2012/12/27 by Jiwei Ke, Hui Luo, Ke, Jiwei +11
Physics and Astronomy · #Particle physics theoretical and experimental studies #High-Energy Particle Collisions Research #Particle Detector Development and Performance
paper · pdf · doi:10.48550/arxiv.1212.6311
The dominant decay mode of standard model Higgs at 126 GeV bb suffers from severe SM background at the LHC even in associated productions Wh\rm SM or Z h\rm SM. The precision measurement of BR(ϕ→ bb) requires more data to reduce its large error bar. We investigate the possibility of this channel with largest uncertainty not dominating the decay of Higgs-like boson discovered at the LHC. In such scenarios, the Higgs signal shows highly suppressed bb, slightly reduced τ+τ- and moderately enhanced gauge bosons comparing with the SM predictions. The model requires two different sources of electroweak symmetry breaking and radiative correction to mb strongly enhanced. However, large reduction in bb usually results large enhancement in τ+τ- mode in particular. The reduction of τ+τ- therefore implies that a new decay mode is inevitable. We find that a non-decoupling MSSM Higgs decay into lighter Higgs H→ hh may fit the signature. Here, MSSM H is identified as the 126 GeV resonance while h is below MH/2 and can evade the direct search bound at LEPII and Tevatron. Large PQ and R symmetry breaking effects mediated by strong interaction can strongly enhance radiative corrections in mb. However, the scenario can only be realized in highly fine-tuned parameter region where GHhh is tiny. Nevertheless, we discuss the discovery potential of this highly fine-tuned H→ hh at the LHC.