The search for low energy anti-nuclei in cosmic rays allows a test of fundamental physics problems such as the possible presence of primordial antimatter or the nature of Dark Matter.
The โPHeSCAMIโ (Pressurized Helium Scintillating Calorimeter for AntiMatter Identification) project is aiming to study a new signature for the identification of anti-nuclei in cosmic rays.
In particular,...
We have proposed a spectroscopic study of antihydrogen ($\mathrm{\bar{H}}$) Lamb shift using a neutral antiatomic beam at keV energies. Direct spectroscopy of the $n=2$ Lamb shift transition of $\mathrm{\bar{H}}$ atoms would enable the first measurement of the antiproton ($\bar{p}$) charge radius. Recently, the GBAR experiment demonstrated the production of 6.1 keV $\mathrm{\bar{H}}$ atoms via...
The neutron-antineutron oscillation violates baryon number conservation and is of great importance in the context of testing Grand Unified Theories and understanding the origin of the baryon asymmetry in the universe [1].
Currently, the oscillation time is constrained to be $> 0.86 \times 10^8$ s for free neutrons, and $> 2.7\times 10^8$ s for bound neutrons [2,3]. In view of experiments...
The Antimatter Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) at CERN's Antimatter Decelerator (AD) is used for the production and study of antimatter bound systems, such as antihydrogen for the gravitational influence on a horizontal beam of cold antihydrogen atoms [1]. AEGIS has achieved remarkable performance in trapping antiprotons and successfully demonstrated the pulsed...
Positronium is the bound state of an electron and its antimatter counterpart, a positron. With just two times the mass of the electron and no nucleus, this exotic compound is the lightest of all known atoms with no gluon contribution to its mass. Its electronic structure resembles the one of hydrogen with a factor two lower reduced mass. Positronium is therefore a system of particular interest...
The formation mechanism of light (anti)nuclei in high-energy hadronic collisions remains an open question in high-energy physics. Their production mechanism is investigated by comparing experimental data with phenomenological models using statistical hadronization or a coalescence approach.
In particular, the coalescence mechanism finds an essential application in cosmic antinuclei studies...
We report on the design and characterization of an antiproton deceleration beamline, based on a pulsed drift tube, for the PUMA experiment at the Antimatter Factory at CERN. The design has been tailored to high-voltage (100 kV) and ultra-high vacuum (below $10^{-10}$ mbar) conditions. A first operation achieved decelerating antiprotons from an initial energy of 100 keV down to $(3898 \pm 3)$...
The advent of the LHC as antimatter factory has enabled an unprecedented effort to measure the production of light (anti)nuclei from pp to heavy-ion collisions, providing input for a detailed study of nucleosynthesis in high-energy interactions. However, the production of these bound states is not modelled in commonly used event generators. Yet the detection of cosmic antinuclei is predicted...
The worldโs only source of low-energy antiprotons is currently the AD/ELENA facility located at CERN. Precision measurements on single antiprotons have been conducted at this facility and provide stringent tests of fundamental interactions and their symmetries. However, magnetic field fluctuations from the facility operation limit the precision of upcoming measurements. To overcome this...
The ASACUSA CUSP experiment upgraded the MUSASHI antiproton trap with a drift tube accelerator to receive antiproton beams from ELENA, which replaced the Radio-Frequency Quadrupole decelerator. ELENA provides antiprotons at a fixed energy of 100 keV. The drift tube adjusted the injection energy of antiproton beams for the thin energy degrader at the entrance of the trap by 19 keV. The number...
The decay of antiprotonic atoms may lead to the formation of hypernuclei that can be produced via strangeness exchange reactions following the antiproton-nucleon annihilation. To estimate the hypernuclei yields that can be expected by these kind of reactions, simulations were performed within the GiBUU transport framework.
Using $^{16}$O, $^{40}$Ar, $^{84}$Kr and $^{132}$Xe as target nuclei,...
