A5041861669- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Dark Matter and Cosmic Phenomena
- Muon and positron interactions and applications
- Quantum, superfluid, helium dynamics
- Electron and X-Ray Spectroscopy Techniques
- Particle accelerators and beam dynamics
- Radioactive Decay and Measurement Techniques
- Mass Spectrometry Techniques and Applications
- Nuclear Physics and Applications
- Quantum and Classical Electrodynamics
- Quantum Information and Cryptography
- Nuclear physics research studies
- Quantum optics and atomic interactions
- Advanced Chemical Physics Studies
- Quantum and electron transport phenomena
- Radiation Detection and Scintillator Technologies
- Quantum Mechanics and Applications
- Particle Accelerators and Free-Electron Lasers
- Mechanical and Optical Resonators
- Magnetic confinement fusion research
- Experimental and Theoretical Physics Studies
- Non-Destructive Testing Techniques
- Inorganic Fluorides and Related Compounds
Northwestern University
2019-2023
Harvard University
2010-2021
Harvard University Press
2005-2017
Yale University
2016
Blackstone (United States)
2016
University of Washington
1979-1991
University of Washington Applied Physics Laboratory
1986
University of Chicago
1976-1981
Argonne National Laboratory
1976-1981
Calvin University
1977
A single charged particle in a Penning trap is bound system that rivals the hydrogen atom its simplicity and provides similar opportunities to calculate measure physical quantities at very high precision. We review theory of this system, beginning with simple first-order orbits progressively dealing small corrections which must be considered owing experimental precision being achieved. Much discussion will also useful for experiments more particles trap, several mathematical techniques have...
A measurement using a one-electron quantum cyclotron gives the electron magnetic moment in Bohr magnetons, g/2 = 1.001 159 652 180 73 (28) [0.28 ppt], with an uncertainty 2.7 and 15 times smaller than for previous measurements 2006 1987. The is used as magnetometer to allow lineshape statistics accumulate, its spontaneous emission rate determines correction interaction cylindrical trap cavity. new QED theory determine fine structure constant, alpha^{-1} 137.035 999 084 (51) [0.37 ppb], 20...
Stubbornly Spherical The shape of the electron's charge distribution reflects degree to which switching direction time impacts basic ingredients universe. Standard Model (SM) particle physics predicts a very slight asphericity distribution, whereas SM extensions such as supersymmetry posit bigger and potentially measurable, but still tiny, deviations from perfect sphere. Polar molecules have been identified ideal settings for measuring this asymmetry, should be reflected in finite electric...
A background-free observation of cold antihydrogen atoms is made using field ionization followed by antiproton storage, a detection method that provides the first experimental information about atomic states. More can be ionized in an hour than all antimatter have been previously reported, and production rate per incident high energy higher ever observed. The Rydberg states suggest formed via three-body recombination.
A new measurement resolves cyclotron and spin levels for a single-electron quantum to obtain an electron magnetic moment, given by g/2=1.001 159 652 180 85 (76) [0.76 ppt]. The uncertainty is nearly 6 times lower than in the past, g shifted downward 1.7 standard deviations. g, with electrodynamics (QED) calculation, determines fine structure constant 0.7 ppb uncertainty--10 smaller atom-recoil determinations. Remarkably, this 100 mK probes internal at 130 GeV.
Measurements with a one-electron quantum cyclotron determine the electron magnetic moment, given by $g/2=1.001 159 652 180 73(28)[0.28\mathrm{ppt}]$, and fine structure constant, $\ensuremath{\alpha}{}^{\ensuremath{-}1}=137.035 999 084(51)[0.37\mathrm{ppb}]$. Announcements of these measurements [Phys. Rev. Lett. 97, 030801 (2006); 100, 120801 (2008)] are supplemented here more complete description measurement methods, discussion cavity control radiation field, summary analysis measurements,...
We describe a measuring system for determining the state of polarization beam light in terms its Stokes parameters. The technique which can be fully automated incorporates monochromator and single photon counting detection thus applied over large wavelength range very weak optical signals. Fourier transformation data by an on-line minicomputer allows immediate calculation discuss special applications to emitted from excited atomic systems with without cylindrical symmetry.
Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of electron (g) and fine structure constant (alpha). A new measurement g using one-electron quantum cyclotron, together with QED calculation involving 891 eighth-order Feynman diagrams, determine alpha(-1)=137.035 999 710 (96) [0.70 ppb]. The uncertainties are 10 times smaller than those nearest rival methods that include atom-recoil measurements. Comparisons measured calculated test most...
The electron magnetic moment, -μ/μ_{B}=g/2=1.001 159 652 180 59 (13) [0.13 ppt], is determined 2.2 times more accurately than the value that stood for fourteen years. most precisely property of an elementary particle tests precise prediction standard model (SM) to 1 part in 10^{12}. test would improve order magnitude if uncertainty from discrepant measurements fine structure constant α eliminated since SM a function α. new measurement and theory together predict α^{-1}=137.035 999 166 (15)...
