scholarly journals On the transition form factors of the axial-vector resonance f1(1285) and its decay into e+e−

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Marvin Zanke ◽  
Martin Hoferichter ◽  
Bastian Kubis

Abstract Estimating the contribution from axial-vector intermediate states to hadronic light-by-light scattering requires input on their transition form factors (TFFs). Due to the Landau–Yang theorem, any experiment sensitive to these TFFs needs to involve at least one virtual photon, which complicates their measurement. Phenomenologically, the situation is best for the f1(1285) resonance, for which information is available from e+e− → e+e−f1, f1 → 4π, f1 → ργ, f1 → ϕγ, and f1 → e+e−. We provide a comprehensive analysis of the f1 TFFs in the framework of vector meson dominance, including short-distance constraints, to determine to which extent the three independent TFFs can be constrained from the available experimental input — a prerequisite for improved calculations of the axial-vector contribution to hadronic light-by-light scattering. In particular, we focus on the process f1 → e+e−, evidence for which has been reported recently by SND for the first time, and discuss the impact that future improved measurements will have on the determination of the f1 TFFs.

2018 ◽  
Vol 166 ◽  
pp. 00012 ◽  
Author(s):  
Bastian Kubis

We discuss status and prospects of a dispersive analysis of the η and η′ transition form factors. Particular focus is put on the various pieces of experimental information that serve as input to such a calculation. These can help improve on the precision of an evaluation of the η and η′ pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.


1990 ◽  
Vol 48 (4) ◽  
pp. 663-671 ◽  
Author(s):  
J. G. Körner ◽  
K. Schilcher ◽  
M. Wirbel ◽  
Y. L. Wu

2019 ◽  
Vol 12 (10) ◽  
pp. 5503-5517 ◽  
Author(s):  
Pascal Hedelt ◽  
Dmitry S. Efremenko ◽  
Diego G. Loyola ◽  
Robert Spurr ◽  
Lieven Clarisse

Abstract. The accurate determination of the location, height, and loading of sulfur dioxide (SO2) plumes emitted by volcanic eruptions is essential for aviation safety. The SO2 layer height is also one of the most critical parameters with respect to determining the impact on the climate. Retrievals of SO2 plume height have been carried out using satellite UV backscatter measurements, but, until now, such algorithms are very time-consuming. We have developed an extremely fast yet accurate SO2 layer height retrieval using the Full-Physics Inverse Learning Machine (FP_ILM) algorithm. This is the first time the algorithm has been applied to measurements from the TROPOMI instrument onboard the Sentinel-5 Precursor platform. In this paper, we demonstrate the ability of the FP_ILM algorithm to retrieve SO2 plume layer heights in near-real-time applications with an accuracy of better than 2 km for SO2 total columns larger than 20 DU. We present SO2 layer height results for the volcanic eruptions of Sinabung in February 2018, Sierra Negra in June 2018, and Raikoke in June 2019, observed by TROPOMI.


2019 ◽  
Vol 218 ◽  
pp. 03001
Author(s):  
Bastian Kubis

We discuss status and prospects of a dispersive analysis of the π0, η, and η ′ transition form factors. Particular focus is put on the various pieces of experimental information that serve as input to such a calculation. These can help improve on the precision of an evaluation of the light pseudoscalar pole contributions to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.**


2001 ◽  
Vol 7 (2) ◽  
pp. 178-192 ◽  
Author(s):  
Dale E. Newbury

Abstract The development of the electron microprobe by Raymond Castaing provided a great stimulus to materials science at a critical time in its history. For the first time, accurate elemental analysis could be performed with a spatial resolution of 1 µm, well within the dimensions of many microstructural features. The impact of the microprobe occurred across the entire spectrum of materials science and engineering. Contributions to the basic infrastructure of materials science included more accurate and efficient determination of phase diagrams and diffusion coefficients. The study of the microstructure of alloys was greatly enhanced by electron microprobe characterization of major, minor, and trace phases, including contamination. Finally, the electron microprobe has proven to be a critical tool for materials engineering, particularly to study failures, which often begin on a micro-scale and then propagate to the macro-scale with catastrophic results.


Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1903 ◽  
Author(s):  
Dorota Papciak ◽  
Barbara Tchórzewska-Cieślak ◽  
Andżelika Domoń ◽  
Anna Wojtuś ◽  
Jakub Żywiec ◽  
...  

The article presents changes in the quality of tap water depending on time spent in installation and its impact on the creation of biofilms on various materials (polyethylene (PE), polyvinyl chloride (PVC), chrome-nickel steel and galvanized steel). For the first time, quantitative analyses of biofilm were performed using methods such as: Adenosine 5’-triphosphate (ATP) measurement, flow cytometry, heterotrophic plate count and using fractographical parameters. In the water, after leaving the experimental installation, the increase of turbidity, content of organic compounds, nitrites and nitrates was found, as well as the decrease in the content of chlorine compounds, dissolved oxygen and phosphorus compounds. There was an increase in the number of mesophilic and psychrophilic bacteria. In addition, the presence of Escherichia coli was also found. The analysis of the quantitative determination of microorganisms in a biofilm indicates that galvanized steel is the most susceptible material for the adhesion of microorganisms. These results were also confirmed by the analysis of the biofilm morphology. The roughness profile, the thickness of the biofilm layer can be estimated at about 300 μm on galvanized steel.


2012 ◽  
Vol 85 (11) ◽  
Author(s):  
Vladimir Pascalutsa ◽  
Vladyslav Pauk ◽  
Marc Vanderhaeghen

2016 ◽  
Vol 31 (31) ◽  
pp. 1630034 ◽  
Author(s):  
Pablo Sanchez-Puertas ◽  
Pere Masjuan

In this work, we present our recent results on a new and alternative data-driven determination for the hadronic light-by-light pseudoscalar pole contribution to the muon (g − 2). Our approach is based on Canterbury approximants, a rational approach to describe the required transition form factors, which provides a systematic and model-independent framework beyond traditional large-[Formula: see text] approaches. As a result, we obtain a competitive determination with errors according to future (g − 2) experiments including, for the first time, a well-defined systematic uncertainty.


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