Thu·Jan 16, 2020Thursday·January 16, 2020

1. 01*

   First glimpse of the $N=82$ shell closure below $Z=50$ from masses of neutron-rich cadmium isotopes and isomers

   V. Manea🇨🇭 · J. Karthein🇨🇭 · D. Atanasov🇩🇪 · M. Bender🇫🇷 · K. Blaum🇩🇪 · T. E. Cocolios🇧🇪 · S. Eliseev🇩🇪 · A. Herlert🇩🇪 · J. D. Holt🇨🇦 · W. J. Huang🇫🇷 · Yu. A. Litvinov🇩🇪 · D. Lunney🇫🇷 and 9 other authors

   We probe the $N=82$ nuclear shell closure by mass measurements of neutron-rich cadmium isotopes with the ISOLTRAP spectrometer at ISOLDE-CERN. The new mass of ${}^{132}$Cd offers the first value of the $N=82$, two-neutron shell gap below $Z=50$ and confirms the phenomenon of mutually enhanced magicity at ${}^{132}$Sn. Using the recently implemented phase-imaging ion-cyclotron-resonance method, the ordering of the low-lying isomers in ${}^{129}$Cd and their energies are determined. The new experimental findings are used to test large-scale shell-model, mean-field and beyond-mean-field calculations, as well as the ab initio valence-space in-medium similarity renormalization group.

   nucl-exnucl-thPRL(2020)·50 citations
2. 02*

   $K^{\ast }(892{)}^0$ meson production in inelastic p+p interactions at 158 GeV/$c$ beam momentum measured by NA61/SHINE at the CERN SPS

   NA61/SHINE Collaboration: A. Aduszkiewicz🇵🇱 · E.V. Andronov🇷🇺 · T. Antićić🇭🇷 · V. Babkin🇷🇺 · M. Baszczyk🇵🇱 · S. Bhosale🇵🇱 · A. Blondel🇨🇭 · M. Bogomilov🇧🇬 · A. Brandin🇷🇺 · A. Bravar🇨🇭 · W. Bryliński🇵🇱 · J. Brzychczyk🇵🇱 and 127 other authors

   The measurement of $K^{\ast }(892{)}^0$ resonance production via its $K^{+}{\pi }^{-}$ decay mode in inelastic p+p collisions at beam momentum 158 GeV/$c$ ($\sqrt{s_{NN}}=17.3$ GeV) is presented. The data were recorded by the NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The \textit{template} method was used to extract the $K^{\ast }(892{)}^0$ signal and double differential transverse momentum and rapidity spectra were obtained. The full phase-space mean multiplicity of $K^{\ast }(892{)}^0$ mesons was found to be $(78.44\pm 0.38(\mathrm{stat})\pm 6.0(\mathrm{sys}))\cdot 10^{-3}$. The NA61/SHINE results are compared with the EPOS1.99 and Hadron Resonance Gas models as well as with world data from p+p and nucleus-nucleus collisions.

   nucl-exEPJC(2020)·25 citations
3. 03*

   Studies of ${\eta }^{{(}^{\prime })}\pi$ Final States Using GlueX Data

   Colin Gleason (for the GlueX Collaboration)🇺🇸

   The primary goal of the GlueX experiment at Jefferson Lab is to search for and map the spectrum of light hybrid mesons. Many experiments have studied and reported evidence of exotic mesons decaying into $\eta \pi$ and ${\eta }^{\prime }\pi$ final states. With a large acceptance to both charged and neutral particles, GlueX has access to both the neutral, $\gamma p\to {\eta }^{{(}^{\prime })}{\pi }^{0}p$, and charged, $\gamma p\to {\eta }^{{(}^{\prime })}{\pi }^{-}{\Delta }^{++}$, exchanges. These proceedings will give an overview of the current studies being performed at GlueX in ${\eta }^{{(}^{\prime })}{\pi }^{-}$ final states. It will discuss early physics goals and outline the strategy for an amplitude analysis as GlueX begins its quest to illuminate the light hybrid meson spectrum.

   nucl-exhep-ex2 citations
4. 04*

   Spectrum and rearrangement decays of tetraquark states with four different flavors

   Jian-Bo Cheng🇨🇳 · Shi-Yuan Li🇨🇳 · Yan-Rui Liu🇨🇳 · Yu-Nan Liu🇨🇳 · Zong-Guo Si🇨🇳 · Tao Yao🇨🇳

   We have systematically investigated the mass spectrum and rearrangement decay properties of the exotic tetraquark states with four different flavors using a color-magnetic interaction model. Their masses are estimated by assuming that the $X(4140)$ is a $cs\bar{c}\bar{s}$ tetraquark state and their decay widths are obtained by assuming that the Hamiltonian for decay is a constant. According to the adopted method, we find that the most stable states are probably the isoscalar $bs\bar{u}\bar{d}$ and $cs\bar{u}\bar{d}$ with $J^P=0^{+}$ and $1^{+}$. The width for most unstable tetraquarks is about tens of MeVs, but that for unstable $cu\bar{s}\bar{d}$ and $cs\bar{u}\bar{d}$ can be around 100 MeV. For the $X(5568)$, our method cannot give consistent mass and width if it is a $bu\bar{s}\bar{d}$ tetraquark state. For the $I(J^P)=0(0^{+}),0(1^{+})$ double-heavy $T_{bc}=bc\bar{u}\bar{d}$ states, their widths can be several MeVs.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2020)·54 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.