Thu·Feb 27, 2025Thursday·February 27, 2025

1. 01*

   Exploring the Onset of Collectivity Approaching N=40 through Manganese Masses

   C. Chambers🇨🇦 · M.P. Reiter🇬🇧 · A.T. Gallant🇺🇸 · M. Yavor🇷🇺 · C. Andreoiu🇨🇦 · C. Babcock🇨🇦 · J. Bergmann🇩🇪 · T. Dickel🇩🇪 · J. Dilling🇨🇦 · E. Dunling🇨🇦 · G. Gwinner🇨🇦 · Z. Hockenbery🇨🇦 and 15 other authors

   Isotopes in the region of the nuclear chart below ${}^{68}\mathrm{Ni}$ have been the subject of intense experimental and theoretical effort due to the potential onset of a new ``island of inversion'' when crossing the harmonic oscillator subshell closure at $N=40$. We have measured the masses of ${}^{64-68}\text{Mn}$ using TITAN's multiple-reflection time-of-flight mass spectrometer, resulting in the first precision mass measurements of ${}^{67}\mathrm{Mn}$ and ${}^{68}\mathrm{Mn}$. These results are compared to \textit{ab initio} calculations and modern shell model calculations and show an increase in collectivity approaching $N=40$.

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

   Recent results on ultra-peripheral collisions with the ALICE experiment

   David Grund (for the ALICE Collaboration)🇨🇿

   Recent measurements of J/$\psi$ photoproduction based on data from ultra-peripheral Pb-Pb and p-Pb collisions recorded by the ALICE experiment during Run 2 of the LHC are presented. Photoproduction as a photon-induced process is sensitive to the structure of hadrons and the results are of great importance for a better understanding of how gluon saturation and nuclear shadowing work in high-energy quantum chromodynamics. The energy evolution of coherent J/$\psi$ photoproduction has been measured, indicating a strong suppression of nuclear gluon densities at high energies. The energy dependence has also been measured for exclusive and dissociative J/$\psi$ production off the proton. The average distribution of the nuclear gluon matter in transverse plane, and fluctuations thereof, have been studied for the first time using the measurements of the dependence of coherent and incoherent J/$\psi$ photoproduction on the transferred momentum $|t|$. Lastly, the data from coherent photoproduction of J/$\psi$ in Pb-Pb ultra-peripheral collisions have been found to be compatible with a transverse polarization.

   nucl-exPhys.Proc.UPC(2024)·2 citations
3. 03*

   Exploring $\beta$ decay and $\beta$-delayed neutron emission in exotic ${}^{46,47}$Cl isotopes

   Vandana Tripathi🇺🇸 · B. Longfellow🇺🇸 · A. Volya🇺🇸 · E. Rubino🇺🇸 · C. Benetti · J. F. Perello · S. L. Tabor · S. N. Liddick🇺🇸 · P. C. Bender🇺🇸 · M. P. Carpenter🇺🇸 · J. J. Carroll🇺🇸 · A. Chester🇺🇸 and 15 other authors

   In this paper, ${\beta }^{-}$ and $\beta$-delayed neutron decays of ${}^{46,47}$Cl are reported from an experiment carried out at the National Superconducting Cyclotron Laboratory using the Beta Counting System. The half-lives of both ${}^{46}$Cl and ${}^{47}$Cl were extracted. Based on the delayed $\gamma$-ray transitions observed, the level structure of $N=28$ ${}^{46}$Ar was determined. Completely different sets of excited states above the first $2^{+}$ state in ${}^{46}$Ar were populated in the ${}^{46}$Cl $\beta 0n$ and ${}^{47}$Cl $\beta 1n$ decay channels. Two new $\gamma$-ray transitions in ${}^{47}$Ar were identified from the very weak ${}^{47}$Cl $\beta 0n$ decay. Furthermore, ${}^{46}$Cl $\beta 1n$ and ${}^{47}$Cl $\beta 2n$ were also observed to yield different population patterns for levels in ${}^{45}$Ar, including states of different parities. The experimental results allow us to address some of the open questions related to the delayed neutron emission process. For isotopes with large neutron excess and high $Q_{\beta }$ values, delayed neutron emission remains an important decay mode and can be utilized as a powerful spectroscopic tool. Experimental results were compared with shell-model calculations using the FSU and $V_{MU}$ effective interactions.

   nucl-exPRC(2025)·2 citations
4. 04*

   Ab Initio Calculations of the Carbon and Oxygen Isotopes: Energies, Correlations, and Superfluid Pairing

   Young-Ho Song · Myungkuk Kim · Youngman Kim🇰🇷 · Kihyeon Cho🇰🇷 · Serdar Elhatisari🇹🇷 · Dean Lee🇺🇸 · Yuan-Zhuo Ma🇺🇸 · Ulf-G. Meißner🇩🇪

   We perform \textit{ab initio} nuclear lattice calculations of the neutron-rich carbon and oxygen isotopes using high-fidelity chiral interactions. We find good agreement with the observed binding energies and compute correlations associated with each two-nucleon interaction channel. For the isospin $T=1$ channels, we show that the dependence on $T_z$ provides a measure of the correlations among the extra neutrons in the neutron-rich nuclei. For the spin-singlet S-wave channel, we observe that any paired neutron interacts with the nuclear core as well as its neutron pair partner, while any unpaired neutron interacts primarily with only the nuclear core. For the other partial waves, the correlations among the extra neutrons grow more slowly and smoothly with the number of neutrons. These general patterns are observed in both the carbon and oxygen isotopes and may be universal features that appear in many neutron-rich nuclei.

