Mon·Aug 19, 2024Monday·August 19, 2024

1. 01*

   Coulomb Excitation of ${}^{80}$Sr and the limits of the $N=Z=40$ island of deformation

   R. Russell🇬🇧 · J. Heery · J. Henderson🇬🇧 · R. Wadsworth🇬🇧 · K. Kaneko · N. Shimizu🇯🇵 · T. Mizusaki · Y. Sun🇨🇳 · C. Andreoiu🇨🇦 · D. W. Annen · A. A. Avaa · G. C. Ball and 24 other authors

   The region of $N\approx Z\approx 40$ has long been associated with strongly deformed nuclear configurations. The presence of this strong deformation was recently confirmed through lifetime measurements in $N\approx Z$ Sr and Zr nuclei. Theoretically, however, these nuclei present a challenge due to the vast valence space required to incorporate all deformation driving interactions. Recent state-of-the-art predictions indicate a near axial prolate deformation for $N=Z$ and $N=Z+2$ nuclei between $N=Z=36$ and $N=Z=40$. In this work we investigate the shores of this island of deformation through a sub-barrier Coulomb excitation study of the $N=Z+4$ nucleus, \textsuperscript{80}Sr. Extracting a spectroscopic quadrupole moment of $Q_s(2_1^{+})=0.45_{-0.88}^{+0.83}$~eb, we find that \textsuperscript{80}Sr is inconsistent with significant axial prolate deformation. This indicates that the predicted region of strong prolate deformation around $N=Z=40$ is tightly constrained to the quartet of nuclei: \textsuperscript{76,78}Sr and \textsuperscript{78,80}Zr.

   nucl-exnucl-thPRC(2025)·0 citations
2. 02*

   Search for the jet-induced diffusion wake in the quark-gluon plasma via measurements of jet-track correlations in photon-jet events in Pb+Pb collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$ = 5.02 TeV with the ATLAS detector

   ATLAS Collaboration

   This paper presents a measurement of jet-track correlations in photon-jet events, using 1.72 nb${}^{-1}$ of Pb+Pb data at $\sqrt{s_{\text{NN}}}$ = 5.02 TeV recorded with the ATLAS detector at the LHC. Events with energetic photon-jet pairs are selected, where the photon and jet are approximately back-to-back in azimuth. The angular correlation between jets and charged-particle tracks with transverse momentum ($p_{\text{T}}$) in the range 0.5-2.0 GeV in the hemisphere opposite to the jet, $|\Delta \varphi \text{(jet,track)}|>\pi /2$, is measured as a function of their relative pseudorapidity difference, $|\Delta \eta \text{(jet,track)}|$. In central Pb+Pb collisions, these correlations are predicted to be sensitive to the diffusion wake in the quark-gluon plasma resulting from the lost energy of high-$p_{\text{T}}$ partons traversing the plasma, with a characteristic modification as a function of $|\Delta \eta \text{(jet,track)}|$. The correlations are examined with different selections on the jet-to-photon $p_{\text{T}}$ ratio to select events with different degrees of energy loss. No diffusion wake signal is observed within the current sensitivity and upper limits at 95% confidence level on the diffusion wake amplitude are reported.

   nucl-exhep-exPRC(2025)·22 citations
3. 03*

   Factorized QED Contribution to Lepton-Hadron DIS

   Justin Cammarota🇺🇸 · Jian-Wei Qiu🇺🇸 · Kazuhiro Watanabe🇯🇵 · Jia-Yue Zhang🇺🇸

   We present the first calculation of next-to-leading order (NLO) factorized QED contributions to the short-distance hard coefficients of inclusive lepton-hadron deep inelastic scattering (DIS) in a joint QCD and QED factorization approach. We demonstrate how the joint factorization consistently factorize all perturbative collinear sensitivities of partonic scattering in both QCD and QED into corresponding universal hadron and lepton distribution functions without the need of any parameters other than the standard factorization scale. We discuss the necessary modification to DGLAP-type evolution of the parton and lepton distribution functions in this joint factorization approach. We also discuss the potential impact of this joint factorization approach on the extraction of partonic information from lepton-hadron DIS.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2025)·4 citations
4. 04*

   Multimessenger study of baryon-charged QCD matter in heavy-ion collisions

   Lipei Du🇨🇦

   Multimessenger studies of heavy-ion collisions, using hadrons and electromagnetic probes, can reveal the properties of the created QCD matter from different perspectives. This study calculates the thermal dilepton invariant mass spectra and thermal photon transverse momentum spectra in Au+Au collisions at low beam energies from the Beam Energy Scan program, using a (3+1)-dimensional multistage hydrodynamic model calibrated by rapidity-dependent hadronic distributions. The effects of thermodynamic rapidity variation, baryon chemical potential, and fluid expansion on the spectra are explored. Methods for extracting temperature from photon and dilepton spectra are examined by comparison with the underlying hydrodynamic temperature. The possibility of combining photon and dilepton spectra to extract radial flow is also investigated. This study provides insights into measuring the thermodynamic properties of the created systems in heavy-ion collisions using multiple messengers through two fundamental interactions within the same framework.

   ↳ nucl-thhep-exhep-phnucl-exPLB(2025)·13 citations
5. 05*

   Sputtering of targets in high-intensity heavy-ion beam experiments

   R. N. Sagaidak

   Based on available models and experimental data, the sputtering of target atoms in long-term experiments with intense heavy ion (HI) beams has been considered. The experiments on the synthesis of superheavy nuclei (SHN), which are carried out in laboratories around the world, are examples of such experiments encountering the target atoms sputtering in specific conditions. Rotating wheels with a relatively large target annulus area are used in these experiments to reduce the temperature and radiation loads on the target. Large areas of rotating targets allow one to reduce the sputtering yields of target atoms significantly. The question arises about the reliability of these yields in experiments on the synthesis of SHN with Z > 118. These nuclei can be produced with extremely low cross sections, requiring HI beam doses exceeding 1020 particles passed through the target to observe several decay events of the thus synthesized SHN. Estimates based on approximations and simulations considered in this work are presented and compared with some data on actinide target sputtering obtained in experiments performed on the synthesis of SHN.

   ↳ physics.atom-phnucl-exphysics.ins-det0 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.