Ian Low, Joseph Lykken, Gabe Shaughnessy
We interpret the new particle at the Large Hadron Collider as a CP-even scalar and investigate its electroweak quantum number. Assuming an unbroken custodial invariance as suggested by precision electroweak measurements, only four possibilities are allowed if the scalar decays to pairs of gauge bosons, as exemplified by a dilaton/radion, a non-dilatonic electroweak singlet scalar, an electroweak doublet scalar, and electroweak triplet scalars. We show that current LHC data already strongly disfavor both the dilatonic and non-dilatonic singlet imposters. On the other hand, a generic Higgs doublet and a triplet imposter give equally good fits to the measured event rates of the newly observed scalar resonance, although a Standard Model Higgs boson gives a slightly better overall fit. The global fit indicates the enhancement in the diphoton channel could be attributed to an enhanced partial decay width, while the production rates are consistent with the Standard Model expectations. We emphasize that more precise measurements of the ratio of event rates in the WW over ZZ channels, as well as the event rates in bb and tau tau channels, are needed to distinguish the Higgs doublet from the triplet imposter.
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http://arxiv.org/abs/1207.1093
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