6D Supersymmetry, Projective Superspace and 4D, N=1 Superfields
  In this note, we establish the formulation of 6D, N=1 hypermultiplets in terms of 4D chiral-nonminimal (CNM) scalar multiplets. The coupling of these to 6D, N=1 Yang-Mills multiplets is described. A 6D, N=1 projective superspace formulation is given in which the above multiplets naturally emerge. The covariant superspace quantization of these multiplets is studied in details. 
S. J. Gates Jr, S. Penati, G. Tartaglino-Mazzucchelli