S. Baeßler
A5037059187- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Nuclear Physics and Applications
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Advanced NMR Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Radiation Detection and Scintillator Technologies
- Cosmology and Gravitation Theories
- Radioactive Decay and Measurement Techniques
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Nuclear physics research studies
- Quantum Electrodynamics and Casimir Effect
- High-Energy Particle Collisions Research
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Geophysics and Sensor Technology
- NMR spectroscopy and applications
- Non-Destructive Testing Techniques
- Black Holes and Theoretical Physics
- Glass properties and applications
- Material Dynamics and Properties
Oak Ridge National Laboratory
2013-2024
University of Virginia
2014-2024
Oak Ridge Associated Universities
2024
Johannes Gutenberg University Mainz
2003-2020
Institut Laue-Langevin
2011-2019
McCormick (United States)
2014-2015
United States Department of Energy
2015
Heidelberg University
1995-2005
Petersburg Nuclear Physics Institute
2005
Laboratoire de Physique Subatomique et de Cosmologie
2005
We present the first results of Fermilab Muon g-2 Experiment for positive muon magnetic anomaly $a_\mu \equiv (g_\mu-2)/2$. The is determined from precision measurements two angular frequencies. Intensity variation high-energy positrons decays directly encodes difference frequency $\omega_a$ between spin-precession and cyclotron frequencies polarized muons in a storage ring. ring field measured using nuclear resonance probes calibrated terms equivalent proton spin precession...
We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. have analyzed more than 4 times number positrons decay our previous result 2018 data. The systematic error is reduced by factor 2 due to better running conditions, stable beam, improved knowledge field weighted distribution, ω[over ˜]_{p}^{'}, anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From ratio...
The Muon g-2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency $ω_a$ to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data collected in four storage ring configurations during its first physics run 2018. When combined a precision measurement magnetic field experiment's ring, determines anomaly $a_μ({\rm FNAL}) = 116\,592\,040(54) \times 10^{-11}$ (0.46 ppm). This article describes...
The lunar-ranging test of the equivalence principle for gravitational self-energy is ambiguous. Although Earth has more than Moon, its sizable Fe/Ni core also gives it a different composition Moon. We removed this ambiguity by comparing, in effect, accelerations ``miniature'' earths and moons toward Sun. Our composition-dependent Earth-Moon acceleration,...
The lowest stationary quantum state of neutrons in the Earth's gravitational field is identified measurement neutron transmission between a horizontal mirror on bottom and an absorber top. Such assembly not transparent for if height smaller than "height" state.
The Fermi National Accelerator Laboratory has measured the anomalous precession frequency $a^{}_\mu = (g^{}_\mu-2)/2$ of muon to a combined precision 0.46 parts per million with data collected during its first physics run in 2018. This paper documents measurement magnetic field storage ring. is monitored by nuclear resonance systems and calibrated terms equivalent proton spin spherical water sample at 34.7$^\circ$C. weighted distribution resulting $\tilde{\omega}'^{}_p$, denominator ratio...
We present details on a new measurement of the muon magnetic anomaly, $a_\mu = (g_\mu -2)/2$. The result is based positive data taken at Fermilab's Muon Campus during 2019 and 2020 accelerator runs. uses $3.1$ GeV$/c$ polarized muons stored in $7.1$-m-radius storage ring with $1.45$ T uniform field. value $ a_{\mu}$ determined from measured difference between spin precession frequency its cyclotron frequency. This normalized to strength field, using Nuclear Magnetic Resonance (NMR). ratio...
We report on a new measurement of neutron beta-decay asymmetry. From the result A(0) = -0.1189(7), we derive ratio axial vector to coupling constant lambda g(A)/g(V) -1.2739(19). When included in world average for lifetime tau 885.7(7) s, this gives first element Cabibbo-Kobayashi-Maskawa (CKM) matrix V(ud). With value and Particle Data Group values V(us) V(ub), find deviation from unitarity condition row CKM Delta 0.0083(28), which is 3.0 times stated error.
We present a new constraint for the axion monopole-dipole coupling in range of $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$--a few mm, previously unavailable experimental study. The was obtained using our recent results on observation neutron quantum states Earth's gravitational field. exploit ultimate sensitivity ultracold neutrons (UCN) lowest above material surface to any additional interaction between UCN and matter, if characteristic is within mentioned domain.
We evaluate the impact of recent developments in hadron phenomenology on extracting possible fundamental tensor interactions beyond standard model. show that a novel class observables, including chiral-odd generalized parton distributions, and transversity distribution function can contribute to constraints this quantity. Experimental extractions hadronic matrix elements, if sufficiently precise, will provide a, so far, absent testing ground for lattice QCD calculations.
On the basis of revisions some systematic errors, we reanalyzed electron-antineutrino angular correlation ($a$ coefficient) in free neutron decay inferred from recoil energy spectrum protons which are detected $4\ensuremath{\pi}$ by aSPECT spectrometer. With $a=\ensuremath{-}0.104\text{ }02(82)$ new value differs only marginally one published 2020. The experiment also has sensitivity to $b$, Fierz interference term. From a correlated $(b,a)$ fit proton spectrum, derive limit...
We report on a precise measurement of the electron-antineutrino angular correlation ($a$ coefficient) in free neutron beta-decay from $a$SPECT experiment. The $a$ coefficient is inferred recoil energy spectrum protons which are detected 4$\pi$ by spectrometer using magnetic adiabatic collimation with an electrostatic filter. Data presented 100 days run at Institut Laue Langevin 2013. sources systematic errors considered and included final result. obtain $a = -0.10430(84)$ most to date. From...
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well those reached directly at high energy colliders. Discrimination between different models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss current status prospects near future a compelling suite such experiments, along with developments needed encompassing theoretical framework.
We present a new measurement of the positive muon magnetic anomaly, $a_\mu \equiv (g_\mu - 2)/2$, from Fermilab Muon $g\!-\!2$ Experiment using data collected in 2019 and 2020. have analyzed more than 4 times number positrons decay our previous result 2018 data. The systematic error is reduced by factor 2 due to better running conditions, stable beam, improved knowledge field weighted distribution, $\tilde{\omega}'^{}_p$, anomalous precession frequency corrected for beam dynamics effects,...
We report the first observation of parity-violating 2.2 MeV gamma-ray asymmetry $A^{np}_\gamma$ in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at Spallation Neutron Source Oak Ridge National Laboratory. isolates $\Delta I=1$, \mbox{$^{3}S_{1}\rightarrow {^{3}P_{1}}$} component weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to single coupling constant either DDH meson model or pionless EFT....
We study theoretically the quantum motion of a neutron in horizontal waveguide gravitational field Earth. The question is equipped with mirror below and rough surface absorber above. show that such system acts as filter, i.e. it effectively absorbs states sufficiently high transversal energy but transmits low-energy states. transmitted are determined mainly by potential well formed Earth mirror. formalism developed for an absorbing applied to description recent experiment on observation...
The strongly spin-dependent absorption of neutrons in nuclear spin-polarized (3)He opens up the possibility polarizing from reactors and spallation sources over full kinematical range cold, thermal hot neutrons. This paper gives a report on neutron spin filter (NSF) development program at Mainz. polarization technique is based direct optical pumping metastable atoms combined with preserving mechanical compression gas to pressure several bar, necessary run NSF. concept remote type operation...
Precision measurements in free neutron beta decay serve to determine the coupling constants of decay, and offer several stringent tests Standard Model.This paper describes program planned for Fundamental Physics Beamline at Spallation Neutron Source Oak Ridge National Laboratory, puts it into context other recent observables.