A5080990877- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Superconducting Materials and Applications
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Particle Detector Development and Performance
- Muon and positron interactions and applications
- Quantum, superfluid, helium dynamics
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Computational Physics and Python Applications
- Quantum and Classical Electrodynamics
- NMR spectroscopy and applications
- Astronomical and nuclear sciences
- Geomagnetism and Paleomagnetism Studies
- Geophysical and Geoelectrical Methods
- Surface and Thin Film Phenomena
- Advanced Electrical Measurement Techniques
- Cellular Automata and Applications
Amherst College
2017-2024
University of Massachusetts Amherst
2015-2023
Temple University
2012-2022
Thomas Jefferson National Accelerator Facility
2017-2021
University of Virginia
2012-2019
High Energy Accelerator Research Organization
2019
University of Ljubljana
2018
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 report the first measurement of parity-violating asymmetry APV in elastic scattering polarized electrons from Pb208. is sensitive to radius neutron distribution (Rn). The result APV=0.656±0.060(stat)±0.014(syst) ppm corresponds a difference between radii and proton distributions Rn−Rp=0.33−0.18+0.16 fm provides electroweak observation skin which expected heavy, neutron-rich nucleus.Received 12 January 2012DOI:https://doi.org/10.1103/PhysRevLett.108.112502© 2012 American Physical Society
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...
We studied simultaneously the 4He(e,e'p), 4He(e,e'pp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with or neutron recoiling almost back missing momentum, leaving residual A=2 system low excitation energy. These data were used identify two-nucleon short-range correlated pairs deduce their isospin structure as function momentum region where nucleon-nucleon force is expected...
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 have measured the beam-normal single-spin asymmetry $A_n$ in elastic scattering of 1-3 GeV transversely polarized electrons from $^1$H and for first time $^4$He, $^{12}$C, $^{208}$Pb. For $^1$H, $^4$He measurements are agreement with calculations that relate to imaginary part two-photon exchange amplitude including inelastic intermediate states. Surprisingly, $^{208}$Pb result is significantly smaller than corresponding prediction using same formalism. These results suggest a systematic...
We present deeply virtual ${\ensuremath{\pi}}^{0}$ electroproduction cross-section measurements at ${x}_{B}=0.36$ and three different ${Q}^{2}$ values ranging from 1.5 to $2\text{ }\text{ }{\mathrm{Ge}\mathrm{V}}^{2}$, obtained Jefferson Lab Hall A experiment E07-007. The Rosenbluth technique is used separate the longitudinal transverse responses. Results demonstrate that cross section dominated by its component and, thus, far asymptotic limit predicted perturbative quantum chromodynamics....
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 on the results of E06-014 experiment performed at Jefferson Lab in Hall A, where a precision measurement twist-3 matrix element ${d}_{2}$ neutron (${d}_{2}^{n}$) was conducted. The quantity ${d}_{2}^{n}$ represents average color Lorentz force struck quark experiences deep inelastic electron scattering event off due to its interaction with hadronizing remnants. This determined from linear combination third moments $^{3}\mathrm{He}$ spin structure functions, ${g}_{1}$ and ${g}_{2}$,...
The parity-violating asymmetries between a longitudinally polarized electron beam and an unpolarized deuterium target have been measured recently. measurement covered two kinematic points in the deep-inelastic scattering region five nucleon resonance region. We provide here details of experimental setup, data analysis, results on all asymmetry measurements including those inclusive pion production beam-normal asymmetries. were used to extract electron-quark weak effective couplings, provided...
We have performed precision measurements of the double-spin virtual-photon asymmetry $A_1$ on neutron in deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer. Our data cover a wide kinematic range $0.277 \leq x 0.548$ at average $Q^2$ value 3.078~(GeV/c)$^2$, doubling available high-precision this $x$ range. combined our results with world proton targets to extract ratio polarized-to-unpolarized parton distribution functions for up quarks and down same are...
We report the first measurement of target single-spin asymmetry, A(y), in quasielastic scattering from inclusive reaction (3)He(↑)(e,e') on a (3)He gas polarized normal to lepton plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero A(y) can arise interference between one- and two-photon exchange processes which sensitive details substructure nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high...
We report development of a highly accurate (parts per billion) absolute magnetometer based on $^{3}\mathrm{He}$ NMR. Optical pumping polarizes the spins, long coherence times provide high sensitivity, and electron shell effectively isolates nuclear spin providing accuracy limited only by corrections including materials, sample shape, magnetization. Our was used to confirm calibration, 32 ppb, magnetic-field sensors in recent measurements muon magnetic moment anomaly...
We report on parity-violating asymmetries in the nucleon resonance region measured using inclusive inelastic scattering of 5–6 GeV longitudinally polarized electrons off an unpolarized deuterium target. These results are first asymmetry data beyond Δ(1232). They provide a verification quark-hadron duality—the equivalence quark- and hadron-based pictures nucleon—at (10–15)% level this electroweak observable, which is dominated by contributions from γZ interference structure functions. In...
The proton is composed of quarks and gluons, bound by the most elusive mechanism strong interaction called confinement. In this work, dynamics gluons are investigated using deeply virtual Compton scattering (DVCS): produced a multi-GeV electron, highly photon scatters off which subsequently radiates high energy photon. Similarly to holography, measuring not only magnitude but also phase DVCS amplitude allows perform 3D images internal structure proton. made accessible through...
The Spin Asymmetries of the Nucleon Experiment measured two double spin asymmetries using a polarized proton target and electron beam at energies, 4.7 5.9 GeV. A large-acceptance open-configuration detector package identified scattered electrons 40\ifmmode^\circ\else\textdegree\fi{} covered wide range in Bjorken $x$ ($0.3<x<0.8$). Proportional to an average color Lorentz force, twist-3 matrix element, ${\stackrel{\texttildelow{}}{d}}_{2}^{p}$, was extracted from ${Q}^{2}$ values ranging 2.0...
Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25≤x≤0.90), in both the deep-inelastic resonance regions, by scattering longitudinally polarized electrons beam energies of 4.7 5.9 GeV from a transversely 3He target. In this dedicated experiment, spin structure function g3He2 was determined with precision x, neutron twist-3 matrix element dn2 ⟨Q2⟩ 3.21 4.32 GeV2/c2, an about 10−5. Our results are found to be agreement lattice QCD calculations resolve...
We report on new p(e,e′p)π∘ measurements at the Δ+(1232) resonance low momentum transfer region, where mesonic cloud dynamics is predicted to be dominant and rapidly changing, offering a test bed for chiral effective field theory calculations. The data explore Q2 dependence of resonant quadrupole amplitudes first time indicate that Electric Coulomb converge as Q2→0. amplitude have been extended lowest ever reached, suggest more than half its magnitude attributed in this region. disagree with...
Short-range correlations (SRCs) have been identified as being responsible for the high-momentum tail of nucleon momentum distribution, $n(k)$. Hard, short-range interactions pairs generate and imprint a universal character on $n(k)$ all nuclei at large momentum. Triple coincidence experiments shown strong dominance $np$ pairs, but these measurements involve final-state interactions. This paper presents results from Jefferson Lab experiment E08014 which measured inclusive electron scattering...