Search for massive rare particles with the SLIM experiment

The SLIM experiment is a large array of nuclear track detectors located at the Chacaltaya High Altitude Laboratory (5260 m a.s.l.). The preliminary results from the analysis of ~383 m^2 exposed for 4.07 y are here reported. The detector is sensitive to Intermediate Mass Magnetic Monopoles, 10^5 < M_M < 10^12 GeV, and to SQM nuggets and Q-balls, which are possible Dark Matter candidates.Comment: 4 pages, 5 EPS figures. Talk given at the 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications, Como, Italy, 8-12 October 200

BCS-BEC crossover in a two-dimensional Fermi gas

We investigate the crossover from Bardeen-Cooper-Schrieffer (BCS) superfluidity to Bose-Einstein condensation (BEC) in a two-dimensional Fermi gas at T=0 using the fixed-node diffusion Monte Carlo method. We calculate the equation of state and the gap parameter as a function of the interaction strength, observing large deviations compared to mean-field predictions. In the BEC regime our results show the important role of dimer-dimer and atom-dimer interaction effects that are completely neglected in the mean-field picture. Results on Tan's contact parameter associated with short-range physics are also reported along the BCS-BEC crossover.Comment: 4 pages, 4 figure

Self-Configuring Socio-Technical Systems: Redesign at Runtime

Modern information systems are becoming more and more socio-technical systems, namely systems composed of human (social) agents and software (technical) systems operating together in a common environment. The structure of such systems has to evolve dynamically in response to the changes of the environment. When new requirements are introduced, when an actor leaves the system or when a new actor comes, the socio-technical structure needs to be redesigned and revised. In this paper, an approach to dynamic reconfiguration of a socio-technical system structure in response to internal or external changes is proposed. The approach is based on planning techniques for generating possible alternative configurations, and local strategies for their evaluation. The reconfiguration mechanism is presented, which makes the socio-technical system self-configuring, and the approach is discussed and analyzed on a simple case study

Atmospheric neutrino oscillations in MACRO

In this paper we first give a short overview of the MACRO detector, which was operational at the Gran Sasso Laboratory from 1989 till 2000. Then we present and discuss the results on atmospheric neutrino oscillations, concerning medium (~4 GeV) and high (~50 GeV) energy data. Using the Multiple Coulomb Scattering of muons inside the lower part of the detector, estimates of neutrino energies were made for the high energy sample. The MACRO data, angular distributions, absolute flux and L/E_nu distributions favour nu_mu nu_tau oscillations with maximal mixing and Dm^2=2.5 x 10^-3 eV^2.Comment: 13 pages, 11 EPS figures included with epsfig, uses article.sty. Talk given at NO-VE, Int. Workshop on Neutrino Oscillations in VEnice, Venice, Italy, 24-26 July 2001. Fig. 9 updated, Ref. 9 changed and content changed in Sect. 6,