Centrality Dependence Of The Pseudorapidity Density Distribution For Charged Particles In Pb-pb Collisions At √snn=2.76tev

7264/Mai61062

Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

7191/Mar294

AE(g)over−ba(g)over-barIS Experiment: Measuring the acceleration g of the earth's gravitational field on antihydrogen beam

see paper for full list of authorsInternational audienc

葡萄柚果實發育後期植株營養調查研究

本試驗目的調查在葡萄柚發育最後四個月，葉內無機養分濃度。由於葉齡逐漸增加情形下，葉內鎂及鉀濃度降低，鈣及鐵濃度增加，氮，磷，錳，鋅及銅濃度有稍減趨勢。The mineral nutrients in the late fruit developed stage of grapefruit leaves over 4 monthes are reported here. Concentration of magnesiun and potassium tended to decrease with the age of leaves, whereas the concentration of calcium and iron increased until mid winter. Nitrogen, phosphorus manganese, copper and zinc concentration decreased slightly during the fruit developed stage

Annihilation of low energy antiprotons in silicon

The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeVThe goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 Me

Annihilation of low energy antiprotons in silicon sensors

The aim of the AEgIS experiment is to measure the gravitational acceleration for anti-hydrogen in the Earth's gravitational field, thus testing the Weak Equivalence Principle, which states that all bodies fall with the same acceleration independent of their mass and composition. AEgIS will make use of a gravity module which includes a silicon detector, in order to measure the deflection of anti-hydrogen from a straight path due to the Earth's gravitational field, by detecting the annihilation position on its surface. A position resolution better than 10 \u3bcm is required to determine the gravitational acceleration with a precision better than 10%. The work presented here is part of a study of different silicon sensor technologies to realise a silicon anti-hydrogen detector for the AEgIS experiment at CERN. We here focus on the study of a 3D pixel sensor with FE-I4 readout, originally designed for the ATLAS detector at the LHC, and compare it to a previous monolithic planar detector studied, the MIMOTERA. The direct annihilation of low energy anti-protons ( 3c 100 keV) takes place in the first layers and we show that the charged annihilation products (pions and nuclear fragments) can be detected by such a sensor. The present study aims at understanding the signature of an annihilation event in a 3D silicon sensor, in order to assess the accuracy that can be achieved by such a sensor in the reconstruction of the position of annihilation, when the same happens directly on the detector surface. We also present a comparison between experimental data and GEANT4 simulations and previous data obtained with a silicon imaging detector. These results are being used to determine the geometrical and process parameters to be adopted by the silicon annihilation detector to be installed in AEgIS. \ua9 2013 IEEE

Annihilation of Low Energy Antiprotons in Silicon Sensors

The aim of the AEg̅IS experiment is to measure the gravitational acceleration for anti-hydrogen in the Earth's gravitational field, thus testing the Weak Equivalence Principle, which states that all bodies fall with the same acceleration independent of their mass and composition. AEg̅IS will make use of a gravity module which includes a silicon detector, in order to measure the deflection of anti-hydrogen from a straight path due to the Earth's gravitational field, by detecting the annihilation position on its surface. A position resolution better than 10 μm is required to determine the gravitational acceleration with a precision better than 10%. The work presented here is part of a study of different silicon sensor technologies to realise a silicon anti-hydrogen detector for the AEg̅IS experiment at CERN. We here focus on the study of a 3D pixel sensor with FE-I4 readout, originally designed for the ATLAS detector at the LHC, and compare it to a previous monolithic planar detector studied, the MIMOTERA. The direct annihilation of low energy anti-protons (~ 100 keV) takes place in the first layers and we show that the charged annihilation products (pions and nuclear fragments) can be detected by such a sensor. The present study aims at understanding the signature of an annihilation event in a 3D silicon sensor, in order to assess the accuracy that can be achieved by such a sensor in the reconstruction of the position of annihilation, when the same happens directly on the detector surface. We also present a comparison between experimental data and GEANT4 simulations and previous data obtained with a silicon imaging detector. These results are being used to determine the geometrical and process parameters to be adopted by the silicon annihilation detector to be installed in AEg̅IS

AEgIS at Cern: Measuring Antihydrogen Fall

The study of antimatter properties is the main objective of the AEGIS experiment at the CERN Antiproton Decelerator. Antihydrogen and Positronium will be produced to perform tests of fundamental laws, such as the Weak Equivalence Principle (WEP) and the CPT symmetry of Particle Physics. In the first phase of the experiment, a beam of Antihydrogen will be formed whose fall in the gravitational field will be measured in a moiré deflectometer. This will constitute the first high-sensitivity test of the WEP with antimatter. The present paper will review the working principle of the experiment

Investigation of silicon sensors for their use as antiproton annihilation detectors

International audienc

Investigation of silicon sensors for their use as antiproton annihilation detectors

We present here a new application of silicon sensors aimed at the direct detection of antinucleons annihilations taking place inside the sensor's volume. Such detectors are interesting particularly for the measurement of antimatter properties and will be used as part of the gravity measurement module in the AEgIS experiment at the CERN Antiproton Decelerator. One of the goals of the AEgIS experiment is to measure the gravitational acceleration of antihydrogen with 1% precision. Three different silicon sensor geometries have been tested with an antiproton beam to investigate their properties as annihilation detection devices: strip planar, 3D pixels and monolithic pixel planar. In all cases we were successfully detecting annihilations taking place in the sensor and we were able to make a first characterization of the clusters and tracks