arXiv subjects

M. Oldenburg

Publications and source records attributed to M. Oldenburg.

6 recordsLinked to original sources

arXiv2013

Dissipationless kinetics of one dimensional interacting fermions

We study the problem of evolution of a density pulse of one-dimensional interacting fermions with a non-linear single-particle spectrum. We show that, despite non-Fermi-liquid nature of the problem, non-equilibrium phenomena can be described in terms of a kinetic equation for certain quasiparticles related to the original fermions by a non-linear transformation which decouples the left- and right-moving excitations. Employing this approach, we investigate the kinetics of the phase space distribution of the quasiparticles and thus determine the time evolution of the density pulse. This allows us to explore a crossover from the essentially free-fermion evolution for weak or short-range interaction to hydrodynamics emerging in the case of sufficiently strong, long-range interaction.

cond-mat.str-el↗

arXiv2006

Centrality Dependence of Azimuthal Anisotropy of Strange Hadrons in 200 GeV Au+Au Collisions

Measurements of azimuthal anisotropy for strange and multi-strange hadrons are presented for the first time in their centrality dependence. The high statistics results of v2(pT) allow for a more detailed comparison to hydrodynamical model calculations. Number-of-constituent-quark scaling was tested for different centrality classes separately. Higher order anisotropies like v4(pT) are measured for multi-strange hadrons. While we observe agreement between measured data and models a deeper understanding and refinement of the models seem to be necessary in order to fully understand the details of the data.

nucl-ex↗

arXiv2005

Azimuthal Anisotropy of Identified Hadrons in 200 GeV Au+Au Collisions

The azimuthal anisotropy parameter v2 has been measured with high statistics for identified hadrons in sqrt(s_NN) = 200 GeV Au+Au collisions with the STAR experiment. At high transverse momentum (pT) a strong v2 for pi+ + pi- and p + pbar is observed. In the intermediate pT region, number-of-constituent-quark scaling was tested to high precision. A detailed comparison of v2 for the multi-strange hadrons phi, Xi + anti-Xi, and Omega + anti-Omega with other particle species substantiates the development of collectivity among partons in the early phase of the collisions at RHIC.

nucl-ex↗

arXiv2002

Recent Results from STAR

Besides an introduction to the Relativistic Heavy-Ion Collider (RHIC) and the experimental setup of STAR recent results are discussed. These include anisotropic flow, jets in nucleus-nucleus collisions and ultra-peripheral heavy-ion collisions.

nucl-ex↗

arXiv2002

The Forward Time Projection Chamber (FTPC) in STAR

Two cylindrical forward TPC detectors are described which were constructed to extend the phase space coverage of the STAR experiment to the region 2.5 < |η| < 4.0. For optimal use of the available space and in order to cope with the high track density of central Au+Au collisions at RHIC, a novel design was developed using radial drift in a low diffusion gas. From prototype measurements a 2-track resolution of 1-2 mm is expected.

nucl-ex↗

arXiv2001

Calibration of the STAR Forward Time Projection Chamber with Krypton-83m

The principles of the calibration of a time projection chamber with radioactive Krypton-83 are explained. The calculation of gain correction factors and the methods of obtaining a precise energy calibration are illustrated. The properties and advantages of \nuc{83m}{Kr} are summarized and compared to other radioactive calibration sources. It was shown that the Krypton calibration for the STAR FTPC is feasible and recommendable although the pad geometry of the FTPC causes a considerable deterioration of the measured spectrum due to only partially detected charge clusters.

nucl-ex↗