Optimized production of large Bose Einstein Condensates

We suggest different simple schemes to efficiently load and evaporate a ''dimple'' crossed dipolar trap. The collisional processes between atoms which are trapped in a reservoir load in a non adiabatic way the dimple. The reservoir trap can be provided either by a dark SPOT Magneto Optical Trap, the (aberrated) laser beam itself or by a quadrupolar or quadratic magnetic trap. Optimal parameters for the dimple are derived from thermodynamical equations and from loading time, including possible inelastic and Majorana losses. We suggest to load at relatively high temperature a tight optical trap. Simple evaporative cooling equations, taking into account gravity, the possible occurrence of hydrodynamical regime, Feshbach resonance processes and three body recombination events are given. To have an efficient evaporation the elastic collisional rate (in s$^{-1}$) is found to be on the order of the trapping frequency and lower than one hundred times the temperature in micro-Kelvin. Bose Einstein condensates with more than $10^7$ atoms should be obtained in much less than one second starting from an usual MOT setup.Comment: 14 page

Observation of a resonant four-body interaction in cold cesium Rydberg atoms

Cold Rydberg atoms subject to long-range dipole-dipole interactions represent a particularly interesting system for exploring few-body interactions and probing the transition from 2-body physics to the many-body regime. In this work we report the direct observation of a resonant 4-body Rydberg interaction. We exploit the occurrence of an accidental quasi-coincidence of a 2-body and a 4-body resonant Stark-tuned Forster process in cesium to observe a resonant energy transfer requiring the simultaneous interaction of at least four neighboring atoms. These results are relevant for the implementation of quantum gates with Rydberg atoms and for further studies of many-body physics.Comment: 5 pages, 5 figure

Simbol-X Background Minimization: Mirror Spacecraft Passive Shielding Trade-Off Study

The present work shows a quantitative trade-off analysis of the Simbol-X Mirror Spacecraft (MSC) passive shielding, in the phase space of the various parameters: mass budget, dimension, geometry, and composition. A simplified physical (and geometrical) model of the sky screen, implemented by means of a GEANT4 simulation, has been developed to perform a performance-driven mass optimization and evaluate the residual background level on Simbol-X focal plane.Comment: 3 pages, 6 figures, to appear in the proceedings of the second Simbol-X International Symposium "Simbol-X - Focusing on the Hard X-ray Universe", AIP Conf. Proc. Series, P. Ferrando and J. Rodriguez ed

Ascaridia galli: a report of erratic migration

This paper describes a case of an unusual recovery of adult Ascaridia galli in hen's egg. Several data are available on this occurrence but it appears to be the first case described in Italy. The worm was identified as an adult female, 6.8 cm in length, with three trilobed lips, cervical narrow alae, oesophagus club-shaped without posterior bulb, vulva near the middle of body, with gravid uteri containing a large number of eggs. The presence of Ascaridia galli in hen's eggs cannot be considered as hazard for public health but may be cause of a potential consumer complaint. Moreover it is a sign of presence of ascaridiosis, parasitosis that still produces economic losses in modern poultry production system

Enhancement of the formation of ultracold 85^{85}Rb2_2 molecules due to resonant coupling

We have studied the effect of resonant electronic state coupling on the formation of ultracold ground-state $^{85}$Rb$_2$. Ultracold Rb$_2$ molecules are formed by photoassociation (PA) to a coupled pair of $0_u^+$ states, $0_u^+(P_{1/2})$ and $0_u^+(P_{3/2})$, in the region below the $5S+5P_{1/2}$ limit. Subsequent radiative decay produces high vibrational levels of the ground state, $X ^1\Sigma_g^+$. The population distribution of these $X$ state vibrational levels is monitored by resonance-enhanced two-photon ionization through the $2 ^1\Sigma_u^+$ state. We find that the populations of vibrational levels $v''$=112$-$116 are far larger than can be accounted for by the Franck-Condon factors for $0_u^+(P_{1/2}) \to X ^1\Sigma_g^+$ transitions with the $0_u^+(P_{1/2})$ state treated as a single channel. Further, the ground-state molecule population exhibits oscillatory behavior as the PA laser is tuned through a succession of $0_u^+$ state vibrational levels. Both of these effects are explained by a new calculation of transition amplitudes that includes the resonant character of the spin-orbit coupling of the two $0_u^+$ states. The resulting enhancement of more deeply bound ground-state molecule formation will be useful for future experiments on ultracold molecules.Comment: 6 pages, 5 figures; corrected author lis

The Severe Heart Failure Questionnaire: Italian translation and linguistic validation

