Signatures of massive sgoldstinos at e(+)e(-) colliders

In supersymmetric extensions of the Standard Model with a very light gravit ino, the effective theory at the weak scale should contain not only the gol dstino (G) over tilde, but also its supersymmetric partners, the sgoldstino s. In the simplest case, the goldstino is a gauge-singlet and its superpart ners are two neutral spin-0 particles, S and P. We study possible signals o f massive sgoldstinos at e(+)e(-) colliders, focusing on those that are mos t relevant at LEP energies. We show that the LEP constraints on e(+)e(-) -- > gamma S(gamma P), ZS(ZP) or e(+)e(-)S(e(+)e(-)P), followed by S(P) decayi ng into two gluon jets, can lead to stringent combined bounds on the gravit ino and sgoldstino masses. (C) 2000 Elsevier Science B.V. All rights reserv ed.