Wed·Jan 8, 2025Wednesday·January 8, 2025

1. 01*

   The Gallium Solar Neutrino Capture Cross Section Revisited

   W. C. Haxton🇺🇸 · Evan Rule🇺🇸

   Solar neutrino flux constraints from the legacy GALLEX/GNO and SAGE experiments continue to influence contemporary global analyses of neutrino properties. The constraints depend on the neutrino absorption cross sections for various solar sources. Following recent work updating the ${}^{51}$Cr and ${}^{37}$Ar neutrino source cross sections, we reevaluate the ${}^{71}$Ga solar neutrino cross sections, focusing on contributions from transitions to ${}^{71}$Ge excited states, but also revising the ground-state transition to take into account new ${}^{71}$Ge electron-capture lifetime measurements and various theory corrections. The excited-state contributions have been traditionally taken from forward-angle $(p,n)$ cross sections. Here we correct this procedure for the $\approx 10\%-20\%$ tensor operator contribution that alters the relationship between Gamow-Teller and $(p,n)$ transition strengths. Using state-of-the-art nuclear shell-model calculations to evaluate this correction, we find that it lowers the ${}^8$B and hep neutrino cross sections. However, the addition of other corrections, including contributions from near-threshold continuum states that radiatively decay, leads to an overall increase in the ${}^8$B and hep cross sections of $\approx 10\%$ relative to the values recommended by Bahcall. Uncertainties are propagated using Monte Carlo simulations.

   nucl-exhep-exhep-phnucl-thPLB(2025)·5 citations
2. 02*

   Elemental and angular fragmentation cross section measurements with the FOOT experiment

   M. Dondi (1 and 2)🇮🇹 · R. Ridolfi (1 and 2) (for the FOOT Collaboration, (1) INFN Section of Bologna, Bologna, Italy, (2) University of Bologna, Department of Physics and Astronomy, Bologna, Italy)🇮🇹

   The FOOT (FragmentatiOn Of Target) experiment was proposed to measure double differential nuclear fragmentation cross sections in angle and kinetic energy of the produced fragments in beam-target settings, interesting for hadrontherapy and space radioprotection applications. In particular, FOOT measures projectile and target fragmentations in the kinetic energy range between $200\text{MeV/u}$ and $800\text{MeV/u}$. In this contribution, differential cross section measurements of a $400\text{MeV/u}$ ${}^{16}$O beam on a Carbon and a polyethylene target with data acquired at GSI (Darmstadt, Germany) beam accelerator facility are presented, along with the extraction of the first total fragmentation cross section for a Hydrogen target within the FOOT experiment.

   nucl-exNuovo Cim.C(2025)·0 citations
3. 03*

   Decay spectroscopy of heavy and superheavy nuclei

   Dieter Ackermann🇫🇷

   After more than half a century since the first predictions of the so-called "island of stability of superheavy nuclei", exploring the limits of nuclear stability at highest atomic numbers is still one of the most prominent challenges in low-energy nuclear physics. These exotic nuclear species reveal their character and details of some of their properties through their induced or spontaneous disintegration. The achievements in the field of superheavy nuclei (SHN) research, which involves studying the production and decay of the heaviest nuclear species, have been reported in a number of review papers. In the introduction of this paper, references are provided to review papers, summarizing the many aspects of SHN research in other disciplines, like chemistry, atomic physics, and earlier work on nuclear structure, including in-beam spectroscopy, and superheavy element (SHE) synthesis. This review is an attempt to summarize the experimental progress that has been made in recent years by employing the versatile tool park of Decay Spectroscopy After Separation (DSAS) for the heaviest isotopes from Z=99 (einsteinium) to Z=118 (oganesson). DSAS, with its major instrumentation components heavy-ion accelerator, separator and decay detection, is the only way to access the heaviest nuclei up to oganesson. While in-beam {\gamma}-spectroscopy has reached 256Rf in terms of the highest atomic number Z and mass number A, SHE chemistry succeeded to sort flerovium (Z = 114) as the heaviest element into the periodic table. Laser spectroscopy and precise mass measurements are limited basically to the nobelium/fermium region, with high-precision Penning-trap mass-measurements being performed for 256Lr and 257Rf, and with the 257Db mass obtained, using a multi-reflection time-of-flight mass spectrometer (MRToF MS).

