Publications (38)
Reaching Fermi degeneracy via universal dipolar scattering
K. Aikawa, A. Frisch, M. Mark +3
We report on the creation of a degenerate dipolar Fermi gas of erbium atoms. We force evaporative cooling in a fully spin-polarized sample down to temperatures as low as 0.2 times…
Direct neutrino-mass measurement based on 259 days of KATRIN data
M. Aker, D. Batzler, A. Beglarian +146
The fact that neutrinos carry a non-vanishing rest mass is evidence of physics beyond the Standard Model of elementary particles. Their absolute mass bears important relevance from…
Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment
M. Aker, A. Beglarian, J. Behrens +132
The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium …
Measurement of the inhomogeneity of the KATRIN tritium source electric potential by high-resolution spectroscopy of conversion electrons from Kr
H. Acharya, M. Aker, D. Batzler +130
Precision spectroscopy of the electron spectrum of the tritium -decay near the kinematic endpoint is a direct method to determine the effective electron antineutrino mass. The…
Measurement of the electric potential and the magnetic field in the shifted analysing plane of the KATRIN experiment
M. Aker, D. Batzler, A. Beglarian +135
The projected sensitivity of the effective electron neutrino-mass measurement with the KATRIN experiment is below 0.3 eV (90 % CL) after five years of data acquisition. The sensiti…
New Constraint on the Local Relic Neutrino Background Overdensity with the First KATRIN Data Runs
M. Aker, D. Batzler, A. Beglarian +129
We report on the direct cosmic relic neutrino background search from the first two science runs of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity molecular…
Magnetically Controlled Exchange Process in an Ultracold Atom-Dimer Mixture
S. Knoop, F. Ferlaino, M. Berninger +5
We report on the observation of an elementary exchange process in an optically trapped ultracold sample of atoms and Feshbach molecules. We can magnetically control the energetic n…
Observation of an Efimov resonance in an ultracold mixture of atoms and weakly bound dimers
S. Knoop, F. Ferlaino, M. Berninger +3
We discuss our recent observation of an atom-dimer Efimov resonance in an ultracold mixture of Cs atoms and Cs_2 Feshbach molecules [Nature Phys. 5, 227 (2009)]. We review our expe…
Collisions between tunable halo dimers: exploring an elementary four-body process with identical bosons
F. Ferlaino, S. Knoop, M. Mark +4
We study inelastic collisions in a pure, trapped sample of Feshbach molecules made of bosonic cesium atoms in the quantum halo regime. We measure the relaxation rate coefficient fo…
Observation of Fermi surface deformation in a dipolar quantum gas
K. Aikawa, S. Baier, A. Frisch +3
The deformation of a Fermi surface is a fundamental phenomenon leading to a plethora of exotic quantum phases. Understanding these phases, which play crucial roles in a wealth of s…
Anisotropic relaxation dynamics in a dipolar Fermi gas driven out of equilibrium
K. Aikawa, A. Frisch, M. Mark +6
We report on the observation of a large anisotropy in the rethermalization dynamics of an ultracold dipolar Fermi gas driven out of equilibrium. Our system consists of an ultracold…
KATRIN: Status and Prospects for the Neutrino Mass and Beyond
M. Aker, M. Balzer, D. Batzler +159
The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region of T2 beta decay, with the primary goal of probi…
The Design, Construction, and Commissioning of the KATRIN Experiment
M. Aker, K. Altenmüller, J. F. Amsbaugh +226
The KArlsruhe TRItium Neutrino (KATRIN) experiment, which aims to make a direct and model-independent determination of the absolute neutrino mass scale, is a complex experiment wit…
Universal behavior of pair correlations in a strongly interacting Fermi gas
E. D. Kuhnle, H. Hu, X. -J. Liu +5
We show that short-range pair correlations in a strongly interacting Fermi gas follow a simple universal law described by Tan's relations. This is achieved through measurements of…
`Stückelberg interferometry' with ultracold molecules
M. Mark, T. Kraemer, P. Waldburger +4
We report on the realization of a time-domain `Stückelberg interferometer', which is based on the internal state structure of ultracold Feshbach molecules. Two subsequent passages…
First direct neutrino-mass measurement with sub-eV sensitivity
M. Aker, A. Beglarian, J. Behrens +125
We report the results of the second measurement campaign of the Karlsruhe Tritium Neutrino (KATRIN) experiment. KATRIN probes the effective electron anti-neutrino mass, , via…
Spectroscopy of Ultracold, Trapped Cesium Feshbach Molecules
M. Mark, F. Ferlaino, S. Knoop +5
We explore the rich internal structure of Cs_2 Feshbach molecules. Pure ultracold molecular samples are prepared in a CO_2-laser trap, and a multitude of weakly bound states is pop…
First constraints on general neutrino interactions based on KATRIN data
M. Aker, D. Batzler, A. Beglarian +130
The precision measurement of the tritium -decay spectrum performed by the KATRIN experiment provides a unique way to search for general neutrino interactions (GNI). All theoret…
Observation of an Efimov-like resonance in ultracold atom-dimer scattering