Antihydrogen positive ions ($\bar{\rm H}^+$) consisting of an antiproton and two positrons are utilized to produce cryogenic antihydrogen atoms. The $\bar{\rm H}^+$ can be collected with an electric field, sympathetically cooled by lasers with Be$^+$ ions, and subsequently neutralized by stripping off one of the positrons. The $\bar{\rm H}^+$ is integrated in the mixture of antihydrogen...
The recent measurement of the antihydrogen gravitational acceleration [Nature 621, 716โ722 (2023)] relies upon the detection of the annihilation of the anti-atoms that are released from their magnetic confinement and that move under the influence of gravity. The ALPHA-g magnetic trap is surrounded by a Time Projection Chamber designed to identify the annihilation products and to reconstruct...
The LSym experiment is a new cryogenic Penning trap experiment currently being designed at the Max-Planck-Institut fรผr Kernphysik of Heidelberg. The goal of LSym is to conduct a stringent CPT test by comparing the properties of matter and antimatter with unprecedented sensitivity by trapping simultaneously one electron and one positron in a Penning trap, which allows performing a...
This work is a sequel to our two publications from 2023 (1,2) where
14 experimental 1s and 1p single-particle binding energies of $\Lambda$ in
hypernuclei led to a quite well-defined optical potential for the
$\Lambda$-nucleus interaction. The potential contains a traditional
linear density term and a quadratic density term, the latter representing
$\Lambda NN$...
In the era of ever-increased precision measurements of the fundamental properties of antihydrogen at the ALPHA experiment at CERN, knowledge of the antihydrogen energy distribution has become vital; for example, it provided a significant contribution to the uncertainty in the first direct measurement of the gravitational acceleration of antihydrogen [1]. Increased precision in ALPHA's...
The ALPHA experiment (CERN) performs precise tests of fundamental Physics using spatially confined samples of antihydrogen atoms ($\bar{\mathrm{H}}$). For a direct $\mathrm{H} - \bar{\mathrm{H}}$ spectroscopic comparison, methods for loading atomic hydrogen into the apparatus are being considered. In this direction, we have demonstrated a novel source for low energy ions, capable of producing...
By using a superconducting transition-edge-sensor (TES) microcalorimeter with ultra-high resolution $\Delta E\sim5~\mathrm{eV}$ (FWHM), a spectroscopic measurement of $dd\mu^*$ was successfully performed for the first time.
The $dd\mu^*$, in which $\mu^-$ is resonantly coupled with two deuterons, is predicted by the latest few-body calculations to emit dissociative X-rays with...
The HIBEAM/NNBAR program is a proposed two-stage experiment at the European Spallation Source (ESS) to search for baryon number violation [1]. The goal of the program is to produce new insights into the origins of baryogenesis by performing searches for neutronโantineutron oscillations, increasing the sensitivity by three orders of magnitude compared with the previously established limit from...
The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET scanner based on plastic scintillators [1]. It is designed to measure momentum vectors and the polarization of photons originating from the decays of positronium [2,3]. In combination with the newly invented positronium imaging method [4], J-PET enables the study of discrete symmetries in positronium without the use of...
Precision comparisons of atomic hydrogen and its antimatter counterpart, antihydrogen, provide stringent tests of fundamental symmetries between matter and antimatter such as CPT invariance and the Weak Equivalence Principle. The most precise measurements of atomic hydrogen properties have traditionally been performed in atomic beams. In contrast, precision measurements of antihydrogen to date...
Laser spectroscopy of muonic hydrogen (ฮผp) is an ideal platform to probe the proton structure. At the Paul Scherrer Institute, the CREMA collaboration aimsย to measure the ground-state hyperfine splitting (1SโHFS) with a relative accuracy of $10^{-6}$ to infer the proton structure contribution (two photon exchange correction) with a relative accuracy of $10^{-4}$. This opens the way for testing...
