190,861 research outputs found
Experimental analysis of the Strato-rotational Instability in a cylindrical Couette flow
This study is devoted to the experimental analysis of the Strato-rotational
Instability (SRI). This instability affects the classical cylindrical Couette
flow when the fluid is stably stratified in the axial direction. In agreement
with recent theoretical and numerical analyses, we describe for the first time
in detail the destabilization of the stratified flow below the Rayleigh line
(i.e. the stability threshold without stratification). We confirm that the
unstable modes of the SRI are non axisymmetric, oscillatory, and take place as
soon as the azimuthal linear velocity decreases along the radial direction.
This new instability is relevant for accretion disks.Comment: 4 pages, 4 figures. PRL in press 200
sPlot: a statistical tool to unfold data distributions
The paper advocates the use of a statistical tool dedicated to the
exploration of data samples populated by several sources of events. This new
technique, called sPlot, is able to unfold the contributions of the different
sources to the distribution of a data sample in a given variable. The sPlot
tool applies in the context of a Likelihood fit which is performed on the data
sample to determine the yields of the various sources.Comment: 27 pages, 8 figures, Accepted for publication in Nucl. Instr. Method
- …