Dual coherent particle emission as generalized two-component Cherenkov-like effect

In this Letter we introduce a new kind of coherent particle production mechanism called dual coherent particle emission (DCPE) as generalized two-component Cherenkov-like effect, which takes place when the phase velocity of emitted particle v_{Mph} and the particle source phase velocity v_{B_1ph} satisfy a specific DCPE condition: v_{Mph} <= v_{B_1ph}^{-1}. The general signatures of the DCPE in dielectric, nuclear and hadronic media are established and some experimental evidences are presented.Comment: 12 pages, 4 fig

Dual coherent particle emission as generalised Cherenkov-like effect in high energy particle collisions

In this paper we introduce a new kind of nuclear/hadronic coherent particle production mechanism in high-energy collisions called \emph{dual coherent particle emission (DCPE)} which takes place when the phase velocities of the emitted particle v_{Mph} and that of particle source v_{B_1ph} satisfy the dual coherence condition: v_{Mph} <= v_{B_1ph}^-1. The general signatures of the DCPE in the nuclear and hadronic media are established and some experimental evidences are given.Comment: 5 pages, 5 eps figs., revtex4 styl

OPTIMAL AREA AND PERFORMANCE MAPPING OF K-LUT BASED FPGAS

FPGA circuits are increasingly used in many fields: for rapid prototyping of new products (including fast ASIC implementation), for logic emulation, for producing a small number of a device, or if a device should be reconfigurable in use (reconfigurable computing). Determining if an arbitrary, given wide, function can be implemented by a programmable logic block, unfortunately, it is generally, a very difficult problem. This problem is called the Boolean matching problem. This paper introduces a new implemented algorithm able to map, both for area and performance, combinational networks using k-LUT based FPGAs.k-LUT based FPGAs, combinational circuits, performance-driven mapping.

Weak Localization and Antilocalization in Topological Insulator Thin Films with Coherent Bulk-Surface Coupling

We evaluate quantum corrections to conductivity in an electrically gated thin film of a three-dimensional (3D) topological insulator (TI). We derive approximate analytical expressions for the low-field magnetoresistance as a function of bulk doping and bulk-surface tunneling rate. Our results reveal parameter regimes for both weak localization and weak antilocalization, and include diffusive Weyl semimetals as a special case.Comment: After publication, we have noticed and corrected two small but potentially misleading typographic errors in Eqs. (2.27) and (2.29), where the definitions of \tau_s and \tau_v were mistakenly switched. Once these typographic errors are fixed, all the results remain unchanged. An Erratum will be published in PR

Topological Properties of the QCD Vacuum at T=0 and T ~ T_c

We study on the lattice the topology of SU(2) and SU(3) Yang-Mills theories at zero temperature and of QCD at temperatures around the phase transition. To smooth out dislocations and the UV noise we cool the configurations with an action which has scale invariant instanton solutions for instanton size above about 2.3 lattice spacings. The corresponding "improved" topological charge stabilizes at an integer value after few cooling sweeps. At zero temperature the susceptibility calculated from this charge (about (195MeV)^4 for SU(2) and (185 MeV)^4 for SU(3)) agrees very well with the phenomenological expectation. At the minimal amount of cooling necessary to resolve the structure in terms of instantons and anti-instantons we observe a dense ensemble where the total number of peaks is by a factor 5-10 larger than the net charge. The average size observed for these peaks at zero temperature is about 0.4-0.45 fm for SU(2) and 0.5-0.6 fm for SU(3). The size distribution changes very little with further cooling, although in this process up to 90% of the peaks disappear by pair annihilation. For QCD we observe below T_c a reduction of the topological susceptibility as an effect of the dynamical fermions. Nevertheless also here the instantons form a dense ensemble with general characteristics similar to those of the quenched theory. A further drop in the susceptibility above T_c is also in rough agreement with what has been observed for pure SU(3). We see no clear signal for dominant formation of instanton - anti-instanton molecules.Comment: Latex, 7 pages, 4 figures (one colour). Contribution to the 31st International Symposium Ahrenshoop on the Theory of Elementary Particles, Buckow, September 2-6, 199

Non-destructive technique to verify clearance of pipes

A semi-empirical, non-destructive technique to evaluate the activity of gamma ray emitters in contaminated pipes is discussed. The technique is based on in-situ measurements by a portable NaI gamma ray spectrometer. The efficiency of the detector for the pipe and detector configuration was evaluated by Monte Carlo calculations performed using the MCNP code. Gamma ray detector full-energy peak efficiency was predicted assuming a homogeneous activity distribution over the internal surface of the pipe for 344 keV, 614 keV, 662 keV, and 1332 keV photons, representing Eu-152, Ag-118m, Cs-137, and Co-60 contamination, respectively. The effect of inhomogeneity on the accuracy of the technique was also examined. The model was validated against experimental measurements performed using a Cs-137 volume calibration source representing a contaminated pipe and good agreement was found between the calculated and experimental results. The technique represents a sensitive and cost-effective technology for calibrating portable gamma ray spectrometry systems and can be applied in a range of radiation protection and waste management applications