Fri·Feb 3, 2023Friday·February 3, 2023

1. 01*

   Symmetry plane correlations in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV

   ALICE Collaboration

   A newly developed observable for correlations between symmetry planes, which characterize the direction of the anisotropic emission of produced particles, is measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with ALICE. This so-called Gaussian Estimator allows for the first time the study of these quantities without the influence of correlations between different flow amplitudes. The centrality dependence of various correlations between two, three and four symmetry planes is presented. The ordering of magnitude between these symmetry plane correlations is discussed and the results of the Gaussian Estimator are compared with measurements of previously used estimators. The results utilizing the new estimator lead to significantly smaller correlations than reported by studies using the Scalar Product method. Furthermore, the obtained symmetry plane correlations are compared to state-of-the-art hydrodynamic model calculations for the evolution of heavy-ion collisions. While the model predictions provide a qualitative description of the data, quantitative agreement is not always observed, particularly for correlators with significant non-linear response of the medium to initial state anisotropies of the collision system. As these results provide unique and independent information, their usage in future Bayesian analysis can further constrain our knowledge on the properties of the QCD matter produced in ultrarelativistic heavy-ion collisions.

   nucl-exhep-exEPJC(2023)·12 citations
2. 02*

   Searching for a dark matter particle with anti-protonic atoms

   M. Doser🇨🇭 · G. Farrar🇺🇸 · G. Kornakov🇵🇱

   A wide range of dark matter candidates have been proposed and are actively being searched for in a large number of experiments, both at high (TeV) and low (sub meV) energies. One dark matter candidate, a deeply bound $uuddss$ sexaquark, $S$, with mass $\sim 2$ GeV (having the same quark content as the hypothesized H-dibaryon, but long lived) is particularly difficult to explore experimentally. In this paper, we propose a scheme in which such a state could be produced at rest through the formation of $\bar{p}{-}^3$He antiprotonic atoms and their annihilation into $S$ + $K^{+}{K}^{+}{\pi }^{-}$, identified both through the unique tag of a S=+2, Q=+1 final state, as well as through full kinematic reconstruction of the final state recoiling against it.

   ↳ hep-phnucl-exnucl-thEPJC(2023)·7 citations
3. 03*

   Study of the $DK$ interaction with femtoscopic correlation functions

   Zhi-Wei Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳

   The $DK$ interaction in isospin zero is known to be attractive to such an extent that a bound state can be generated, which can be associated with the mysterious $D_{s0}^{\ast }(2317)$. In this work, we calculate the $DK$ femtoscopic correlation function in the coupled-channel framework for different source sizes that can directly probe the strongly attractive $DK$ interaction, which is otherwise inaccessible due to the unstable nature of $D$ and $K$ mesons, and therefore can help elucidate the nature of $D_{s0}^{\ast }(2317)$. We further generalize the study of source size dependence to various interactions, ranging from repulsive, weakly attractive, moderately attractive, and strongly attractive, in a square-well model. We hope that our study can motivate future experimental measurements of the $DK$ correlation function and other interactions relevant to the understanding of the nature of the many exotic hadrons discovered so far.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2023)·68 citations
4. 04*

   ALICE upgrades during the LHC Long Shutdown 2

   ALICE Collaboration

   A Large Ion Collider Experiment (ALICE) has been conceived and constructed as a heavy-ion experiment at the LHC. During LHC Runs 1 and 2, it has produced a wide range of physics results using all collision systems available at the LHC. In order to best exploit new physics opportunities opening up with the upgraded LHC and new detector technologies, the experiment has undergone a major upgrade during the LHC Long Shutdown 2 (2019-2022). This comprises the move to continuous readout, the complete overhaul of core detectors, as well as a new online event processing farm with a redesigned online-offline software framework. These improvements will allow to record Pb-Pb collisions at rates up to 50 kHz, while ensuring sensitivity for signals without a triggerable signature.

   ↳ physics.ins-dethep-exnucl-exJINST(2024)·188 citations
5. 05*

   Thermal and atomic effects on coupled-channels heavy-ion fusion

   Iain Lee🇬🇧 · Gilbert Gosselin🇫🇷 · Alexis Diaz-Torres🇬🇧

   Stellar nuclear fusion reactions take place in a hot, dense plasma within stars. To account for the effect of these environments, the theory of open quantum systems is used to conduct pioneering studies of thermal and atomic effects on fusion probability at a broad range of temperatures and densities. Since low-lying excited states are more likely to be populated at stellar temperatures and increase nuclear plasma interaction rates, a 188Os nucleus was used as a target that interacts with an inert 16O projectile. Key results showed thermal effects yield an average increase in fusion probability of 15.5% and 36.9% for our test nuclei at temperatures of 0.1 and 0.5 MeV respectively, compared to calculations at zero temperature. Thermal effects could be tested in a laboratory using targets prepared in excited states as envisaged in facilities exploiting laser-nucleus interactions.

   ↳ nucl-thastro-ph.SRnucl-exPRC(2023)·6 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.