A5064367382- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Muon and positron interactions and applications
Technical University of Munich
2010-2018
Bavarian Academy of Sciences and Humanities
2016-2018
Excellence Cluster Universe
2015
We report magnetic and calorimetric measurements down to T = 1 mK on the canonical heavy-electron metal YbRh2Si2. The data reveal development of nuclear antiferromagnetic order slightly above 2 mK. latter weakens primary electronic antiferromagnetism, thereby paving way for superconductivity below Tc Our results demonstrate that driven by quantum criticality is a general phenomenon.
LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. Its large target mass allows to search for the Diffuse Supernova Background (DSNB), which was generated by cumulative emissions of all core-collapse supernovae throughout universe. Indistinguishable background from reactor and atmospheric electron antineutrinos limits detection window energy range between 9.5 MeV 25 MeV. Depending on mean supernova neutrino energy, about 5 10...
For liquid-scintillator neutrino detectors of kiloton scale, the transparency organic solvent is central importance. The present paper reports on laboratory measurements optical scattering lengths solvents PXE, LAB, and Dodecane which are under discussion for next-generation experiments like SNO+, Hanohano, or LENA. Results comprise wavelength range from 415 to 440nm. contributions Rayleigh Mie as well absorption/re-emission processes discussed. Based results, LAB seems be preferred a...
In this paper the low-temperature properties of two isostructural canonical heavy-fermion compounds are contrasted with regards to interplay between antiferromagnetic (AF) quantum criticality and superconductivity. For CeCu$_2$Si$_2$, fully-gapped d-wave superconductivity forms in vicinity an itinerant three-dimensional spin-density-wave (SDW) critical point (QCP). Inelastic neutron scattering results highlight that both SDW fluctuations as well Mott-type local magnetic moments contribute...
A next-generation liquid-scintillator detector will be able to perform high-statistics measurements of the solar neutrino flux. In LENA, $^{7}\mathrm{Be}$ neutrinos are expected cause $1.7\ifmmode\times\else\texttimes\fi{}{10}^{4}$ electron recoil events per day in a fiducial volume 35 kilotons. Based on this signal, search for periodic modulations subpercent level can conducted, surpassing sensitivity current detectors by at least factor 20. The range accessible periods reaches from several...
LENA (Low Energy Neutrino Astronomy) has been proposed as a next generation 50 kt liquid scintillator detector. The large target mass allows high precision measurement of the solar $^8$B neutrino spectrum, with an unprecedented energy threshold 2 MeV. Hence, it can probe MSW-LMA prediction for electron survival probability in transition region between vacuum and matter-dominated oscillations. Based on Monte Carlo simulations corresponding background spectra, was found that predicted upturn...
YbRh2Si2, a heavy fermion compound, is in the center of interest for its unconventional behavior around quantum critical point (QCP) which can be tuned by magnetic field. To study system at lowest possible temperatures, we have measured dc magnetization fields up to 60 mT and down 1 mK using an rf SQUID magnetometer. Our were high enough reach QCP B ∥ (a, b) crystal orientation. Both field cooled (fc) zero (zfc) data taken. We found sharp transition low ground state 2.2 differences between...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation R. Möllenberg, F. von Feilitzsch, M. Göger‐Neff, D. Hellgartner, T. Lewke, Q. Meindl, L. Oberauer, J. Peltoniemi, W. Potzel, Tippmann, Winter, Wurm; Reconstruction of GeV Neutrino Events in LENA. AIP Conf. Proc. 6 October 2011; 1382 (1): 141–143. https://doi.org/10.1063/1.3644294 Download citation file: Ris...
YbRh2Si2 is a widely studied heavy Fermion system with variety of interesting properties, among them quantum critical point at 60 mT for B // a,b-plane 1. At low temperatures we previously found new magnetically ordered phase below 2.2 mK 2 taking place in the well known antiferromagnetic which starts 70 3. In addition to this “A” phase, now observe second, weaker transition 14 and 5 named phase. To study these phases lowest possible temperatures, measured DC magnetization magnetic fields up...
Recently, we reported on the discovery of superconductivity in YbRh2Si2 at very low temperature Tc = 2 mK. We present here complementary measurements and field dependence ac susceptibility χac (T) this heavy-fermion system for temperatures down to 1 mK magnetic fields basal plane up 75 mT. The in-phase response shows a steep drop Tc, but it does not become negative, possibly because presence earth that was compensated. out-of-phase an increase right below indicating transition is first...
The proposed large-volume detector LENA (Low Energy Neutrino Astronomy) is a multi-purpose liquid-scintillator experiment. Its sensitive mass of 50 kt allows for high-statistic measurements astrophysical and terrestrial low-energy neutrino sources. Moreover, new limits might be put on the lifetime proton decay channel into K+.
In the last years, liquid-scintillator detectors have opened a new window for observation of low-energetic astrophysical neutrino sources. 2007, solar experiment Borexino began its data-taking in Gran Sasso underground laboratory. High energy resolution and excellent radioactive background conditions detector allow first-time spectroscopic measurement neutrinos sub-MeV regime. The experimental results Beryllium-7 flux measurements as well prospects detection Boron-8, pep CNO are presented...
The large-volume liquid-scintillator detector LENA (Low Energy Neutrino Astronomy) has been proposed as a next-generation experiment for low-energy neutrinos. High-precision spectroscopy of solar, Supernova and geo-neutrinos provides new access to the otherwise unobservable interiors Earth, Sun heavy stars. Due potent background discrimination, detection Diffuse Background is expected first time in LENA. sensitivity proton lifetime decay into Kaon antineutrino will be increased by an order...