F. Mulhauser
A5036268116- Muon and positron interactions and applications
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Advanced Chemical Physics Studies
- Radiation Detection and Scintillator Technologies
- Quantum, superfluid, helium dynamics
- Quantum Chromodynamics and Particle Interactions
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Nuclear physics research studies
- Neutrino Physics Research
- Scientific Research and Discoveries
- X-ray Spectroscopy and Fluorescence Analysis
- High-Energy Particle Collisions Research
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- High-pressure geophysics and materials
- Radiation Therapy and Dosimetry
- Advanced Optical Sensing Technologies
- Plasma Diagnostics and Applications
- Dark Matter and Cosmic Phenomena
- Scientific Measurement and Uncertainty Evaluation
- Earthquake Detection and Analysis
Max Planck Institute of Quantum Optics
2011-2021
University of Fribourg
2002-2017
University of Aveiro
2011-2016
Max Planck Society
2001-2016
University of Zurich
2011-2013
Paul Scherrer Institute
2006-2013
University of Illinois Urbana-Champaign
2006-2013
University of Illinois System
2011-2013
International Atomic Energy Agency
2010-2012
École Normale Supérieure - PSL
2011
Proton Still Too Small Despite a proton's tiny size, it is possible to measure its radius based on charge or magnetization distributions. Traditional measurements of proton were the scattering between protons and electrons. Recently, precision measurement line in spectrum muonium—an atom consisting muon, instead an electron—revealed inconsistent with that deduced from studies. Antognini et al. (p. 417 ; see Perspective by Margolis ) examined different spectral muonium, results less dependent...
The deuteron is too small, radius of the proton has remained a point debate ever since spectroscopy muonic hydrogen indicated large discrepancy from previously accepted value. Pohl et al. add an important clue for solving this so-called puzzle. They determined charge deuteron, nucleus consisting and neutron, transition frequencies in deuterium. Mirroring puzzle, was several standard deviations smaller than value inferred previous spectroscopic measurements electronic This independent points...
The DEAR (DAPhiNE exotic atom research) experiment measured the energy of x rays emitted in transitions to ground state kaonic hydrogen. values for shift epsilon and width Gamma 1s due K(-)p strong interaction are epsilon(1s)=-193 +/- 37 (stat) 6 (syst) eV Gamma(1s)=249 111 30 eV, most precise yet obtained. pattern hydrogen K-series lines, K(alpha), K(beta), K(gamma), was disentangled first time.
Abstract The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include electron spin, relativistic and field effects, tiny shifts related complex structure nucleus. These caused by nuclear are vastly magnified in formed a negative muon nucleus, so spectroscopy these muonic ions used investigate high Here we present measurement two 2S–2P transitions helium-4 ion that...
We report a measurement of the positive muon lifetime to precision 1.0 ppm; it is most precise particle ever measured. The experiment used time-structured, low-energy beam and segmented plastic scintillator array record more than 2×1012 decays. Two different stopping target configurations were employed in independent data-taking periods. combined results give τμ+(MuLan)=2 196 980.3(2.2) ps, 15 times as any previous experiment. gives value for Fermi constant: GF(MuLan)=1.166 378 8(7)×10−5...
We present a detailed report of the method, setup, analysis and results precision measurement positive muon lifetime. The experiment was conducted at Paul Scherrer Institute using time-structured, nearly 100%-polarized, surface beam segmented, fast-timing, plastic scintillator array. employed two target arrangements; magnetized ferromagnetic with ~4 kG internal magnetic field crystal quartz in 130 G external field. Approximately 1.6 x 10^{12} positrons were accumulated together data yield...
The rate of nuclear muon capture by the proton has been measured using a new technique based on time projection chamber operating in ultraclean, deuterium-depleted hydrogen gas, which is key to avoiding uncertainties from muonic molecule formation. hyperfine singlet ground state μp atom was obtained difference between μ− disappearance and world average for μ+ decay rate, yielding ΛS=725.0±17.4 s−1, induced pseudoscalar coupling nucleon, gP(q2=−0.88m2μ)=7.3±1.1, extracted.Received 16 April...
We plan to measure several 2S–2P transition frequencies in μ 4 He + and 3 by means of laser spectroscopy with an accuracy 50 ppm. This will lead a determination the corresponding nuclear rms charge radii relative × 10 −4 , limited uncertainty polarization contribution. First, these measurements help solve proton radius puzzle. Second, very precise are benchmarks for ab initio few-nucleon theories potentials. Finally when combined ongoing measurement 1S–2S enhanced bound-state QED test 1S Lamb shift .
