Wed·Oct 26, 2022Wednesday·October 26, 2022

1. 01*

   First Measurement of $\Lambda$ Electroproduction off Nuclei in the Current and Target Fragmentation Regions

   T. Chetry · L. El Fassi · W.K. Brooks · R. Dupré · A. El Alaoui · K. Hafidi · P. Achenbach · K.P. Adhikari · Z. Akbar · W.R. Armstrong · M. Arratia · H. Atac and 142 other authors

   We report results of $\Lambda$ hyperon production in semi-inclusive deep-inelastic scattering off deuterium, carbon, iron, and lead targets obtained with the CLAS detector and the Continuous Electron Beam Accelerator Facility 5.014~GeV electron beam. These results represent the first measurements of the $\Lambda$ multiplicity ratio and transverse momentum broadening as a function of the energy fraction~($z$) in the current and target fragmentation regions. The multiplicity ratio exhibits a strong suppression at high~$z$~and~an enhancement at~low~$z$. The measured transverse momentum broadening is an order of magnitude greater than that seen for light mesons. This indicates that the propagating entity interacts very strongly with the nuclear medium, which suggests that propagation of diquark configurations in the nuclear medium takes place at least part of the time, even at high~$z$. The trends of these results are qualitatively described by the Giessen Boltzmann-Uehling-Uhlenbeck transport model, particularly for the multiplicity ratios. These observations will potentially open a new era of studies of the structure of the nucleon as well as of strange baryons.

   nucl-exhep-exPRL(2023)·9 citations
2. 02*

   Search for the chiral magnetic wave using anisotropic flow of identified particles at RHIC

   The STAR Collaboration

   The chiral magnetic wave (CMW) has been theorized to propagate in the deconfined nuclear medium formed in high-energy heavy-ion collisions, and to cause a difference in elliptic flow ($v_2$) between negatively and positively charged hadrons. Experimental data consistent with the CMW have been reported by the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC), based on the charge asymmetry dependence of the pion $v_2$ from Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 27 to 200 GeV. In this comprehensive study, we present the STAR measurements of elliptic flow and triangular flow of charged pions, along with the $v_2$ of charged kaons and protons, as a function of charge asymmetry in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 27, 39, 62.4 and 200 GeV. The slope parameters extracted from the linear dependence of the $v_2$ difference on charge asymmetry for different particle species are reported and compared in different centrality intervals. In addition, the slopes of $v_2$ for charged pions in small systems, \textit{i.e.}, $p$+Au and $d$+Au at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV, are also presented and compared with those in large systems, \textit{i.e.}, Au+Au at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV and U+U at 193 GeV. Our results provide new insights for the possible existence of the CMW, and further constrain the background contributions in heavy-ion collisions at RHIC energies.

   nucl-exPRC(2023)·13 citations
3. 03*

   Evidence of Antineutrinos from Distant Reactors using Pure Water at SNO+

   SNO+ Collaboration: A. Allega🇨🇦 · M. R. Anderson🇨🇦 · S. Andringa🇵🇹 · J. Antunes🇵🇹 · M. Askins🇺🇸 · D. J. Auty🇨🇦 · A. Bacon🇺🇸 · N. Barros🇵🇹 · F. Barao🇵🇹 · R. Bayes🇨🇦 · E. W. Beier🇺🇸 · T. S. Bezerra🇬🇧 and 103 other authors

   The SNO+ Collaboration reports the first evidence of reactor antineutrinos in a Cherenkov detector. The nearest nuclear reactors are located 240~km away in Ontario, Canada. This analysis uses events with energies lower than in any previous analysis with a large water Cherenkov detector. Two analytical methods are used to distinguish reactor antineutrinos from background events in 190 days of data and yield consistent evidence for antineutrinos with a combined significance of 3.5$\sigma$.

   nucl-exhep-exPRL(2023)·37 citations
4. 04*

   Characterizing the initial and final state effects of relativistic nuclear collisions

   Niseem Magdy🇺🇸

   The Multi-Phase Transport model (AMPT) is used to study the final state effects on the Symmetric Correlations (SC), Asymmetric Correlations (ASC), Normalized Symmetric Correlations (NSC), and Normalized Asymmetric Correlations (NASC) in Au+Au collisions at 200~GeV. The correlators' sensitivity to non-flow effects associated with long- and short-range non-flow correlations are also discussed using the HIJING model. The results indicate that SC, ASC, NSC, and NASC can give accompanying constraints for initial and final state effects. In addition, conducting further detailed experimental measurements spanning a broad range of collision systems and beam energies will serve as an additional constraint for the theoretical models' calculations.

   ↳ nucl-thhep-phnucl-exPRC(2023)·14 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.