the production of high-energy muons (E/sub / > 5 TeV) in extensive air showers from primary el rays is the production of muon pairs by shower photons in the field of a nucleus.
123747264
Heavy states of hadron string as weak interacting massive particles for Dark Matter
Massive states (of order 10 Gev and more) of hadron string (with scale 1 Gev) can have very small coupling constants with usual baryons of the Universe. Corresponding mean times for them are found to be order and even more than the age of the Universe. They are proposed as possible candidates for weak interacting massive particles (WIMP) of Dark Matter.
14749699
A possible description of the quantum numbers in a hadronic string model
Institute of Theoretical PhysicsUniversity of Stockholm, Box 6730S-113 85 Stockholm, SwedenABSTRACT: We consider a critical composite superconformalstring model to desribe hadronic interactions. We present a newapproach of introducing hadronic quantum numbers in the scat-tering amplitudes. The physical states carry the quantum num-bers and form a common system of eigenfunctions of the opera-tors in this string model. We give explicit constructions of thequantum number operators.
118178535
Unified description of hadronic and leptonic degrees of freedom in a superstring model involving supercurrent conditions