Phase transitions and light scalars in bottom-up holography
Ali Fatemiabhari, Swansea University
325 seminar (3rd floor)
Abstract: In this talk, within the bottom-up approach to holography, I will consider a class of six-dimensional gravity models and solutions that can be interpreted in terms of dual five-dimensional conformal field theories deformed by a single scalar operator. I will discuss the mass spectrum of bosonic states, and along the confining branch of solutions, appearance of a tachyonic instability in part of the parameter space.
In a region of parameter space, the lightest scalar particle can be interpreted as an approximate dilaton and its mass is parametrically suppressed. The dilatonic and tachyonic regions will be hidden behind a first-order phase transition, and the (approximate) dilaton will appear in the metastable solutions. Finally, toward minimal composite Higgs models, I study the spontaneous breaking of an SO(5) global symmetry added to our model to its SO(4) subgroup, paying attention to composite states with the right quantum numbers to be a candidate for the Higgs particle.