A5069288849- Atomic and Molecular Physics
- Muon and positron interactions and applications
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Advanced Frequency and Time Standards
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Spectroscopy and Laser Applications
- Particle accelerators and beam dynamics
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Atmospheric aerosols and clouds
- Quantum Mechanics and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Neutrino Physics Research
- Laser Design and Applications
- Inorganic Fluorides and Related Compounds
- Quantum and Classical Electrodynamics
- Radioactive Decay and Measurement Techniques
- Mass Spectrometry Techniques and Applications
- Solar and Space Plasma Dynamics
- Geophysics and Sensor Technology
- Advanced Image Fusion Techniques
Bulgarian Academy of Sciences
2009-2024
Institute for Nuclear Research and Nuclear Energy
2012-2024
University of Bologna
2024
Joint Institute for Nuclear Research
1980-2021
Heinrich Heine University Düsseldorf
2021
Institute of Nuclear Physics, Polish Academy of Sciences
2013
Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes
2003
Laboratoire Collisions Agrégats Réactivité
2003
Université Toulouse III - Paul Sabatier
2003
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro
1998
The precise measurement of transition frequencies in cold, trapped molecules has applications fundamental physics, and extremely high accuracies are desirable. We determine suitable candidates by considering the simplest with a single electron, for which external-field shift corrections can be calculated theoretically precision. Our calculations show that H2+ exhibits particular transitions whose fractional systematic uncertainties may reduced to 5×10−17 at room temperature. also generalize...
Abstract The FAMU experiment aims to measure for the first time hyperfine splitting of muonic hydrogen ground state. From this measurement proton Zemach radius can be derived and will shed light on determination charge radius. In paper, we describe scientific goal, method detailed preparatory work. This includes outcome preliminary measurements, subsequent refined simulations evaluation expected results. experimental setup being built performed at RAL laboratory muon facility is also described.
High-precision laser spectroscopy of ultracold hydrogen molecular ions has the potential improving precision electron-to-proton mass ratio. An accurate knowledge spin structure transition is required in order to permit precise comparison with experimental frequencies. We calculate a relative accuracy O(alpha2) hyperfine splitting rovibrational states HD+ orbital momentum L<or=4 and vibrational quantum numbers up v=17, using Breit-Pauli interaction Hamiltonian. These are first complete ab...
We calculate the dc Stark effect for three molecular hydrogen ions in nonrelativistic approximation. The is calculated both dependence on rovibrational state and hyperfine state. discuss special cases approximations. also ac polarizabilities several levels therefrom evaluate accurately blackbody radiation shift, including effects of excited electronic states. results enable detailed evaluation certain systematic shifts transitions frequencies purpose ultrahigh-precision optical, microwave,...
The high precision measurement of the hyperfine splitting muonic-hydrogen atom ground state with pulsed and intense muon beam requires careful technological choices both in construction a gas target detectors. In June 2014, pressurized FAMU experiment was exposed to low energy at RIKEN RAL facility. objectives test were characterization target, hodoscope X-ray apparatus consisted X-rays detectors made purity Germanium Lanthanum Bromide crystals. this paper experimental setup is described...
While measurements of the hyperfine structure hydrogen-like atoms are traditionally regarded as test bound-state QED, we assume that theoretical QED predictions accurate and discuss information about electromagnetic protons could be extracted from experimental values ground state splitting in hydrogen muonic hydrogen. Using recent results on proton polarizability effects obtain for Zemach radius value 1.040(16) fm. We compare it to various estimates uncertainty which is shown larger 0.016...
We present a theoretical calculation of the fine and hyperfine splittings energy levels in metastable states antiprotonic helium ${}^{4}{\mathrm{He}}^{+}\overline{p},$ performed with accuracy ${10}^{\ensuremath{-}4}.$ also discuss perspectives obtaining experimental data on magnetic moment antiproton from measurements structure helium.
We analyse the effects of an external magnetic field on ro-vibrational, rotational and radiofrequency transitions HD+ molecular ion—an important systematic effect in precision spectroscopy HD+, which is interest for metrology fundamental constants. The (hyperfine) ion are considered, one-photon and, where relevant, two-photon transitions. hyperfine structure spectrum lines taken into account. Particular attention has been devoted to those most insensitive its orientation with respect...
We describe the principle and status of PVLAS experiment which is being assembled at INFN Laboratori Nazionali di Legnaro (Legnaro, Padua, Italy) to look for coherent effects, related QED vacuum structure, on propagation a polarized light beam in strong magnetic field.
We present accurate results for the energy levels of antiprotonic helium atoms with relativistic and QED corrections order ${\ensuremath{\alpha}}^{4}{\mathrm{mc}}^{2}$ taken into account. These reduce discrepancy between theory experiment to about 5--10 ppm rigorously confirm Condo's model metastability long-lived fraction helium. The level precision enables unambiguous ascription quantum numbers all transition lines observed so far.
A very accurate variational expansion is suggested for calculation of nonrelativistic energies the metastable antiprotonic helium atoms ${\mathrm{He}}^{+}\overline{p}.$ This reflects dual atomic-molecular nature system. Convergence results as a function increasing sets basis functions shows an accuracy better than ${10}^{\ensuremath{-}10}\mathrm{a}.\mathrm{u}.,$ two orders magnitude in our previous calculations.
Abstract The FAMU experiment at RIKEN-RAL is a muonic atom with the aim to determine Zemach radius of proton by measuring 1s hyperfine splitting in hydrogen. activity Collaboration years 2015–2023 enabled final optimisation detector-target setup as well gas working condition terms temperature, pressure and mixture composition. has started its data taking July 2023. status detector for 2023 experimental runs, beam characterisation X-ray detection 100–200 keV energy range, presented discussed.
We calculate the density shift and broadening of selected dipole transition lines pionic helium in gaseous at low temperatures up to T=12 K pressure a few bar. In approximation binary collisions depend linearly on density; we evaluate slope this linear dependence for spectral known experimental interest, also investigate its temperature dependence. find blue resonance frequencies $(n,l)=(16,15) \rightarrow (16,14)$, $(17,16) (17,15)$, $(16,15)\rightarrow(17,14)$ unfavored transitions, red...
We report the experimental determination of collision-energy dependence muon transfer rate from ground state muonic hydrogen to oxygen at near-thermal energies. A sharp increase by nearly an order magnitude in energy range 0--70 meV was found that is not observed other gases. The results set a reliable reference for quantum-mechanical calculations low-energy processes with exotic atoms and provide firm measurement hyperfine splitting Zemach radius proton FAMU collaboration.
Recently new calculations of the hyperfine structure (HFS) for metastable state (37, 35) 4He+ atom have been performed using variational coupled rearrangement channel method. They reveal a discrepancy ~200 ppm with our previous result on HFS based molecular type expansion. In order to solve this disagreement we undertake particular more accurate method exponential basis functions, which yields non-relativistic energy 15 significant digits state.
The relativistic shift, including the corrections to binding energy due vacuum polarization, hyperfine splitting, and nuclear finite-size effects have been calculated for (J=1,\ensuremath{\nu}=1) states of dd\ensuremath{\mu} dt\ensuremath{\mu}. determined by first-order perturbation theory using nonrelativistic wave functions Alexander Monkhorst [S. A. H. J. Monkhorst, Phys. Rev. A 38, 26 (1988)]. results show rapid convergence with basis-set size. overall calculations is better than 0.01...