K. van Bibber
A5077185115- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Cosmology and Gravitation Theories
- Particle Detector Development and Performance
- Nuclear physics research studies
- High-Energy Particle Collisions Research
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Cosmic Phenomena
- Nuclear reactor physics and engineering
- Neutrino Physics Research
- Scientific Research and Discoveries
- Particle accelerators and beam dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- X-ray Spectroscopy and Fluorescence Analysis
- Computational Physics and Python Applications
- Superconducting Materials and Applications
- Radiation Detection and Scintillator Technologies
- Atomic and Molecular Physics
- Black Holes and Theoretical Physics
- Astronomical and nuclear sciences
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
University of California, Berkeley
2015-2025
Berkeley College
2021
Hearst (United States)
2021
University of Washington
2016
European Organization for Nuclear Research
2016
University of Bonn
2015
Lawrence Livermore National Laboratory
2005-2014
Los Alamos National Laboratory
2014
Naval Postgraduate School
2009-2011
University of Florida
2010
Axions in the micro eV mass range are a plausible cold dark matter candidate and may be detected by their conversion into microwave photons resonant cavity immersed static magnetic field. The first result from such an axion search using superconducting first-stage amplifier (SQUID) is reported. SQUID amplifier, replacing conventional GaAs field-effect transistor successfully reached axion-photon coupling sensitivity band set present models sets stage for definitive utilizing near...
We overview the current status of axions as dark matter. The axion is pseudo-Nambu–Goldstone boson which arises from Peccei–Quinn solution to strong CP problem. Additionally, cold populations that can contribute matter universe will be generated via this mechanism. After reviewing these topics, we focus on constraints laboratory, astrophysics and cosmology. discuss experimental searches consequences distribution in galactic halo for searches. remains an excellent candidate future...
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....
A search for dark matter axions with masses $>10\text{ }\text{ }\mathrm{\ensuremath{\mu}}\mathrm{eV}/{\mathrm{c}}^{2}$ has been performed using the HAYSTAC experiment's squeezed state receiver to achieve subquantum limited noise. This work includes details of design and operation experiment previously used in mass ranges 16.96--17.12 $17.14--17.28\text{ (4.100--4.140 GHz 4.145--4.178 GHz) as well upgrades facilitate an extended at higher masses. These include improvements data acquisition...
We report measurements of the proton form factors GEp and GMp extracted from elastic scattering in range 1≤Q2≤3 (GeV/c)2 with total uncertainties < 15% 3% GMp. Comparisons are made to theoretical models, including those based on perturbative QCD, vector-meson dominance, QCD sum rules, diquark constituents proton. The results for somewhat larger than indicated by most parametrizations, ratios Pauli Dirac Q2(F2pF1p) lower value demonstrate a weaker Q2 dependence predictions. A global...
We propose a laboratory experiment to produce and detect light neutral pseudoscalar particle that couples two photons. The would be produced by (real) photon from laser beam interacting with second (virtual) static magnetic field; it detected after reconverts real in duplicate field. bounds on the coupling constant could obtained null result such an compete favorably astrophysical limits substantially improve those direct measurements.
Recent determinations of cosmological parameters point to a flat Universe, whose total energy density is composed about two-thirds vacuum and one-third matter. Ordinary baryonic matter relegated small fraction the latter, within which luminous part an order magnitude smaller yet. Particle dark matter, i.e., one or more relic particle species from big bang, thus strongly suggested as dominant component in Universe. The axion, hypothetical elementary pseudoscalar arising Peccei-Quinn solution...
We have searched for solar axions or other pseudoscalar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup. Whereas we previously reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here report where were filled 4He gas II) of variable pressure. The introduction generates a refractive photon mγ, thereby achieving maximum possible conversion rate those axion masses ma match mγ. With 160 different...
We present a practical design for detector sensitive to axions and other light particles with two-photon interaction vertex. Such would be produced in the solar interior by Primakoff conversion of blackbody photons could detected their reconversion into x rays (average energy about 4 keV) strong laboratory magnetic field. An existing large superconducting magnet suitable this purpose. The transition rate is enhanced filling region buffer gas (${\mathrm{H}}_{2}$ or He). This induces an...
