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qBounce: Systematic shifts of transition frequencies of gravitational states of ultra-cold neutrons using Ramsey gravity resonance spectroscopy
Authors:
Jakob Micko,
J. Bosina,
S. S. Cranganore,
T. Jenke,
M. Pitschmann,
S. Roccia,
R. I. P. Sedmik,
H. Abele
Abstract:
qBounce is using quantum states of ultra-cold neutrons in the gravitational field of the Earth to investigate gravitation in the micrometre range. We present current measurements taken in 2021 at the Institut Laue-Langevin (ILL) to determine energy differences of these states by mechanically induced transitions. This allows a determination of the local acceleration $g$ using a quantum measurement.…
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qBounce is using quantum states of ultra-cold neutrons in the gravitational field of the Earth to investigate gravitation in the micrometre range. We present current measurements taken in 2021 at the Institut Laue-Langevin (ILL) to determine energy differences of these states by mechanically induced transitions. This allows a determination of the local acceleration $g$ using a quantum measurement. The data presented here results in $g=9.8120(18) m/s^2$. The classical local value at the experiment is $g_c=9.8049 m/s^2$. We present an analysis of systematic effects that induces shifts of the transition frequency of order 100 mHz. The inferred value for $g$ at the experiment shows a systematic shift of $δg\approx3.9σ$.
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Submitted 20 January, 2023;
originally announced January 2023.
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qBounce: First Measurement of the Neutron Electric Charge with a Ramsey-type GRS Experiment
Authors:
Joachim Bosina,
Hanno Filter,
Jakob Micko,
Tobias Jenke,
Mario Pitschmann,
Stéphanie Roccia,
R. I. P. Sedmik,
Hartmut Abele
Abstract:
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 was able to measure the Ramsey transitions with GRS for the first time. Here we present a search of the hypothetical charge of the neutron as an application of GRS to study nonstandard model interactions. This article will…
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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 was able to measure the Ramsey transitions with GRS for the first time. Here we present a search of the hypothetical charge of the neutron as an application of GRS to study nonstandard model interactions. This article will describe the measuring principle and the setup in detail.
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Submitted 14 January, 2023;
originally announced January 2023.
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A Novel Nuclear Emulsion Detector for Measurement of Quantum States of Ultracold Neutrons in the Earth's Gravitational Field
Authors:
Naoto Muto,
Hartmut Abele,
Tomoko Ariga,
Joachim Bosina,
Masahiro Hino,
Katsuya Hirota,
Go Ichikawa,
Tobias Jenke,
Hiroaki Kawahara,
Shinsuke Kawasaki,
Masaaki Kitaguchi,
Jakob Micko,
Kenji Mishima,
Naotaka Naganawa,
Mitsuhiro Nakamura,
Stéphanie Roccia,
Osamu Sato,
René I. P. Sedmik,
Yoshichika Seki,
Hirohiko M. Shimizu,
Satomi Tada,
Atsuhiro Umemoto
Abstract:
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 Searches require detectors with higher spatial resolution. We are developing a UCN detector for the with a high spatial resolution, which consists of a Si substrate, a thin converter layer including $^{10}$B$_{4}$C, and a la…
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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 Searches require detectors with higher spatial resolution. We are developing a UCN detector for the with a high spatial resolution, which consists of a Si substrate, a thin converter layer including $^{10}$B$_{4}$C, and a layer of fine-grained nuclear emulsion. Its resolution was estimated to be less than 100 nm by fitting tracks of either $^{7}$Li nuclei or $α$-particles, which were created when neutrons interacted with the $^{10}$B$_{4}$C layer. For actual measurements of the spatial distributions, the following two improvements were made: The first was to establish a method to align microscopic images with high accuracy within a wide region of 65 mm $\times$ 0.2 mm. We created reference marks of 1 $μ$m and 5 $μ$m diameter with an interval of 50 $μ$m and 500 $μ$m, respectively, on the Si substrate by electron beam lithography and realized a position accuracy of less than 30 nm. The second was to build a holder that could maintain the atmospheric pressure around the nuclear emulsion to utilize it under vacuum during exposure to UCNs. The intrinsic resolution of the improved detector was estimated by evaluating the blur of a transmission image of a gadolinium grating taken by cold neutrons as better than 0.56 $\pm$ 0.08 $μ$m, which included the grating accuracy. A test exposure to UCNs was conducted to obtain the spatial distribution of UCNs in the Earth's gravitational field. Although the test was successful, a blurring of 6.9 $μ$m was found in the measurements, compared with a theoretical curve. We identified the blurring caused by the refraction of UCNs due to the roughness of the upstream surface of the substrate. Polishing of the surface makes the resolution less than 100 nm.
