arXiv subjects

S. Velle

Publications and source records attributed to S. Velle.

7 recordsLinked to original sources

arXiv2017

Quantitative assessment of increasing complexity

We study the build up of complexity on the example of 1 kg matter in different forms. We start on the simplest example of ideal gases, and then continue with more complex chemical, biological, life and social and technical structures. We assess the complexity of these systems quantitatively, based on their entropy. We present a method to attribute the same entropy to known physical systems and to complex organic molecules up to a DNA. The important steps in this program and the basic obstacles are discussed.

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arXiv2016

Interferometry for rotating sources

The two particle interferometry method to determine the size of the emitting source after a heavy ion collision is extended. Following the extension of the method to spherical expansion dynamics, here we extend the method to rotating systems. It is shown that rotation of a cylindrically symmetric system leads to modifications, which can be perceived as spatial asymmetry by the "azimuthal HBT" method. We study an exact rotating and expanding solution of the fluid dynamical model of heavy ion reactions. We consider a source that is azimuthally symmetric in space around the axis of rotation, and discuss the features of the resulting two particle correlation function. This shows the azimuthal asymmetry arising from the rotation. We show that this asymmetry leads to results similar to those given by spatially asymmetric sources.

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arXiv2015

Differential Hanbury-Brown-Twiss for an exact hydrodynamic model with rotation

We study an exact rotating and expanding solution of the fluid dynamical model of heavy ion reactions, that take into account the rate of slowing down of the rotation due to the longitudinal and transverse expansion of the system. The parameters of the model are set on the basis of realistic 3+1D fluid dynamical calculation at TeV energies, where the rotation is enhanced by the build up of the Kelvin Helmholtz Instability in the flow.

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arXiv2015

Two particle correlation effects and Differential HBT for rotation in heavy ion collisions

Peripheral heavy ion reactions at ultra relativistic energies have large angular momentum that can be studied via two particle correlations using the Differential Hanbury Brown and Twiss method. We analyze the possibilities and sensitivity of the method in a rotating system. We also study an expanding solution of the fluid dynamical model of heavy ion reactions.

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arXiv2014

Study of Rotating High Energy Systems with the Differential HBT Method

Peripheral heavy ion reactions at ultra relativistic energies have large angular momentum that can be studied via two particle correlations using the Differential Hanbury Brown and Twiss method. In the present work we analyze the possibilities and sensitivity of the method in rotating, few source systems. Analytic results provide insight in the advantages of this method.

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arXiv2014

Differential HBT Applied to Relativistic Fluid Dynamics

The earlier introduced Differential HBT method aiming for detecting rotation is used to analyze the fluid dynamical model results of ultra-relativistic heavy ion reactions where the initial state has substantial angular momentum. The rotation effect and Kelvin Helmholtz Instability, lead to space-time momentum correlations, which can be detected by the method.

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arXiv2013

Differential HBT Method to Analyze Rotation

Two particle correlations are studied in the reaction plane of peripheral relativistic heavy ion reactions where the initial state has substantial angular momentum. The earlier predicted rotation effect and Kelvin Helmholtz Instability, leads to space-time momentum correlations among the emitted particles. A specific combination of two particle correlation measurements is proposed, which can sensitively detect the rotation of the emitting system. Here the method is presented in simple few source models where the symmetries and the possibilities of the detection can be demonstrated in a transparent way.

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