More on R-parity and lepton-family number violating couplings from muon(ium) conversion, and τand π 0 decays
Abstract
We present a new class of constraints to the lepton-family number and R-parity violating couplings from muonium conversion,
μ
−
+
48
22
Ti→
e
−
+
48
22
Ti
, a class of tau decays,
τ→l+
(light meson) with
l=μore
, and
J/ψ
and
π
0
decays into a lepton pair. We find that
μ
−
+
48
22
Ti→
e
−
+
48
22
Ti
provides one of the strongest constraints along with
Δ
m
K
,Δ
m
B
,
μ→eγ
and the neutrinoless double
β
decay. Search for these lepton-family number violating (LFNV) decays forbidden in the standard model is clearly warranted in various low-energy experiments such as Tau-Charm Factories and PSI, etc.