Negative Elliptic Flow of J/ψJ/\psi's: A Qualitative Signature for Charm Collectivity at RHIC

We discuss one of the most prominent features of the very recent preliminary elliptic flow data of $J/\Psi$ meson from the PHENIX collaboration \cite{Silvestre:2008tw}. Even within the the rather large error bars of the measured data a negative elliptic flow parameter ($v_2$) for $J/\Psi$ in the range of p_T=0.5-2.5 \GeV/c is visible. We argue that this negative elliptic flow at intermediate $p_T$ is a clear and qualitative signature for the collectivity of charm quarks produced in nucleus-nucleus reactions at RHIC. Within a parton recombination approach we show that a negative elliptic flow puts a lower limit on the collective transverse velocity of heavy quarks. The numerical value of the transverse flow velocity $\beta_T$ for charm quarks that is necessary to reproduce the data is $\beta_T(charm)\sim 0.55-0.6c$ and therefore compatible with the flow of light quarks.Comment: 4 pages, 3 figures; to be published in EPJ A; Changes: Added B-meson elliptic flow and data on non-photonic electron v_2 to Fig. 2; Added a plot showing the quark v_2; Added discussion about D^0 flo

Introduction to the Anthropocene

https://nanocrit.com/issues/issue13/Editors-Introduction-for-NANO-Special-Issue-13-The-Anthropocenehttps://nanocrit.com/issues/issue13/Editors-Introduction-for-NANO-Special-Issue-13-The-AnthropoceneAccepted manuscrip

Moisture content and gas sampling device

An apparatus is described for measuring minute quantities of moisture and other contaminants within sealed enclosures such as electronic assemblies which may be subject to large external atmospheric pressure variations. An array of vacuum quality valves is arranged to permit cleansing of the test apparatus of residual atmospheric components from a vacuum source. This purging operation evacuates a gas sample bottle, which is then connected by valve settings to provide the drive for withdrawing a gas sample from the sealed enclosure under test into the sample bottle through a colometric detector tube (Drager tube) which indicates moisture content. The sample bottle may be disconnected and its contents (drawn from the test enclosure) separately subjected to mass spectrograph analysis