Abstract provided as attached pdf-file.
abstract provided as attached pdf-file
The evidence of dark matter so far is based only on gravitational effects observed at cosmological level. To explain these effects, many theoretical models suggest other non-gravitational very-weak interactions between dark matter and ordinary matter. To test this hypothesis, different experiments are trying to directly produce dark matter at particle accelerators.
The Positron Annihilation...
Collaboration
Benetti M. (Napoli), Bentum M.-J. (Eindhoven), Bonetti L. (Orléans), Capozziello S. (Napoli), dos Santos Filho L.R. (Rio de Janeiro), Ellis J. (CERN London), Helayël-Neto J.A. (Rio de Janeiro), Lämmerzahl C. (Bremen), López-Corredoira M. (La Laguna), Mavromatos N.E. (CERN London), Perlick V. (Bremen), Randriamboarison O. (Orléans), Retinò A. (Paris), Sakharov A.S. (CERN),...
abstract attached as pdf
A positron trap is a powerful and adaptable tool for performing experiments with positrons and positronium. These devices use a strong magnetic field, a stepped potential well and Nitrogen and CF$_4$ buffer gas. Positrons are initially trapped via the electronic excitation of N$_2$, CF$_4$ is added for efficient cooling via vibrational and rotational excitations. This type of positron trap can...
abstract provided as attached pdf-file
The search for physics beyond the Standard Model (BSM) is one of the main goals of the LHC. Compared to standard proton-proton collision studies, heavy-ion collisions provide unique and complementary means to search for new phenomena. In particular, ultra-peripheral collisions (UPCs) of heavy ions offer a natural environment for the studies of photon-mediated processes, such as light-by-light...
abstract provided as attached pdf-file
As the simplest neutral molecule, molecular hydrogen (H2) is a good testing ground for molecular quantum theory. Its dissociation energy D0 has become a benchmark value to test ab initio quantum molecular calculations. An experimental value for D0 can be obtained by relating the ionization energy of H2, to the ionization energy of atomic hydrogen and the dissociation energy of the H2 ion. By...
abstract provided as attached pdf-file
A number of experiments at CERN’s Antiproton Decelerator aim to measure the properties of antihydrogen to find structural differences hinting at CPT symmetry breaking that would explain the observed baryon-antibaryon asymmetry in our universe. These experiments detect antihydrogen through annihilation making the antiproton-nucleus ($\bar{p}A$) annihilation one of the main processes of...
abstract provided as attached pdf file
abstract provided as attached pdf-file
abstract provided as attached pdf-file
The no-pair Dirac--Coulomb(--Breit) equation is solved with high-accuracy \cite{allorder,DiracCoulomb,Breit,LScoupling} to provide a starting point for a new alternative theoretical method in relation with high-resolution atomic and molecular spectroscopy \cite{QEDcorr}. The sub-parts-per-billion convergence of the energy is achieved by considering the relativistic symmetry with an $LS$...
Precision spectroscopy of narrow transitions of atoms and molecules has been the subject of numerous studies in recent decades and has been widely applied in sensing,metrology, and frequency references for optical clocks. Narrow optical resonances also provide excellent probes for determining fundamental physics constants, such as the Rydberg constant and the proton-to-electron mass ratio. In...
Precision spectroscopy of molecular hydrogen and its isotopes, combined with accurate calculations, allows us to test the fundamental quantum chemistry theory and to determine the fundamental physical constants such as the proton-to-electron mass ratio[1,2]. In general, high overtone transitions may allow for measurements with a better fractional accuracy. However, direct measurement of high...
abstract provided as attached pdf-file
Abstract provided as an attached pdf file.
A precise knowledge of the elements $|V_{cb}|$ and $|V_{ub}|$ of the CKM matrix is important to constraint the Standard Model of particle physics and predict the rate of ultra-rare $B$ meson decays such as $B\to\mu\nu$ or $B\to K\nu\bar\nu$. In this talk I will review the experimental status of these fundamental parameters with a focus on the latest developments and new results from the Belle...
The latest results of Higgs boson searches beyond the Standard Model are reviewed from the ATLAS and CMS experiments. This includes searches for additional neutral, charged and double charged Higgs-like bosons, searches for dark matter produced in association with a Higgs boson and sesarches for new physics in Higgs boson pair production processes. Exotic Higgs boson decays are addressed as...
The superweak (SW) force is a minimal, anomaly-free U(1) extension of the standard model (SM), designed to explain the origin of (i) neutrino masses and mixing matrix elements, (ii) dark matter, (iii) cosmic inflation, (iv) stabilization of the electroweak vacuum and (v) leptogenesis. In this talk we discuss how the parameter space of the model is constrained by providing viable scenarios for...
Searches for permanent electric dipole moments (EDM) of fundamental particles and systems are among the most sensitive probes for CP violation beyond the Standard Model, which is required in order to explain the baryon asymmetry of the Universe. The current limit on the EDM of the neutron is set by our collaboration, $|d_n|$ < $1.8 \times 10^{-26}$ ecm (C.L. 90%) in the nEDM experiment....
To explain the open questions in the fundaments of physics, new theories that reach beyond the standard model of particle physics are needed. A great number of these indirectly predict electric dipole moments (EDM) of fundamental particles in ranges that are just within reach for modern atomic and molecular physics experiments. While measurements in atomic and molecular beams, and more...
