Probing Majorana phases and the neutrino mass spectrum in the Higgs triplet model at the CERN LHC

Doubly charged Higgs bosons (H^±±) are a distinctive signature of the Higgs triplet model of neutrino mass generation. If H^±± is relatively light (m_H^±±<400 GeV), it will be produced copiously at the LHC, which could enable precise measurements of the branching ratios of the decay channels H^±±→lᵢ^±lⱼ^±. Such branching ratios are determined solely by the neutrino mass matrix which allows the model to be tested at the LHC. We quantify the dependence of the leptonic branching ratios on the absolute neutrino mass and Majorana phases, and present the permitted values for the channels e^±e^±, e^±μ^±, and μ^±μ^±. It is shown that precise measurements of these three branching ratios are sufficient to extract information on the neutrino mass spectrum and probe the presence of $CP$ violation from Majorana phases.