Thu·Apr 6, 2017Thursday·April 6, 2017

1. 01*

   Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates

   Sam Austin · Christopher West · Alexander Heger🇦🇺

   We have used effective reaction rates (ERR) for the helium burning reactions to predict the yield of the gamma-emitting nuclei 26Al, 44Ti, and 60Fe in core col- lapse supernovae. The variations in the predicted yields for values of the reaction rates allowed by the ERR are much smaller than obtained previously, and smaller than other uncertainties. A "filter" for supernova nucleosynthesis yields based on pre-supernova structure was used to estimate the effect of failed supernovae on the initial mass function-averaged yields; this substantially reduced the yields of all these isotopes, but the predicted yield ratio 60Fe/26Al was little affected. The robustness of this ratio is promising for comparison with data, but it is larger than observed in nature; possible causes for this discrepancy are discussed.

   ↳ astro-ph.SRnucl-exnucl-thApJL(2017)·9 citations
2. 02*

   Design and Beam Test Results for the sPHENIX Electromagnetic and Hadronic Calorimeter Prototypes

   C.A. Aidala🇺🇸 · V. Bailey🇺🇸 · S. Beckman🇺🇸 · R. Belmont🇺🇸 · C. Biggs🇺🇸 · J. Blackburn🇺🇸 · S. Boose🇺🇸 · M. Chiu🇺🇸 · M. Connors🇺🇸 · E. Desmond🇺🇸 · A. Franz🇺🇸 · J.S. Haggerty🇺🇸 and 38 other authors

   The super Pioneering High Energy Nuclear Interaction eXperiment (sPHENIX) at the Relativistic Heavy Ion Collider (RHIC) will perform high precision measurements of jets and heavy flavor observables for a wide selection of nuclear collision systems, elucidating the microscopic nature of strongly interacting matter ranging from nucleons to the strongly coupled quark-gluon plasma. A prototype of the sPHENIX calorimeter system was tested at the Fermilab Test Beam Facility as experiment T-1044 in the spring of 2016. The electromagnetic calorimeter (EMCal) prototype is composed of scintillating fibers embedded in a mixture of tungsten powder and epoxy. The hadronic calorimeter (HCal) prototype is composed of tilted steel plates alternating with plastic scintillator. Results of the test beam reveal the energy resolution for electrons in the EMCal is $2.8\%\oplus 15.5\%/\sqrt{E}$ and the energy resolution for hadrons in the combined EMCal plus HCal system is $13.5\%\oplus 64.9\%/\sqrt{E}$. These results demonstrate that the performance of the proposed calorimeter system satisfies the sPHENIX specifications.

   ↳ physics.ins-dethep-exnucl-exIEEE Trans.Nucl.Sci.(2018)·41 citations
3. 03*

   Searching for $0\nu \beta \beta$ decay in ${}^{136}$Xe -- towards the tonne-scale and beyond

   Thomas Brunner🇨🇦 · Lindley Winslow🇺🇸

   The quest for neutrinoless double-beta decay ($0\nu \beta \beta$) is a promising experimental approach to search for lepton number violation in weak interactions, a key ingredient in generating the matter-antimatter asymmetry through models of Leptogenesis. The ${}^{136}$Xe-based $0\nu \beta \beta$ experiments KamLAND-Zen and EXO-200 currently set the most stringent limits on this process using two very different techniques. Each are preparing the next generation experiment, which will search for $0\nu \beta \beta$ in the parameter space corresponding to the inverted hierarchy for neutrino mass. Both of these techniques scale well to larger volumes while incorporating interesting new techniques. We present the status of current and next generation experiments of these collaborations and present two developments with the potential to identify $\beta \beta$ decay events.

   ↳ hep-exnucl-exphysics.ins-detNucl.Phys.News(2017)·19 citations
4. 04*

   Statistical moments in superposition models and strongly intensive measures

   Wojciech Broniowski🇵🇱 · Adam Olszewski🇵🇱

   First, we present a concise glossary of formulas for composition of standard, cumulant, factorial, and factorial cumulant moments in superposition (compound) models, where final particles are created via independent emission from a collection of sources. Explicit mathematical formulas for the composed moments are given to all orders. We discuss the composition laws for various types of moments via the generating-function methods and list the formulas for the unfolding of the unwanted fluctuations. Second, the technique is applied to the difference of the scaled multiplicities of two particle types. This allows us for a systematic derivation and a simple algebraic interpretation of the so-called strongly intensive fluctuation measures. With the help of the formalism we obtain several new strongly intensive measures involving higher-rank moments. The reviewed as well as the new results may be useful in investigations of mechanisms of particle production and event-by-event fluctuations in high-energy nuclear and hadronic collisions, and in particular in the search for signatures of the QCD phase transition at a finite baryon density.

   ↳ nucl-thnucl-exPRC(2017)·12 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.