Chiral properties of SU(3) sextet fermions

SU(3) gauge theory with overlap fermions in the 2-index symmetric (sextet) and fundamentalrepresentations is considered. A priori it is not known what the pattern of chiral symmetry breakingis in a higher dimensional representation although the general expectation is that if two representationsare both complex, the breaking pattern will be the same. This expectation is verified for the sextetat Nf = 0 in several exact zero mode sectors. It is shown that if the volume is large enough the samerandom matrix ensemble describes both the sextet and fundamental Dirac eigenvalues. The numberof zero modes for the sextet increases approximately 5-fold relative to the fundamental in accordancewith the index theorem for small lattice spacing but zero modes which do not correspond to integertopological charge do exist at larger lattice spacings. The zero mode number dependence of the randommatrix model predictions correctly match the simulations in each sector and each representation.