R. Holzmann
A5030486863- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Astronomical and nuclear sciences
- Advanced Chemical Physics Studies
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Particle accelerators and beam dynamics
- Quantum, superfluid, helium dynamics
- Astro and Planetary Science
- Radiation Therapy and Dosimetry
- Markov Chains and Monte Carlo Methods
- Neutrino Physics Research
- Scientific Research and Discoveries
- Sleep and Wakefulness Research
- Stochastic processes and statistical mechanics
- Mass Spectrometry Techniques and Applications
GSI Helmholtz Centre for Heavy Ion Research
2015-2025
University of Wuppertal
2022
Helmholtz-Zentrum Dresden-Rossendorf
2008-2021
Slovak Academy of Sciences
2018-2019
Institute of Physics of the Slovak Academy of Sciences
2018-2019
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud
2010-2015
Istituto Nazionale di Fisica Nucleare
2010-2015
Universidade de Santiago de Compostela
2004-2014
École Polytechnique
2012
Research Association for Combustion Engines
1997-2009
The goal of the study was to seek physiological correlates lucid dreaming. Lucid dreaming is a dissociated state with aspects waking and combined in way so as suggest specific alteration brain physiology for which we now present preliminary but intriguing evidence. We show that unusual combination hallucinatory dream activity wake-like reflective awareness agentive control experienced dreams paralleled by significant changes electrophysiology.
The three-body breakup ${}^{6}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}}^{4}\mathrm{He}+n+n$ is studied experimentally, using a secondary ${}^{6}\mathrm{He}$ ion beam of 240 MeV/nucleon incident on carbon and lead targets. Integrated cross sections for one- two-neutron knockout differential $d\ensuremath{\sigma}{/dE}^{*}$ $d\ensuremath{\sigma}/d\ensuremath{\vartheta}$ inelastic nuclear or electromagnetic excitations into the continuum are presented. $E$1-strength distribution deduced...
Partial decay schemes for the very neutron-rich nuclei $^{142}$,144Ba and $^{146}\mathrm{Ba}$ have been determined by study of \ensuremath{\gamma}-\ensuremath{\gamma} coincidences in $^{252}\mathrm{Cf}$ fission fragments. Interlaced positive- negative-parity levels connected fast electric dipole transitions are observed $^{144}\mathrm{Ba}$ above spin 7\ensuremath{\Elzxh}. This is similar to situation some light actinide nuclei, where data interpreted terms reflection-asymmetric shapes.
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....
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...
This report summarizes the presentations and discussions during Rapid Reaction Task Force "Dynamics of critical fluctuations: Theory – phenomenology heavy-ion collisions", which was organized by ExtreMe Matter Institute EMMI held at GSI, Darmstadt, Germany in April 2019. We address current understanding dynamics fluctuations QCD their measurement collision experiments. In addition, we outline what might be learned from studying correlations other physical systems, such as cold atomic gases.
The dipole response of stable and unstable neutron-rich oxygen nuclei masses A = 17 to 22 has been investigated experimentally utilizing electromagnetic excitation in heavy-ion collisions at beam energies about 600 MeV/nucleon. kinematically complete measurement the neutron decay channel inelastic scattering secondary projectiles from a Pb target was performed. Differential cross sections d sigma/dE were derived up 30 MeV energy. In contrast nuclei, deduced strength distribution appears be...
Peripheral fragmentation of a 287 MeV/nucleon beam the halo nucleus ${}^{11}\mathrm{Li}$ incident on carbon target has been studied in fragment-neutron coincidence experiment. The momentum distribution ${}^{10}\mathrm{Li}$ fragments gives access to removed neutron ${}^{11}\mathrm{Li}$. From shape distribution, $({1s}_{1/2}{)}^{2}$ contribution mixture and $({0p}_{1/2}{)}^{2}$ components ground-state wave function was determined be $(45\ifmmode\pm\else\textpm\fi{}10)%$. angular correlation...
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...
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 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...
Flow coefficients $v_{n}$ of the orders $n = 1 - 6$ are measured with High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons as a function centrality, transverse momentum rapidity in Au+Au collisions $\sqrt{s_{NN}} 2.4$ GeV. Combining information from flow all allows to construct first time, collision energies few GeV, multi-differential picture angular emission pattern these particles. It reflects complicated interplay between effect central fireball...
The global polarization of {\Lambda} hyperons along the total orbital angular momentum a relativistic heavy-ion collision is presented based on high statistics data samples collected in Au+Au collisions at \sqrt{s_{NN}} = 2.4 GeV and Ag+Ag 2.55 with High-Acceptance Di-Electron Spectrometer (HADES) GSI, Darmstadt. This first measurement below strangeness production threshold nucleon-nucleon collisions. Results are reported as function centrality well hyperon transverse (p_T) rapidity (y_{CM})...
Opportunities for searches phenomena beyond the Standard Model (BSM) using heavy-ions beams at high energies are outlined. Different BSM proposed in last years collisions of heavy ions, mostly Large Hadron Collider, summarized. A few concrete selected cases reviewed including axion-like particles, anomalous $\tau$ electromagnetic moments, magnetic monopoles, and dark photons. Expectations achievable sensitivities these coming given. Studies CP violation hot dense QCD matter connections to...
Reactions of the halo systems 11Be and 11Li (at 460 280 MeV/nucleon) with a carbon target demonstrate that ( n+9Li) has an (unbound) l=0 ground state very close to threshold. The neutron appreciable (1s1/2)2 (0p1/2)2 components.Received 20 December 1994DOI:https://doi.org/10.1103/PhysRevLett.75.1719©1995 American Physical Society