https://doi.org/10.1140/epjc/s10052-023-12270-8
Regular Article - Theoretical Physics
The
–
interference contributions to
at
for the physical value of
1
Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, 02-093, Warsaw, Poland
2
Institut für Theoretische Teilchenphysik und Kosmologie, RWTH Aachen University, 52056, Aachen, Germany
3
Theoretische Physik 1, Center for Particle Physics Siegen (CPPS), Universität Siegen, 57068, Siegen, Germany
4
Max Planck Institute for Physics, Föhringer Ring 6, 80805, Munich, Germany
5
Department of Physics, University of Alberta, T6G 2E1, Edmonton, AB, Canada
6
National Centre for Physics, Quaid-i-Azam University Campus, 45320, Islamabad, Pakistan
7
Physik Institut, Universität Zürich, 8057, Zurich, Switzerland
8
Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany
Received:
27
September
2023
Accepted:
19
November
2023
Published online:
6
December
2023
The branching ratio is currently measured with around
accuracy. Further improvement is expected from Belle II. To match such a precision on the theoretical side, evaluation of
corrections to the partonic decay
are necessary, which includes the
,
,
,
decay channels. Here, we evaluate the unrenormalized contribution to
that stems from the interference of the photonic dipole operator
and the current–current operators
and
. Our results, obtained in the cut propagator approach at the 4-loop level, agree with those found in parallel by Fael et al. who have applied the amplitude approach at the 3-loop level. Partial results for the same quantities recently determined by Greub et al. agree with our findings, too.
© The Author(s) 2023
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