1. Dipartimento di Fisica “E.R.Caianiello”, Universitá di Salerno and INFN, Fisciano (Salerno) 84084, Italy. E-mails: capolupo@sa.infn.it, vitiello@sa.infn.it
2. Department of Mathematics, University of Memphis, Memphis, TN 38152, USA. E-mail: rkozma@memphis.edu
3. Department of Computer Science, University of Massachusetts, Amherst, MA 001003, USA
4. Institute for Particle Physics Phenomenology, Durham University, South Road, Durham, DH1 3LE, UK. E-mail: andres.olivares@durham.ac.uk