Tue·Nov 17, 2020Tuesday·November 17, 2020

1. 01*

   Branching Ratios for the Three Most Intense Gamma Rays in the Decay of ${}^{47}$Ca

   E. Paige Abel (1 and 2) · Chloe Kleinfeldt (2) · Colton Kalman (2) · Gregory W. Severin (1 and 2) ((1) Department of Chemistry Michigan State University, (2) National Superconducting Cyclotron Laboratory Michigan State University)

   A sample of ${}^{47}$Ca produced through isotope harvesting at the National Superconducting Cyclotron Laboratory was used to measure branching ratios of 7.17(5)%, 7.11(5)%, and 75.0(5)% for the 489.2, 807.9, and 1297.1 keV characteristic gamma-rays, respectively. Based on these updated branching ratios, the ground state to ground state ${}^{47}$Ca to ${}^{47}$Sc beta decay branching ratio has been indirectly measured as 17.7(5)% and the ground state to 1297.1 keV excited state as 82.2(5)%. These values represent a greatly increased precision for all five branching ratios compared to the currently accepted values. The measurements presented here were made relative to the ingrown ${}^{47}$Sc daughter in a ${}^{47}$Ca sample and the well-established 159.4 keV gamma-ray branching ratio and the half-life for the decay of ${}^{47}$Sc. These measurements were supported by verifying that the half-lives measured from characteristic gamma-ray peaks over multiple spectra for both ${}^{47}$Ca and ${}^{47}$Sc were consistent with previously reported values. Additionally, the half-lives of both ${}^{47}$Ca and ${}^{47}$Sc were independently measured with Liquid Scintillation Counting to reverify the previously reported values used in this study to find updated gamma-ray branching ratio values.

   nucl-exAppl.Radiat.Isot.(2022)·1 citation
2. 02*

   Search for Periodic Modulations of the Rate of Double-Beta Decay of ${}^{100}$Mo in the NEMO-3 Detector

   NEMO-3 Collaboration: R. Arnold🇫🇷 · C. Augier🇫🇷 · A.S. Barabash🇷🇺 · A. Basharina-Freshville🇬🇧 · S. Blondel🇫🇷 · S. Blot🇬🇧 · M. Bongrand🇫🇷 · D. Boursette🇫🇷 · R. Breier🇸🇰 · V. Brudanin🇷🇺 · J. Busto🇫🇷 · A.J. Caffrey🇺🇸 and 95 other authors

   Double-beta decays of ${}^{100}$Mo from the 6.0195-year exposure of a 6.914 kg high-purity sample were recorded by the NEMO-3 experiment that searched for neutrinoless double-beta decays. These ultra-rare transitions to ${}^{100}$Ru have a half-life of approximately $7\times 10^{18}$ years, and have been used to conduct the first ever search for periodic variations of this decay mode. The Lomb-Scargle periodogram technique, and its error-weighted extension, were employed to look for periodic modulations of the half-life. Monte Carlo modeling was used to study the modulation sensitivity of the data over a broad range of amplitudes and frequencies. Data show no evidence of modulations with amplitude greater than 2.5% in the frequency range of $0.33225{\mathrm{y}}^{-1}$ to $365.25{\mathrm{y}}^{-1}$.

   nucl-exhep-exPRC(2021)·5 citations
3. 03*

   Understanding the background in dark matter searches by studying antinucleosynthesis in the laboratory with ALICE

   Sebastian Hornung (for the ALICE Collaboration)🇩🇪

   Antinuclei are considered to be one of the most promising probes in the indirect search for dark matter (DM) annihilation in space. However, in light of recent results on the production of light antinuclei in pp collisions at the LHC, an abundant production of light (anti)nuclei is also expected from Standard Model (SM) collisions of primary cosmic rays with the interstellar medium. Hence further precise measurements are required to constrain the production models of antinuclei in SM collisions to be sensitive to additional DM annihilation events. The most recent results of the ALICE collaboration on the production of antideuterons ($\overline{\mathrm{d}}$) and antihelium-3 (${}^3\overline{\text{He}}$) in proton-proton (pp) and proton-lead (p--Pb) collisions are shown. These results provide valuable input for state-of-the-art calculations of the production models currently used to estimate the SM background to DM searches.

