Publications (36)
Gravity Resonance Spectroscopy and Einstein-Cartan Gravity
Hartmut Abele, Andrei Ivanov, Tobias Jenke +2
The qBounce experiment offers a new way of looking at gravitation based on quantum interference. An ultracold neutron is reflected in well-defined quantum states in the gravity pot…
A Novel Nuclear Emulsion Detector for Measurement of Quantum States of Ultracold Neutrons in the Earth's Gravitational Field
Naoto Muto, Hartmut Abele, Tomoko Ariga +19
Hypothetical short-range interactions could be detected by measuring the wavefunctions of ultracold neutrons (UCNs) on a mirror bounded by the Earth's gravitational field. The Sear…
Prospects for Searching Thermal Effects, Non-Newtonian Gravity and Axion-Like Particles: Cannex Test of the Quantum Vacuum
Galina L. Klimchitskaya, Vladimir M. Mostepanenko, René I. P. Sedmik +1
We consider the CANNEX (Casimir And Non-Newtonian force EXperiment) test of the quantum vacuum intended for measuring the gradient of the Casimir pressure between two flat parallel…
Is the Unitarity of the Quark-Mixing-CKM-Matrix Violated in Neutron Decay?
Hartmut Abele
Measurements by various international groups of researchers determine the strength of the weak interaction of the neutron, which gives us unique information on the question of the…
Happy Birthday, Ultra-Cold Neutron!
Hartmut Abele, Tobias Jenke, Hartmut Lemmel
What is driving the accelerated expansion of the universe and do we have an alternative for Einstein's cosmological constant? What is dark matter made of? Do extra dimensions of sp…
Acoustic Rabi oscillations between gravitational quantum states and impact on symmetron dark energy
Gunther Cronenberg, Philippe Brax, Hanno Filter +6
The standard model of cosmology provides a robust description of the evolution of the universe. Nevertheless, the small magnitude of the vacuum energy is troubling from a theoretic…
qBounce: First Measurement of the Neutron Electric Charge with a Ramsey-type GRS Experiment
Joachim Bosina, Hanno Filter, Jakob Micko +5
The qBounce collaboration built over the last years a new Ramsey-type Gravitational Resonance Spectroscopy (GRS) experiment. After commissioning between 2016 and 2018, the setup wa…
Very Special Relativity in Accelerated Frames: Non-relativistic Effects in Gravitational Spectroscopy of Ultracold Neutrons
Alessandro Santoni, Enrique Muñoz, Hartmut Abele +1
In this paper, we investigate the phenomenology of fermionic systems in uniform gravitational fields within the framework of Very Special Relativity (VSR). We focus on the case of…
Decoherence-Free Entropic Gravity: Model and Experimental Tests
Alex J. Schimmoller, Gerard McCaul, Hartmut Abele +1
Erik Verlinde's theory of entropic gravity [arXiv:1001.0785], postulating that gravity is not a fundamental force but rather emerges thermodynamically, has garnered much attention…
Proof of Principle for Ramsey-type Gravity Resonance Spectroscopy with qBounce
René I. P. Sedmik, Joachim Bosina, Lukas Achatz +10
Ultracold neutrons (UCNs) are formidable probes in precision tests of gravity. With their negligible electric charge, dielectric moment, and polarizability they naturally evade som…
ANNI - A pulsed cold neutron beam facility for particle physics at the ESS
Torsten Soldner, Hartmut Abele, Gertrud Konrad +5
Pulsed beams have tremendous advantages for precision experiments with cold neutrons. In order to minimise and measure systematic effects, they are used at continuous sources in sp…
Gravity Resonance Spectroscopy and Dark Energy Symmetron Fields
Tobias Jenke, Joachim Bosina, Jakob Micko +3
Spectroscopic methods allow to measure energy differences with unrivaled precision. In the case of gravity resonance spectroscopy, energy differences of different gravitational sta…
Gravitation and quantum interference experiments with neutrons
Hartmut Abele, Helmut Leeb
This article describes gravity experiments, where the outcome depends upon both the gravitational acceleration and the Planck constant . We focus on the work done with a…
Decoherence-Free Entropic Gravity for Dirac Fermion
Eric J. Sung, Andre G. Campos, Hartmut Abele +1
The theory of entropic gravity conjectures that gravity emerges thermodynamically rather than being a fundamental force. One of the main criticisms of entropic gravity is that it w…
Tests of Fundamental Quantum Mechanics and Dark Interactions with Low Energy Neutrons -- Extended Version
Stephan Sponar, Rene I. P. Sedmik, Mario Pitschmann +2
Among the known particles, the neutron takes a special position, as it provides experimental access to all four fundamental forces and a wide range of hypothetical interactions. De…
Chirped-Frequency Excitation of Gravitationally Bound Ultracold Neutrons
Giovanni Manfredi, Omar Morandi, Lazar Friedland +2
Ultracold neutrons confined in the Earth's gravitational field display quantized energy levels that have been observed for over a decade. In recent resonance spectroscopy experimen…
Limit on the Fierz Interference Term b from a Measurement of the Beta Asymmetry in Neutron Decay
Heiko Saul, Christoph Roick, Hartmut Abele +7
In the standard model of particle physics, the weak interaction is described by vector and axial-vector couplings only. Non-zero scalar or tensor interactions would imply an additi…
Measurement of the Axial-Vector Coupling Constant in Neutron Beta Decay
Bastian Maerkisch, Hartmut Abele
