Wed·Aug 10, 2022Wednesday·August 10, 2022

1. 01*

   Measurement of Light Nuclei Production in Heavy-ion Collisions by the STAR experiment

   Hui Liu (for the STAR Collaboration)🇨🇳

   In these proceedings, we present the measurements of centrality, transverse momentum and rapidity dependences of proton ($p$) and light nuclei ($d$ ($\overline{d}$), $t$, ${}^3\mathrm{He}$ ($\overline{{}^3\mathrm{He}}$), and ${}^4\mathrm{He}$) production in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 3 GeV, and isobaric (Ru+Ru and Zr+Zr) collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV. The compound yield ratios in central collisions at 3 GeV are found to be larger than the transport model calculations. Furthermore, the kinetic freeze-out parameters at 3 GeV show a different trend compared to those of light hadrons ($\pi$, $K$, $p$) at higher energies.

   nucl-exnucl-thActa Phys.Polon.Supp.(2023)·8 citations
2. 02*

   Measurements of groomed-jet substructure of charm jets tagged by ${\mathrm{D}}^0$ mesons in proton-proton collisions at $\sqrt{s}$ = 13 TeV

   ALICE Collaboration

   Understanding the role of parton mass and Casimir colour factors in the quantum chromodynamics parton shower represents an important step in characterising the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterise gluon emissions from heavy quarks. In this work, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed ${\mathrm{D}}^0$ meson. The measurement is made in proton-proton collisions at $\sqrt{s}$ = 13 TeV, in the low jet transverse-momentum interval of $15\le p_{\mathrm{T}}^{\mathrm{jet}\mathrm{ch}}<30$ GeV/$c$ where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.

   nucl-exhep-exPRL(2023)·27 citations
3. 03*

   Nuclear mass predictions with machine learning reaching the accuracy required by $r$-process studies

   Z. M. Niu🇨🇳 · H. Z. Liang🇯🇵

   Nuclear masses are predicted with the Bayesian neural networks by learning the mass surface of even-even nuclei and the correlation energies to their neighbouring nuclei. By keeping the known physics in various sophisticated mass models and performing the delicate design of neural networks, the proposed Bayesian machine learning (BML) mass model achieves an accuracy of $84$~keV, which crosses the accuracy threshold of the $100$~keV in the experimentally known region. It is also demonstrated the corresponding uncertainties of mass predictions are properly evaluated, while the uncertainties increase by about $50$~keV each step along the isotopic chains towards the unknown region. The shell structures in the known region are well described and several important features in the unknown region are predicted, such as the new magic numbers around $N=40$, the robustness of $N=82$ shell, the quenching of $N=126$ shell, and the smooth separation energies around $N=104$.

   ↳ nucl-thastro-ph.SRnucl-exPRC(2022)·100 citations
4. 04*

   Thermal fluctuations on the freeze-out surface of heavy-ion collisions and their impact on particle correlations

   Adrian Skasberg Aasen🇩🇪 · Stefan Floerchinger🇩🇪 · Giuliano Giacalone🇩🇪 · Deniz Guenduez🇩🇪

   Particle momentum distributions originating from a quark-gluon plasma as produced in high-energy nuclear collisions can be influenced by thermal fluctuations in fluid dynamic fields. We study this effect by generalizing the commonly used kinetic freeze-out prescription by allowing for small fluctuations around an average in fluid velocity, chemical potentials and temperature. This leads to the appearance of specific two-body momentum correlations. Combining a blast-wave parametrization of the kinetic freeze-out surface with the thermal correlation functions of an ideal resonance gas, we perform an exploratory study of angular net-charge correlations induced by thermal fluctuations around vanishing chemical potential. We note a diffusion of the near-side peak around $\Delta y=\Delta \varphi =0$ induced by variances of different chemical potentials, which could be investigated experimentally.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2023)·4 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.