S. Knoop, F. Ferlaino, M. Mark +4
The field of few-body physics has originally been motivated by understanding nuclear matter. New model systems to experimentally explore few-body quantum systems can now be realize…
Improved eV-scale Sterile-Neutrino Constraints from the Second KATRIN Measurement Campaign
M. Aker, D. Batzler, A. Beglarian +128
We present the results of the light sterile neutrino search from the second KATRIN measurement campaign in 2019. Approaching nominal activity, tritium -elect…
Analysis methods for the first KATRIN neutrino-mass measurement
M. Aker, K. Altenmüller, A. Beglarian +126
We report on the data set, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probe…
Experimental Evidence for Efimov Quantum States
H. -C. Naegerl, T. Kraemer, M. Mark +8
Three interacting particles form a system which is well known for its complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov's prediction of…
Search for Lorentz-Invariance Violation with the first KATRIN data
M. Aker, D. Batzler, A. Beglarian +130
Some extensions of the Standard Model of Particle Physics allow for Lorentz invariance and Charge-Parity-Time (CPT)-invariance violations. In the neutrino sector strong constraints…
An improved upper limit on the neutrino mass from a direct kinematic method by KATRIN
M. Aker, K. Altenmüller, M. Arenz +205
We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from…
Search for keV-scale Sterile Neutrinos with first KATRIN Data
M. Aker, D. Batzler, A. Beglarian +128
In this work we present a keV-scale sterile-neutrino search with the first tritium data of the KATRIN experiment, acquired in the commissioning run in 2018. KATRIN performs a spect…
Narrow-line magneto-optical trap for erbium
A. Frisch, K. Aikawa, M. Mark +5
We report on the experimental realization of a robust and efficient magneto-optical trap for erbium atoms, based on a narrow cooling transition at 583nm. We observe up to $N=2 \tim…
Metastable Feshbach Molecules in High Rotational States
S. Knoop, M. Mark, F. Ferlaino +4
We experimentally demonstrate Cs2 Feshbach molecules well above the dissociation threshold, which are stable against spontaneous decay on the timescale of one second. An optically…
Ultracold Dipolar Molecules Composed of Strongly Magnetic Atoms
A. Frisch, M. Mark, K. Aikawa +8
In a combined experimental and theoretical effort, we demonstrate a novel type of dipolar system made of ultracold bosonic dipolar molecules with large magnetic dipole moments. Our…
Bound on 3+1 active-sterile neutrino mixing from the first four-week science run of KATRIN
M. Aker, K. Altenmueller, A. Beglarian +126
We report on the light sterile neutrino search from the first four-week science run of the KATRIN experiment in~2019. Beta-decay electrons from a high-purity gaseous molecular trit…
Evidence for Efimov quantum states in an ultracold gas of cesium atoms
T. Kraemer, M. Mark, P. Waldburger +8
Systems of three interacting particles are notorious for their complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov's prediction of a univ…
Bose-Einstein Condensation of Erbium
K. Aikawa, A. Frisch, M. Mark +4
We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic field. By means of evaporative coo…
Observation of Feshbach-like resonances in collisions between ultracold molecules
C. Chin, T. Kraemer, M. Mark +4
We observe magnetically tuned collision resonances for ultracold Cs2 molecules stored in a CO2-laser trap. By magnetically levitating the molecules against gravity, we precisely me…
Commissioning of the vacuum system of the KATRIN Main Spectrometer
M. Arenz, M. Babutzka, M. Bahr +147
The KATRIN experiment will probe the neutrino mass by measuring the beta-electron energy spectrum near the endpoint of tritium beta-decay. An integral energy analysis will be perfo…
Efficient creation of molecules from a cesium Bose-Einstein condensate
M. Mark, T. Kraemer, J. Herbig +3
We report a new scheme to create weakly bound Cs molecules from an atomic Bose-Einstein condensate. The method is based on switching the magnetic field to a narrow Feshbach res…
Collisions of Ultracold Trapped Cesium Feshbach Molecules
F. Ferlaino, S. Knoop, M. Berninger +3
We study collisions in an optically trapped, pure sample of ultracold Cs molecules in various internal states. The molecular gas is created by Feshbach association from a near-…
Crossover from 2D to 3D in a weakly interacting Fermi gas
P. Dyke, E. D. Kuhnle, S. Whitlock +6
We have studied the transition from two to three dimensions in a low temperature weakly interacting Li Fermi gas. Below a critical atom number, , only the lowest transv…
First operation of the KATRIN experiment with tritium
M. Aker, K. Altenmüller, M. Arenz +168
The determination of the neutrino mass is one of the major challenges in astroparticle physics today. Direct neutrino mass experiments, based solely on the kinematics of beta-decay…
KATRIN Sensitivity to keV Sterile Neutrinos with the TRISTAN Detector Upgrade
H. Acharya, M. Aker, D. Batzler +127
Sterile neutrinos in the keV mass range are a well-motivated extension of the Standard Model and viable dark matter candidates. Their existence can be probed in laboratory experime…