A 35 GHz solid state transmitter/driver

Solid state transmitter/driver /multiplier/ signal source has been designed and fabricated to produce a stable crystal-controlled CW power output of 100 mw at 35 GHz

Neural networks for gamma-hadron separation in MAGIC

Neural networks have proved to be versatile and robust for particle separation in many experiments related to particle astrophysics. We apply these techniques to separate gamma rays from hadrons for the MAGIC Cerenkov Telescope. Two types of neural network architectures have been used for the classi cation task: one is the MultiLayer Perceptron (MLP) based on supervised learning, and the other is the Self-Organising Tree Algorithm (SOTA), which is based on unsupervised learning. We propose a new architecture by combining these two neural networks types to yield better and faster classi cation results for our classi cation problem.Comment: 6 pages, 4 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200

Why the xE distribution triggered by a leading particle does not measure the fragmentation function but does measure the ratio of the transverse momenta of the away-side jet to the trigger-side jet

Hard-scattering of point-like constituents (or partons) in p-p collisions was discovered at the CERN-ISR in 1972 by measurements utilizing inclusive single or pairs of hadrons with large transverse momentum ($p_T$). It was generally assumed, following Feynman, Field and Fox, as shown by data from the CERN-ISR experiments, that the $p_{T_a}$ distribution of away side hadrons from a single particle trigger [with $p_{T_t}$], corrected for of fragmentation would be the same as that from a jet-trigger and follow the same fragmentation function as observed in $e^+ e^-$ or DIS. PHENIX attempted to measure the fragmentation function from the away side $x_E\sim p_{T_a}/p_{T_t}$ distribution of charged particles triggered by a $\pi^0$ in p-p collisions at RHIC and showed by explicit calculation that the $x_E$ distribution is actually quite insensitive to the fragmentation function. Illustrations of the original arguments and ISR results will be presented. Then the lack of sensitivity to the fragmentation function will be explained, and an analytic formula for the $x_E$ distribution given, in terms of incomplete Gamma functions, for the case where the fragmentation function is exponential. The away-side distribution in this formulation has the nice property that it both exhibits $x_E$ scaling and is directly sensitive to the ratio of the away jet $\hat{p}_{T_a}$ to that of the trigger jet, $\hat{p}_{T_t}$, and thus can be used, for example, to measure the relative energy loss of the two jets from a hard-scattering which escape from the medium in A+A collisions. Comparisons of the analytical formula to RHIC measurements will be presented, including data from STAR and PHENIX, leading to some interesting conclusions.Comment: 6 pages, 5 figures, Proceedings of Poster Session, 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006), November 14-20, 2006, Shanghai, P. R. Chin

Retrospective analysis of the correlation between the facial biotype and the inclination of the upper canine cusp axis to the occlusal plane

Permanent maxillary canines are the second most frequently impacted teeth and the prevalence of this clinical condition is estimated to be 1-2% in the general population. The diagnosis of maxillary canine impaction should be based on both clinical and radiographic examinations. The aim of this study was to evaluate the presence of a correlation between the facial biotype and the inclination of the upper cusp axis. A correlation between the total radicular length of the lateral incisors was also evaluated, by comparing the side of impaction with the healthy side. Twenty three patients with a diagnosis of unilateral upper cusp impaction were recruited. For each patient, dental casts and radiographic material (panoramic radiographs and lateral cephalograms) were examined. Statistical analyses were done with Spearman's rank correlation coefficient or Spearman's rho (V). X-ray examinations demonstrated that canine impaction was associated to other dental anomalies (32% of the sample). The mean S angle measurements were 22.9° ± 4.1°, and mean values of the T angle were 34.7°± 4.0°. The mean distance “d” value was 14.6 mm ± 1.2 mm. The mean values of the angle between the upper cusp axis and the perpendicular-to-Fh plane were 20.8 °± 2.6°. Among the 23 subjects recruited, 5 showed values included in the range 25°-45° and 1 an inclination > 45°. The results obtained in the present study demonstrate a significant inverse correlation between the MM angle and the inclination of the upper cusp axis to the perpendicular-to-Fh plan

Exact ground state for a class of matrix Hamiltonian models: quantum phase transition and universality in the thermodynamic limit

By using a recently proposed probabilistic approach, we determine the exact ground state of a class of matrix Hamiltonian models characterized by the fact that in the thermodynamic limit the multiplicities of the potential values assumed by the system during its evolution are distributed according to a multinomial probability density. The class includes i) the uniformly fully connected models, namely a collection of states all connected with equal hopping coefficients and in the presence of a potential operator with arbitrary levels and degeneracies, and ii) the random potential systems, in which the hopping operator is generic and arbitrary potential levels are assigned randomly to the states with arbitrary probabilities. For this class of models we find a universal thermodynamic limit characterized only by the levels of the potential, rescaled by the ground-state energy of the system for zero potential, and by the corresponding degeneracies (probabilities). If the degeneracy (probability) of the lowest potential level tends to zero, the ground state of the system undergoes a quantum phase transition between a normal phase and a frozen phase with zero hopping energy. In the frozen phase the ground state condensates into the subspace spanned by the states of the system associated with the lowest potential level.Comment: 31 pages, 13 figure