This last of a series three measurements improves the comparison antiproton $(\overline{p})$ and proton $(p)$ by almost factor ${10}^{6}$ over earlier exotic atom measurements, is most precise $\mathrm{CPT}$ test with baryons similar large factor. Measuring cyclotron frequencies simultaneously trapped $\overline{p}$ ${H}^{\ensuremath{-}}$ ion establishes that ratio $q/m$ for $p$ $\ensuremath{-}0.99999999991\ifmmode\pm\else\textpm\fi{}0.00000000009$, more than 10 times accuracy our previous...
The radiative decay of the cyclotron motion a single electron is significantly inhibited when located within microwave cavity (formed by electrodes Penning trap) rather than in free space. This first observation such spontaneous emission and use promising new system for physics. Implications precision measurements are mentioned.
Comparisons of antiproton and proton cyclotron frequencies yield the ratio inertial masses M(p\ifmmode\bar\else\textasciimacron\fi{})/M(p)=0.999 999 977 \ifmmode\pm\else\textpm\fi{}0.000 000 042. The fractional uncertainty 4\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}8}$ is 1000 times more accurate than previous measurements this using exotic atoms most precise test CPT invariance with baryons. Independent comparisons to electrons mass ratios...
Electron cooling of trapped antiprotons allows their storage at energies 10 million times lower than is available in any antiproton ring. More 60 000 with from 0 to 3000 eV are stored an ion trap a single pulse 5.9-MeV LEAR. Trapped maintain initial energy distribution over lifetime exceeding 50 h unless allowed collide cold buffer gas electrons, where- upon they cool dramatically 1 tens seconds. The cooled can be stacked into harmonic potential well suited for long-term and precision measurements.
The phenomenal accuracies achieved for the spectroscopy of single charged particles suspended in Penning traps has prompted this study imperfect trap. principal result is a new prescription cyclotron frequency terms observable eigenfrequencies completely insensitive to misalignment magnetic field direction with axis electrodes, and it also most significant imperfections electrostatic potential. These systematic effects can therefore be circumvented measurements anomalous moments electron...
Cold antihydrogen is produced when antiprotons are repeatedly driven into collisions with cold positrons within a nested Penning trap. Efficient production takes place during many cycles of positron cooling antiprotons. A first measurement distribution states made using preionizing electric field between separated and detection regions. Surviving stripped in an ionization well that captures stores the freed antiproton for background-free detection.
Quantum jumps between Fock states of a one-electron oscillator reveal the quantum limit cyclotron. With surrounding cavity inhibiting synchrotron radiation 140-fold, show 13 s state lifetime and cyclotron in thermal equilibrium with 1.6 to 4.2 K blackbody photons. These disappear by 80 mK, temperature 50 times lower than previously achieved an isolated elementary particle. The stays its ground until resonant photon is injected. A offers new route measuring electron magnetic moment fine...
Antiprotons from the Low Energy Antiproton Ring of CERN are slowed 21 MeV to below 3 keV by being passed through mm material, mostly Be. While still in flight, kiloelectronvolt antiprotons captured a Penning trap created sudden application 3-kV potential. held for 100 s and more. Prospects now excellent much longer trapping times under better vacuum conditions. This demonstrates feasibility greatly improved measurement inertial mass antiproton opens way other intriguing experiments.
Antihydrogen atoms (H¯) are confined in an Ioffe trap for 15-1000 s-long enough to ensure that they reach their ground state. Though reproducibility challenges remain making large numbers of cold antiprotons (p¯) and positrons (e(+)) interact, 5±1 simultaneously ground-state produced observed on average, substantially more than previously reported. Increases the number trapped H¯ critical if laser cooling is be demonstrated spectroscopic studies at interesting levels precision carried out.
STIRAP (Stimulated Raman Adiabatic Passage) is a powerful laser-based method, usually involving two photons, for efficient and selective transfer of population between quantum states. A particularly interesting feature the fact that coupling initial final states via an intermediate state even though lifetime latter can be much shorter than interaction time with laser radiation. Nevertheless, spontaneous emission from prevented by interference. Maintaining coherence throughout process...
Lasers are used for the first time to control production of antihydrogen (H ). Sequential, resonant charge exchange collisions involved in a method that is very different than only other so far-producing slow H during positron cooling antiprotons nested Penning trap. Two attractive features laser frequencies determine binding energy, and extremely cold should be possible principle-likely close what needed confinement trap, as precise spectroscopy.
A bistable hysteresis in the cyclotron motion of a single electron has been observed which is so pronounced that it provides best signal-to-noise ratio ever with elementary particle trap. The effect due entirely to relativistic mass increase despite very low kinetic energies between 0.016 and 10 eV. During these experiments, was trapped continuously for more than months Penning