We investigate whether flavor changing neutrino interactions (FCNIs) can be sufficiently large to provide a viable solution to the atmospheric neutrino problem. Effective operators induced by heavy boson exchange that allow for flavor changing neutrino sca
atenergieswellbelowthebosonmassMB.Thus,intermsofthetrilinearcouplingλαfthatdescribesthecouplingofsomeheavybosonBtoνα(α=µ,τ)andachargedfermionf=u,d,ethee ectiveparametersin(1.1)aregivenby
fν=λ τfλµf
22MBGFandf ′ν|λτf|2 |λµf|2=.22MBGF(2.2)
Thecrucialpointofouranalysisisthefollowing:SincetheSMneutrinosarecomponents
′fofSU(2)Ldoublets,thesametrilinearcouplingsλαfthatgiverisetonon-zero for ννalso
induceotherfour-fermionoperators.TheseoperatorsinvolvetheSU(2)Lpartnersoftheneutrinos,i.e.thechargedleptons,andcanbeusedtoconstraintherelevantcouplings.
BilinearB
(LL)s
(LL)t
¯)s(LL
¯)t(LLCouplestoBosonBS(1,1,1)S(1,3,1)Example c(SUSYR p)R L(LRSM)5.9(M1/M2)2maxV(1,1,0)V(1,3,0)
¯RLd
(LQ)t
¯)s(LQ
LuR¯,2, 1/6)S(3¯,3,1/3)S(3¯,1, 2/3)V(3¯,2, 1/6)V(3 c(SUSYRQp)5.22.5
¯)t(QQ
Tab.3:Quark-QuarkBilinearsV(1,3,0)