Tue·Aug 13, 2024Tuesday·August 13, 2024

1. 01*

   Measurement of the Isomeric Yield Ratio for Zirconium-88 Thermal Neutron Absorption

   Isaac Kelly · Will Flanagan · Jacob Moldenhauer · William Charlton · Joseph Lapka · Donald Nolting

   In light of the recently observed 800,000 barn thermal neutron absorption cross section of zirconium-88, this work investigates the fraction (isomeric yield ratio) of metastable versus ground state production of zirconium-89 and implications for ongoing measurements around zirconium-88 neutron absorption. The metastable state of zirconium-89 resides at 588 keV above the ground state with a half life of 4.2 minutes. A 5 $\mu$Ci zirconium-88 sample was irradiated for 10 minutes in the core of a TRIGA Mark II nuclear research reactor and measured with a high purity germanium detector 3 minutes after irradiation. The isomeric yield ratio was measured to be 74.9$\pm$0.6\%.

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

   Prominent bump in the two-neutron separation energies of neutron-rich lanthanum isotopes revealed by high-precision mass spectrometry

   A. Jaries🇫🇮 · M. Stryjczyk🇫🇮 · A. Kankainen🇫🇮 · T. Eronen🇫🇮 · O. Beliuskina🇫🇮 · T. Dickel🇩🇪 · M. Flayol🇫🇷 · Z. Ge🇫🇮 · M. Hukkanen🇫🇮 · M. Mougeot🇫🇮 · S. Nikas🇫🇮 · I. Pohjalainen🇫🇮 and 4 other authors

   We report on high-precision atomic mass measurements of ${}^{148\text{-}153}$La and ${}^{151}$Ce performed with the JYFLTRAP double Penning trap using the Phase-Imaging Ion-Cyclotron-Resonance technique. The masses of ${}^{152,153}$La were experimentally determined for the first time. We confirm the sharp kink in the two-neutron separation energies at the neutron number $N=93$ in the cerium ($Z=58$) isotopic chain. Our precision mass measurements of the most exotic neutron-rich lanthanum ($Z=57$) isotopes reveal a sudden increase in two-neutron separation energies from $N=92$ to $N=93$. Unlike in the cerium isotopic chain, the kink is not sharp but extends to $N=94$ forming a prominent bump. The gain in energy is about 0.4 MeV, making it one of the strongest changes in two-neutron separation energies over the whole chart of nuclides, away from nuclear shell closures. The results call for further studies to elucidate the structure of neutron-rich lanthanum isotopes.

   nucl-exnucl-thPRL(2025)·7 citations
3. 03*

   Modified Trento initial condition and its impact on collective flows and global polarization in Cu+Au collisions

   Ze-Fang Jiang🇨🇳 · Shanshan Cao🇨🇳 · Ben-Wei Zhang🇨🇳

   Collective flow coefficients and spin polarization are valuable probes of the geometry and flow velocity field of the quark-gluon plasma (QGP) produced in relativistic heavy-ion collisions. Using a modified TRENTo initial condition coupled to a (3+1)-dimensional (D) viscous hydrodynamic model CLVisc, we study the directed flow and elliptic flow coefficients of hadrons, together with the global polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons in asymmetric Cu+Au collisions. We extend the 2D TRENTo model to the 3D space, and find that the initial tilted geometry of the QGP fireball with respect to the longitudinal direction leads to a decrease of directed flow from positive to negative values with increasing pseudorapidity, an enhancement of elliptic flow at forward and backward pseudorapidities, and a non-monotonic dependence of global polarization on the transverse momentum of hyperons. The initial longitudinal flow velocity gradient further enhances the values of directed flow and global polarization. Our model calculation provides a satisfactory description of the rapidity, transverse momentum, and centrality dependences of the directed flow of charged hadrons in Cu+Au collisions for the first time, and proposes that such asymmetric heavy-ion collisions create a better environment for studying the initial tilted geometry and longitudinal flow field of the QGP than symmetric Au+Au collisions do.

   ↳ nucl-thhep-phnucl-exPRC(2025)·3 citations
4. 04*

   Testing for coherence and nonstandard neutrino interactions in COHERENT data

   Jiajun Liao🇨🇳 · Danny Marfatia🇺🇸 · Jiajie Zhang🇨🇳

   We analyze data from the CsI, liquid Ar and Ge detectors of the COHERENT experiment and confirm within $1.5\sigma$ that the measured elastic neutrino-nucleus scattering cross section is proportional to the square of the number of neutrons in the nucleus, as expected for coherent scattering in the standard model. We also show how various degeneracies involving nonstandard neutrino interaction parameters are broken in a combined analysis of the three datasets.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2024)·11 citations
5. 05*

   Dissecting Lepton Number Violating Interactions in the Left-Right Symmetric Model: $0\nu \beta \beta$ decay, Møller scattering, and collider searches

   Gang Li🇨🇳 · Michael J. Ramsey-Musolf🇨🇳 · Sebastián Urrutia Quiroga🇺🇸 · Juan Carlos Vasquez🇺🇸

   In the context of the left-right symmetric model, we study the interplay of neutrinoless double beta ($0\nu \beta \beta$) decay, parity-violating Møller scattering, and high-energy colliders, resulting from the Yukawa interaction of the right-handed doubly-charged scalar to electrons, which could evade the severe constraints from charged lepton flavor violation. The $0\nu \beta \beta$ decay amplitude receives additional contributions from right-handed sterile neutrinos. The half-life, calculated in the effective field theory (EFT) framework, allows for an improved description of the contributions involving non-zero mixing between left- and right-handed $W$ bosons and those arising from exchanging a light right-handed neutrino. We find that the relative sensitivities between the low-energy (or high-precision) and high-energy experiments are affected by the left-right mixing. On the other hand, our results show how the interplay of collider and low-energy searches provides a manner to explore regions that are inaccessible to $0\nu \beta \beta$ decay experiments.

   ↳ hep-phnucl-exnucl-thPLB(2026)·8 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.