Case Report: A rare case of bilateral molar natal teeth in a term newborn

Reports of natal and neonatal teeth have been well documented in the literature, although the presence of natal primary molars remains rare, and a clear management strategy does not exist. This is a case study of a female newborn delivered at a gestational age of 41 weeks 1 day to a 31-year-old G1P1001 mother. Apgar scores were 8 and 9 at 1 and 5 min, respectively. The infant was delivered by cesarean section and was admitted to the Mass General Hospital Newborn Nursery, where she received routine care. The patient had two posterior molars, which warranted consultation for oral maxillofacial surgery. Due to the gross mobility of the natal teeth and the risk of aspiration in a small breastfeeding newborn, the decision was made to extract the natal teeth immediately. Understanding the management of natal teeth is important for the pediatrician

Experimental Search for Neutron to Mirror Neutron Oscillations as an Explanation of the Neutron Lifetime Anomaly

An unexplained $>4\,\sigma$ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions of neutrons $n$ into mirror neutrons $n'$, part of a dark mirror sector, can increase the apparent neutron lifetime by $1\%$ via a small mass splitting $\Delta{m}$ between $n$ and $n'$ inside the 4.6 T magnetic field of the National Institute of Standards and Technology Beam Lifetime experiment. A search for neutron conversions in a 6.6 T magnetic field was performed at the Spallation Neutron Source which excludes this explanation for the neutron lifetime discrepancy

The Beta-decay Paul Trap Mk IV: Design and commissioning

The Beta-decay Paul Trap is an open-geometry, linear trap used to measure the decays of $^8$Li and $^8$B to search for a tensor contribution to the weak interaction. In the latest $^8$Li measurement of Burkey et al. (2022), $\beta$ scattering was the dominant experimental systematic uncertainty. The Beta-decay Paul Trap Mk IV reduces the prevalence of $\beta$ scattering by a factor of 4 through a redesigned electrode geometry and the use of glassy carbon and graphite as electrode materials. The trap has been constructed and successfully commissioned with $^8$Li in a new data campaign that collected 2.6 million triple coincidence events, an increase in statistics by 30% with 4 times less $\beta$ scattering compared to the previous $^8$Li data set.Comment: 17 pages, 7 figure

Improved Tensor Current Limit from B 8 β Decay Including New Recoil-Order Calculations

A precision measurement of the β+ decay of B8 was performed using the Beta-decay Paul Trap to determine the β-ν angular correlation coefficient aβν. The experimental results were combined with new ab initio symmetry-adapted no-core shell-model calculations to yield the second-most precise measurement from Gamow-Teller decays, aβν=-0.3345±0.0019stat±0.0021syst. This value agrees with the standard model value of -1/3 and improves uncertainties in B8 by nearly a factor of 2. By combining results from B8 and Li8, a tight limit on tensor current coupling to right-handed neutrinos was obtained. A recent global evaluation of all other precision β decay studies suggested a nonzero value for right-handed neutrino coupling in contradiction with the standard model at just above 3σ. The present results are of comparable sensitivity and do not support this finding

New high-sensitivity searches for neutrons converting into antineutrons and/or sterile neutrons at the HIBEAM/NNBAR experiment at the European Spallation Source

The violation of baryon number, B, is an essential ingredient for the preferential creation of matter over antimatter needed to account for the observed baryon asymmetry in the Universe. However, such a process has yet to be experimentally observed. The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source to search for baryon number violation. The program will include high-sensitivity searches for processes that violate baryon number by one or two units: free neutron-antineutron oscillation (n -> (n) over bar) via mixing, neutron-antineutron oscillation via regeneration from a sterile neutron state (n -> [n',(n) over bar'] -> (n) over bar), and neutron disappearance (n -> n'); the effective Delta B = 0 process of neutron regeneration (n ->[n',(n) over bar'] -> n) is also possible. The program can be used to discover and characterize mixing in the neutron, antineutron and sterile neutron sectors. The experiment addresses topical open questions such as the origins of baryogenesis and the nature of dark matter, and is sensitive to scales of new physics substantially in excess of those available at colliders. A goal of the program is to open a discovery window to neutron conversion probabilities (sensitivities) by up to three orders of magnitude compared with previous searches. The opportunity to make such a leap in sensitivity tests should not be squandered. The experiment pulls together a diverse international team of physicists from the particle (collider and low energy) and nuclear physics communities, while also including specialists in neutronics and magnetics.Peer reviewe

Fundamental Symmetries, Neutrons, and Neutrinos (FSNN): Whitepaper for the 2023 NSAC Long Range Plan

This whitepaper presents the research priorities decided on by attendees of the 2022 Town Meeting for Fundamental Symmetries, Neutrons and Neutrinos, which took place December 13-15, 2022 in Chapel Hill, NC, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 275 scientists registered for the meeting. The whitepaper makes a number of explicit recommendations and justifies them in detail

Investigating the effects of precise mass measurements of Ru and Pd isotopes on machine learning mass modeling

Atomic masses are a foundational quantity in our understanding of nuclear structure, astrophysics and fundamental symmetries. The long-standing goal of creating a predictive global model for the binding energy of a nucleus remains a significant challenge, however, and prompts the need for precise measurements of atomic masses to serve as anchor points for model developments. We present precise mass measurements of neutron-rich Ru and Pd isotopes performed at the Californium Rare Isotope Breeder Upgrade facility at Argonne National Laboratory using the Canadian Penning Trap mass spectrometer. The masses of $^{108}$Ru, $^{110}$Ru and $^{116}$Pd were measured to a relative mass precision $δm/m \approx 10^{-8}$ via the phase-imaging ion-cyclotron-resonance technique, and represent an improvement of approximately an order of magnitude over previous measurements. These mass data were used in conjunction with the physically interpretable machine learning (PIML) model, which uses a mixture density neural network to model mass excesses via a mixture of Gaussian distributions. The effects of our new mass data on a Bayesian-updating of a PIML model are presented.6 pages, 4 figure

Angular Correlations in the β Decay of B 8: First Tensor-Current Limits from a Mirror-Nucleus Pair

We present the first measurement of the α-β-ν angular correlation in the Gamow-Teller β+ decay of B8. This was accomplished using the Beta-decay Paul Trap, expanding on our previous work on the β- decay of Li8. The B8 result is consistent with the V-A electroweak interaction of the standard model and, on its own, provides a limit on the exotic right-handed tensor current relative to the axial-vector current of |CT/CA|2\u3c 0.013 at the 95.5% confidence level. This represents the first high-precision angular correlation measurements in mirror decays and was made possible through the use of an ion trap. By combining this B8 result with our previous Li8 results, we demonstrate a new pathway for increased precision in searches for exotic currents