On 2-Arc-Transitive Covers of Complete Graphs

Regular covers of complete graphs which are 2-arc-transitive are investigated. A classification is given of all such graphs whose group of covering transformations is either cyclic or isomorphic to Zp×Zp, wherepis a prime and whose fibre- preserving subgroup of automorphisms acts 2-arc-transitively. As a result two new families of 2-arc-transitive graphs are obtained.