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Submitted 26 May, 2022; v1 submitted 12 January, 2022;
originally announced January 2022.
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Proof of Principle for Ramsey-type Gravity Resonance Spectroscopy with qBounce
Authors:
René I. P. Sedmik,
Joachim Bosina,
Lukas Achatz,
Peter Geltenbort,
Manuel Heiß,
Andrey N. Ivanov,
Tobias Jenke,
Jakob Micko,
Mario Pitschmann,
Tobias Rechberger,
Patrick Schmidt,
Martin Thalhammer,
Hartmut Abele
Abstract:
Ultracold neutrons (UCNs) are formidable probes in precision tests of gravity. With their negligible electric charge, dielectric moment, and polarizability they naturally evade some of the problems plaguing gravity experiments with atomic or macroscopic test bodies. Taking advantage of this fact, the qBounce collaboration has developed a technique - gravity resonance spectroscopy (GRS) - to study…
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Ultracold neutrons (UCNs) are formidable probes in precision tests of gravity. With their negligible electric charge, dielectric moment, and polarizability they naturally evade some of the problems plaguing gravity experiments with atomic or macroscopic test bodies. Taking advantage of this fact, the qBounce collaboration has developed a technique - gravity resonance spectroscopy (GRS) - to study bound quantum states of UCN in the gravity field of the Earth. This technique is used as a high-precision tool to search for hypothetical Non-Newtonian gravity on the micrometer scale. In the present article, we describe the recently commissioned Ramsey-type GRS setup, give an unambiguous proof of principle, and discuss possible measurements that will be performed.
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Submitted 26 August, 2019;
originally announced August 2019.
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NoMoS: An $R \times B$ Drift Momentum Spectrometer for Beta Decay Studies
Authors:
Daniel Moser,
Hartmut Abele,
Joachim Bosina,
Harald Fillunger,
Torsten Soldner,
Xiangzun Wang,
Johann Zmeskal,
Gertrud Konrad
Abstract:
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 investigating the decay have already been performed, are under way or are being prepared. These measure the mean lifetime, angular correlation coefficients or various spectra of the charged decay products (proton and elec…
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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 investigating the decay have already been performed, are under way or are being prepared. These measure the mean lifetime, angular correlation coefficients or various spectra of the charged decay products (proton and electron). NoMoS, the Neutron decay prOducts MOmentum Spectrometer, presents a novel method of momentum spectroscopy: it utilizes the $R \times B$ drift effect to disperse charged particles dependent on their momentum in an uniformly curved magnetic field. This spectrometer is designed to precisely measure momentum spectra and angular correlation coefficients in free neutron beta decay to test the Standard Model and to search for new physics beyond. With NoMoS, we aim to measure inter alia the electron-antineutrino correlation coefficient $a$ and the Fierz interference term $b$ with an ultimate precision of $Δa/a < 0.3\%$ and $Δb < 10^{-3}$ respectively. In this paper, we present the measurement principles, discuss measurement uncertainties and systematics, and give a status update.
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Submitted 11 June, 2019;
originally announced June 2019.