A5075930699- Atomic and Molecular Physics
- Muon and positron interactions and applications
- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Quantum, superfluid, helium dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Astronomical and nuclear sciences
- Particle Detector Development and Performance
- Plasma Diagnostics and Applications
- Scientific Research and Discoveries
- Mass Spectrometry Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Fusion materials and technologies
- Nuclear reactor physics and engineering
- Chemical Reactions and Isotopes
- Radiation Detection and Scintillator Technologies
TRIUMF
2014-2025
University of Victoria
2006-2024
Swansea University
2011
Aarhus University
2011
Simon Fraser University
2011
University of California, Berkeley
2011
Universidade Federal do Rio de Janeiro
2011
High Energy Accelerator Research Organization
2006-2009
Istituto Nazionale di Fisica Nucleare, Sezione di Pavia
2005
University of Northern British Columbia
2003
We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at e+e− collider DAΦNE. Almost monochromatic K−’s produced through decay of ϕ(1020) mesons are used to observe K− absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we succeeded detect kaon-bound K−pp its two-body into Λ hyperon and proton. The binding energy width determined from invariant-mass distribution as 115+6−5(stat)+3−4(syst) MeV 67+14−11(stat)+2−3(syst)...
Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those itself. Although there are many indirect indications that no such differences exist weak equivalence principle holds, been direct, free-fall style, experimental tests of gravity on antimatter. Here we describe a novel direct test methodology; search for propensity antihydrogen atoms to fall downward when released ALPHA trap. In absence systematic errors, can reject...
This paper introduces a new approach to measure the muon magnetic moment anomaly |$a_{\mu} = (g-2)/2$| and electric dipole (EDM) |$d_{\mu}$| at J-PARC facility. The goal of our experiment is |$a_{\mu}$| using an independent method with factor 10 lower momentum, 20 smaller diameter storage-ring solenoid compared previous ongoing |$g-2$| experiments unprecedented quality storage field. Additional significant differences from present experimental include 1000 transverse emittance beam...
The antimatter equivalent of atomic hydrogen—antihydrogen—is an outstanding testbed for precision studies matter–antimatter symmetry. Here we report on the simultaneous observation both accessible hyperfine components 1S–2S transition in trapped antihydrogen. We determine 2S splitting antihydrogen and—by comparing our results with those obtained hydrogen—constrain charge–parity–time-reversal symmetry-violating coefficients standard model extension framework. Our experimental protocol allows...
We have measured the shift and width of kaonic hydrogen $1s$ state due to $\overline{K}N$ strong interaction. observed, for first time, distinct $K$-series x rays with good signal-to-noise ratio in energy spectrum. The were determined be $\ensuremath{\Delta}E(1s)\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}323\ifmmode\pm\else\textpm\fi{}63(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}11(\mathrm{syst})\mathrm{eV}$ (repulsive)...
The spectrum of the hydrogen atom has played a central part in fundamental physics over past 200 years. Historical examples its importance include wavelength measurements absorption lines solar by Fraunhofer, identification transition Balmer, Lyman and others, empirical description allowed wavelengths Rydberg, quantum model Bohr, capability electrodynamics to precisely predict frequencies, modern 1S-2S Hänsch precision few parts 1015. Recent technological advances have us focus on...
In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved unimagined particles-antimatter. The existence particles antimatter was confirmed with the discovery positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, antimatter, survived after Big Bang. As result, experimental studies...
The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers the measurement zero-field ground-state splitting at level seven parts 1013 are important achievements mid-twentieth-century physics. work that led to these also provided first evidence for anomalous magnetic moment electron, inspired Schwinger's relativistic theory quantum electrodynamics gave rise maser, which is a critical component modern navigation, geo-positioning very-long-baseline interferometry systems....
Abstract The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision 1 . Slowing translational motion atoms and ions by application such 2,3 , known as laser cooling, was first demonstrated 40 years ago 4,5 It revolutionized atomic physics over following decades 6–8 it is now workhorse in many fields, including studies degenerate gases, information, clocks tests fundamental physics. However,...
