  Recently, both ATLAS and CMS collaborations report an excess at 750GeV in the
diphoton invariant mass spectrum at 13TeV LHC. If it is a new scalar produced
via loop induced gluon-gluon fusion process, it is important to know what is
the particle in the loop. In this work, we investigate the possibility of
determine the fraction of the contribution from the standard model top-quark in
the loop.
