2015/12/30 by Ian Low, Low, Ian, Joseph Lykken +1 · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.1512.09089
openalex publication_date 2015/12/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Assuming a heavy electroweak singlet scalar, which couples to the Standard Model gauge bosons only through loop-induced couplings, SU(2)L x U(1)Y gauge invariance imposes interesting patterns on its decays into electroweak gauge bosons, which are dictated by only two free parameters. Therefore experimental measurements on any two of the four possible electroweak channels would determine the remaining two decay channels completely. Furthermore, searches in the WW/ZZ channels probe a complimentary region of parameter space from searches in the gamma-gamma/Z-gamma channels. We derive a model-independent upper bound on the branching fraction in each decay channel, which for the diphoton channel turns out to be about 61%. Including the coupling to gluons, the upper bound on the diphoton branching fraction implies an upper bound on the mass scale of additional colored particles mediating the gluon-fusion production. Using an event rate of about 5 fb for the reported 750 GeV diphoton excess, we find the new colored particle must be lighter than O(1.7 TeV) and O(2.6 TeV) for a pure CP-even and a pure CP-odd singlet scalar, respectively.