Abstract The projected sensitivity of the effective electron neutrino-mass measurement with the KATRIN experiment is below 0.3 eV (90 % CL) after 5 years of data acquisition. The sensitivity is affected by the increased rate of the background electrons from KATRIN’s main spectrometer. A special shifted-analysing-plane (SAP) configuration was developed to reduce this background by a factor of two. The complex layout of electromagnetic fields in the SAP configuration requires a robust method of estimating these fields. We present in this paper a dedicated calibration measurement of the fields using conversion electrons of gaseous $$^\textrm{83m}$$ 83m Kr, which enables the neutrino-mass measurements in the SAP configuration.
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 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 $(a_{\text{of}}^{(3)})_{00}$, $(a_{\text{of}}^{(3)})_{10}$ and $(a_{\text{of}}^{(3)})_{11}$ which would manifest themselves in a non-isotropic beta-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 limit on $\left|(a_{\text{of}}^{(3)})_{11}\right|$ of $<3.7\cdot10^{-6}$ GeV at 90\% confidence level. Moreover, we derive new constraints on $(a_{\text{of}}^{(3)})_{00}$ and $(a_{\text{of}}^{(3)})_{10}$.
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 x 10(6) tritium ss-electrons are analyzed in an energy window extending down to 40 eV below the tritium end point at E-0 = 18.57 keV. We consider the 3 nu + 1 framework with three active and one sterile neutrino flavors. The analysis is sensitive to a fourth mass eigenstate m(4)(2) less than or similar to 1600 eV(2) and active-to-sterile mixing |U-e4|(2) greater than or similar to 6 x 10(-3). As no sterile-neutrino signal was observed, we provide improved exclusion contours on m(4)(2) and |U-e4|(2) at 95% C.L. Our results supersede the limits from the Mainz and Troitsk experiments. Furthermore, we are able to exclude the large Delta m(41)(2) 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 Delta m(41)(2) are mostly excluded by short-baseline reactor experiments, KATRIN is the only ongoing laboratory experiment to be sensitive to relevant solutions at large Delta m(41)(2) through a robust spectral shape analysis.
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<9.7×10^{10}/α (1.1×10^{11}/α) at a 90% (95%) confidence level with α=1 (0.5) for Majorana (Dirac) neutrinos. A fit of the integrated electron spectrum over a narrow interval around the end point accounting for relic neutrino captures in the tritium source reveals no significant overdensity. This work improves the results obtained by the previous neutrino mass experiments at Los Alamos and Troitsk. We furthermore update the projected final sensitivity of the KATRIN experiment to η<1×10^{10}/α at 90% confidence level, by relying on updated operational conditions.
Author(s): Aker, M; Altenmuller, K; Beglarian, A; Behrens, J; Berlev, A; Besserer, U; Bieringer, B; Blaum, K; Block, F; Bornschein, B; Bornschein, L; Bottcher, M; Brunst, T; Caldwell, TS; La Cascio, L; Chilingaryan, S; Choi, W; Diaz 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; Frankle, FM; Franklin, GB; Friedel, F; Fulst, A; Gauda, K; Gil, W; Gluck, F; Grossle, R; Gumbsheimer, R; Hohn, T; Hannen, V; Hausmann, N; Helbing, K; Hickford, S; Hiller, R; Hillesheimer, D; Hinz, D; Houdy, T; Huber, A; Jansen, A; Kollenberger, L; Karl, C; Kellerer, J; Kippenbrock, L; Klein, M; Kopmann, A; Korzeczek, M; Kovalik, A; Krasch, B; Krause, H; Lasserre, T; Le, TL; Lebeda, O; Lehnert, B; Lokhov, A; Lopez Poyato, JM; Muller, 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; Rollig, M; Rottele, C | 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.
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}<30 eV^{2}. The reactor and gallium anomalies are constrained for 100<Δm_{41}^{2}<1000 eV^{2}.
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 with many components. More than 15 years ago, we published a technical design report (TDR) [1] to describe the hardware design and requirements to achieve our sensitivity goal of 0.2 eV at 90% C.L. on the neutrino mass. Since then there has been considerable progress, culminating in the publication of first neutrino mass results with the entire beamline operating [2]. In this paper, we document the current state of all completed beamline components (as of the first neutrino mass measurement campaign), demonstrate our ability to reliably and stably control them over long times, and present details on their respective commissioning campaigns.
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 a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (-1.0_{-1.1}^{+0.9}) eV^{2}. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation.
The therapeutic acquisition to be retained for 2004 are: 1. The elderly patients with heart failure also should receive beta blocker treatment. The correction of anaemia, aggravating factor in heart failure, improves symptoms and survival of the patient. 2. It remains to prove that the treatment of sleep apnea, which seems to be an additional factor for mortality in cardiovascular diseases, is able to reduce the risk. 3. The interventions in the endocanabinoïd system which regulates weight and metabolic processes might be a promising new therapeutic acquisition. 4. Prevention of coronary disease with lipid lowering drugs is still a major topic, and the trend goes the lower the better. The problems observed with Rofecoxybe and other drug interactions reminds us to be conscious when prescribing multiple drugs. 5. The implantable defibrillator seems to be a life insurance in the event of ventricular fibrillation. However, it is not so easy to identify the patient who might really benefit.
Management of cardiac murmur varies with its characteristics and clinical features. Cardiac echography should not be done systematically, as proposed by the guidelines. The aim of this article is to define which situations do require a cardiac echography, and which do not, thus restricting the expenses without harming the patients care.
The therapeutic acquisition to be retained for 2004 are: 1. The elderly patients with heart failure also should receive beta blocker treatment. The correction of anaemia, aggravating factor in heart failure, improves symptoms and survival of the patient. 2. It remains to prove that the treatment of sleep apnea, which seems to be an additional factor for mortality in cardiovascular diseases, is able to reduce the risk. 3. The interventions in the endocanabinoïd system which regulates weight and metabolic processes might be a promising new therapeutic acquisition. 4. Prevention of coronary disease with lipid lowering drugs is still a major topic, and the trend goes the lower the better. The problems observed with Rofecoxybe and other drug interactions reminds us to be conscious when prescribing multiple drugs. 5. The implantable defibrillator seems to be a life insurance in the event of ventricular fibrillation. However, it is not so easy to identify the patient who might really benefit.
A 25‐year‐old male asylum‐seeker presented with chest pain, exertional dyspnea, and orthopnea 20 years after the surgical repair of a pentalogy of Fallot. An extracardiac mass compressing the right ventricle was subsequently detected and surgical decompression was performed to relieve the resulting right intraventricular hypertension. At operation, the mass proved to be a coagulase‐negative, staphylococcal abscess. In addition, the removal of the mass unmasked a previously nonrecognized pulmonary outflow stenosis that required balloon dilatation and β‐blocker therapy. While infections are known to occur after sternotomy, the formation of an abscess in the anterior mediastinum several years after the intervention appears to be exceptional; this diagnosis came to mind only after the more common complications had been considered, e.g., pseudoaneurysm or pericardial hematoma. To our knowledge, this is the first report of an abscess in the anterior mediastinum that had probably formed over many years following a sternotomy, compressed the right ventricle and masked a pulmonary stenosis.