Mon·Aug 22, 2016Monday·August 22, 2016

1. 01*

   Higher harmonic anisotropic flow of identified particles in Pb-Pb collisions with the ALICE detector

   Naghmeh Mohammadi (for the ALICE collaboration)🇳🇱

   Anisotropic flow plays a crucial role in establishing the equation of state of the Quark Gluon Plasma. The results at RHIC and LHC have demonstrated that the matter created in heavy-ion collisions behaves as a nearly perfect fluid reflected in the low value of the shear viscosity over entropy density ratio ($\eta /s$). The higher flow harmonics are particularly sensitive to the value of $\eta /s$ in hydrodynamic calculations. In this analysis, we present the first ALICE results on the $p_{\mathrm{T}}$ differential $v_2$, $v_3$ and $v_4$ for ${\pi }^{\pm }$, ${\mathrm{K}}^{\pm }$, p($\bar{p}$) from the high statistics 2011 heavy-ion run. We investigate how these $v_n$ coefficients evolve with particle mass and centrality for the 0--1\% and 20--30\% centrality ranges. These new measurements aim at differentiating between models that use different initial conditions, constraining further the value of $\eta /s$ and allowing to decouple the influence of the late hadronic stage from the hydrodynamic evolution of the system.

   nucl-exNPA(2016)·1 citation
2. 02*

   First application of superconducting transition-edge-sensor microcalorimeters to hadronic-atom x-ray spectroscopy

   S. Okada🇯🇵 · D. A. Bennett🇺🇸 · C. Curceanu🇮🇹 · W. B. Doriese🇺🇸 · J. W. Fowler🇺🇸 · J. Gard🇺🇸 · F. P. Gustafsson🇸🇪 · T. Hashimoto🇯🇵 · R. S. Hayano🇯🇵 · S. Hirenzaki🇯🇵 · J. P. Hays-Wehle🇺🇸 · G. C. Hilton🇺🇸 and 26 other authors

   High-resolution pionic-atom x-ray spectroscopy was performed with an x-ray spectrometer based on a 240-pixel array of superconducting transition-edge-sensor (TES) microcalorimeters at the piM1 beam line of the Paul Scherrer Institute. X-rays emitted by pionic carbon via the 4f->3d transition and the parallel 4d->3p transition were observed with a full-width-at-half-maximum energy resolution of 6.8 eV at 6.4 keV. Measured x-ray energies are consistent with calculated electromagnetic values which considered the strong-interaction effect assessed via the Seki-Masutani potential for the 3p energy level, and favor the electronic population of two filled 1s electrons in the K-shell. Absolute energy calibration with an uncertainty of 0.1 eV was demonstrated under a high-rate hadron beam condition of 1.45 MHz. This is the first application of a TES spectrometer to hadronic-atom x-ray spectroscopy and is an important milestone towards next-generation high-resolution kaonic-atom x-ray spectroscopy.

   ↳ physics.ins-detnucl-exnucl-thphysics.atom-phPTEP(2016)·23 citations
3. 03*

   Formation of hypernuclei in heavy-ion collisions around the threshold energies

   A.S. Botvina (Frankfurt U., FIAS, ITP & Moscow, INR)🇩🇪 · K.K. Gudima (Kishinev, IAP)🇲🇩 · J. Steinheimer (Frankfurt U., FIAS)🇩🇪 · M. Bleicher (Frankfurt U., FIAS, ITP)🇩🇪 · J. Pochodzalla (Mainz U., HIM, IKP)🇩🇪

   In relativistic ion collisions there are excellent opportunities to produce and investigate hyper-nuclei. We have systematically studied the formation of hypernuclear spectator residues in peripheral heavy-ion collisions with the transport DCM and UrQMD models. The hyperon capture was calculated within the potential and coalescence approaches. We demonstrate that even at the beam energies around and lower than the threshold for producing Lambda hyperons in binary nucleon-nucleon interactions a considerable amount of hypernuclei, including multi-strange ones, can be produced. This is important for preparation of new experiments on hypernuclei in the wide energy range. The uncertainties of the predictions are investigated within the models, and the comparison with the strangeness production measured in experiments is also performed.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2017)·44 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.