Nonlinear Regge trayectories in the context of bottom-up holography

Motivated by the non-holographic phenomenology, where the mesonic constituent mass breaks linearity in Regge trajectories, we discuss how to implement nonlinear Regge trajectories by deforming the static (monoparametric) quadratic dilaton into a non-quadratic one. This deformation adds an extra parameter into the dilaton, which measures the constituent mass effect, accounting for nonlinearity in the hadronic trajectory. We applied this model to the description of the isovector multiplet spectrum. The set of isovector parameters defines a set of hadronic calibration curves for the dilaton slope and linearity deviation parameter, allowing us to extrapolate the model to other vector states, such as heavy-light mesons or vector non-qq¯ hadrons. In other words, this approach allows us to consider the hadronic inner structure by modifying the dilaton profile.