We measure the branching fraction of the decayusing data collected with the Belle II detector. The data contain 387 millionpairs produced incollisions at theresonance. We reconstructdecays from an analysis of the distributions of theenergy and thehelicity angle. We determine the branching fraction to be, in agreement with previous results. Our measurement improves the relative precision of the world average by more than a factor of two.
This content will become publicly available on August 1, 2025
We discuss numerical aspects of instantons in two- and three-dimensionaltheories with an internalsymmetry group, the so-called-vector model. By combining asymptotic transseries expansions for large arguments with convergence acceleration techniques, we obtain high-precision values for certain integrals of the instanton that naturally occur in loop corrections around instanton configurations. Knowledge of these numerical properties is necessary in order to evaluate corrections to the large-order factorial growth of perturbation theory intheories. The results contribute to the understanding of the mathematical structures underlying the instanton configurations.
- Award ID(s):
- 2110294
- PAR ID:
- 10530889
- Publisher / Repository:
- American Physical Society
- Date Published:
- Journal Name:
- Physical Review D
- Volume:
- 110
- Issue:
- 3
- ISSN:
- 2470-0010
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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