Abstract:
If decays of a heavy particle $S$ are responsible for the diphoton excess with invariant mass $750$ GeV observed at the $13$ TeV LHC run, it can be easily accomodated in the Standard Model. Two scenarios are considered: production in gluon fusion through a loop of heavy isosinglet quark(s) and production in photon fusion through a loop of heavy isosinglet leptons. In the second case many heavy leptons are needed or/and they should have large electric charges in order to reproduce experimental data on $\sigma_{pp \to SX} \cdot \text{Br}(S \to \gamma \gamma)$.
Federation Government under the grant NSh-6792.2016.2. S.G. and E.Zh. are also supported by MK-4234.2015.2 and RFBR # 16-32-00241. In addition, S.G. is supported by RFBR under grant 16-32-60115, by Dynasty Foundation and by the Russian Federation Government under Grant # 11.G34.31.0047.
Citation:
S. I. Godunov, A. N. Rozanov, M. I. Vysotsky, E. V. Zhemchugov, “New Physics at 1 TeV?”, Pis'ma v Zh. Èksper. Teoret. Fiz., 103:9 (2016), 635–640; JETP Letters, 103:9 (2016), 557–562