Thu·May 22, 2025Thursday·May 22, 2025

1. 01*

   Reduction in nuclear size and quadrupole deformation of high-spin isomers of 127,129In

   A.R. Vernon🇬🇧 · C.L. Binnersley🇬🇧 · R.F. Garcia Ruiz🇺🇸 · K.M. Lynch🇬🇧 · T. Miyagi🇩🇪 · J. Billowes🇬🇧 · M.L. Bissell🇬🇧 · T.E. Cocolios🇧🇪 · J.P. Delaroche🇫🇷 · J. Dobaczewski🇬🇧 · M. Dupuis🇫🇷 · K.T. Flanagan🇬🇧 and 20 other authors

   We employed laser spectroscopy of atomic transitions to measure the nuclear charge radii and electromagnetic properties of the high-spin isomeric states in neutron-rich indium isotopes (Z = 49) near the closed proton and neutron shells at Z = 50 and N = 82. Our data reveal a reduction in the nuclear charge radius and intrinsic quadrupole moment when protons and neutrons are fully aligned in 129In(N = 80), to form the high spin isomer. Such a reduction is not observed in 127In(N = 78), where more complex configurations can be formed by the existence of four neutron-holes. These observations are not consistently described by nuclear theory.

   nucl-exnucl-thphysics.atom-phPRL(2025)·3 citations
2. 02*

   Probing the quantum phase transition around $N\approx 60$ via mass measurements of technetium isotopes

   J. Ruotsalainen🇫🇮 · A. Jaries🇫🇮 · M. Stryjczyk🇫🇮 · A. Kankainen🇫🇮 · B. Andel🇸🇰 · M. Araszkiewicz🇵🇱 · O. Beliuskina🇫🇮 · A. Bruce🇬🇧 · S. Cannarozzo🇸🇪 · S. Chinthakayala🇫🇮 · S. Doshi🇬🇧 · T. Eronen🇫🇮 and 19 other authors

   The masses of neutron-rich ${}^{104-106}$Tc isotopes were measured using the JYFLTRAP double Penning trap and found to deviate from the Atomic Mass Evaluation 2020 by $-79(25)$, $40(12)$ and $94(41)$ keV, respectively. In the case of ${}^{105,106}$Tc, the updated $Q_{\beta }$ values are in agreement with a previous JYFLTRAP measurement, disagreeing with the values from the mass evaluation. The new mass values result in a more linear trend in two-neutron separation energies indicating that technetium ($Z=43$) isotopes around $N\approx 60$ are not a part of the island of shape coexistence around ${}^{100}$Zr${}_{60}$.

   nucl-exPRC(2025)·0 citations
3. 03*

   Low-energy ${}^{12}$C continuum states in three-$\alpha$ model

   Souichi Ishikawa

   The electric multipole strength distributions for transitions from the ${}^{12}\mathrm{C}(0_1^{+})$ ground state to $3\alpha$ ($0^{+}$, $1^{-}$, $2^{+}$, and $3^{-}$) continuum states are studied in terms of $3\alpha$ model. Several sets of the $3\alpha$ Hamiltonian are introduced phenomenologically with conventional $\alpha$-$\alpha$ interaction potentials and $3\alpha$ potentials with different range parameters. The transition strength distributions are obtained from wave functions of $3\alpha$ bound- and continuum states calculated by the Faddeev three-body formalism. From these strength distributions, the resonance parameters (energy, $3\alpha$-decay width, and transition strength) of $3\alpha$ resonance states are extracted. Dependencies of these observables on interaction potential models are studied to examine the introduced interaction models. Using the transition strength distributions, excitation-energy spectra in the ${}^{12}\mathrm{C}(\alpha ,{\alpha }^{\prime })3\alpha$ reaction are calculated to compare with experimental data.

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

   Exploring Event-by-Event $p_{\mathrm{T}}$ Fluctuations in pp Collisions at $\sqrt{s}=13$ TeV: An Insight from ALICE

   Bushra Ali (for the ALICE Collaboration)🇮🇳

   Event-by-event fluctuations of the mean transverse momentum ($p_{\mathrm{T}}$) of relativistic charged particles are analyzed using the two-particle correlator $\sqrt{C_m}/M(p_{\mathrm{T}}{)}_m$, which quantifies the correlations strength in units of the mean $p_{\mathrm{T}}$ in proton-proton collision at $\sqrt{s}=13$ TeV in ALICE both for minimum bias and and high-multiplicity triggered events. The non-monotonic variations in $p_{\mathrm{T}}$ correlations with changing energy could serve as a signature of QGP formation. A comprehensive investigation across soft-, intermediate-, and hard-$p_{\mathrm{T}}$ regions could provide crucial insights into both equilibrium (e.g., thermal radial flow) and non-equilibrium (e.g., jet/minijet) contributions to $p_{\mathrm{T}}$ fluctuations. The dependence of the correlator on particle multiplicity for different $p_{\mathrm{T}}$ window widths and positions is explored. The correlator values are found to decrease with increasing charged particle density, following a power-law behavior similar to observations in both small and large systems at lower energies. Additionally, the influence of $p_{\mathrm{T}}$ range on the power-law coefficient is studied and results are compared with predictions from Monte Carlo models, such as PYTHIA (pQCD string model) and EPOS (core-corona model), to enhance understanding of the underlying mechanisms driving $p_{\mathrm{T}}$ fluctuations.

   ↳ hep-exnucl-ex1 citation
5. 05*

   Enhancing the creation of elements in laser-assisted heavy-ion fusion reactions

   Nicholas Thomson · Laura Moschini · Alexis Diaz-Torres🇬🇧

   Low-energy fusion of heavy ions is a fascinating coupling-assisted quantum tunnelling problem, whose understanding is crucial for advancing the synthesis of new elements and isotopes. Quantum dynamical coupled-channels calculations of laser-assisted ${}^{16}$O + ${}^{238}$U fusion are presented for both a central collision and the total fusion cross-sections, suggesting that laser-nucleus interaction can enhance the average ${}^{16}$O + ${}^{238}$U fusion probability by $6-60\%$ at subbarrier energies using quasi-static laser fields of intensity $10^{27}-10^{29}$ Wcm${}^{-2}$ and photon's energy of $1$ eV. Femtosecond laser pulses are shown to reduce this enhancement by many orders of magnitude.

   ↳ nucl-thnucl-exPRC(2025)·1 citation
6. 06*

   Polarizing 3He via Metastability Exchange Optical Pumping Using a 1.2 mbar Sealed Cell at Magnetic Fields up to 5 T

   Pushpa Pandey · Hao Lu🇺🇸 · James Maxwell🇺🇸 · James Brock · Christopher Keith🇺🇸 · Xiaqing Li🇨🇳 · Richard Milner🇺🇸 · Dien Nguyen

   We report high nuclear polarization of 1.2 mbar 3He gas in a sealed cell in magnetic fields up to 5 T using Metastability Exchange Optical Pumping (MEOP). The creation of a highly polarized 3He gas target for use in the 5 T field of Jefferson Lab's CLAS12 spectrometer would enable new studies of spin-dependent asymmetries on the neutron. A systematic study was conducted to evaluate the effects of discharge intensity, pump laser power, and optical pumping transition schemes on nuclear polarization and pumping rates. Steady-state polarizations up to 86 % in magnetic fields between 2 and 5 T were achieved, with a discharge-on relaxation time of 898 s at 5 T. These results underscore the potential of MEOP for high-field applications in nuclear physics experiments.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2026)·1 citation

* 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.