Fri·Feb 19, 2021Friday·February 19, 2021

1. 01*

   Electron-Ion Collider in China

   Daniele P. Anderle🇨🇳 · Valerio Bertone🇫🇷 · Xu Cao🇨🇳 · Lei Chang · Ningbo Chang · Gu Chen · Xurong Chen · Zhuojun Chen · Zhufang Cui🇨🇳 · Lingyun Dai🇨🇳 · Weitian Deng🇨🇳 · Minghui Ding🇮🇹 and 90 other authors

   Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a polarization of $\sim$80%) and protons (with a polarization of $\sim$70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2-3) $\times$ 10${}^{33}$ cm${}^{-2}$ s${}^{-1}$. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC. The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies. This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.

   nucl-exhep-exhep-phnucl-thFront.Phys.(Beijing)(2021)·612 citations
2. 02*

   Correlation in formation of ${}^8$Be nuclei and $\alpha$-particles in fragmentation of relativistic nuclei

   A.A. Zaitsev🇷🇺 · D.A. Artemenkov🇷🇺 · V.V. Glagolev🇨🇿 · M.M. Chernyavsky · N.G. Peresadko · V.V. Rusakova🇷🇺 · P.I. Zarubin🇷🇺

   In the events of peripheral dissociation of relativistic nuclei in the nuclear track emulsion, it is possible to study the emerging ensembles of He and H nuclei, including those from decays of unstable ${}^8$Be and ${}^9$B nuclei, as well as the Hoyle state. These extremely short-lived states are identified by invariant masses calculated from the angles in 2$\alpha$-pairs, 2$\alpha p$- and 3$\alpha$-triplets in the approximation of conservation of momentum per nucleon of the primary nucleus. In the same approach, it is possible to search for more complex states. This paper explores the correlation between the formation of ${}^8$Be nuclei and the multiplicity of accompanying $\alpha$-particles in the dissociation of relativistic ${}^{16}$O, ${}^{22}$Ne, ${}^{28}$Si, and ${}^{197}$Au nuclei. On the above basis, estimates of this correlation are presented for the unstable ${}^9$B nucleus and the Hoyle state. The enhancement in the ${}^8$Be contribution to dissociation with the $\alpha$-particle multiplicity has been found. Decays of ${}^9$B nuclei and Hoyle states follow the same trend.

   nucl-exPLB(2021)·10 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.