   nucl-exhep-exPoS(2021)·0 citations
4. 04*

   The origin of the elements and other implications of gravitational wave detection for nuclear physics

   David Lunney🇫🇷

   The neutron-star collision revealed by the event GW170817 gave us a first glimpse of a possible birthplace of most of our heavy elements. The multi-messenger nature of this historical event combined gravitational waves, a gamma-ray burst and optical astronomy of a ``kilonova'', bringing the first observations of rapid neutron capture (r process) nucleosynthesis after 60 years of speculation. Modeling the r process requires a prodigious amount of nuclear-physics ingredients: practically all the quantum state and interaction properties of virtually all neutron-rich nuclides, many of which may never be produced in the laboratory! Another essential contribution of nuclear physics to neutron stars (and their eventual coalescence) is the equation of state (EoS) that defines their structure and composition. The EoS, combined with the knowledge of nuclear binding energies, determines the elemental profile of the outer crust of a neutron star and the relationship between its radius and mass. In addition, the EoS determines the form of the gravitational wave signal. This article combines a tutorial presentation and bibliography with recent results that link nuclear mass spectrometry to gravitational waves via neutron stars.

   nucl-exastro-ph.HEnucl-th4open(2020)·2 citations
5. 05*

   Tracking Algorithms for TPCs using Consensus-Based Robust Estimators

   J.C. Zamora🇧🇷 · G.F. Fortino🇧🇷

   A tracking algorithm based on consensus-robust estimators was implemented for the analysis of experiments with time-projection chambers. In this work, few algorithms beyond RANSAC were successfully tested using experimental data taken with the AT-TPC, ACTAR and TexAT detectors. The present tracking algorithm has a better inlier-outlier detection than the simple sequential RANSAC routine. Modifications in the random sampling and clustering were included to improve the tracking efficiency. Very good results were obtained in all the test cases, in particular for fitting short tracks in the detection limit.

   ↳ physics.ins-detnucl-exphysics.comp-phphysics.data-anNucl.Instrum.Meth.A(2021)·10 citations
6. 06*

   Summary of the NuSTEC Workshop on Neutrino-Nucleus Pion Production in the Resonance Region

   L. Aliaga🇺🇸 · A. Ashkenazi🇺🇸 · C. Bronner🇯🇵 · J. Calcutt🇺🇸 · D. Cherdack🇺🇸 · K. Duffy🇺🇸 · S. Dytman🇺🇸 · N. Jachowicz🇧🇪 · M. Kabirnezhad🇬🇧 · K. Kuzmin🇷🇺 · G. A. Miller🇺🇸 · T. Le🇺🇸 and 11 other authors

   The NuSTEC workshop held at the University of Pittsburgh in October 2019 brought theorists and experimentalists together to discuss the state of modeling and measurements related to pion production in neutrino-nucleus scattering in the kinematic region where pions are produced through both resonant and non-resonant mechanisms. Modeling of this region is of critical importance to the current and future accelerator- and atmospheric-based neutrino oscillation experiments. For the benefit of the community, links to the presentations are accompanied by annotations from the speakers highlighting significant points made during the presentations and resulting discussions.