Introduction. The quality of life (QoL) is an important outcome indicator for heart failure management. As the use of a validate questionnaire in a different cultural context can affect data interpretation our main objective is the Italian translation and linguistic validation of the Severe Heart Failure Questionnaire (SHF) and its comparison with the MLHF (Minnesota Living with Heart Failure) Questionnaire. Methods. The SHF and ?The Minnesota Living with Heart Failure Questionnaire? were translated. A consensus involving parallel back-translations was established among a group of cardiologists, psychologists and biostatisticians. SHF and MLHF were both administrated to a sample of 50 patients Results. The patients? median age was 63 years. Ace inhibitors therapy was administered in 88% of cases and betablockers in 56% of cases. Finally the Italian version of SHF correlates well with MLHF for all domains, except life satisfaction SHF domain. Discussion: The Italian version of the SHF correlates well with MLHF for almost all domains and it represents a valid alterna- tive for quality of life assessment in heart failure patients

Noninvasive assessment of reperfusion and reocclusion after thrombolysis in acute myocardial infarction.

The clinical significance of ST-segment changes and of the time course of appearance in serum of different cardiac proteins has been reviewed for the diagnosis of coronary reperfusion and reocclusion after thrombolysis. In particular, the value of serial 12-lead electrocardiographic (ECG) studies, of Holter monitoring, and of continuous multilead computer-assisted ECG monitoring is compared. Regarding the serum proteins, the clinical significance of reperfusion indices described so far for serum creatine kinase (CK), its isoenzyme serum creatinine kinase MB, the CK isoforms, and myoglobin is reviewed. Emphasis is placed on (1) the calculation method used for deriving the reperfusion indices; (2) the sensitivity and the specificity of the reperfusion indices; (3) the minimum turn-around time needed to produce the reperfusion indices (depending on the practicability of the analytical and calculation methods and their applicability in an em

L\'evy flights of photons in hot atomic vapours

Properties of random and fluctuating systems are often studied through the use of Gaussian distributions. However, in a number of situations, rare events have drastic consequences, which can not be explained by Gaussian statistics. Considerable efforts have thus been devoted to the study of non Gaussian fluctuations such as L\'evy statistics, generalizing the standard description of random walks. Unfortunately only macroscopic signatures, obtained by averaging over many random steps, are usually observed in physical systems. We present experimental results investigating the elementary process of anomalous diffusion of photons in hot atomic vapours. We measure the step size distribution of the random walk and show that it follows a power law characteristic of L\'evy flights.Comment: This final version is identical to the one published in Nature Physic

Formation of ultracold LiCs molecules

We present the first observation of ultracold LiCs molecules. The molecules are formed in a two-species magneto-optical trap and detected by two-photon ionization and time-of-flight mass spectrometry. The production rate coefficient is found to be in the range 10^{-18}\unit{cm^3s^{-1}} to 10^{-16}\unit{cm^3s^{-1}}, at least an order of magnitude smaller than for other heteronuclear diatomic molecules directly formed in a magneto-optical trap.Comment: 8 pages, 2 figure

On the Angular Resolution of the AGILE gamma-ray imaging detector

We present a study of the Angular Resolution of the AGILE gamma-ray imaging detector (GRID) that is operational in space since April 2007. The AGILE instrument is made of an array of 12 planes each equipped with a Tungsten converter and Silicon micros trip detectors and is sensitive in the energy range 50 MeV - 10 GeV. Among the space instruments devoted to gamma-ray astrophysics, AGILE uniquely exploits an analog readout system with dedicated electronics coupled with Silicon detectors. We show the results of Monte Carlo simulations carried out to reproduce the gamma-ray detection by the GRID, and we compare them to in-flight data. We use the Crab (pulsar + Nebula) system for discussion of real data performance, since its E^{-2} energy spectrum is representative of the majority of gamma-ray sources. For Crab-like spectrum sources, the GRID angular resolution (FWHM of ~4deg at 100 MeV; ~0.8deg at 1 GeV; ~0.9deg integrating the full energy band from 100 MeV to tens of GeV) is stable across a large field of view, being characterized by a flat response up to 30deg off-axis. A comparison of the angular resolution obtained by the two operational gamma-ray instruments, AGILE-GRID and Fermi-LAT, is interesting in view of future gamma-ray missions, that are currently under study. The two instruments exploit different detector configurations affecting the angular resolution: the former being optimized in the readout and track reconstruction especially in the low-energy band, the latter in terms of converter thickness and power consumption. We show that, despite these differences, the angular resolution of both instruments is very similar between 100 MeV and a few GeV.Comment: 19 pages, 8 figures, accepted for publication in Ap