K+ → π+ ν(ν)over-bar and FCNC from nonuniversal Z′ bosons -: art. no. 053003

Motivated by the E787 and E949 result for K+-->pi(+)nu(nu) over bar we examine the effects of a new nonuniversal right-handed Z(') boson on flavor changing processes. We place bounds on the tree-level flavor-changing neutral current from K-(K) over bar and B-(B) over bar mixing as well as from the observed CP violation in kaon decay. We discuss the implications for K-->pinu(nu) over bar, B-->Xnu(nu) over bar and B-->tau(+)tau(-). We find that the existing bounds allow substantial enhancements in the K+-->pi(+)nu<(nu())over bar> rate, particularly through a new one-loop Z(') penguin operator.