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Start Over Author "Melzer, C." Publisher escholarship, university of california
12 results on '"Melzer, C."'

1. Direct neutrino-mass measurement based on 259 days of KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Beisenkötter, J, Biassoni, M, Bieringer, B, Biondi, Y, Block, F, Bobien, S, Böttcher, M, Bornschein, B, Bornschein, L, Caldwell, TS, Carminati, M, Chatrabhuti, A, Chilingaryan, S, Daniel, BA, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Fengler, C, Fiorini, C, Formaggio, JA, Forstner, C, Fränkle, FM, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Gutknecht, N, Hannen, V, Hasselmann, L, Haußmann, N, Helbing, K, Henke, H, Heyns, S, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Khosonthongkee, K, Kleifges, M, Klein, M, Kohpeiß, J, Köhler, C, Köllenberger, L, Kopmann, A, Kovač, N, Kovalík, A, Krause, H, Cascio, L La, Lasserre, T, Lauer, J, Le, T, Lebeda, O, Lehnert, B, Li, G, Lokhov, A, Machatschek, M, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mohanty, S, Mostafa, J, Müller, K, Nava, A, Neumann, H, Niemes, S, Onillon, A, Parno, DS, Pavan, M, Pinsook, U, Poon, AWP, Poyato, JM Lopez, Pozzi, S, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, and Rodenbeck, C

Subjects
nucl-ex, hep-ex
Abstract

The fact that neutrinos carry a non-vanishing rest mass is evidence ofphysics beyond the Standard Model of elementary particles. Their absolute massbears important relevance from particle physics to cosmology. In this work, wereport on the search for the effective electron antineutrino mass with theKATRIN experiment. KATRIN performs precision spectroscopy of the tritium$\beta$-decay close to the kinematic endpoint. Based on the first fiveneutrino-mass measurement campaigns, we derive a best-fit value of $m_u^{2} ={-0.14^{+0.13}_{-0.15}}~\mathrm{eV^2}$, resulting in an upper limit of $m_u <{0.45}~\mathrm{eV}$ at 90 % confidence level. With six times the statistics ofprevious data sets, amounting to 36 million electrons collected in 259measurement days, a substantial reduction of the background level and improvedsystematic uncertainties, this result tightens KATRIN's previous bound by afactor of almost two.

Published
2024

2. Search for Lorentz-invariance violation with the first KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, and Schlüter, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences
Abstract

Some extensions of the Standard Model of particle physics allow for Lorentz invariance and charge-parity-time invariance violations. In the neutrino sector strong constraints have been set by neutrino-oscillation and time-of-flight experiments. However, some Lorentz-invariance-violating parameters are not accessible via these probes. In this work, we focus on the parameters (aof(3))00, (aof(3))10, and (aof(3))11 which would manifest themselves in a nonisotropic β-decaying source as a sidereal oscillation and an overall shift of the spectral endpoint. Based on the data of the first scientific run of the KATRIN experiment, we set the first 90% confidence-level limit on |(aof(3))11| of

Published
2023

3. Search for keV-scale sterile neutrinos with the first KATRIN data

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, Schlüter, L, and Schneidewind, S

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Astronomical sciences, Atomic, molecular and optical physics, Particle and high energy physics
Abstract

In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium β -decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to 1.6keV . We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of sin 2θ< 5 × 10 - 4 (95 % C.L.) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.

Published
2023

4. KATRIN: status and prospects for the neutrino mass and beyond

Author

Aker, M, Balzer, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Biassoni, M, Bieringer, B, Block, F, Bobien, S, Bombelli, L, Bormann, D, Bornschein, B, Bornschein, L, Böttcher, M, Brofferio, C, Bruch, C, Brunst, T, Caldwell, TS, Carminati, M, Carney, RMD, Chilingaryan, S, Choi, W, Cremonesi, O, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Fink, D, Fiorini, C, Formaggio, JA, Forstner, C, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grande, A, Grössle, R, Gugiatti, M, Gumbsheimer, R, Hannen, V, Hartmann, J, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, King, P, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, La Cascio, L, Lebeda, O, Lechner, P, Lehnert, B, Le, TL, Lokhov, A, Machatschek, M, Malcherek, E, Manfrin, D, Mark, M, Marsteller, A, Martin, EL, Mazzola, E, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Nava, A, Neumann, H, Niemes, S, Oelpmann, P, and Onillon, A

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, neutrino, neutrino mass, sterile neutrino, tritium beta decay, krypton, beyond standard model, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, Nuclear and plasma physics, Particle and high energy physics
Abstract

The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to measure a high-precision integral spectrum of the endpoint region of T2 β decay, with the primary goal of probing the absolute mass scale of the neutrino. After a first tritium commissioning campaign in 2018, the experiment has been regularly running since 2019, and in its first two measurement campaigns has already achieved a sub-eV sensitivity. After 1000 days of data-taking, KATRIN’s design sensitivity is 0.2 eV at the 90% confidence level. In this white paper we describe the current status of KATRIN; explore prospects for measuring the neutrino mass and other physics observables, including sterile neutrinos and other beyond-Standard-Model hypotheses; and discuss research-and-development projects that may further improve the KATRIN sensitivity.

