The Short-Baseline Near Detector (SBND) sits in an intense stream of neutrinos from the Booster Neutrino Beam at Fermilab. With only 110 m between the detector volume and the beam target, SBND will have unprecedented statistics of over a million neutrino interactions per year, allowing for precise cross-section measurements and Beyond the Standard Model physics searches. Importantly, SBND is the near detector of the Short-Baseline Neutrino (SBN) program which will allow the study of neutrino oscillations with much greater statistics capabilities than have been previously possible. SBND is a 112-ton active volume Liquid Argon Time Projection Chamber (LArTPC) neutrino detector and it is anticipated to start operations in late 2023. This seminar will focus on the recent progress in construction and commissioning as well as novel analysis tools and the physics which SBND is expected to probe.

Although the existence of neutrino mass is firmly established, the precise neutrino mass scale remains unknown.  To directly probe this property, measurements of the endpoint of the tritium beta spectrum have achieved the greatest sensitivity, recently reaching the sub-eV scale.  In this talk, I will present Project 8, an experimental concept based on the novel Cyclotron Radiation Emission Spectroscopy (CRES) technique.  Project 8 has recently released its first measurements of the tritium beta spectral endpoint and demonstrated its high precision spectroscopy using krypton calibration.  An R&D campaign is now underway to demonstrate scalability of the CRES technique and to develop the atomic tritium source required.  Building on these successes, a next-generation experiment is envisioned with neutrino mass sensitivity down to 40 meV.

Abstract:  In April 2021, the Muon g-2 Experiment at Fermilab reported its first measurement of the muon magnetic anomaly to an unprecedented precision of 460 ppb. The result agrees with the previous measurement performed at Brookhaven National Laboratory, and the combined experimental value is in tension with the Standard Model prediction at 4.2 sigma, a possible hint of new physics. The first result from the Fermilab experiment was based on its Run-1 data, collected in 2018, which comprises just 6% of the experiment’s target statistics. The Runs 2 & 3 data, collected between 2019-2020, amount to a four-fold increase in statistics and consequently, a factor of two reduction in the statistical uncertainty. The measurement relies on the precise determination of two key quantities: the anomalous precession frequency of the muon and the magnetic field. In this seminar, I will describe the Fermilab experiment with a focus on the anomalous precession frequency analysis of the Run-2 and Run-3 data. I detail the procedures used, highlighting improvements compared to the Run-1 analysis. I also show blinded results and discuss some of the largest systematic uncertainties in the analysis, as well as provide an outlook and current status of the experiment.

The hyperfine structure of hydrogen-like ions are a unique probe to access nuclear magnetic
moments and nuclear structure. Thus, while eliminating the ignorance of essential links in
metrology due to insufficiently known magnetic moments, at the same time these ions
provide complementary insight into the inner nucleus. The very recently started 3He-
experiment exploits these characteristics to provide a new standard for absolute precision-
magnetometry and determine the nuclear charge and current distribution of 3He.

To this end, a novel four Penning-trap experiment was designed and built. Using novel
techniques, this system enables non-demolition measurements of the nuclear quantum state
and allows sympathetic laser cooling of single, spatially separated ions to sub-thermal
energies [1].

In the first measurement campaign, 3He was investigated by exciting microwave transitions
between the ground-state hyperfine states. This enabled us to determine the nuclear g-factor,
the electronic g-factor and the zero-field ground-state hyperfine-splitting of 3He+ with a
precision of 5*10-10, 3*10-10 and 2*10-11, respectively [2].

Our measurement constitutes the first direct and most precise determination of the 3He+
nuclear magnetic moment. The result is of utmost relevance for absolute precision
magnetometry, as it allows the use of He NMR probes as an independent new standard with
much higher accuracy. In addition, the comparison to advanced theoretical calculations
enables us to determine the size of the 3He nucleus with a precision of 2,4*10-17m.

In future, we aim at a direct determination of the bare nuclear magnetic moment of 3He to be
compared to the bound-state result. For this measurement, it is essential to implement new
methods and technology such as sympathetic laser cooling and a high-precision voltage
source based on Josephson junctions [3]. The latest results, status and the future prospect of
the experiment will be presented.

References
[1] A Mooser et al., J. Phys.: Conf. Ser. 1138, 012004 (2018)
[2] A. Schneider et al., Nature 606, 878 (2022)
[3] A. Schneider et al., Ann. Phys. 531, 1800485 (2019)

Precision measurements of rare decays of charged pions offer important tests of the standard model. The ratio of pi+ -> e+ nu to mu+ nu decay provides the best test of electron–muon weak universality and is uniquely sensitive to non-V-A exotic currents. The rate of pion beta decay pi+ -> pi0 e nu offers a theoretically pristine sensitivity to the Vud matrix element of the CKM matrix.