   ↳ hep-phhep-exnucl-exnucl-th15 citations
7. 07*

   Cluster effective field theory and nuclear reactions

   Shung-Ichi Ando (Sunmoon U.)🇰🇷

   An effective field theory (EFT) for a nuclear reaction at low energies is studied. The astrophysical $S$-factor of radiative $\alpha$ capture on ${}^{12}$C at the Gamow-peak energy, $T_G=0.3$ MeV, is a fundamental quantity in nuclear-astrophysics, and we construct an EFT for the reaction. To fix parameters appearing in the effective Lagrangian, the EFT is applied to the study for three reactions: elastic $\alpha$-${}^{12}$C scattering at low energies, $E1$ transition of radiative $\alpha$ capture on ${}^{12}$C, and $\beta$ delayed $\alpha$ emission from ${}^{16}$N. We report an estimate of the $S_{E1}$-factor of the reaction through the $E1$ transition at $T_G$ by employing the EFT. We also discuss applications of EFTs to nuclear reactions at low energies.

   ↳ nucl-thnucl-exEPJA(2021)·15 citations
8. 08*

   Observation of a near-threshold structure in the $K^{+}$ recoil-mass spectra in $e^{+}{e}^{-}\to K^{+}(D_s^{-}{D}^{\ast 0}+D_s^{\ast -}{D}^0)$

   BESIII Collaboration: M. Ablikim🇨🇳 · M. N. Achasov🇷🇺 · P. Adlarson🇸🇪 · S. Ahmed🇩🇪 · M. Albrecht🇩🇪 · R. Aliberti🇩🇪 · A. Amoroso🇮🇹 · Q. An🇨🇳 · Anita🇮🇳 · X. H. Bai🇨🇳 · Y. Bai🇨🇳 · O. Bakina🇷🇺 and 493 other authors

   We report a study of the processes of $e^{+}{e}^{-}\to K^{+}(D_s^{-}{D}^{\ast 0}+D_s^{\ast -}{D}^0)$ based on $e^{+}{e}^{-}$ annihilation samples collected with the BESIII detector operating at BEPCII at five center-of-mass energies ranging from 4.628 to 4.698 GeV with a total integrated luminosity of 3.7 fb${}^{-1}$. An excess over the known contributions of the conventional charmed mesons is observed near the $D_s^{-}{D}^{\ast 0}$ and $D_s^{\ast -}{D}^0$ mass thresholds in the $K^{+}$ recoil-mass spectrum for events collected at $\sqrt{s}=4.681$ GeV. The structure matches a mass-dependent-width Breit-Wigner line shape, whose pole mass and width are determined as $(3982.5_{-2.6}^{+1.8}\pm 2.1)$ MeV/$c^2$ and $(12.8_{-4.4}^{+5.3}\pm 3.0)$ MeV, respectively. The first uncertainties are statistical and the second are systematic. The significance of the resonance hypothesis is estimated to be 5.3 $\sigma$ over the contributions only from the conventional charmed mesons. This is the first candidate of the charged hidden-charm tetraquark with strangeness, decaying into $D_s^{-}{D}^{\ast 0}$ and $D_s^{\ast -}{D}^0$. However, the properties of the excess need further exploration with more statistics.

   ↳ hep-exhep-phnucl-exnucl-thPRL(2021)·290 citations
9. 09*

   A novel approach to the localization and the estimate of radioactivity in contaminated waste packages via imaging techniques

   Michele Pastena · Bastian Weinhorst · Günter Kanisch · Edgar Perez Lezama · Johannes Ratdke · Tim Thomas🇩🇪

   Dismantling nuclear power plants entails the production of a large amount of contaminated (or potentially contaminated) material whose disposal is of crucial importance. Most of the end products have to be stored in special repositories but it can happen that some of them are slightly contaminated or not contaminated at all, making it possible to free release them. One possible approach to free release measurements uses Large Clearance Monitors, chambers surrounded by plastic scintillation detectors that allow a decision about the clearance of waste packages up to 1000 kg. Due to the composite nature of the detectors in a Large Clearance Monitor, it is easy to imagine that one can apply 3D imaging algorithms to localize radioactive sources inside a waste package. In this work we will show how a special algorithm that maximizes the conditional informational entropy allows decisions about the clearance of portions of the sample.

   ↳ physics.data-annucl-exMeasur.Sci.Tech.(2021)·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.