Tue·Aug 19, 2014Tuesday·August 19, 2014

1. 01*

   Measurement of electrons from heavy-flavor decays from $p$+$p$, $d$+Au, and Cu+Cu collisions in the PHENIX experiment

   Sanghoon Lim (PHENIX collaboration)🇰🇷

   Charm and bottom quarks are formed predominantly by gluon fusion in the initial hard scatterings at RHIC, making them good probes of the full medium evolution. Previous measurements at RHIC have shown large suppression and azimuthal anisotropy of open heavy-flavor hadrons in Au+Au collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$. Explaining the simultaneously large suppression and flow of heavy quarks has been challenging. To further understand the heavy-flavor transport in the hot and dense medium, it is imperative to also measure cold nuclear matter effects which affect the initial distribution of heavy quarks as well as the system size dependence of the final state suppression. In this talk, new measurements by the PHENIX collaboration of electrons from heavy-flavor decays in $p$+$p$, $d$+Au, and Cu+Cu collisions at $\sqrt{s_{NN}}=200\mathrm{GeV}$ are presented. In particular, a surprising enhancement of intermediate transverse momentum heavy-flavor decay leptons in $d$+Au at mid and backward rapidity are also seen in mid-central Cu+Cu collisions. This enhancement is much larger than the expectation from anti-shadowing of the parton distributions and is theoretically unexplained.

   nucl-exNPA(2014)·0 citations
2. 02*

   The Karlsruhe Astrophysical Database of Nucleosynthesis in Stars Project - Status and Prospects

   Iris Dillmann🇩🇪 · Tamas Szücs🇭🇺 · Zsolt Fülöp🇭🇺 · Ralf Plag🇩🇪 · Franz Käppeler🇩🇪 · Thomas Rauscher🇬🇧

   The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars) project is an astrophysical online database for cross sections relevant for nucleosynthesis in the $s$ process and the $\gamma$ process. The $s$-process database (www.kadonis.org) was started in 2005 and is presently facing its 4th update (KADoNiS v1.0). The $\gamma$-process database (KADoNiS-p, www.kadonis.org/pprocess) was recently revised and re-launched in March 2013. Both databases are compilations for experimental cross sections with relevance to heavy ion nucleosynthesis. For the $s$ process recommended Maxwellian averaged cross sections for $kT$= 5-100~keV are given for more than 360 isotopes between ${}^1$H and ${}^{210}$Bi. For the $\gamma$-process database all available experimental data from $(p,\gamma ),(p,n),(p,\alpha ),(\alpha ,\gamma ),(\alpha ,n)$, and $(\alpha ,p)$ reactions between ${}^{70}$Ge and ${}^{209}$Bi in or close to the respective Gamow window were collected and can be compared to theoretical predictions. The aim of both databases is a quick and user-friendly access to the available data in the astrophysically relevant energy regions.

   ↳ astro-ph.SRnucl-exNucl.Data Sheets(2014)·39 citations
3. 03*

   J=0 T=1 Pairing Interaction Selection Rules

   Matthew Harper · Larry Zamick🇺🇸

   Wave functions arising form a pairing Hamiltonian E(0) i,e, one in which the interaction is only between J=0^{+}T=1 pairs, lead to magnetic dipole and Gamow-Teller transition rates that are much larger than those from an interaction E(J_{max}) in which a proton and a neutron couple to J=2j. With realistic interactions the results are in between the 2 extremes. In the course of this study we found that certain M1 and GT matrix elements vanish with E(0) . These are connected to seniority and reduced isospin isospin selection rules. We find the surprising result that The M1 strength to the single j scissors is larger for a J=0 T=1 pairing interaction than it is for Q.Q.

   ↳ nucl-thnucl-exPRC(2015)·11 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.