We have measured the K-series x rays from kaonic hydrogen atoms and succeeded for first time in observing a distinct $K\ensuremath{\alpha}$ peak. The L x-ray peak has also been observed. strong-interaction shift width of atom $1s$ state were determined transition energy line rays. sign was confirmed to be repulsive, with results $\ensuremath{\Delta}{E}_{1s}=\ensuremath{-}323\ifmmode\pm\else\textpm\fi{}63 (\mathrm{statistical})\ifmmode\pm\else\textpm\fi{}11 (\mathrm{systematic}) \mathrm{eV}$...
We report the application of evaporative cooling to clouds trapped antiprotons, resulting in plasmas with measured temperature as low 9 K. have modeled evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction efficiency future experiments. The technique opens up new possibilities ions particular interest antiproton physics, where a precise $CPT$ test on antihydrogen long-standing goal.
Abstract Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected mirror those of hydrogen atom. Prospects for precision comparisons two, as tests fundamental symmetries, driving vibrant programme research. In this regard, limiting factor in most experiments availability large numbers cold ground state antihydrogen atoms. Here, we describe how improved synthesis process results maximum rate 10.5 ± 0.6 atoms trapped detected per...
In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region atomic hydrogen spectrum1,2. The patterns spectrum helped to establish emerging theory quantum mechanics, which we now know governs world at scale. Since then, studies involving Lyman-α line-the 1S-2P transition a wavelength 121.6 nanometres-have played an important part physics and astronomy, as one most fundamental Universe. For example, this has long been used by astronomers studying...
The 21Na(p,gamma)22Mg reaction is expected to play an important role in the nucleosynthesis of 22Na oxygen-neon novae. decay leads emission a characteristic 1.275 MeV gamma-ray line. This report provides first direct measurement rate this using radioactive 21Na beam, and discusses its astrophysical implications. energy state was measured be E(c.m.)=205.7+/-0.5 keV with resonance strength omegagamma=1.03+/-0.16(stat)+/-0.14(sys) meV.
The positron spectrum from the decay ${\ensuremath{\pi}}^{+}\ensuremath{\rightarrow}{e}^{+}{\ensuremath{\nu}}_{e}$ has been examined for evidence of peaks arising an admixture in ${\ensuremath{\nu}}_{e}$ weak eigenstate massive neutrinos. Limits on intensity such peaks, together with measured $\ensuremath{\pi}\ensuremath{\rightarrow}e\ensuremath{\nu}$ branching ratio, have used to derive constraints neutrino mixing parameters over range $4 \mathrm{MeV}<m(\ensuremath{\nu})<135 \mathrm{MeV}$.
We demonstrate controllable excitation of the center-of-mass longitudinal motion a thermal antiproton plasma using swept-frequency autoresonant drive. When is cold, dense, and highly collective in nature, we observe that entire system behaves as single-particle nonlinear oscillator, predicted by recent theory. In contrast, only fraction antiprotons warm can be similarly excited. Antihydrogen was produced trapped this technique to drive into positron plasma, thereby initiating atomic recombination.
The ALPHA collaboration, based at CERN, has recently succeeded in confining cold antihydrogen atoms a magnetic minimum neutral atom trap and performed the first study of resonant transition anti-atoms. apparatus will be described herein, with emphasis on structural aspects, diagnostic methods techniques that have enabled trapping experimentation to achieved.
Stochastic acceleration applied to 1,000 trapped antihydrogen atoms yields a 20-fold reduction of the experimental upper bound on magnitude charge antihydrogen, which is expected be neutral. One most puzzling current questions in physics why we see so much more matter than antimatter Universe. Studying properties might give hints about reasons for this imbalance. According Standard Model particle physics, should neutral, but it challenging test experimentally as difficult produce and measure...
Emission of muonium (|$\mu ^+e^-$|) atoms from a laser-processed aerogel surface into vacuum was studied for the first time. Laser ablation used to create hole-like regions with diameter about 270 |$\mu $|m in triangular pattern hole separation range 300–500 $|m. The emission probability sample is at least eight times higher than uniform one.