In this talk I'll discuss the plans by the Pioneer collaboration for a twenty-fold improvement in the determinations for the rare pi+ -> e+ nu and pi+ -> pi0 e nu decays. These determinations involve measurements of relative yields from stopped pions of 70 MeV monoenergetic electrons from pi+ -> e+ nu decay, coincident photons from pi0's produced in pi+ -> pi0 e nu decay, and the 0-53 MeV Michel electrons from mu decay.  

The measurements demand both high statistics and careful understanding of systematic effects. To reach these goals we plan to utilize emergent technologies for both electromagnetic calorimetry and 4-dimensional, high-granularity tracking of pions, muons and electrons.

Meeting recording:

https://uky.zoom.us/rec/share/_sYhrDbeFzAofANoh-RDLtpKrzOrPY0fTuTICOMX7…

Large-momentum effective theory is Feynman's approach to patron physics in the context of QCD, in which partons emerge as static properties of the hadrons in the infinite momentum limit. Therefore, not only partons are now accessible through Euclidean field theories such as lattice QCD, almost all parton observables and light-cone physics can be numerically simulated. However, current precision calculations of few percent accuracy require controls of resummations of perturbative large logarithms in EFT matching as well as higher twist effects. I will discuss how these can be done in simple examples. 

The gluon distribution function grows with lower and lower momentum fraction very fast. As the total scattering cross section is bound by quantum mechanics, the raise of the gluon density has to be tamed, which is explained by gluon recombination under the color glass condensate (CGC) framework. A definitive discovery of nonlinear effects in QCD and as such the saturation regime would significantly improve our understanding of the nucleon structure and of nuclear interactions at high energy. Two particle azimuthal correlation is one of the most direct and sensitive channels to access the underlying nonlinear gluon dynamics. In this talk, we will present the recent results of forward di-hadron correlations measured at RHIC, together with the signatures of gluon saturation predicted by CGC. New opportunities for measurements with the STAR forward upgrade and future EIC to study the nonlinear effects in QCD will also be discussed.

Precision nuclear physics experiments have long played an important role in searches for physics Beyond the Standard Model (BSM). The traditional particle detection technologies of many of these experiments, semiconductor and scintillation detectors, face fundamental performance limitations that greatly restrict the sensitivity achievable. A new detector paradigm for charged particle detection has the potential to dramatically improve sensitivity in BSM searches. We are working toward this goal by adapting Thermal Kinetic Inductance Detectors (TKIDs) for external charged particle detection. These cryogenic detectors, used in X-ray and gamma spectroscopy as well as dark matter searches, have shown photon energy resolutions on the order of tens of eV and can be multiplexed to create large area detectors. However, TKIDs have not yet been developed for non-embedded charged particle detection. We have designed a Charged Particle TKID (CP-TKID) prototype to optimized for the  detection of the neutron beta decay electron.  In this seminar, I will discuss the development of our initial prototype design and our efforts to characterize its response.

The era of multi-messenger astronomy has unlocked new probes of physics, allowing natural experiments to be carried out on matter at extremes unattainable using terrestrial experiments. Neutron stars, and their mergers, are natural sites to seek probes of nuclear physics, as these compact objects contain the densest matter in the universe. I will discuss multi-messenger astrophysical observables from the point of view of nuclear physics constraints. In particular I will highlight resonant shattering flares (RSFs), which can provide strong constraints on the nuclear symmetry energy parameters of nuclear matter, comparable to those obtained by terrestrial nuclear experiments, such as those found in dipole polarizability and neutron skin thickness measurements.

Pulsar Timing Arrays (PTAs) are exceptionally sensitive detectors in the nHz to uHz frequency window. While their primary purpose is to detect the stochastic gravitational wave background, they can also be used to search for new physics. Ultralight dark matter (ULDM), with mass between 10^{-23} eV and 10^{-20} eV, can generate a variety of different signals within the sensitivity window of PTAs. I will give an overview of the effects which have been studied previously, and then discuss new signals generated by variations in the fundamental constants. There are two main avenues to induce a PTA signal via variations in fundamental constants: changing the pulsar spin rate, e.g., by fluctutating particle masses, or shifting the reference clock. Using the standard analysis pipeline of the PTA collaborations, PTAs are shown to be competitive with atomic clock and torsion balance constraints for many ULDM models, especially those varying the electron and muon mass. Lastly, I will discuss how future PTAs may improve the sensitivity, and unique correlations in the signals which may further distinguish them from background.