Published
2022

5. New Constraint on the Local Relic Neutrino Background Overdensity with the First KATRIN Data Runs

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, F, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, and Schlösser, K

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KATRIN Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

We report on the direct search for cosmic relic neutrinos using data acquired during the first two science campaigns of the KATRIN experiment in 2019. Beta-decay electrons from a high-purity molecular tritium gas source are analyzed by a high-resolution MAC-E filter around the end point at 18.57 keV. The analysis is sensitive to a local relic neutrino overdensity ratio of η

Published
2022

6. Improved eV-scale sterile-neutrino constraints from the second KATRIN measurement campaign

Author

Aker, M, Batzler, D, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gavin, AS, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleifges, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, La Cascio, L, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Mostafa, J, Müller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ráliš, J, Ramachandran, S, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Salomon, R, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, and Schlüter, L

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Mathematical physics, Astronomical sciences, Particle and high energy physics
Abstract

We present the results of the light sterile neutrino search from the second Karlsruhe Tritium Neutrino (KATRIN) measurement campaign in 2019. Approaching nominal activity, 3.76×106 tritium β-electrons are analyzed in an energy window extending down to 40 eV below the tritium end point at E0=18.57 keV. We consider the 3ν+1 framework with three active and one sterile neutrino flavors. The analysis is sensitive to a fourth mass eigenstate m42≲1600 eV2 and active-to-sterile mixing |Ue4|2≳6×10-3. As no sterile-neutrino signal was observed, we provide improved exclusion contours on m42 and |Ue4|2 at 95% C.L. Our results supersede the limits from the Mainz and Troitsk experiments. Furthermore, we are able to exclude the large Δm412 solutions of the reactor antineutrino and gallium anomalies to a great extent. The latter has recently been reaffirmed by the BEST Collaboration and could be explained by a sterile neutrino with large mixing. While the remaining solutions at small Δm412 are mostly excluded by short-baseline reactor experiments, KATRIN is the only ongoing laboratory experiment to be sensitive to relevant solutions at large Δm412 through a robust spectral shape analysis.

Published
2022

7. Direct neutrino-mass measurement with sub-electronvolt sensitivity

Author

Aker, M, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bobien, S, Boettcher, M, Bornschein, B, Bornschein, L, Brunst, T, Caldwell, TS, Carney, RMD, La Cascio, L, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Barrero, D Diaz, Doe, PJ, Dragoun, O, Drexlin, G, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fraenkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glueck, F, Groessle, R, Gumbsheimer, R, Gupta, V, Hoehn, T, Hannen, V, Haussmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, F, Kellerer, J, Kleifges, M, Klein, M, Koehler, C, Koellenberger, L, Kopmann, A, Korzeczek, M, Kovalik, A, Krasch, B, Krause, H, Kunka, N, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Menshikov, A, Mertens, S, Mostafa, J, Mueller, K, Neumann, H, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ramachandran, S, Robertson, RGH, Rodejohann, W, Roellig, M, Roettele, C, Rodenbeck, C, Rysavy, M, Sack, R, Saenz, A, Schaefer, P, Pollithy, A Schaller Nee, Schimpf, L, Schloesser, K, and Schloesser, M

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, Mathematical Sciences, Fluids & Plasmas, Mathematical sciences, Physical sciences
Abstract

Since the discovery of neutrino oscillations, we know that neutrinos have non-zero mass. However, the absolute neutrino-mass scale remains unknown. Here we report the upper limits on effective electron anti-neutrino mass, mν, from the second physics run of the Karlsruhe Tritium Neutrino experiment. In this experiment, mν is probed via a high-precision measurement of the tritium β-decay spectrum close to its endpoint. This method is independent of any cosmological model and does not rely on assumptions whether the neutrino is a Dirac or Majorana particle. By increasing the source activity and reducing the background with respect to the first physics campaign, we reached a sensitivity on mν of 0.7 eV c–2 at a 90% confidence level (CL). The best fit to the spectral data yields mν2 = (0.26 ± 0.34) eV2 c–4, resulting in an upper limit of mν < 0.9 eV c–2 at 90% CL. By combining this result with the first neutrino-mass campaign, we find an upper limit of mν < 0.8 eV c–2 at 90% CL.