The matrix element \Vud of the CKM matrix can be determined by two independent measurements in neutron decay: the neutron lifetime and the ratio of coupling constants $λ=g_…
Green's function analysis of the Neutron Lloyd interferometer
Christian Käding, Mario Pitschmann, Hartmut Abele
The neutron optical Lloyd interferometer can serve as a potent experiment for probing fundamental physics beyond the standard models of particles and cosmology. In this article, we…
Design of the Magnet System of the Neutron Decay Facility PERC
Xiangzun Wang, Carmen Ziener, Hartmut Abele +27
The PERC (Proton and Electron Radiation Channel) facility is currently under construction at the research reactor FRM II, Garching. It will serve as an intense and clean source of…
Quantum states of neutrons in the gravitational field and limits for non-Newtonian interaction in the range between 1 micron and 10 microns
Hartmut Abele, Stefan Baessler, Alexander Westphal
Quantum states in the Earth's gravitational field can be observed, when ultra-cold neutrons fall under gravity. In an experiment at the Institut Laue-Langevin in Grenoble, neutrons…
Spectra of Neutron Wave Functions in Earth's Gravitational Field
Martin Suda, Manfried Faber, Joachim Bosina +5
The time evolution of a quantum wave packet in the linear gravity potential is known as Quantum Bouncing Ball. The qBounce collaboration recently observed such a system by dropping…
High Precision Experiments with Cold and Ultra-Cold Neutrons
Hartmut Abele, Tobias Jenke, Erwin Jericha +5
This work presents selected results from the first round of the DFG Priority Programme SPP 1491 "precision experiments in particle and astroparticle physics with cold and ultra-col…
NoMoS: An Drift Momentum Spectrometer for Beta Decay Studies
Daniel Moser, Hartmut Abele, Joachim Bosina +5
The beta decay of the free neutron provides several probes to test the Standard Model of particle physics as well as to search for extensions thereof. Hence, multiple experiments i…
Analytically derived limits on short-range fifth forces from quantum states of neutrons in the Earth's gravitational field
Alexander Westphal, Hartmut Abele, Stefan Baessler
Recently, quantum states of ultra-cold neutrons in the Earth's gravitational field have been observed for the first time. From the fact that they are consistent with Newtonian grav…
Undetected Electron Backscattering in PERKEO III
Christoph Roick, Heiko Saul, Hartmut Abele +1
The beta asymmetry in neutron beta decay is used to determine the ratio of axial-vector coupling to vector coupling most precisely. In electron spectroscopy, backscattering of elec…
Search for environment-dependent dilatons
Hauke Fischer, Christian Käding, René I. P. Sedmik +3
The environment-dependent dilaton field is a well-motivated candidate for dark energy and naturally arises in the strong coupling limit of string theory. In this article, we presen…
Generalized Boundary Conditions for the qBounce Experiment
Eric J. Sung, Benjamin Koch, Tobias Jenke +2
Discrepancies between theory and recent qBounce data have prompted renewed scrutiny of how boundary conditions are implemented for ultracold neutrons bouncing above a mirror in Ear…
Neutron interference from a split-crystal interferometer
Hartmut Lemmel, Michael Jentschel, Hartmut Abele +5
We report the first successful operation of a neutron interferometer having a separate beam recombining crystal. We achieved this result at the neutron interferometry setup S18 at…
Schrödinger Equation for a Non-Relativistic Particle in a Gravitational Field confined by Two Vibrating Mirrors
Mario Pitschmann, Hartmut Abele
We derive approximate analytical solutions for a particle in a homogenous gravitational field and confined between two independently vibrating mirrors. This constitutes an extensio…
Neutron beta-decay and the quark-mixing CKM-matrix
Hartmut Abele
Neutrons study a number of hot topics from the field of particle physics and cosmology: Recent measurements of various mixed American-British-French-German-Hungarian-Japan-Russian…
CANISIUS The Austrian Neutron Spin Echo Interferometer
Niels Geerits, Simon Hack, Lara Brukner +4
The broad band resonant spin echo interferometer, CANISIUS, is presented. CANISIUS is built in a versatile way, such that it can be operated in both a continuous broad band beam or…
Spectroscopy with cold and ultra-cold neutrons
Hartmut Abele, Tobias Jenke, Gertrud Konrad
We present two new types of spectroscopy methods for cold and ultra-cold neutrons. The first method, which uses the \RB drift effect to disperse charged particles in a uniformly cu…
Probing neutron's electric neutrality with Ramsey Spectroscopy of gravitational quantum states of ultra-cold neutrons
Katharina Durstberger-Rennhofer, Tobias Jenke, Hartmut Abele
We propose to test the electric neutrality of neutrons by a new technique using the spectroscopy of quantum states of ultra-cold neutrons in the gravity potential above a vertical…
Quark-Mixing, CKM-Unitarity
Hartmut Abele, Daniela Mund
With these proceedings, we present both a review of the experimental and theoretical information on quark-mixing with focus on the first quark generation. The papers present new fi…
Measurement of the Weak Axial-Vector Coupling Constant in the Decay of Free Neutrons Using a Pulsed Cold Neutron Beam
Bastian Märkisch, Holger Mest, Heiko Saul +8
We present a precision measurement of the axial-vector coupling constant in the decay of polarized free neutrons. For the first time, a pulsed cold neutron beam was used for…