P. Grabmayr
A5033384215- Nuclear physics research studies
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Astrophysics and Cosmic Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Advanced Chemical Physics Studies
- Particle Detector Development and Performance
- Advanced NMR Techniques and Applications
- Nuclear reactor physics and engineering
- Astronomical and nuclear sciences
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Radiation Therapy and Dosimetry
- Muon and positron interactions and applications
- Medical Imaging Techniques and Applications
- Radiopharmaceutical Chemistry and Applications
- Gamma-ray bursts and supernovae
University of Tübingen
2015-2024
Joint Institute for Nuclear Research
2010
Lomonosov Moscow State University
2008
Johannes Gutenberg University Mainz
2002
University of Glasgow
1999-2001
Lund University
1999
Max Planck Society
1981-1990
Utrecht University
1987
Indiana University Bloomington
1987
Max Planck Institute for Nuclear Physics
1982-1983
Neutrinoless double beta decay is a process that violates lepton number conservation. It predicted to occur in extensions of the standard model particle physics. This Letter reports results from phase I Germanium Detector Array (GERDA) experiment at Gran Sasso Laboratory (Italy) searching for neutrinoless isotope $^{76}\mathrm{Ge}$. Data considered present analysis have been collected between November 2011 and May 2013 with total exposure 21.6 kg yr. A blind performed. The background index...
The GERmanium Detector Array (GERDA) experiment searched for the lepton-number-violating neutrinoless double-$\beta$ ($0\nu\beta\beta$) decay of $^{76}$Ge, whose discovery would have far-reaching implications in cosmology and particle physics. By operating bare germanium diodes, enriched an active liquid argon shield, GERDA achieved unprecedently low background index $5.2\times10^{-4}$ counts/(keV$\cdot$kg$\cdot$yr) signal region met design goal to collect exposure 100 kg$\cdot$yr a...
The GERDA experiment searches for the lepton-number-violating neutrinoless double-β decay of ^{76}Ge (^{76}Ge→^{76}Se+2e^{-}) operating bare Ge diodes with an enriched fraction in liquid argon. exposure broad-energy germanium type (BEGe) detectors is increased threefold respect to our previous data release. BEGe feature excellent background suppression from analysis time profile detector signals. In window a level 1.0_{-0.4}^{+0.6}×10^{-3} counts/(keV kg yr) has been achieved; if normalized...
The Gerda collaboration is performing a search for neutrinoless double beta decay of 76Ge with the eponymous detector. experiment has been installed and commissioned at Laboratori Nazionali del Gran Sasso started operation in November 2011. design, construction first operational results are described, along detailed information from R&D phase.
Information on the size and shape of neutron skin (208)Pb is extracted from coherent pion photoproduction cross sections measured using Crystal Ball detector together with Glasgow tagger at MAMI electron beam facility. On exploitation an interpolated fit a theoretical model to sections, half-height radius diffuseness distribution are found be c(n)=6.70±0.03(stat.) fm a(n)=0.55±0.01(stat.)(-0.03)(+0.02)(sys.) fm, respectively, corresponding thickness...
The observation of neutrinoless double-beta decay (0${\nu}{\beta}{\beta}$) would show that lepton number is violated, reveal neutrinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective masses 15 - 50 meV, will require a tonne-scale excellent energy resolution extremely low backgrounds, at level $\sim$0.1 count /(FWHM$\cdot$t$\cdot$yr) in region signal. current generation $^{76}$Ge experiments...
A discovery that neutrinos are not the usual Dirac but Majorana fermions, i.e. identical to their antiparticles, would be a manifestation of new physics with profound implications for particle and cosmology. generate neutrinoless double-$\beta$ ($0\nu\beta\beta$) decay, matter-creating process without balancing emission antimatter. So far, 0$\nu\beta\beta$ decay has eluded detection. The GERDA collaboration searches $0\nu\beta\beta$ $^{76}$Ge by operating bare germanium detectors in an...
The electric form factor of the neutron ${G}_{E,n}$ has been measured in quasifree ${}^{2}\mathrm{H}(\stackrel{\ensuremath{\rightarrow}}{e}{,e}^{\ensuremath{'}}\stackrel{\ensuremath{\rightarrow}}{n})p$ reaction using 855 MeV polarized cw electron beam Mainz Microtron MAMI. polarization scattered neutrons was analyzed a polarimeter consisting two walls plastic scintillators. precession spin magnetic field used for first time to circumvent measurement effective analyzing power and...
A direct measurement of the helicity dependence total photoabsorption cross section on proton was carried out at MAMI (Mainz) in energy range 200<Eγ<800MeV. The experiment used a 4π detection system, circularly polarized tagged photon beam, and frozen spin target. contributions to Gerasimov-Drell-Hearn sum rule forward polarizability γ0 determined from data are 226±5(stat)±12(syst)μb −187±8(stat)±10(syst)×10−6fm4, respectively, for 200<Eγ<800MeV.Received 13 March...
