Thu·Nov 10, 2022Thursday·November 10, 2022

1. 01*

   Future ALICE upgrades for Run 4 and Beyond

   H. Sebastian Scheid (for the ALICE Collaboration)🇩🇪

   For Run 4, ALICE is pioneering the construction of truly cylindrical tracking layers, which will improve the measurements of heavy-flavour hadrons and dielectrons. In addition, a Forward Calorimeter (FoCal) for the measurement of direct photons is being developed to access the gluon distributions of nucleons and nuclei at low $x$. For Run 5 and beyond, ALICE 3 is proposed. It combines a unique high-resolution vertex detector with a silicon pixel tracker and modern particle identification solutions over a large acceptance. This will permit heavy-flavour and dielectron measurements with unprecedented precision to access fundamental properties and dynamics of the quark-gluon plasma (QGP). We will discuss the upgrade plans, report on R\&D results for ITS3 and FoCal, and present the requirements and concepts for ALICE 3.

   nucl-exhep-exActa Phys.Polon.Supp.(2023)·2 citations
2. 02*

   Faddeev fixed-center approximation to the $\eta K^{\ast }{\bar{K}}^{\ast }$, $\pi K^{\ast }{\bar{K}}^{\ast }$ and $K{K}^{\ast }{\bar{K}}^{\ast }$ systems

   Qing-Hua Shen🇨🇳 · Ju-Jun Xie🇨🇳

   The three-body $\eta K^{\ast }{\bar{K}}^{\ast }$, $\pi K^{\ast }{\bar{K}}^{\ast }$ and $K{K}^{\ast }{\bar{K}}^{\ast }$ systems are investigated within the framework of fixed-center approximation to the Faddeev equations, where $K^{\ast }{\bar{K}}^{\ast }$ is treated as the scalar meson $f_0(1710)$. The interactions between $\pi$, $\eta$, $K$ and $K^{\ast }$ are taking from the chiral unitary approach. By scattering the $\eta$ meson on the clusterized $(K^{\ast }{\bar{K}}^{\ast }{)}_{f_0(1710)}$ system, we find a peak in the modulus squared of the three-body scattering amplitude and it can be associated as a bound state with quantum numbers $I^G(J^{PC})=0^{+}(0^{-+})$. Its mass and width are around 2054 MeV and 60 MeV, respectively. This state could be associated to the $\eta (2100)$ meson. For the $\pi (K^{\ast }{\bar{K}}^{\ast }{)}_{f_0(1710)}$ scattering, we find a bump structure around 1900-2000 MeV with quantum numbers $1^{-}(0^{-+})$. While for the $K{K}^{\ast }{\bar{K}}^{\ast }{)}_{f_0(1710)}$ system, there are three structures. One of them is much stable and its mass is about 2130 MeV. It is expected that these theoretical predictions here could be tested by future experimental measurements, such as by the BESIII, BelleII and LHCb collaborations.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2023)·5 citations
3. 03*

   Testing the phase transition parameters inside neutron stars with the production of protons and lambdas in relativistic heavy-ion collisions

   Ang Li🇨🇳 · Gao-Chan Yong🇨🇳 · Ying-Xun Zhang🇨🇳

   We demonstrate the consistency of the quark deconfinement phase transition parameters in the beta-stable neutron star matter and in the nearly symmetric nuclear matter formed in heavy-ion collisions (HICs). We investigate the proton and $\Lambda$ flow in Au+Au collisions at 3 and 4.5 GeV/nucleon incident beam energies with the pure hadron cascade version of a multi-phase transport model. The phase transition in HICs and neutron stars is described based on a class of hybrid equations of state from the quark mean-field model for the hadronic phase and a constant-speed-of-sound parametrization for the high-density quark phase. The measurements of the anisotropic proton flow at 3 GeV/nucleon by the STAR collaboration favor a relatively low phase transition density lower than $\sim 2.5$ times saturation density indicated by the gravitational wave and electromagnetic observations of neutron stars. And the proton flow data at the higher energy of 4.5 GeV/nucleon can be used to effectively constrain the softness of high-density quark matter equations of state. Finally, compared to the proton flow, the $\Lambda$ flow is found to be less sensitive and not constraining to the equations of state.

   ↳ nucl-thastro-ph.HEnucl-exPRD(2023)·24 citations
4. 04*

   Calibration sources for the LEGEND-200 experiment

   L. Baudis🇨🇭 · G. Benato🇮🇹 · E. M. Bond🇺🇸 · P.-J. Chiu🇨🇭 · S. R. Elliott🇺🇸 · R. Massarczyk🇺🇸 · S. Meijer🇺🇸 · Y. Müller🇨🇭

   In the search for a monochromatic peak as the signature of neutrinoless double beta decay an excellent energy resolution and an ultra-low background around the $Q$-value of the decay are essential. The LEGEND-200 experiment performs such a search with high-purity germanium detectors enriched in ${}^{76}$Ge immersed in liquid argon. To determine and monitor the stability of the energy scale and resolution of the germanium diodes, custom-made, low-neutron emission ${}^{228}$Th sources are regularly deployed in the vicinity of the crystals. Here we describe the production process of the 17 sources available for installation in the experiment, the measurements of their alpha- and gamma-activities, as well as the determination of the neutron emission rates with a low-background LiI(Eu) detector operated deep underground. With a flux of \left( 4.27 \pm 0.60_{\rm stat} \pm 0.92_{\rm syst} \right) \times 10^{-4} ~\text{n / (kBq\cdots)}, approximately one order of magnitude below that of commercial sources, the neutron-induced background rate, mainly from the activation of ${}^{76}$Ge, is negligible compared to other background sources in LEGEND-200.

   ↳ physics.ins-detnucl-exJINST(2023)·5 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.