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doi:10.1140/epjc/s10052-016-4449-2

Dispersive treatment of KS→γγ and KS→γℓ+ℓ-

We analyse the rare kaon decays KS→γγ and KS→γℓ+ℓ-(ℓ=eorμ) in a dispersive framework in which the weak Hamiltonian carries momentum. Our analysis extends predictions from lowest order SU(3)L×SU(3)R chiral perturbation theory (χPT3) to fully account for effects from final-state interactions, and is free from ambiguities associated with extrapolating the kaon off-shell. Given input from KS→ππ and γγ(∗)→ππ, we solve the once-subtracted dispersion relations numerically to predict the rates for KS→γγ and KS→γℓ+ℓ-. In the leptonic modes, we find sizeable corrections to the χPT3 predictions for the integrated rates.

Publication:

European Physical Journal C

Pub Date:

November 2016

DOI:

10.1140/epjc/s10052-016-4449-2

arXiv:

arXiv:1609.03574

Bibcode:

2016EPJC...76..604C

Keywords:

Perturbation Theory;
Chiral Perturbation Theory;
Pion Form Factor;
Scalar Form Factor;
Subtraction Constant;
High Energy Physics - Phenomenology;
High Energy Physics - Lattice;
Nuclear Theory

E-Print:

12 pages, 9 figures. v2: Improved assessment of systematic uncertainties, some typos corrected, matches published version

NASA/ADS

Dispersive treatment of KS→γγ and KS→γℓ+ℓ-

Abstract