Abstract
Abstract
The amplitudes for the rare decay modes K
± → π
±
ℓ
+
ℓ
− and K
S
→ π
0
ℓ
+ℓ− are studied with the aim of obtaining predictions for them, such as to enable the possibility to search for violations of lepton-flavour universality in the kaon sector. The issue is first addressed from the perspective of the low-energy expansion, and a two-loop representation of the corresponding form factors is constructed, leaving as unknown quantities their values and slopes at vanishing momentum transfer. In a second step a phenomenological determination of the latter is proposed. It consists of the contribution of the resonant two-pion state in the P wave, and of the leading short-distance contribution determined by the operator-product expansion. The interpolation between the two energy regimes is described by an infinite tower of zero-width resonances matching the QCD short-distance behaviour. Finally, perspectives for future improvements in the theoretical understanding of these amplitudes are discussed.
Publisher
Springer Science and Business Media LLC
Subject
Nuclear and High Energy Physics
Reference149 articles.
1. V. Cirigliano, G. Ecker, H. Neufeld, A. Pich and J. Portolés, Kaon Decays in the Standard Model, Rev. Mod. Phys.
84 (2012) 399 [arXiv:1107.6001] [INSPIRE].
2. A. Ceccucci, Review and Outlook on Kaon Physics, Acta Phys. Polon.
B 49 (2018) 1079 [INSPIRE].
3. A. Ceccucci on behalf of the NA62 collaboration, In-flight Search for
$$ {K}^{+}\to {\pi}^{+}\nu \overline{\nu} $$
: First NA62 Results, PoS(ALPS2018)006.
4. T.K. Komatsubara, Experiments with K-Meson Decays, Prog. Part. Nucl. Phys.
67 (2012) 995 [arXiv:1203.6437] [INSPIRE].
5. KOTO collaboration, $$ {K}_L^0\to {\pi}^0\nu \overline{\nu} $$
at KOTO, in 8th International Workshop on the CKM Unitarity Triangle (CKM 2014) Vienna, Austria, September 8–12, 2014, arXiv:1411.4250 [INSPIRE].
Cited by
10 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献