Search results for " Experiments"

Energy dependence and fluctuations of anisotropic flow in Pb-Pb collisions at √sNN = 5.02 and 2.76 TeV

2018

Measurements of anisotropic flow coefficients with two- and multi-particle cumulants for inclusive charged particles in Pb-Pb collisions at sNN−−−√=5.02 and 2.76 TeV are reported in the pseudorapidity range |η| < 0.8 and transverse momentum 0.2 < pT < 50 GeV/c. The full data sample collected by the ALICE detector in 2015 (2010), corresponding to an integrated luminosity of 12.7 (2.0) μb−1 in the centrality range 0-80%, is analysed. Flow coefficients up to the sixth flow harmonic (v6) are reported and a detailed comparison among results at the two energies is carried out. The pT dependence of anisotropic flow coefficients and its evolution with respect to centrality and harmonic number n are…

High-resolution scattering experiments at the K130 cyclotron in Jyväskylä

2018

Abstract An experimental setup for nuclear reaction studies induced by light and heavy ions is described. It consists of a versatile Large Scattering Chamber equipped with two rotating tables for mounting detectors. A dedicated beam diagnostic system is used to monitor the energy spectrum of the beam on target. The system provides the necessary feedback for tuning of the K-130 cyclotron to reduce the energy spread of the accelerated beam by at least a factor of 3 down to about 0.3% of the nominal energy while maintaining beam currents around 20 pnA. At lower beam currents a 0.1% energy spread can be achieved. This improvement makes a significant impact on the scope of reaction studies possi…

Microwave experiments on electromagnetic evanescent waves and tunneling effect

1993

A set of experiments is described to measure the decay of electromagnetic evanescent waves and the tunneling effect through an airgap. The experiments are performed using microwaves and have been designed to be carried out by third year students of physics. The proposed experimental setup can be regarded as a quantum mechanical simulator for the one‐dimensional motion of a particle.

Turbulence structure and coherent motion in a straight laboratory flume

2012

Calibration of the RPC charge readout in the ARGO-YBJ experiment

2012

""The charge readout of Resistive Plate Chambers (RPCs) is implemented in the ARGO-YBJ experiment to measure the charged particle density of the shower front up to 10^4\\\/m^2, enabling the study of the primary cosmic rays with energies in the ''knee'' region. As the first time for RPCs being used this way, a telescope with RPCs and scintillation detectors is setup to calibrate the number of charged particles hitting a RPC versus its charge readout. Air shower particles are taken as the calibration beam. The telescope was tested at sea level and then moved to the ARGO-YBJ site for coincident operation with the ARGO-YBJ experiment. The charge readout shows good linearity with the particle de…

Adaptive design optimization: a mutual information-based approach to model discrimination in cognitive science.

2010

Discriminating among competing statistical models is a pressing issue for many experimentalists in the field of cognitive science. Resolving this issue begins with designing maximally informative experiments. To this end, the problem to be solved in adaptive design optimization is identifying experimental designs under which one can infer the underlying model in the fewest possible steps. When the models under consideration are nonlinear, as is often the case in cognitive science, this problem can be impossible to solve analytically without simplifying assumptions. However, as we show in this letter, a full solution can be found numerically with the help of a Bayesian computational trick d…

Beobachtungen nach einer neuen optischen Methode: ein Beitrag zur Experimental-Physik

1864

Inhalt: Princip der Beobachtungs-Methode... 2 Specielle Beschreibung des Apparates... 8 Bemerkungen über den Gebrauch und die Adjustirung... 13 Schlieren in Gläsern ... 16 Beobachtungen mittels des Schlieren-Apparates... 18 Veränderung durchsichtiger Körper durch Temperatur und Druck... 19 Diffusionsbewegungen... 21 Untersuchung der Flammen... 23 Beugungsphänomene... 26 Sichtbarmachung der Schallwellen... 27 Beobachtungen über den electrischen Funken... 29 Der Inductionsfunken... 35 Der Flaschenfunken... 42 Schlussbemerkungen... 49

The design of artificial nestboxes for the study of secondary hole-nesting birds: A review of methodological inconsistencies and potential biases

2010

The widespread use of artificial nestboxes has led to significant advances in our knowledge of the ecology, behaviour and physiology of cavity nesting birds, especially small passerines. Nestboxes have made it easier to perform routine monitoring and experimental manipulation of eggs or nestlings, and also repeatedly to capture, identify and manipulate the parents. However, when comparing results across study sites the use of nestboxes may also introduce a potentially significant confounding variable in the form of differences in nestbox design amongst studies, such as their physical dimensions, placement height, and the way in which they are constructed and maintained. However, the use of …

First results on dark matter annihilation in the Sun using the ANTARES neutrino telescope

2013

A search for high-energy neutrinos coming from the direction of the Sun has been performed using the data recorded by the ANTARES neutrino telescope during 2007 and 2008. The neutrino selection criteria have been chosen to maximize the selection of possible signals produced by the self-annihilation of weakly interacting massive particles accumulated in the centre of the Sun with respect to the atmospheric background. After data unblinding, the number of neutrinos observed towards the Sun was found to be compatible with background expectations. The 90% CL upper limits in terms of spin-dependent and spin-independent WIMP-proton cross-sections are derived and compared to predictions of two sup…

Precision calculations of dark matter relic abundance

2019

The dark matter annihilation channels sometimes involve sharp resonances. In such cases the usual momentum averaged approximations for computing the DM abundance may not be accurate. We develop an easily accessible momentum dependent framework for computing the DM abundance accurately and efficiently near such features. We apply the method to the case of a singlet scalar dark matter $s$ interacting with SM through higgs portal $\lambda_{\rm hs}s^2 h^2$ and compare the results with different momentum averaged methods. The accuracy of the latter depend strongly on the strength of the elastic interactions and corrections are large if WIMP has negligible interactions beyond the main annihilatio…