In this work, we present benchmark variational calculations for the ground and 15 lowest bound excited 1S and 1P states of doubly ionized Carbon (C III). The nonrelativistic wave function of each of these states is generated in an independent calculation by expanding it in terms of a large number (8,000−12,000) of all-electron explicitly correlated Gaussian functions (ECG) who’s nonlinear...
abstract attached as pdf
Defining the values of constants is the best method to define units since it separates the definition from the realization. For example, there are two very different methods to realize the kg. In the future, there can be other methods of realizing the kg that adapt to possible advancements in technology without changing the definition. With the reform of the SI system, all but one of the units...
The ASACUSA-CUSP experiment located at CERN’s antiproton decelerator aims at measuring the ground state hyperfine splitting of antihydrogen (H̄) using a beam technique to test CPT symmetry. For this purpose, a beam of cold (~50K) hydrogen has been developed to characterize the antihydrogen spectroscopy apparatus [1]. Beyond serving as a test bench for the H̄ experiment, the hydrogen beamline...
Abstract provided as an attached pdf file.
The ASACUSA-Cusp experiment aims to perform spectroscopy of the hyperfine structure of antihydrogen by producing a beam of cold, spin polarised, ground state antihydrogen. The beam will be produced by mixing positrons and antiprotons in our unique Cusp trap which uses a pair of superconducting coils in an anti-Helmholtz configuration to produce a magnetic field capable of both confining the...
Abstract provided as attached pdf-file.
Negative ions are complex quantum systems in which an additional electron is bound to the neutral atom or molecule by a weak van der Waals force resulting from polarization of the electron shell. This binding depends strongly on the electron configuration of the shell and is therefore sensitive to electron correlation effects. Due to the lack of long ranged Coulomb force the resulting binding...
see attachment
Abstract provided as attached pdf-file
The energy levels of hydrogen-like atoms and ions are accurately described by bound-state quantum electrodynamics (QED). The frequency of the narrow 1s-2s transition of atomic hydrogen has been measured with a relative uncertainty of less than $10^{-14}$. In combination with other spectroscopic measurements of hydrogen and hydrogen-like atoms, the Rydberg constant and the proton charge radius...
abstract provided as attached pdf file
abstract provided as attached pdf-file
The Muon g-2 experiment at FNAL measured the muon magnetic anomaly to 0.46 ppm in 2021 and expects to increase the precision on this quantity to 0.23 ppm in 2023 and to 0.14 ppm in 2025, providing a stronger test of the Standard Model prediction, whose uncertainty has been recently estimated at 0.37 ppm. We report on how the measurement is performed, on the improvements with respect to the...
The electron anomalous magnetic moment is the most precise value in microphysics. The agreement between theoretical calculations and experiments is good, but last years it became not so ideal due to an improved experimental precision. The current status of this agreement/disagreement for the electron g-2 will be reviewed as well as for the fine-structure constant.
In 2019 the author has...
abstract attached as a pdf file
The most precise determination of the top-left corner element of the CKM quark mixing matrix $V_{ud}$ is obtained from accurate measurements of superallowed nuclear $\beta$ decays. Among the theoretical ingredients in this determination, the isospin symmetry-breaking (ISB) correction $\delta_\mathrm{C}$ plays a crucial role in aligning the $Ft$-values across all superallowed transitions. This...
We present our recent experimental advances on laser spectroscopy of cold, trapped molecular hydrogen ions. The contribution to the determination of fundamental constants and tests of physical laws is discussed.
abstract provided as attached pdf-file
The Penning-trap mass spectrometer Pentatrap [1] located at the Max Planck Institute for Nuclear Physics in Heidelberg is performing mass-ratio measurements with a relative uncertainty in the 10^−11 regime. One of the unique features of the Pentatrap experiment is the external ion source producing a wide range of charge states from gaseous or solid-state samples down to only 10^15 atoms. the...
sponsored by the Physics Journal
abstract provided as attached pdf-file
The \textsc{Alphatrap} experiment \cite{alphatrap} is a double Penning trap setup at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The cryogenic trap setup allows for high precision spectroscopic measurements on single ions while utilizing the continuous Stern-Gerlach effect for state detection \cite{csge}.
It is connected to a room temperature beamline with access to...
emphasized textIn this contribution, we discuss the theory of the bound-electron g factor. This quantity can be measured nowadays to high precision in Penning-trap setups. The collaboration of theory and experiment enables impactful and detailed tests of quantum electrodynamics in a strong background electric field, and a competitive determination of fundamental constants [1] and nuclear...
Hard spin-independent three-loop radiative corrections to energy levels in muonium and positronium are calculated.
These corrections could be relevant for the new generation of precise 1S-2S and 2S-2P measurements in muonium and
positronium.
abstract provided as attached pdf-file
Abstract provided as attached pdf-file
The Standard Model of particle physics is incredibly successful and glaringly incomplete. Among the questions left open is the striking imbalance of matter and antimatter in our universe, which inspires experiments to compare the fundamental properties of matter/antimatter conjugates with high precision. The BASE collaboration at the antiproton decelerator of CERN is performing such...
Beta decay of a free neutron is the simplest form of "semi-leptonic" weak interaction and is free from nuclear structure effects. Despite the simplicity of the process, its lifetime measurement remains one of the most challenging measurements, bearing different results depending on the technique ("bottle" or "beam") [1, 2]. Another critical measurement from the decay is the correlation (Ao)...
