https://doi.org/10.1140/epjc/s10052-013-2678-1
Regular Article - Theoretical Physics
Standard model and new physics contributions to K L and K S into four leptons
1
INFN-Sezione di Napoli, Via Cintia, 80126, Napoli, Italy
2
Dipartimento di Scienze Fisiche, Universitá di Napoli Federico II, Via Cintia, 80126, Napoli, Italy
3
Departament de Física Teòrica, IFIC, Universitat de València—CSIC, Apt. Correus 22085, 46071, València, Spain
* e-mail: gdambros@na.infn.it
Received:
25
September
2013
Revised:
25
November
2013
Published online:
11
December
2013
We study the K
L
and K
S
decays into four leptons (
, 
, 
) where we use a form factor motivated by vector meson dominance, and show the dependence of the branching ratios and spectra from the slopes. A precise determination of short-distance contribution to K
L
→μμ is affected by our ignorance on the sign of the amplitude 
but we show a possibility to measure the sign of this amplitude by studying K
L
and K
S
decays in four leptons. We also investigate the effect of New Physics contributions for these decays.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