We have built and operated a large-scale axion detector, based on method originally proposed by Sikivie, to search for halo axions. The apparatus consists of cylindrical tunable high-Q microwave cavity threaded axially static high magnetic field. This field stimulates axions that enter the convert into single photons. conversion is resonantly enhanced when resonant frequency near rest mass energy. experiment cooled 1.5 K electromagnetic power spectrum emitted measured an ultra-low-noise...
The axion is a hypothetical elementary particle and cold dark matter candidate. In this rf cavity experiment, halo axions entering resonant immersed in static magnetic field convert into microwave photons, with the resulting photons detected by low-noise receiver. ADMX Collaboration presents new limits on axion-to-photon coupling local mass density from search range $1.9--2.3\ensuremath{\mu}\mathrm{eV},$ broadening to $1.9--3.3\ensuremath{\mu}\mathrm{eV}.$ addition, we report first results...
We have performed a high resolution search for galactic halo axions in cold flows using microwave cavity detector. The analysis procedure and other details of this are described. No axion signal was found the mass range $1.98--2.17\text{ }\text{ }\ensuremath{\mu}\mathrm{eV}$. place upper limits on density local discrete based result.
The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each 252 different we have scanned the mass range 0.39 eV < m_a 0.64 eV. From absence excess X-rays when magnet was pointing Sun set typical upper limit on axion-photon coupling g_ag 2.3 x 10^{-10} GeV^{-1} 95% CL, exact...
We study the feasibility of a new generation axion helioscope, most ambitious and promising detector solar axions to date. show that large improvements in magnetic field volume, x-ray focusing optics backgrounds are possible beyond those achieved CERN Axion Solar Telescope (CAST). For hadronic models, sensitivity axion-photon coupling gaγ ≳ few × 10−12 GeV−1 is conceivable, 1–1.5 orders magnitude CAST sensitivity. If also couple electrons, Sun produces larger flux for same value Peccei-Quinn...
The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the range 0.64 eV ≲ ma 1.17 eV. This closes gap to cosmological hot dark matter limit and actually overlaps it. From absence of excess x rays when magnet was pointing Sun we set a typical upper on axion-photon coupling gaγ 3.3 × 10(-10) GeV(-1) at 95% C.L., exact value depending pressure setting. Future direct axion searches will focus increasing sensitivity smaller values gaγ, example by...
The QCD axion is one of the most compelling candidates to explain dark matter abundance universe. With its extremely small mass ($\ll 1\,\mathrm{eV}/c^2$), interacts as a classical field rather than particle. Its coupling photons leads modification Maxwell's equations that can be measured with sensitive readout circuits. DMRadio-m$^3$ next-generation search for below $1\,\mu$eV using $>4$ T static magnetic field, coaxial inductive pickup, tunable LC resonator, and DC-SQUID readout. It...
We summarize the recent progress of Axion Longitudinal Plasma Haloscope (ALPHA) Consortium, a new experimental collaboration to build plasma haloscope search for axions and dark photons. The is novel method detection resonant conversion light matter ALPHA will be sensitive QCD over almost decade parameter space, potentially discovering resolving strong $CP$ problem. Unlike traditional cavity haloscopes, which are generally limited in volume by Compton wavelength matter, haloscopes use wire...
This Letter reports new results from the HAYSTAC experiment's search for dark matter axions in our galactic halo. It represents widest to date that utilizes squeezing realize subquantum limited noise. The cover 1.71 μeV of newly scanned parameter space mass ranges 17.28-18.44 and 18.71-19.46 μeV. No statistically significant evidence an axion signal was observed, excluding couplings |g_{γ}|≥2.75×|g_{γ}^{KSVZ}| |g_{γ}|≥2.96×|g_{γ}^{KSVZ}| at 90% confidence level over respective region. By...
We report the first results of a high-sensitivity $(\ensuremath{\sim}{10}^{\ensuremath{-}23}\mathrm{W})$ search for light halo axions through their conversion to microwave photons. At 90% confidence level, we exclude Kim-Shifman-Vainshtein-Zakharov axion mass $2.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$ $3.3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\mathrm{eV}$ as dark matter in our galaxy.
The cross section for quasielastic $^{12}\mathrm{C}$(e,e'p) scattering has been measured at momentum transfer ${\mathit{Q}}^{2}$=1, 3, 5, and 6.8 (GeV/c${)}^{2}$. results are consistent with from a single nucleon as the dominant process. nuclear transparency is obtained compared theoretical calculations that incorporate color effects. No significant rise of ${\mathit{Q}}^{2}$ observed.