Many of the Air Force Research Laboratory’s experimental efforts are focused on precision navigation and timing. The establishment and testing of an optical frequency standard is useful for numerous terrestrial and space based applications. Therefore, an optical atomic clock based upon a 778 nm two-photon transition in rubidium, is an excellent candidate to meet GPS-III frequency stability requirements, as commercial off-the-shelf components allow for a simple set-up that supports 7 x 10^-13 at 1 second.

The Nab collaboration proposes to measure the electron-neutrino correlation parameter a with a precision of δa/a = 10^−3 and the Fierz interference term b to δb = 3 × 10^−3 in unpolarized free neutron β decay. These results are expected to lead to a new, precise, independent determination of the ratio λ = GA/GV that will sensitively test CKM unitarity. A long asymmetric spectrometer guides the decay products to two large area silicon detectors in order to precisely determine the electron energy and proton momentum. The Nab apparatus is under installation on the Fundamental Neutron Physics Beamline at the SNS at ORNL and commissioning will begin in the near future. An overview of the Nab experiment, systematics effects associated with spectrometer magnetic fields, and the first tests of the spectrometer will be presented.

Neutron-induced failures in semiconductor devices are an increasing concern in the semiconductor industry. Neutrons are produced in the upper atmosphere by cosmic-ray bombardment of nuclei in the air. Because the neutrons are uncharged, they have long mean-free paths and can reach aircraft altitudes and below. Neutron interactions in semiconductor devices produce ionized recoils or reaction products that deposit charge in the vicinity of nodes and cause the devices to fail. These types of failures include bit flips, latchups, burnout etc. Many semiconductor companies have measured the system response at an accelerated rate by using the high-energy Los Alamos Neutron Science Center (LANSCE) spallation neutron source. The LANSCE source produces a neutron spectrum that is very similar in shape to the neutron spectrum produced by cosmic rays in the earth’s atmosphere but is approximately 108 times more intense than the sea-level neutron flux. This acceleration factor allows testing of semiconductor devices to measure their response, and to develop and test failure models and mitigation approaches.

Cosmic microwave background Stage-IV experiments and thirty-meter-class
telescopes will come on line in the next decade. The convolution of these data
sets will provide on order 1% precision for observables related to neutrino
cosmology. Beyond Standard Model (BSM) physics could manifest itself in slight
deviations from the standard predictions of quantities such as the neutrino
energy density and the primordial abundances from Big Bang Nucleosynthesis
(BBN). In this talk, I will argue for the need for precise and accurate
numerical calculations of BBN. I will first show the detailed evolution of the
neutrino spectra as they go out of equilibrium with the plasma. The spectra
are important in changing the ratio of neutrons to protons. I will show how
sensitive the primordial mass fraction of helium is to the weak interaction
rates which evolve the neutron-to-proton ratio. Finally, I will present an
example of how BSM physics can affect BBN by instituting an asymmetry between
neutrinos and antineutrinos, commonly characterized by a lepton number.

In the lattice QCD approach to hadron spectroscopy one can extract

finite-volume stationary-state energies, including excited states, from

temporal correlators.  Probe interpolating operators from correlators

which are estimated via Monte Carlo integration: these operators create

single- and two-hadron states with spatially displaced quarks, with an eye

towards possible tetraquark states.  Studies of dynamical quarks in SU(3)

gauge theory on large lattices with near-physical pion masses are made

possible by new techniques in operator smearing and stochastic estimation

of quark propagators.  Given the spectrum in finite-volume, the Luscher

method allows one to relate this to infinite-volume resonances; recent

results include the rho resonance in pion scattering, on a large 32^3 by

256 lattice at a heavy pion mass of 240 MeV.

Because neutrinos are so penetrating, they allow a nearly-unobstructed view of the nuclear, particle and astrophysical processes occurring deep in the interiors of the Sun and stars. Already a spectacular object at optical wavelengths, a core-collapse supernova liberates 99% of its energy in the form of neutrinos of various flavors, each of which has a distinctive energy spectrum and time dependence. Neutrinos is where the action is! A neutrino detector constructed of lead would be primarily sensitive to the electron-type neutrinos from a supernova, and would complement the existing water Cerenkov and organic scintillator detectors which are sensitive primarily to electron anti-neutrinos. We have tentative ideas for a 1 kiloton lead detector at the Gran Sasso laboratory in Italy, as a successor to the much smaller HALO-1 detector now operating at SNOLAB in Canada. We would welcome new collaborators.

The Scintillator-Layered Imaging Microscope for Environmental Research (SLIMER) is a tool under development by researchers at Los Alamos National Lab and Tennessee Tech University to measure uptake of specific isotopes in biological systems. SLIMER incorporates a microcolumnar scintillator in a fluorescent microscope in order to study microbial systems exposed to 32P, 33P, or 14C. For this purpose, SLIMER needs to have excellent position resolution and light collection. If SLIMER can pinpoint the area of the slide where the radioactive decay event occurs, this would indicate the area in which a microbe has absorbed the isotope. The microbes in that area of the slide can then be identified using DNA analysis. In order to study and refine the capabilities of SLIMER, a simulation was developed with C++ and GEANT4. The GEANT4 packages for radiation and scintillation were used to provide a realistic model of radioactive decay and scintillator activity. At Los Alamos National Laboratory, the physical setup of the experiment was tested and refined, and data was collected. Data analysis is still ongoing. Further objectives include improvement of the position resolution; identification of a minimum detectable activity; and developing a calibration consistent for all sources. Possible applications of SLIMER will also be discussed.

We present a lattice QCD calculation of the strange quark contribution to the nucleon’s magnetic moment and charge radius using 2+1 flavor dynamical fermion. We have performed a model-independent extraction of the strange quark magnetic moment and charge radius and present the most precise and accurate estimates to date. We also find that the total contribution to the nucleon charge radius from the nucleon sea u, d, s-quarks is negative and this hints a shift of the proton charge radius towards the value obtained from the muonic hydrogen Lamb shift experiment.

In the Standard Model (SM) baryon number – lepton number (B-L) is perfectly conserved. Therefore, the observation of the transition from a neutron to an antineutron reveals the existence of physics beyond the SM. I will start with the Lorentz invariant B-L violating operators of lowest mass dimension and discuss the “wrong” CPT problem associated with their transformation properties under CPT. Then I will argue how the special transformation properties of Majorana fermion under the discrete symmetries CPT, CP, and C can help solve this problem and lead to the discovery of discrete-symmetry phase constraints on the fermion fields in B-L violating theories. I will discuss how the incorporation of these phase constraints leads to new ways of discovering neutron-antineutron transitions.

There are two problems that are hidden behind the moniker "proton radius puzzle". One is the discrepancy between the spectroscopic measurements of the proton radius in ordinary and muonic hydrogen. Another is the discrepancy between the proton radius extracted from the electron-proton scattering and from the muonic hydrogen spectroscopy. I will remind how the proton radius is measured in all three types of experiments. The current status of the proton radius puzzle and the progress on the road to its resolution will be discussed.