A5014614419- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Atomic and Molecular Physics
- High-Energy Particle Collisions Research
- Muon and positron interactions and applications
- Nuclear physics research studies
- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Dark Matter and Cosmic Phenomena
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Radioactive Decay and Measurement Techniques
- Advanced Chemical Physics Studies
- Quantum and Classical Electrodynamics
- Atomic and Subatomic Physics Research
- Coding theory and cryptography
- High-pressure geophysics and materials
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Geophysical and Geoelectrical Methods
- Magnetic confinement fusion research
- Algebraic structures and combinatorial models
- Quantum, superfluid, helium dynamics
- Advanced Data Storage Technologies
Amherst College
2024
University of Massachusetts Amherst
2018-2023
University of Maryland, College Park
2017
Princeton University
1986-2000
National Research Council Canada
1977-2000
University of California, Irvine
1986-2000
Carleton University
1969-1987
University of Oxford
1986
University of Guelph
1986
Laurentian University
1986
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 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 have measured muonic x rays in the energy region 150 to 440 keV nine elements with an absolute precision of 15 21 eV for transitions small nuclear effects. Calculated transition energies were found be consistently larger than those by amount that varied from \ifmmode\pm\else\textpm\fi{} 16 at 157 137 22 438 keV. For these transitions, principal correction Dirac is vacuum polarization. The discrepancy, however, lies outside expected validity quantum-electrodynamic calculations and we are...
The size and shape of the nuclear charge distribution was determined for Pb isotopes from precise measurements their $\ensuremath{\mu}$-atomic transition energies. Use $2p\ensuremath{-}1s$ transitions avoided in determining parameters because perturbation caused by presence muon $1s$ orbit. A simple two-parameter Fermi used analysis, but rms radius thereby should be fairly model-independent. We find ${〈{r}^{2}〉}^{\frac{1}{2}}=5.4839\ifmmode\pm\else\textpm\fi{}0.0028$ fm...
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,...
General relativity predicts that massless waves should scatter from the Riemann curvature of their backgrounds. These scattered are sometimes called $\textit{tails}$ and have never been directly observed. Here we calculate gravitational in backward direction (scattering angle $\vartheta=\pi$) weak-field an extended massive object, finding close agreement with previous results long-wavelength limit. then applied to Laser Interferometer Space Antenna (LISA) sensitivity band scattering Sun...
Results of an experiment to measure muonic transition energies in separated lead isotopes are presented. The main results as follows: 1. Muonic spectra the four $^{204}\mathrm{Pb}$, $^{206}\mathrm{Pb}$, $^{207}\mathrm{Pb}$, and $^{208}\mathrm{Pb}$ were studied with high resolution. No anomalous splitting or broadening lines was detected. effect natural linewidth could, however, be observed. 2. An anomaly found $3d$ fine structure whose measured value turned out larger than calculated by...
$\ensuremath{\mu}$-atomic Lyman and Balmer series were observed in Ti, Ti${\mathrm{O}}_{2}$, Mn using a large high-resolution Ge(Li) detector. While the relative line intensities are, for most part, accounted reasonably well by cascade model, systematic differences found comparing Ti${\mathrm{O}}_{2}$ Ti. The $2p\ensuremath{-}2s$ splitting was first time muonic atoms.
Computational techniques previously used by the authors for treatment of ${\ensuremath{\mu}}^{\ensuremath{-}}$- and ${\ensuremath{\pi}}^{\ensuremath{-}}$-mesonic atoms are extended to ${K}^{\ensuremath{-}}$-mesonic x-ray yields most important transitions calculated as a function atomic number. It is shown that experimental measurement these will provide sensitive determination imaginary part ${K}^{\ensuremath{-}}$-nucleus optical potential. The level shifts due meson scattering interaction...
Neutron emission by radiationless $\ensuremath{\mu}$-atomic transitions in ${\mathrm{Bi}}^{209}$ has been observed. The analysis of the neutron time-of-flight spectrum shows that this process takes place muon from $n=3$ or higher states to ground state muonic atom while nucleus is left either an excited state, possibly one belonging a particle-hole multiplet ${\mathrm{Bi}}^{208}$. investigated here occurs 7 \ifmmode\pm\else\textpm\fi{} 2% all stops bismuth.
Muonic x rays in ${\mathrm{Pb}}^{206}$ were measured with high precision and addition two of the weak transitions involving $2s$ state identified for first time. The new constraints make it difficult to fit data Dirac energies calculated a finite nucleus corrected radiative effects. Consistency can, however, be achieved by depressing $1s$ energy 6.8\ifmmode\times\else\texttimes\fi{}2.3 keV, an effect tentatively interpreted as due polarization muon.
We present an analysis of $\ensuremath{\pi}$-mesonic atoms, based upon cascade calculations taking into account the known processes radiation, Auger transitions, and nuclear absorption. This analysis, together with previous one on $\ensuremath{\mu}$-mesonic is intended to provide a deeper insight unsolved problem deficiency x rays in mesonic atoms. It shown that $L$ x-ray yields (for $Z\ensuremath{\le}20$) are quite insensitive strength absorption depend only chosen initial meson population...
In order to check the discrepancy between calculation and experiment in muonic atoms, we have remeasured $5g\ensuremath{-}4f$ transitions Pb $4f\ensuremath{-}3d$ Ba. Our new results show no confirm recent theoretical calculations of vacuum polarization within 0.5%.
We have accurately measured eleven muonic-atom transition energies in five elements sensitive to the vacuum-polarization corrections. find good agreement between theoretical and experimental values, average difference being (0.18\ifmmode\pm\else\textpm\fi{} 0.15)% of correction.
The main mu-atomic transition energies in 89 Y were measured with a high-resolution Ge(Li) spectrometer. nuclear charge parameters of yttrium derived by fitting the observed to those obtained numerically solving Dirac equation, using radially symmetric Fermi distribution. line intensities also and shown agree reasonably well results cascade calculation. Finally, we most prominent capture γ rays. Most these rays could be assigned known transitions strontium isotopes 86 through 89.
A missing-mass spectrometer, employing optical spark chambers with automatic vidicon readout, was used to measure the forward differential cross section ($cos{\ensuremath{\theta}}_{\mathrm{c}.\mathrm{m}.}\ensuremath{\approx}0.995$) for reaction $p+p\ensuremath{\rightarrow}d+{\ensuremath{\pi}}^{+}$ at closely spaced settings of incident proton momentum in range ${p}_{0}=3.4\ensuremath{-}12.3 \frac{\mathrm{GeV}}{c}$. The deuterons from were identified by time flight, and their angle emission...
A measurement of the complete differential cross section for reaction $\mathrm{pp}\ensuremath{\rightarrow}d{\ensuremath{\pi}}^{+}$ at 3.00, 3.20, 3.43, 3.65, 3.83, 4.00, 4.20, and 5.05 $\frac{\mathrm{GeV}}{c}$ incident proton momentum has been made in an attempt to establish role $\ensuremath{\Delta}$ (1950) this region. The data show that previously observed enhancement forward between 3 4 due isobar is effect which damps out quickly as production angle departs from zero degrees, contrast...