P. Geltenbort
A5003408244- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Quantum, superfluid, helium dynamics
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Nuclear reactor physics and engineering
- Cold Atom Physics and Bose-Einstein Condensates
- Dark Matter and Cosmic Phenomena
- Nuclear Materials and Properties
- Particle Detector Development and Performance
- Photorefractive and Nonlinear Optics
- X-ray Spectroscopy and Fluorescence Analysis
- Particle physics theoretical and experimental studies
- Mechanical and Optical Resonators
- Cosmology and Gravitation Theories
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- Cold Fusion and Nuclear Reactions
- Medical Imaging Techniques and Applications
- Astro and Planetary Science
- Geophysics and Sensor Technology
- Metal and Thin Film Mechanics
- Superconducting Materials and Applications
Institut Laue-Langevin
2015-2024
Institut Langevin
1987-2022
California Institute of Technology
2021
Stanford University
2020
University of Vienna
2020
Technical University of Munich
2020
Adelphi Technology (United States)
2020
Kyoto University
2020
Los Alamos National Laboratory
2019
TU Wien
2016
We report an improved measurement of the free neutron lifetime τ_{n} using UCNτ apparatus at Los Alamos Neutron Science Center. count a total approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns 2017 and 2018. extract from three blinded, independent analyses by both pairing long short storage time runs to find set replicate measurements performing global likelihood fit all while self-consistently...
We report on precision resonance spectroscopy measurements of quantum states ultracold neutrons confined above the surface a horizontal mirror by gravity potential Earth. Resonant transitions between several lowest are observed for first time. These demonstrate that Newton's inverse square law is understood at micron distances an energy scale $1{0}^{\ensuremath{-}14}\text{ }\text{ }\mathrm{eV}$. At this level precision, we able to provide constraints any possible gravitylike interaction. In...
The precise value of the mean neutron lifetime, $\tau_n$, plays an important role in nuclear and particle physics cosmology. It is a key input for predicting ratio protons to helium atoms primordial universe used search new beyond Standard Model physics. There 3.9 standard deviation discrepancy between $\tau_n$ measured by counting decay rate free neutrons beam (887.7 $\pm$ 2.2 s) surviving ultracold stored different storage times material trap (878.5$\pm$0.8 s). experiment described here...
A neutron $\ensuremath{\beta}$-decay asymmetry measurement using polarized ultracold neutrons (UCN) determines the correlation between spin of and momentum decay electron. The authors extract ratio weak axial-vector to vector couplings with reduced uncertainties. This new result from first this UCN contributes a benchmark for lattice QCD calculations possibility improved precision on CKM matrix element ${V}_{u\phantom{\rule{0}{0ex}}d}$ $\ensuremath{\beta}$ decay.
The violation of Baryon Number, $\mathcal{B}$, is an essential ingredient for the preferential creation matter over antimatter needed to account observed baryon asymmetry in universe. However, such a process has yet be experimentally observed. HIBEAM/NNBAR %experiment program proposed two-stage experiment at European Spallation Source (ESS) search number violation. will include high-sensitivity searches processes that violate by one or two units: free neutron-antineutron oscillation...
The geometric phase has been proposed as a candidate for noise resilient coherent manipulation of fragile quantum systems. Since it is determined only by the path state, presence fluctuations affects in different way than dynamical phase. We have experimentally tested robustness Berry's spin-1/2 particles cyclically varying magnetic field. Using trapped polarized ultra-cold neutrons demonstrated that contributions to dephasing due adiabatic field vanish long evolution times.
The idea of a hidden sector mirror partners elementary particles has attracted considerable interest as possible candidate for dark matter. Recently it was pointed out by Berezhiani and Bento that the present experimental data cannot exclude possibility rapid oscillation neutron n to n' with time much smaller than lifetime. A dedicated search vacuum transitions n->n' be performed at weak magnetic field, where both states are degenerate. We report result our experiment, which compares...
A new measurement of the neutron $β$-decay asymmetry $A_0$ has been carried out by UCNA collaboration using polarized ultracold neutrons (UCN) from solid deuterium UCN source at Los Alamos Neutron Science Center (LANSCE). Improvements in experiment have led to reductions both statistical and systematic uncertainties leading $A_0 = -0.11954(55)_{\rm stat.}(98)_{\rm syst.}$, corresponding ratio axial-vector vector coupling $λ\equiv g_A/g_V -1.2756(30)$.