   ↳ nucl-thhep-phnucl-exPLB(2026)·8 citations
5. 05*

   Forbidden non-unique ${\beta }^{-}$ transitions and $g_A$-sensitive electron spectral-shapes

   Archana Saxena · Praveen C. Srivastava🇮🇳

   In the present work, we have done a systematic study of beta decay properties such as electron spectral-shapes, shape factors, and log$ft$ values for the higher forbidden non-unique ${\beta }^{-}$ transitions in the mass region A=85-123. We have performed the nuclear shell model (SM) calculations to explore the sensitivity of the electron spectral-shapes for different axial-vector coupling constants $g_A=0.8-1.27$. The effective interactions GWBXG, G-matrix, SNET and SN100PN are used for different model spaces. In the present work, we have computed the electron spectral-shapes of ${}^{85}$Br, ${}^{87}$Rb, ${}^{93}$Zr, ${}^{97}$Zr, ${}^{101}$Mo, ${}^{115}$Cd, ${}^{117}$Cd, ${}^{119}$In, ${}^{123}$Sn and ${}^{135}$Cs by constraining the small relativistic nuclear matrix element from conserved vector-current hypothesis (CVC). We have found that the electron spectral-shapes are strongly dependent on $g_A$ except the second forbidden non-unique ${\beta }^{-}$ transition ${}^{93}$Zr.

   ↳ nucl-thnucl-exPRC(2025)·0 citations
6. 06*

   A hybrid model for multi-particle production and multi-fragment emission in electron-nucleus collisions at the forthcoming Electron-Ion Collider

   Ting-Ting Duan🇨🇳 · Sahanaa Büriechin🇨🇳 · Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

   To present a prediction of the multi-particle production and multi-fragment emission in electron-nucleus ($eA$) collisions at the forthcoming Electron-Ion Collider (EIC), a simple hybrid model which is based on the multi-source thermal model and the ideal gas model is proposed in this article. According to the hybrid model, some statistical laws such as the two-component Erlang distribution and others are presented, which means a two-source production. These statistical laws are hopeful to describe the bulk properties of multiple particles produced in the scattering of electron-nucleon ($eN$) and multiple fragments emitted in the fragmentation of excited residual nucleus. Although both the scattering and fragmentation can occur in $eA$ collisions at the EIC, their two-sources are different. In $eN$ scattering, the multiple particles come from the soft excitation and hard scattering processes respectively, which are classified as two different types of events. In nuclear fragmentation, the multiple fragments come from the cold and hot sources which exist in the same excited nucleus.

   ↳ hep-phhep-exnucl-exnucl-thMod.Phys.Lett.A(2025)·0 citations
7. 07*

   Rescattering effects on spin-interference for ${\rho }^0$ photoproduction in heavy-ion collisions

   Yusong Wang🇨🇳 · Xinbai Li🇨🇳 · Ziyang Li🇨🇳 · Zebo Tang🇨🇳 · Xin Wu🇨🇳 · Wangmei Zha🇨🇳

   Recent measurements by various experiments in ultra-peripheral collisions have observed spin-interference in ${\rho }^0$ photoproduction, marking a breakthrough in Fermi-scale quantum interference experiments. Building on this, STAR extended the measurement to hadronic heavy-ion collisions, where significant rescattering effects on ${\rho }^0$ mesons were expected. In this study, we investigate how these rescattering effects influence the measurement of spin-interference. By embedding ${\rho }^0$ mesons produced via photoproduction, modeled by the Vector Meson Dominance model, into the Ultrarelativistic Quantum Molecular Dynamics framework, we estimate the impact on the $\cos 2\varphi$ and $\cos 4\varphi$ modulations, where $\varphi$ is the angle between ${\rho }^0$ and one of the daughters' (${\pi }^{\pm }$) transverse momentum. The results indicate a significant suppression of the $\cos 2\varphi$ modulation, while the $\cos 4\varphi$ modulation remains largely unaffected, which provides insight for understanding the difference due to rescattering effects between experimental measurements and theoretical predictions for ${\rho }^0$ photoproduction in heavy-ion collisions.

   ↳ nucl-thhep-exnucl-exPRC(2025)·0 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.