Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm.

We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω[over ˜]_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}.

Microgel Particle Collision with Smooth and Nanofiber Hydrophobic Surfaces during Three-Dimensional Printing of a Biopolymer Layer.

The impact of microgel particles onto a wall represents an elementary process that determines the one-stage production of a biopolymer layer on a nanofiber scaffold in the framework of tissue bioengineering. The formation of a microgel layer is experimentally examined on a hydrophobic uniform surface and a nonwoven polymer membrane made of vinylidene fluoride-tetrafluoroethylene copolymer. In-air microfluidics methods, namely, an external vibration disturbance on the microflow of a cross-linkable biopolymer, make it possible to form the microstructures of "beads-on-thread" with a uniform distance between microgel particles of identical size (340-480 μm, depending on the sample).

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm.

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring.

Test of Lorentz invariance with spin precession of ultracold neutrons.

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and 199Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b perpendicular < 2 x 10(-20) eV (95% C.L.

New precise measurement of the pion weak form factors in pi+-->e+ nugamma decay.

We have measured the pi+-->e+ nugamma branching ratio over a wide region of phase space, based on a total of 65 460 events acquired using the PIBETA detector. Minimum-chi2 fits to the measured (E(e+), E(gamma) energy distributions result in the weak form factor value of F(A)=0.0119(1) with a fixed value of F(V)=0.