Thu·Mar 8, 2018Thursday·March 8, 2018

1. 01*

   Examination of the observability of a chiral magnetically-driven charge-separation difference in collisions of the ${}_{44}^{96}\mathrm{Ru}+{}_{44}^{96}\mathrm{Ru}$ and ${}_{40}^{96}\mathrm{Zr}+{}_{40}^{96}\mathrm{Zr}$ isobars at energies available at RHIC

   Niseem Magdy (1)🇺🇸 · Shuzhe Shi (2)🇺🇸 · Jinfeng Liao (2)🇺🇸 · Peifeng Liu (1,3)🇺🇸 · Roy A. Lacey (1,3) ((1) Department of Chemistry, Stony Brook University, (2) Physics Department and Center for Exploration of Energy and Matter, Indiana University, (3) Department of Physics, Stony Brook University)🇺🇸

   Anomalous Viscous Fluid Dynamics (AVFD) model calculations for ${}_{44}^{96}\mathrm{Ru}+{}_{44}^{96}\mathrm{Ru}$ and ${}_{40}^{96}\mathrm{Zr}+{}_{40}^{96}\mathrm{Zr}$ collisions ($\sqrt{s_{\mathrm{NN}}}=200$ GeV) are used in concert with a charge-sensitive correlator, to test its ability to detect and characterize the charge separation difference expected from the Chiral Magnetic Effect (CME) in these isobaric collisions. The tests indicate a larger charge separation for ${}_{44}^{96}\mathrm{Ru}+{}_{44}^{96}\mathrm{Ru}$ than for ${}_{40}^{96}\mathrm{Zr}+{}_{40}^{96}\mathrm{Zr}$ collisions, and a discernible CME-driven difference of $\sim 10$\% in the presence of realistic non-CME backgrounds. They also indicate a strategy for evaluating the relative influence of the background correlations, present for each isobar. These results suggest that charge separation measurements for these isobaric species could serve to further constrain unambiguous identification and characterization of the CME in upcoming measurements at RHIC.

   nucl-exPRC(2018)·26 citations
2. 02*

   Probing the $N=14$ subshell closure: $g$ factor of the ${}^{26}$Mg(2${}_1^{+}$) state

   B.P.McCormick🇦🇺 · A.E. Stuchbery🇦🇺 · T. Kibédi🇦🇺 · G.J. Lane🇦🇺 · M.W. Reed🇦🇺 · T.K. Eriksen🇳🇴 · S.S. Hota🇦🇺 · B.Q. Lee · N. Palalani

   The first-excited state $g$~factor of ${}^{26}$Mg has been measured relative to the $g$ factor of the ${}^{24}$Mg($2_1^{+}$) state using the high-velocity transient-field technique, giving $g=+0.86\pm 0.10$. This new measurement is in strong disagreement with the currently adopted value, but in agreement with the $sd$-shell model using the USDB interaction. The newly measured $g$ factor, along with $E(2_1^{+})$ and $B(E2)$ systematics, signal the closure of the $\nu d_{5/2}$ subshell at $N=14$. The possibility that precise $g$-factor measurements may indicate the onset of neutron $pf$ admixtures in first-excited state even-even magnesium isotopes below ${}^{32}$Mg is discussed and the importance of precise excited-state $g$-factor measurements on $sd$~shell nuclei with $N\ne Z$ to test shell-model wavefunctions is noted.

   nucl-exPLB(2018)·6 citations
3. 03*

   The kaonic atoms research program at DA{\Phi}NE: from SIDDHARTA to SIDDHARTA-2

   A. Scordo🇮🇹 · A. Amirkhani🇮🇹 · M. Bazzi🇮🇹 · G. Bellotti🇮🇹 · C. Berucci🇮🇹 · D. Bosnar🇭🇷 · A.M. Bragadireanu🇷🇴 · M. Cargnelli🇦🇹 · C. Curceanu🇮🇹 · A. Dawood Butt🇮🇹 · R. Del Grande🇮🇹 · L. Fabbietti🇩🇪 and 22 other authors

   The interaction of antikaons with nucleons and nuclei in the low-energy regime represents an active research field in hadron physics with still many important open questions. The investigation of light kaonic atoms, in which one electron is replaced by a negatively charged kaon, is a unique tool to provide precise information on this interaction; the energy shift and the broadening of the low-lying states of such atoms, induced by the kaon-nucleus hadronic interaction, can be determined with high precision from the atomic X-ray spectroscopy, and this experimental method provides unique information to understand the low energy kaon-nucleus interaction at the production threshold. The lightest atomic systems, like the kaonic hydrogen and the kaonic deuterium deliver, in a model-independent way, the isospin-dependent kaon-nucleon scattering lengths. The most precise kaonic hydrogen measurement to-date, together with an exploratory measurement of kaonic deuterium, were carried out in 2009 by the SIDDHARTA collaboration at the DA{\Phi}NE electron-positron collider of LNF-INFN, combining the excellent quality kaon beam delivered by the collider with new experimental techniques, as fast and very precise X-ray detectors, like the Silicon Drift Detectors. The SIDDHARTA results triggered new theoretical work, which achieved major progress in the understanding of the low-energy strong interaction with strangeness reflected by the antikaon-nucleon scattering lengths calculated with the antikaon-proton amplitudes constrained by the SIDDHARTA data. The most important open question is the experimental determination of the hadronic energy shift and width of kaonic deuterium; presently, a major upgrade of the setup, SIDDHARTA-2, is being realized to reach this goal. In this paper, the results obtained in 2009 and the proposed SIDDHARTA-2 upgrades are presented.

   nucl-exEPJ Web Conf.(2018)·4 citations
4. 04*

   High-statistics measurement of the eta->3pi^0 decay at the Mainz Microtron

   S. Prakhov · S. Abt · P. Achenbach · P. Adlarson · F. Afzal · P. Aguar-Bartolomé · Z. Ahmed · J. Ahrens · J. R. M. Annand · H. J. Arends · K. Bantawa · M. Bashkanov and 76 other authors

   The largest, at the moment, statistics of 7x10^6 eta->3pi^0 decays, based on 6.2x10^7 eta mesons produced in the gamma p -> eta p reaction, has been accumulated by the A2 Collaboration at the Mainz Microtron, MAMI. It allowed a detailed study of the eta->3pi^0 dynamics beyond its conventional parametrization with just the quadratic slope parameter alpha and enabled, for the first time, a measurement of the second-order term and a better understanding of the cusp structure in the neutral decay. The present data are also compared to recent theoretical calculations that predict a nonlinear dependence along the quadratic distance from the Dalitz-plot center.

   ↳ hep-exnucl-exPRC(2018)·24 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.