The MuCap experiment at the Paul Scherrer Institute has measured rate L_S of muon capture from singlet state muonic hydrogen atom to a precision 1%. A beam was stopped in time projection chamber filled with 10-bar, ultra-pure gas. Cylindrical wire chambers and segmented scintillator barrel detected electrons decay. is determined difference between mu- disappearance free decay rate. result based on analysis 1.2 10^10 decays, which we extract = (714.9 +- 5.4(stat) 5.1(syst)) s^-1 derive...
The mean life of the positive muon has been measured to a precision 11 ppm using low-energy, pulsed beam stopped in ferromagnetic target, which was surrounded by scintillator detector array. result, tau(micro)=2.197 013(24) micros, is excellent agreement with previous world average. new average 019(21) micros determines Fermi constant G(F)=1.166 371(6)x10(-5) GeV-2 (5 ppm). Additionally, measurement positive-muon lifetime needed determine nucleon pseudoscalar coupling g(P).
Hydrogen-like light muonic ions, in which one negative muon replaces all the electrons, are extremely sensitive probes of nuclear structure, because large mass increases tremendously wave function overlap with nucleus. Using pulsed laser spectroscopy we have measured three 2S-2P transitions helium-3 ion ($\mu^3$He$^+$), an formed by a and bare This allowed us to extract Lamb shift $E(2P_{1/2}-2S_{1/2})= 1258.598(48)^{\rm exp}(3)^{\rm theo}$ meV, 2P fine structure splitting $E_{\rm FS}^{\rm...
We review the status of proton charge radius puzzle. Emphasis is given to various experiments initiated resolve conflict between muonic hydrogen results and from scattering regular spectroscopy.
An alternate approach was used to study the reactions of muonic atoms and molecules in solid layers hydrogen isotopes. Muons stopped a protium layer with small admixture tritium producing \ensuremath{\mu}p atoms. Muon transfer from proton triton generated \ensuremath{\mu}t atoms, which were emitted into deuterium layer. Subsequent epithermal dt\ensuremath{\mu} molecular formation followed by dt fusion gave prompt signal for emission. Fusion time spectra at various concentrations measured...
The first measurement of the yields three kaonic nitrogen X-ray transitions, using DEAR (DAΦNE Exotic Atom Research) setup at DAΦNE collider Frascati, is reported. are 41.5±8.7(stat.)±4.1(sys.)% for n=7→6 transition, 55.0±3.9(stat.)±5.5(sys.)% n=6→5 transition and 57.4±15.2(stat.)±5.7(sys.)% n=5→4 a density ρ=3.4ρNTP. By experimental in an atomic cascade calculation, 1 to 3% K-shell electron population n=6 level was deduced.
Laser spectroscopy of the Lamb shift (2S-2P energy difference) in light muonic atoms or ions, which one negative muon µ -is bound to a nucleus, has been performed.The measurements yield significantly improved values root-mean-square charge radii nuclei, owing large mass, results vastly increased wave function overlap with nucleus.The proton and deuteron are 10 3 times more accurate than respective CODATA values, but 7 standard deviations smaller.Data on helium-3 -4 ions is being analyzed...
The charge radius of the proton, simplest nucleus, is known from electron-scattering experiments only with a surprisingly low precision about 2%. poor knowledge proton restricts tests bound-state quantum electrodynamics (QED) to level 6 × 10 6 , although experimental data themselves (1S Lamb shift in hydrogen) have reached 2 . determination an accuracy 3 main goal our experiment, opening way check QED predictions 7 principle measure 2S2P energy difference muonic hydrogen (µ p) by...
The present manuscript summarizes novel studies on the application of large area avalanche photodiodes (LAAPDs) to detection X-rays and vacuum ultraviolet (VUV) light. operational characteristics four different LAAPDs manufactured by Advanced Photonix Inc., with active areas 80 200 mm^2 were investigated for X-ray at room temperature. best energy resolution was found be in 10-18% range 5.9 keV X-rays. LAAPD, being compact, simple operate high counting rate capability (up about 10^5/s),...
Received 7 February 2011DOI:https://doi.org/10.1103/PhysRevLett.106.079901© 2011 American Physical Society
Resonant formation of d&mgr;t molecules in collisions muonic tritium ( &mgr;t) on D2 was investigated using a beam &mgr;t atoms, demonstrating new direct approach muon catalyzed fusion studies. Strong epithermal resonances were directly revealed for the first time. From time-of-flight analysis 2036+/-116 dt events, rate consistent with 0.73+/-(0.16)(meas)+/-(0.09)(model) times theoretical prediction obtained. For largest peak at resonance energy 0.423+/-0.037 eV, this corresponds to...