Aspects ofZ′-mediated supersymmetry breaking

Abstract

In a recent paper, we proposed the possibility that supersymmetry breaking is communicated dominantly via a $U(1{)}^{\ensuremath{'}}$ vector multiplet. We also required that the $U(1{)}^{\ensuremath{'}}$ plays a crucial role in solving the $\ensuremath{\mu}$ problem. We discuss here in detail both the construction and the phenomenology of one class of such models. The low-energy spectrum generically contains heavy sfermions, Higgsinos and exotics $\ensuremath{\sim}10--100\text{ }\text{ }\mathrm{TeV}$; an intermediate ${M}_{{Z}^{\ensuremath{'}}}$ $\ensuremath{\sim}3--30\text{ }\text{ }\mathrm{TeV}$; light gauginos $\ensuremath{\sim}100--1000\text{ }\text{ }\mathrm{GeV}$, of which the lightest can be $W$-ino-like; a light Higgs with a mass of $\ensuremath{\sim}140\text{ }\text{ }\mathrm{GeV}$; and a singlino which can be very light. We present a set of possible consistent charge choices. Several benchmark models are used to demonstrate characteristic phenomenological features. Special attention is devoted to interesting LHC (Large Hadron Collider) signatures such as gluino decay and the decay patterns of the electroweak-inos. Implications for neutrino masses, exotic decays, $R$-parity, gauge unification, and the gravitino mass are briefly discussed.