TY  - JOUR
AU  - von Detten, L.
AU  - Noël, F.
AU  - Hanhart, Christoph
AU  - Hoferichter, M.
AU  - Kubis, B.
TI  - On the scalar ${\pi K}$ form factor beyond the elastic region
JO  - The European physical journal / C
VL  - 81
IS  - 5
SN  - 1434-6052
CY  - Heidelberg
PB  - Springer
M1  - FZJ-2021-02196
SP  - 420
PY  - 2021
AB  - Pion–kaon (πK) pairs occur frequently as final states in heavy-particle decays. A consistent treatment of πK scattering and production amplitudes over a wide energy range is therefore mandatory for multiple applications: in Standard Model tests; to describe crossed channels in the quest for exotic hadronic states; and for an improved spectroscopy of excited kaon resonances. In the elastic region, the phase shifts of πK scattering in a given partial wave are related to the phases of the respective πK form factors by Watson’s theorem. Going beyond that, we here construct a representation of the scalar πK form factor that includes inelastic effects via resonance exchange, while fulfilling all constraints from πK scattering and maintaining the correct analytic structure. As a first application, we consider the decay τ→KSπντ, in particular, we study to which extent the S-wave K∗0(1430) and the P-wave K∗(1410) resonances can be differentiated and provide an improved estimate of the CP asymmetry produced by a tensor operator.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000650628100001
DO  - DOI:10.1140/epjc/s10052-021-09169-7
UR  - https://juser.fz-juelich.de/record/892607
ER  -