Study of some rare decays of the K+ meson

Search for Lepton Flavor Violation inK+Decays into a Charged Pion and Two Leptons

“…The previous searches for K eep , K mep , and K pem were performed at CERN 25 years ago [4]. At the 90% confidence level (C.L.…”

“…e 1 m 2 ͒ , 3.4 3 10 29 . The limits on K pem , K mep , and K eep represent an improvement of more than a factor of 10 over the previous searches [4]. The upper limit on B͑p 0 !…”

Vector leptoquarks could be rather light?

“…Among the charged K + meson rare decays which go at the tree level in this model, the tightest limits are established on the decays K + → π + µ − e + [10] and K + → π + µ + e − [11]. An amplitude of the process K + → π + µ + e − can be written in the form…”

Upper limit on the decayK+→e+νμ+Adler1, Atiya2, Chiang3 et al. 1998Phys. Rev. D4000View full textAdd to dashboardCite

“…This decay is a particularly good test of the chiral expansion because the structure dependent terms dominate over the inner bremsstrahlung term due to helicity suppression. The decay K + → e + νµ + µ − has not been seen and no previous limit has been reported, in contrast to the decays K + → e + νe + e − and K + → µ + νe + e − , which have been observed [2] and K + → µ + νµ + µ − for which an upper limit has been reported [3].…”