Constraints on Light Particles from Kaon Decays

Aug, 1982
26 pages
Published in:
  • Nucl.Phys.B 217 (1983) 189-214
  • Published: 1983
Report number:
  • CERN-TH-3390

Citations per year

19831993200320132023051015
Abstract: (Elsevier)
We show that the decay K + → π + + unobserved neutrals (?) can give useful information about light neutral particles, including the number of neutrino types. Observation of the decay K + → π + +? would give a lower bound on the number of neutrinos, which would be strengthened by improvement of the present lower bound on the top quark mass m t . Non-observation of the decay K + → π + +? gives an upper bound on the number of neutrinos whose associated leptons have masses outside a window whose width shrinks as m t increases. Peeturbative strong interactions are included in our calculations. We also estimate the rates for K + → π + + light neutral supersymmetric particles such as photinos, gravitinos and shiggses. We find that decays into photinos and gravitinos are suppressed relative to conventional neutrinos whereas decays into shiggses may be comparable with one conventional neutrino flavour. We stress the desirability of a new round of K + → π + +? decay experiments.
  • K+: NONLEPTONIC DECAY
  • NONLEPTONIC DECAY: K+
  • K+: SEMILEPTONIC DECAY
  • SEMILEPTONIC DECAY: K+
  • K0(L): LEPTONIC DECAY
  • LEPTONIC DECAY: K0(L)
  • K+: BRANCHING RATIO
  • top
  • QUARK: MASS
  • MASS: QUARK