Fornal and Grinstein recently proposed that the discrepancy between two different methods of neutron lifetime measurements, beam bottle methods, can be explained by a previously unobserved dark matter decay mode, $n\ensuremath{\rightarrow}X+\ensuremath{\gamma}$. We perform search for this mode over allowed range energies monoenergetic $\ensuremath{\gamma}$ ray $X$ to matter. A Compton-suppressed high-purity germanium detector is used identify rays from in nickel-phosphorous-coated...
The ultracold neutron (UCN) source at Los Alamos National Laboratory (LANL), which uses solid deuterium as the UCN converter and is driven by accelerator spallation neutrons, has been successfully operated for over 10 years, providing to various experiments, first production based on superthermal process. It recently undergone a major upgrade. This paper describes design performance of upgraded LANL source. Measurements cold spectrum density are presented compared Monte Carlo predictions....
In this paper, we describe the performance of Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements cold flux, very low energy production rate, and UCN rates density at exit from biological shield are presented compared to Monte Carlo predictions. The compare well with predictions code MCNPX agree our custom code. source is shown perform as modeled. maximum delivered 52(9) UCN/cc a solid deuterium volume ∼1500 cm3.
We report on first experimental tests of a neutron magnetic spin resonator at very cold beam port the high flux reactor ILL Grenoble. When placed between two supermirror polarizers and operated in pulsed traveling-wave mode it allows to decouple its time- wavelength-resolution can therefore be used simultaneously as electronically tunable monochromator fast chopper. As 'real' scientific application we intend implementation PERC (p roton e lectron r adiation c hannel) project related...
A precise measurement of the neutron decay β asymmetry A₀ has been carried out using polarized ultracold neutrons from pulsed spallation source at Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report = -0.119 66±0.000 89{-0.001 40}{+0.001 23}, which determine ratio axial-vector to vector weak coupling nucleon g{A}/g{V}=-1.275 90{-0.004 45}{+0.004 09}.
We present a detailed report of measurement the neutron $\beta$-asymmetry parameter $A_0$, parity-violating angular correlation between spin and decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from pulsed spallation solid deuterium source via transport through 7-T magnetic field. The then transported an adiabatic-fast-passage spin-flipper field region, prior to storage in cylindrical volume situated within 1-T $2 \times 2\pi$ solenoidal...
It has been proposed recently that a previously unobserved neutron decay branch to dark matter particle ($\ensuremath{\chi}$) could account for the discrepancy in lifetime observed experiments use two different measurement techniques. One of possible final states discussed includes single $\ensuremath{\chi}$ along with an ${e}^{+}{e}^{\ensuremath{-}}$ pair. We data from UCNA (Ultracold Neutron Asymmetry) experiment set limits on this channel. Coincident electron-like events are detected...
Ultracold neutrons (UCNs) can be bound by the potential of terrestrial gravity and a reflecting mirror. The wave function state has characteristic modulations. We carried out an experiment to observe vertical distribution UCNs above such mirror at Institut Laue-Langevin in 2011. observed modulation is good agreement with that prediction quantum mechanics using Wigner function. spatial resolution detector system estimated 0.7 micro meter. This first observation gravitationally states...
A precise value for the neutron lifetime (about 880 s) is needed nuclear astrophysics predictions of Big-Bang nucleosynthesis and solar neutrino production, as well in precision searches new physics beyond Standard Model. This work reports on a type magnetic trap that has potential to resolve present 4-sigma inconsistency measurements lifetime, suggests next generation with less than one second uncertainty possible.
The Ultracold Neutron Asymmetry (UCNA) experiment was designed to measure the $\beta$-decay asymmetry parameter, $A_0$, for free neutron decay. In experiment, polarized ultracold neutrons are transported into a decay trap, and their electrons detected with $\approx 4\pi$ acceptance two detector packages which provide position energy reconstruction. also has sensitivity $b_{n}$, Fierz interference term in rate. this work, we determine $b_{n}$ from dependence of $A_0$ using data taken during...