R. Gernhäuser
A5083491999- Nuclear physics research studies
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Radiation Detection and Scintillator Technologies
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Advanced Chemical Physics Studies
- Particle accelerators and beam dynamics
- Astrophysics and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Medical Imaging Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Advancements in Battery Materials
- Boron Compounds in Chemistry
- Electron and X-Ray Spectroscopy Techniques
- Inorganic Fluorides and Related Compounds
- Advanced Battery Technologies Research
- Particle Accelerators and Free-Electron Lasers
Technical University of Munich
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Milano
2019-2021
University of Milan
2021
Goethe University Frankfurt
2021
Helmholtz-Zentrum Dresden-Rossendorf
2021
Saha Institute of Nuclear Physics
2020
Slovak Academy of Sciences
2018-2019
Institute of Physics of the Slovak Academy of Sciences
2018-2019
Chalmers University of Technology
2019
Universidade de Santiago de Compostela
2004-2019
The β-decay half-lives of 110 neutron-rich isotopes the elements from _{37}Rb to _{50}Sn were measured at Radioactive Isotope Beam Factory. 40 new follow robust systematics and highlight persistence shell effects. data have direct implications for r-process calculations reinforce notion that second (A≈130) rare-earth-element (A≈160) abundance peaks may result freeze-out an (n,γ)⇄(γ,n) equilibrium. In such equilibrium, are important factors determining rare-earth elements, allow a more...
A long-standing question in nuclear physics is whether chargeless systems can exist. To our knowledge, only neutron stars represent near-pure systems, where neutrons are squeezed together by the gravitational force to very high densities. The experimental search for isolated multi-neutron has been an ongoing quest several decades1, with a particular focus on four-neutron system called tetraneutron, resulting few indications of its existence so far2-4, leaving tetraneutron elusive six...
The first measurement of the momentum distribution for one-neutron removal from $^{24}\mathrm{O}$ at $920A\text{ }\text{ }\mathrm{MeV}$ performed GSI, Darmstadt is reported. observed has a width (FWHM) $99\ifmmode\pm\else\textpm\fi{}4\text{ }\mathrm{MeV}/c$ in projectile rest frame and cross section $63\ifmmode\pm\else\textpm\fi{}7\text{ }\mathrm{mb}$. results are well explained with nearly pure $2{s}_{1/2}$ neutron spectroscopic factor $1.74\ifmmode\pm\else\textpm\fi{}0.19$ within eikonal...
The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator Isotope Separator On-Line facility ISOLDE CERN since 2001. During last decade, a series of successful Coulomb excitation and transfer reaction studies have performed with this array, utilizing unique high-quality radioactive beams which are available ISOLDE. In article, an overview is given technical details full setup, including description $\gamma$ -ray particle...
The "island of inversion" nucleus 32 Mg has been studied by a (t, p) two neutron transfer reaction in inverse kinematics at REX-ISOLDE. shape coexistent excited 0+ state identified the characteristic angular distribution protons Δ L=0 transfer. excitation energy 1058 keV is much lower than predicted any theoretical model. low γ-ray intensity observed for decay this indicates lifetime more 10 ns. Deduced spectroscopic amplitudes are compared with occupation numbers from shell-model calculations.
We present phase space distributions and multiplicities of K+, K−, ϕ mesons produced in Ar+KCl reactions at a kinetic beam energy 1.756 GeV/nucleon measured with the HADES spectrometer. The inverse slope parameters yields kaons supplement systematics previous measurements. percentage K− coming from decay is found to be 18±7%.6 MoreReceived 9 March 2009DOI:https://doi.org/10.1103/PhysRevC.80.025209©2009 American Physical Society
We present transverse momentum spectra, rapidity distribution and multiplicity of $ \Lambda$ -hyperons measured with the HADES spectrometer in reaction Ar(1.76AGeV) + KCl . The yield \Xi^{{-}}_{}$ is calculated from our previously reported /( \Sigma^{{0}}_{}$ ) ratio compared to other strange particle multiplicities. Employing a strangeness balance equation multiplicities yet unmeasured \Sigma^{{\pm}}_{}$ can be estimated. Finally statistical hadronization model used fit yields \pi^{-}_{}$ ,...
We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in heavy-ion reaction. At beam energy 1.76A GeV reaction Ar + KCl was studied with High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample collected, allowing for investigation decay channel --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda Sigma;{0}) ratio (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.
We present a search for the e+e− decay of hypothetical dark photon, also named U vector boson, in inclusive dielectron spectra measured by HADES p(3.5 GeV) + p, Nb reactions, as well Ar (1.756 GeV/u) KCl reaction. An upper limit on kinetic mixing parameter squared ϵ2 at 90% CL has been obtained mass range MU=0.02–0.55 GeV/c2 and is compared with world data set. For masses 0.03–0.1 GeV/c2, lowered respect to previous results, allowing now exclude large part region favored muon g−2 anomaly....
Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with $2.85\text{ }\mathrm{MeV}/\mathrm{nucleon}\text{ }\mathrm{mercury}$ beams from REX-ISOLDE. Magnitudes and relative signs the reduced $E2$ matrix elements that couple ground state low-lying excited states in $^{182\ensuremath{-}188}\mathrm{Hg}$ extracted. Information on deformation first ${0}^{+}$ was deduced using quadrupole sum rules approach. Results show is slightly...
Neutron-rich {96,98}Sr isotopes have been investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility. Reduced transition probabilities and spectroscopic quadrupole moments extracted from differential cross sections. These results allow, for first time, drawing definite conclusions about shape coexistence highly deformed prolate spherical configurations. In particular, a very small mixing between coexisting states is observed, contrary to other mass regions where...
We present an analysis of proton number fluctuations in $\sqrt{s_{NN}}$ = 2.4 GeV Au+Au collisions measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI. With help extensive detector simulations done IQMD transport model events including nuclear clusters, various nuisance effects influencing observed cumulants have been investigated. Acceptance and efficiency corrections applied as a function fine grained rapidity transverse momentum bins, well considering local track...
The invariant-mass spectrum of $e^+ e^-$ pairs produced in $^{12}$C+$^{12}$C collisions at an incident energy 2 GeV per nucleon has been measured for the first time. pair production probabilities span over five orders magnitude from $\pi^0$-Dalitz to $\rho/\omega$ region. Dalitz decays $\pi^0$ and $\eta$ account all yield up 0.15 GeV/c$^2$, but only about 50% above this mass. A comparison with model calculations shows that excess is likely due baryon-resonance vector-meson decays. Transport...
Excited states in $^{38,40,42}\mathrm{Si}$ nuclei have been studied via in-beam $\ensuremath{\gamma}$-ray spectroscopy with multinucleon removal reactions. Intense radioactive beams of $^{40}\mathrm{S}$ and $^{44}\mathrm{S}$ provided at the new facility RIKEN Radioactive Isotope Beam Factory enabled $\ensuremath{\gamma}\mathrm{\text{\ensuremath{-}}}\ensuremath{\gamma}$ coincidence measurements. A prominent $\ensuremath{\gamma}$ line observed an energy 742(8) keV $^{42}\mathrm{Si}$ confirms...
We present the transverse momentum spectra and rapidity distributions of ${\ensuremath{\pi}}^{\ensuremath{-}}$ ${\mathrm{K}}_{S}^{0}$ in Ar $+$ KCl reactions at a beam kinetic energy $1.756$ $A$ GeV measured with High Acceptance Di-Electron Spectrometer (HADES). The reconstructed sample is characterized by good event statistics for wide range rapidity. compare experimental to predictions Isospin Quantum Molecular Dynamics (IQMD) model. model calculations show that low momenta constitute...
We report on the first spectroscopic study of N=22 nucleus 32Ne at newly completed RIKEN Radioactive Ion Beam Factory. A single gamma-ray line with an energy 722(9) keV was observed in both inelastic scattering a 226 MeV/u beam carbon target and proton removal from 33Na 245 MeV/u. This transition is assigned to deexcitation Jpi=2+ state 0+ ground state. Interpreted through comparison state-of-the-art shell-model calculations, low excitation demonstrates that "island inversion" extends least...
We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For first time, pairs were reconstructed for n+p by detecting proton spectator from deuteron breakup. find that yield invariant mass Me+e- > 0.15 GeV/c2 is about an order magnitude larger as compared to p+p. A comparison model calculations demonstrates mechanism not sufficiently described yet. The spectra measured C+C are compatible a superposition collisions,...
We present results on dielectron production in ${}^{40}\mathrm{Ar}+\mathrm{KCl}$ collisions at 1.76$A$ GeV. For the first time $\ensuremath{\omega}$ mesons could be reconstructed a heavy-ion reaction bombarding energy which is well below threshold free nucleon-nucleon collisions. The multiplicity has been extracted and compared to yields of other particles, particular $\ensuremath{\varphi}$ meson. At intermediate ${e}^{+}{e}^{\ensuremath{-}}$ invariant masses, we find strong enhancement pair...
Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure stable and exotic oxygen isotopes at ${\mathrm{R}}^{3}\mathrm{B}/\mathrm{LAND}$ setup with incident beam energies range $300--450\text{ }\mathrm{MeV}/\mathrm{u}$. The isotopic chain offers large variation separation that allows quantitative understanding single-particle strength changing isospin asymmetry. provide complementary approach to intermediate-energy one-nucleon...
The neutron-rich nuclei 94,96Kr were studied via projectile Coulomb excitation at the REX-ISOLDE facility CERN. Level energies of first excited 2(+) states and their absolute E2 transition strengths to ground state are determined discussed in context E(2(1)(+)) B(E2;2(1)(+)→0(1)(+)) systematics krypton chain. Contrary previously published results no sudden onset deformation is observed. This experimental result supported by a new proton-neutron interacting boson model calculation based on...