Overview of LHCb

An overview of LHCb experiment is given, focusing on detector, trigger and expected physics performances. LHCb is a second generation b physics experiment design to do precise measurements of CP violation in B meson system and to study b hadron rare decays.Comment: 4 pages, 3 figures, prepared for the Proceedings of the XXXXth Rencontres de Moriond conference, QCD and High Energy Hadronic Interactions, March 12-19 2005, La Thuile, Ital

Maggay\u27s Global kingdom, global people: Living faithfully in a multicultural world

Ce numéro de Trivium est consacré à un aspect de la réflexion de l’un des plus grands représentants de la pensée sociale en France, Emile Durkheim (1858-1917). Aussi bien en dehors qu’au dedans des cercles de spécialistes, on attribue communément à Durkheim la fondation de la sociologie comme discipline scientifique autonome ; on l’évoque comme l’un des « pères fondateurs », et aussi comme l’un des plus éminents représentants, de cette branche des sciences sociales. Qu’il existe un rapport ét..

Using Bayes formula to estimate rates of rare events in transition path sampling simulations

Transition path sampling is a method for estimating the rates of rare events in molecular systems based on the gradual transformation of a path distribution containing a small fraction of reactive trajectories into a biased distribution in which these rare trajectories have become frequent. Then, a multistate reweighting scheme is implemented to postprocess data collected from the staged simulations. Herein, we show how Bayes formula allows to directly construct a biased sample containing an enhanced fraction of reactive trajectories and to concomitantly estimate the transition rate from this sample. The approach can remediate the convergence issues encountered in free energy perturbation or umbrella sampling simulations when the transformed distribution insufficiently overlaps with the reference distribution.Comment: 11 pages, 8 figure

Experimental Study of Heat Pump Thermodynamic Cycles Using CO 2 Based Mixtures -Methodology and First Results

The aim of this work is to study heat pump cycles, using CO 2 based mixtures as working fluids. Since adding other chemicals to CO 2 moves the critical point and generally equilibrium lines, it is expected that lower operating pressures as well as higher global efficiencies may be reached. A simple stage pure CO 2 cycle is used as reference, with fixed external conditions. Two scenarios are considered: water is heated from 10 {\textdegree}C to 65 {\textdegree}C for Domestic Hot Water scenario and from 30 {\textdegree}C to 35 {\textdegree}C for Central Heating scenario. In both cases, water at the evaporator inlet is set at 7 {\textdegree}C to account for such outdoor temperature conditions. In order to understand the dynamic behaviour of thermodynamic cycles with mixtures, it is essential to measure the fluid circulating composition. To this end, we have developed a non intrusive method. Online optical flow cells allow the recording of infrared spectra by means of a Fourier Transform Infra Red spectrometer. A careful calibration is performed by measuring a statistically significant number of spectra for samples of known composition. Then, a statistical model is constructed to relate spectra to compositions. After calibration, compositions are obtained by recording the spectrum in few seconds, thus allowing for a dynamic analysis. This article will describe the experimental setup and the composition measurement techniques. Then a first account of results with pure CO 2 , and with the addition of propane or R-1234yf will be given

The γ\gamma-ray Milky Way above 10 GeV: Distinguishing Sources from Diffuse Emission

One of the most prominent features of the $\gamma$-ray sky is the emission from our own Galaxy. The Galactic plane has been observed by Fermi-LAT in GeV and H.E.S.S. in TeV light. Fermi has modeled the Galactic emission as the sum of a complex 'diffuse' emission model with the predominately point source catalogs of 1FHL and 2FGL, while H.E.S.S. has primarily detected extended TeV sources. At GeV energies, Galactic diffuse emission dominates the $\gamma$-ray Milky Way but, as sources have hard spectra, it is likely their emission dominates at TeV energies. Generally the spatial shape and fraction of source emission compared to diffuse emission in the Galactic plane is not well known and is dependent on the source detection method, threshold and diffuse emission modeling methods used. We present a simple image-analysis based method applied to Fermi-LAT data from 10 GeV to 500 GeV, covering a region of +/- 5 degrees in Galactic latitude and +/- 100 degrees in Galactic longitude, to separate source and diffuse emission. This method involves elongated filter smoothing, combined with significance clipping to exclude sources. We test the method against models based on the 1FHL catalog and very simple model Galaxies to evaluate the response for an input of known fraction and shape of diffuse and source emission.Comment: 6 pages, 5 figures; Proceedings of the 10th Workshop on Science with the New Generation of High-Energy Gamma-ray experiments (SciNeGHE) - PoS(Scineghe2014)03