Higgs-flavon mixing and LHC phenomenology in a simplified model of broken flavor symmetry

The LHC phenomenology of a low-scale gauged flavor symmetry model with inverted hierarchy is studied, through introduction of a simplified model of broken flavor symmetry. A new scalar (a flavon) and a new neutral top-philic massive gauge boson emerge with mass in the TeV range, along with a new heavy fermion associated with the standard model top quark. After checking constraints from electroweak precision observables, we investigate the influence of the model on Higgs boson physics, notably on its production cross section and decay branching fractions. Limits on the flavon phi from heavy Higgs boson searches at the LHC at 7 and 8 TeV are presented. The branching fractions of the flavon are computed as a function of the flavon mass and the Higgs-flavon mixing angle. We also explore possible discovery of the flavon at 14 TeV, particularly via the phi --> Z(0)Z(0) decay channel in the 2l2l' final state, and through standard model Higgs boson pair production phi --> hh in the b (b) over bar gamma gamma final state. We conclude that the flavon mass range up to 500 GeV could be probed down to quite small values of the Higgs-flavon mixing angle with 100 fb(-1) of integrated luminosity at 14 TeV.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)2ARTICLEberger@anl.gov; giddings@physics.ucsb.edu; haichenwang@lbl.gov; zhanghao@physics.ucsb.edu7null9