Published
2022

8. Analysis methods for the first KATRIN neutrino-mass measurement

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Blaum, K, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, La Cascio, L, Chilingaryan, S, Choi, W, Díaz Barrero, D, Debowski, K, Deffert, M, Descher, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Höhn, T, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Köllenberger, L, Karl, C, Kellerer, J, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, Le, TL, Lebeda, O, Lehnert, B, Lokhov, A, Lopez Poyato, JM, Müller, K, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Niemes, S, Oelpmann, P, Osipowicz, A, Parno, DS, Poon, AWP, Priester, F, Röllig, M, Röttele, C, Rest, O, Robertson, RGH, Rodenbeck, C, Ryšavý, M, Sack, R, Saenz, A, Schaller, A, Schäfer, P, Schimpf, L, Schlösser, K, Schlösser, M, Schlüter, L, Schrank, M, Schulz, B, and Šefčík, M

Abstract

We report on the dataset, data handling, and detailed analysis techniques of the first neutrino-mass measurement by the Karlsruhe Tritium Neutrino (KATRIN) experiment, which probes the absolute neutrino-mass scale via the β-decay kinematics of molecular tritium. The source is highly pure, cryogenic T2 gas. The β electrons are guided along magnetic field lines toward a high-resolution, integrating spectrometer for energy analysis. A silicon detector counts β electrons above the energy threshold of the spectrometer, so that a scan of the thresholds produces a precise measurement of the high-energy spectral tail. After detailed theoretical studies, simulations, and commissioning measurements, extending from the molecular final-state distribution to inelastic scattering in the source to subtleties of the electromagnetic fields, our independent, blind analyses allow us to set an upper limit of 1.1 eV on the neutrino-mass scale at a 90% confidence level. This first result, based on a few weeks of running at a reduced source intensity and dominated by statistical uncertainty, improves on prior limits by nearly a factor of two. This result establishes an analysis framework for future KATRIN measurements, and provides important input to both particle theory and cosmology.

Published
2021

9. Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment

Author

Aker, M, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, Carney, RMD, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Barrero, D Díaz, Doe, PJ, Dragoun, O, Drexlin, G, Edzards, F, Eitel, K, Ellinger, E, Miniawy, A El, Engel, R, Enomoto, S, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Groh, S, Grössle, R, Gumbsheimer, R, Hannen, V, Haußmann, N, Heizmann, F, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Höhn, T, Houdy, T, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kleesiek, M, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lehnert, B, Le, TL, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Meier, M, Melzer, C, Menshikov, A, Mertens, S, Mostafa, J, Müller, K, Niemes, S, Oelpmann, P, Parno, DS, Poon, AWP, Poyato, JML, Priester, F, Ranitzsch, PC-O, Robertson, RGH, Rodejohann, W, Rodenbeck, C, Röllig, M, Röttele, C, Ryšavý, M, Sack, R, Saenz, A, Schäfer, P, Schaller, A, Schimpf, L, and Schlösser, K

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics
Abstract

AbstractThe 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 $$\upbeta $$ β -decay endpoint region with a sensitivity on $$m_\nu $$ m ν of 0.2 $$\hbox {eV}/\hbox {c}^2$$ eV / c 2 (90% CL). For this purpose, the $$\upbeta $$ β -electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 keV. A dominant systematic effect of the response of the experimental setup is the energy loss of $$\upbeta $$ β -electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% $$\hbox {T}_2$$ T 2 gas mixture at 30 K, as used in the first KATRIN neutrino-mass analyses, as well as a $$\hbox {D}_2$$ D 2 gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of $$\sigma (m_\nu ^2)< {{10}^{-2}}{\hbox {eV}^{2}}$$ σ ( m ν 2 ) < 10 - 2 eV 2 [1] in the KATRIN neutrino-mass measurement to a subdominant level.

Published
2021

10. Bound on 3+1 Active-Sterile Neutrino Mixing from the First Four-Week Science Run of KATRIN

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Bieringer, B, Blaum, K, Block, F, Bornschein, B, Bornschein, L, Böttcher, M, Brunst, T, Caldwell, TS, La Cascio, L, Chilingaryan, S, Choi, W, Barrero, D Díaz, Debowski, K, Deffert, M, Descher, M, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grössle, R, Gumbsheimer, R, Höhn, T, Hannen, V, Haußmann, N, Helbing, K, Hickford, S, Hiller, R, Hillesheimer, D, Hinz, D, Houdy, T, Huber, A, Jansen, A, Köllenberger, L, Karl, C, Kellerer, J, Kippenbrock, L, Klein, M, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Lasserre, T, Le, TL, Lebeda, O, Le Guennic, N, Lehnert, B, Lokhov, A, Poyato, JM Lopez, Müller, K, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Melzer, C, Mertens, S, Niemes, S, Oelpmann, P, Osipowicz, A, Parno, DS, Poon, AWP, Priester, F, Röllig, M, Röttele, C, Rest, O, Robertson, RGH, Rodenbeck, C, Ryšavý, M, Sack, R, Saenz, A, Schaller, A, Schäfer, P, Schimpf, L, Schlösser, M, Schlösser, K, Schlüter, L, Schrank, M, and Schulz, B