The possibility of observing neutrinoless double $\ensuremath{\beta}$ decay offers the opportunity determining effective neutrino mass if nuclear matrix element were known. Theoretical calculations are uncertain, and occupation valence orbits by nucleons active in is likely to be important. proton ground states $^{76}\mathrm{Ge}$, a candidate for such decay, $^{76}\mathrm{Se}$, corresponding daughter nucleus, determined precisely measuring cross sections proton-removing transfer reactions....
A search for neutrinoless $\beta\beta$ decay processes accompanied with Majoron emission has been performed using data collected during Phase I of the GERmanium Detector Array (GERDA) experiment at Laboratori Nazionali del Gran Sasso INFN (Italy). Processes spectral indices n = 1, 2, 3, 7 were searched for. No signals found and lower limits order 10$^{23}$ yr on their half-lives derived, yielding substantially improved results compared to previous experiments $^{76}$Ge. new result half-life...
The GERmanium Detector Array (GERDA) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double beta decay 76Ge. signature signal a monoenergetic peak 2039 keV, Q-value decay, Q_bb. To avoid bias in search, present analysis does not consider all those events, that fall 40 keV wide region centered around main parameters needed are described. A background model was developed to describe observed energy spectrum. contains several contributions,...
The GERDA experiment located at the LNGS searches for neutrinoless double beta (0\nu\beta\beta) decay of ^{76}Ge using germanium diodes as source and detector. In Phase I eight semi-coaxial five BEGe type detectors have been deployed. latter is used in this field research first time. All are made from material with enriched fraction. experimental sensitivity can be improved by analyzing pulse shape detector signals aim to reject background events. This paper documents algorithms developed...
The GERDA collaboration is performing a sensitive search for neutrinoless double beta decay of $^{76}$Ge at the INFN Laboratori Nazionali del Gran Sasso, Italy. upgrade experiment from Phase I to II has been concluded in December 2015. first data release shows that goal suppress background by one order magnitude compared achieved. thus will remain background-free up its design exposure (100 kg yr). It reach thereby half-life sensitivity more than 10$^{26}$ yr within 3 years collection. This...
The GERmanium Detector Array (Gerda) at the Gran Sasso Underground Laboratory (LNGS) searches for neutrinoless double beta decay ( $$0\nu \beta $$ ) of $$^{76}$$ Ge. Germanium detectors made material with an enriched Ge fraction act simultaneously as sources and this decay. During Phase I theexperiment mainly refurbished semi-coaxial from former experiments were used. For upcoming II, 30 new broad energy germanium (BEGe)-type produced. A subgroup these has already been deployed in Gerda...
The pronounced l=0 selectivity of the (e,e'p) proton knockout reaction has been exploited to determine relative occupation 3${s}_{1/2}$ orbit in $^{205}\mathrm{Tl}$ and $^{206}\mathrm{Pb}$. This value, when combined with previous electron scattering data, enables us extract a largely model-independent fashion absolute probability $^{208}\mathrm{Pb}$. depletion is found be (18\ifmmode\pm\else\textpm\fi{}9)%, compatible predictions many-body theories.
The primary goal of the GERmanium Detector Array (Gerda) experiment at Laboratori Nazionali del Gran Sasso INFN is search for neutrinoless double beta decay 76 Ge.High-purity germanium detectors made from material enriched in Ge are operated directly immersed liquid argon, allowing a substantial reduction background with respect to predecessor experiments.The first 5.04 kg•yr data collected Phase I have been analyzed measure half-life neutrinoaccompanied Ge.The observed spectrum energy range...
We present the measurement of two-neutrino double-β decay rate 76Ge performed with GERDA Phase II experiment. With a subset entire exposure, 11.8 kg yr, half-life process has been determined: T2ν1/2=(2.022±0.018stat±0.038syst)×1021 yr. This is most precise determination and one measurements process. The relevant nuclear matrix element can be extracted: M2νeff=(0.101±0.001).Received 13 May 2023Accepted 15 August 2023DOI:https://doi.org/10.1103/PhysRevLett.131.142501Published by American...
The helicity dependence of the single pion photoproduction on proton has been measured in energy range from 200 to 450 MeV for first time. experiment, performed at Mainz microtron MAMI, used a 4π-detector system, circularly polarized, tagged photon beam, and frozen-spin target. data obtained provide new information multipole analyses determine main contributions Gerasimov-Drell-Hearn sum rule forward spin polarizability γ0.Received 6 January...
To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for first time experimentally, we measured helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally nucleons in photon energy range 0.68-1.82 GeV tagged facility at ELSA. The experiment was carried out a 4pi detection system, beam, frozen spin proton target. contribution to GDH this is [49.9+/-2.4(stat)+/-2.2(syst)] microb.