RESUMEN
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}â²1000 eV^{2} and to active-to-sterile neutrino mixing down to |U_{e4}|^{2}â³2×10^{-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}â²1000 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}.
RESUMEN
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.
Asunto(s)
Úlcera Duodenal/rehabilitación , Colonias de Salud , Cuidados Posoperatorios/métodos , Vagotomía Gástrica Proximal , Adulto , Enfermedad Crónica , Terapia Combinada , Síndrome de Vaciamiento Rápido/rehabilitación , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Píloro , UcraniaRESUMEN
In the experiments on rabbits the reactions of arterial pressure fall during unilateral and bilateral simultaneous stimulation of the aortic nerve and during conditioning of arterial pressure change effects preceding stimulation of the same nerve, contralateral aortic nerve, vagal afferents and tibial nerve were investigated under general anaesthesia with urethane. The main effect of simultaneous stimulation of both aortic nerves was occlusion. Facilitation developed in a very narrow range of stimulation intensities used. The results of conditioning of depressor response pressure fall reaction obtained from the aortic nerve using various afferent fibres point to differences in the degree of utilization of common interneuronal pathways stimulated in both these ways.
Asunto(s)
Aorta/inervación , Presión Sanguínea , Potenciales de Acción , Animales , Estimulación Eléctrica , Femenino , Masculino , Conejos , Nervio Tibial/fisiología , Vagotomía , Nervio Vago/fisiologíaRESUMEN
The influence of cisplatinum and goserelinum on the magnesium and calcium concentration in rat serum has been studied. The cisplatinum induces decrease in serum magnesium concentration (to 70%), and calcium concentration (to 63%). Goserelinum activity was similar to cisplatinum activity. The magnesium concentration decreased to 60%, and calcium to 44%. In condition of cisplatinum and goserelinum activity the hypomagnesemia and hypocalcemia were noted.