Subjects
Nuclear and Plasma Physics, Particle and High Energy Physics, Physical Sciences, KATRIN Collaboration, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

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 tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. We consider the framework with three active neutrinos and one sterile neutrino. The analysis is sensitive to the mass, m_{4}, of the fourth mass state for m_{4}^{2}≲1000  eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}≳2×10^{-2}. No significant spectral distortion is observed and exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results for m_{4}^{2}≲1000  eV^{2} and improve the Troitsk bound for m_{4}^{2}

Published
2021

11. Suppression of Penning discharges between the KATRIN spectrometers

Author

Aker, M, Altenmüller, K, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Díaz Barrero, D, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Eversheim, D, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, F, Franklin, GB, Frankrone, H, Friedel, F, Fulst, A, Gauda, K, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Hartmann, J, Haußmann, N, Heizmann, F, Heizmann, J, Helbing, K, Hickford, S, Hillesheimer, D, Hinz, D, Höhn, T, Holzapfel, B, Holzmann, S, Houdy, T, Jansen, A, Karl, C, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kuffner, B, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lehnert, B, Letnev, J, Leven, F, Le, TL, Lichter, S, Lokhov, A, Machatschek, M, Malcherek, E, Marsteller, A, Martin, EL, Melzer, C, Menshikov, A, Mertens, S, Mirz, S, Monreal, B, Müller, K, Naumann, U, Neumann, H, Niemes, S, Noe, M, Ortjohann, HW, Osipowicz, A, Otten, E, Parno, DS, and Pollithy, A

Subjects
Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c2 by precisely measuring the endpoint region of the tritium β-decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background.

Published
2020

12. First operation of the KATRIN experiment with tritium

Author

Aker, M, Altenmüller, K, Arenz, M, Baek, WJ, Barrett, J, Beglarian, A, Behrens, J, Berlev, A, Besserer, U, Blaum, K, Block, F, Bobien, S, Bornschein, B, Bornschein, L, Bouquet, H, Brunst, T, Caldwell, TS, Chilingaryan, S, Choi, W, Debowski, K, Deffert, M, Descher, M, Díaz Barrero, D, Doe, PJ, Dragoun, O, Drexlin, G, Dyba, S, Edzards, F, Eitel, K, Ellinger, E, Engel, R, Enomoto, S, Eversheim, D, Fedkevych, M, Felden, A, Formaggio, JA, Fränkle, FM, Franklin, GB, Frankrone, H, Friedel, F, Fuchs, D, Fulst, A, Gauda, K, Gil, W, Glück, F, Grohmann, S, Grössle, R, Gumbsheimer, R, Hackenjos, M, Hannen, V, Hartmann, J, Haußmann, N, Ha-Minh, M, Heizmann, F, Heizmann, J, Helbing, K, Hickford, S, Hillesheimer, D, Hinz, D, Höhn, T, Holzapfel, B, Holzmann, S, Houdy, T, Howe, MA, Huber, A, Jansen, A, Karl, C, Kellerer, J, Kernert, N, Kippenbrock, L, Klein, M, Köhler, C, Köllenberger, L, Kopmann, A, Korzeczek, M, Kovalík, A, Krasch, B, Krause, H, Kuffner, B, Kunka, N, Lasserre, T, La Cascio, L, Lebeda, O, Lebert, M, Lehnert, B, Letnev, J, Leven, F, Le, TL, Lichter, S, Lokhov, A, Machatschek, M, Malcherek, E, Mark, M, Marsteller, A, Martin, EL, Megas, F, Melzer, C, Menshikov, A, Mertens, S, and Meier, M

Subjects
Nuclear & Particles Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Quantum Physics, Atomic, Molecular, Nuclear, Particle and Plasma Physics
Abstract

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 β -decay, provide a largely model-independent probe to the neutrino mass scale. The Karlsruhe Tritium Neutrino (KATRIN) experiment is designed to directly measure the effective electron antineutrino mass with a sensitivity of 0.2eV (90 % CL). In this work we report on the first operation of KATRIN with tritium which took place in 2018. During this commissioning phase of the tritium circulation system, excellent agreement of the theoretical prediction with the recorded spectra was found and stable conditions over a time period of 13 days could be established. These results are an essential prerequisite for the subsequent neutrino mass measurements with KATRIN in 2019.

Published
2020

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