0000000000140158
AUTHOR
K. Unger
showing 7 related works from this author
Search for an Invisibly Decaying Z′ Boson at Belle II in e+e−→μ+μ−(e±μ∓) Plus Missing Energy Final States
2020
Theories beyond the standard model often predict the existence of an additional neutral boson, the Z′. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z′ in the process e+e-→μ+μ-Z′ and of a lepton-flavor-violating Z′ in e+e-→e±μZ′. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an Lμ-Lτ theory, into upper limits on the Z′ coupling constant at the level of 5×10-2-1 for MZ′≤6 GeV/c2.
The use of porous and surface modified silicas as drug delivery and stabilizing agents
1983
(1983). The use of porous and surface modified silicas as drug delivery and stabilizing agents. Drug Development and Industrial Pharmacy: Vol. 9, No. 1-2, pp. 69-91.
Search for Axionlike Particles Produced in e+e− Collisions at Belle II
2020
We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e+e-→γa, a→γγ in the mass range 0.2<ma<9.7 GeV/c2 using data corresponding to an integrated luminosity of (445±3) pb-1. Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength gaγγ of ALPs to photons at the level of 10-3 GeV-1. The limits are the most restrictive to date for 0.2<ma<1 GeV/c2.
Precise Measurement of the D0 and D+ Lifetimes at Belle II
2021
We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72 fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst) fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst) fs, are the most precise to date and are consistent with previous determinations.
Bestimmung der Oberflächenacidität von porösem Siliciumdioxid durch Titration im aprotischen Solvens und Vergleich der Ergebnisse mit denen aus infra…
2008
Ziel der Untersuchung war es, die Amintitrationsmethode mit Arylmethanol-Indikatoren im aprotischen Solvens zur Bestimmung der Saurestarke und Saurestarkeverteilung von porosem Siliciumdioxid einzusetzen. Zur Standardisierung des Verfahrens wurde der Einflus zahlreicher Parameter wie Vorbehandlung des Festkorpers, Art und Wassergehalt des aprotischen Losungsmittels, Art und Konzentration des zur Titration eingesetzten Amins, Porengrose des Festkorpers und Dauer der Gleichgewichtseinstellung untersucht und die Methode bezuglich ihrer Reproduzierbarkeit, sowie auf ihren Gultigkeitsbereich und ihre Aussagekraft hin uberpruft. Dieselben Festkorperproben wurden unter den gleichen Vorbehandlungsb…
Effect of Impregnation and Activation Conditions of Al2O3/CuO Supported Monolith Catalysts in the Reduction of NO
1979
Reduction of NO in the presence of CO and Ar was examined on two series of monolithic sheets carrying an active CuO/Al 2 O 3 layer. In the impregnation procedure the ratio of Al 2 O 3 to CuO was varied in a wide range. The texture of the layer and the dispersion of CuO therein was controlled by mercury porosimetry, scanning electron microscopy and secondary ion mass spectrometry (SIMS). It could be established that the surface concentration of CuO determined by SIMS measurements is the most decisive quantity of the catalyst correlating linearly with the conversion of NO.
The application of Jäntti's method for the fast calculation of equilibrium in case of multilayer adsorption
2002
On the basis of a molecular model for sorption kinetics Jäntti introduced a method to calculate equilibria shortly after a change of the pressure of the sorptive gas. In the present paper we apply that method for the description of multilayer adsorption.