   nucl-exnucl-thPPNP(2026)·6 citations
4. 04*

   Right-handed weak currents in neutrinoless $\beta \beta$ decays and ton scale $\beta \beta$ detectors

   H. Ejiri🇯🇵 · T. Fukuyama🇯🇵 · T. Sato🇯🇵

   Right handed weak-currents (RHCs) in the left-right (L-R) symmetric model for neutrinoless double beta decays (DBDs) of both the $0^{+}\to 0^{+}$ and $0^{+}\to 2^{+}$ transitions are discussed from both theoretical and experimental view points. $<\lambda >$ and $<\eta >$-terms are related by $<\lambda >/<\eta >\approx \tan \beta$, which is constrained in the regions of $1-60$ for SUSY grand unified theories (GUTs) and of $1-165$ for non-SUSY GUTs. The enhancement mechanisms of the $<\eta >$ term over the $<\lambda >$ term in the $0^{+}$ transition are shown, and the $\Delta$ isobar contribution to the NME for the transition to the 2${}^{+}$ state is found to be of the order of $20\%$ of the NME with the quenched weak coupling. The new and interesting RHC regions of $<\lambda >\approx 5\times 10^{-8}$ and $<\eta >\approx 1.5\times 10^{-10}$ are shown to be exclusively explored by measuring both the $\beta \beta$ and $\gamma$ rays associated with the ground and excited DBDs by means of the ton-scale DBD detectors for the IH (inverted hierarchy) $\nu$-masses. The actual RHCs to be studied depend on the RHC NMEs.

   ↳ hep-phnucl-exnucl-thPRC(2025)·1 citation
5. 05*

   First In-Beam Demonstration of a hybrid LaBr3/CeBr3/BGO array to measure radiative capture resonance energies in an extended gas target using a novel time of flight technique

   G. Christian · D. Hutcheon🇨🇦 · I. Casandjian🇨🇦 · S.M. Collins · A.C. Edwin · E. Desmarais · U. Greife🇺🇸 · A. Katrusiak · A. Lennarz🇨🇦 · M. Loria · S. Mollo · J. O'Connell and 10 other authors

   We have deployed a new hybrid array of LaBr3, CeBr3, and BGO scintillators for detecting $\gamma$ rays at the DRAGON recoil separator at TRIUMF. The array was developed to improve $\gamma$-ray timing resolution over the existing BGO array. This allows the average position of resonant capture in an extended gas target to be determined with $\sim$15 mm precision or better, even with five or fewer detected capture events. This, in turn, allows determination of resonant capture energies with statistical uncertainties below $\sim 1\%$. Here we report the results of a first in-beam demonstration of the array, measuring the $E_{cm}=0.4906(3)$ MeV resonance in the ${}^{23}\mathrm{Na}(p,\gamma ){}^{24}\mathrm{Mg}$ reaction, focusing on the timing properties of the array and its anticipated performance in future experiments with radioactive beams.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2025)·0 citations
6. 06*

   Kinematics Calibration and Excitation Energy Reconstruction for Solenoidal Spectrometers

   T. L. Tang🇺🇸

   This work introduces a novel method for reconstructing excitation energy and center-of-mass scattering angle from energy-position data in solenoidal spectrometers, addressing challenges posed by non-linearities at small scattering angles. The approach employs a robust calibration of experimental energy-position data using known excited states, followed by an analytical inverse transformation based on relativistic kinematics and cyclotron motion. Integrated into the HELIOS online analysis routines, this method enables real-time generation of excitation energy spectra and angular distributions during experiments, improving efficiency and accuracy over traditional projection-based methods. The method's effectiveness is demonstrated using the 25Mg(d,p) reaction, highlighting its ability to handle forward-angle data and produce precise kinematic reconstructions.

   ↳ physics.ins-detnucl-ex0 citations
7. 07*

   Search for double beta decay of 106Cd Monte Carlo simulation and cosmogenic activation of the CdWO4 detectros

   Ester Ricci

   The thesis describes the experimental setup designed to study the decay spectrum of 106Cd, a candidate for positive double-$\beta$ decay and the Monte Carlo simulation used to estimate the background expected in 1 year of measurements.

   ↳ hep-exnucl-ex0 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.