Completing the framework of AdS/QCD: New operators and interactions.

摘要

This thesis explores the inclusion of new interaction terms and tensor operators in AdS/QCD models. We first study the Chern-Simons term of the bulk gauge fields, generated in top-down frameworks by interactions of Ramond-Ramond excitations with flavor brane fields. This supergravity interaction term translates to natural-parity-violating couplings among QCD mesons. We catalog these couplings, and use them to make predictions for the photoproduction of axial-vector and vector mesons. We also find that the Chern-Simons term generates an anomalous dispersion relation that mixes transverse vector and axial-vector meson mass eigenstates. We predict the formation of a Lorentz-symmetry-violating condensate of mesons at baryon densities comparable to those found in neutron stars.;We then include an antisymmetric two-tensor field in the dual model, which may arise in top-down models from dimensional reduction of ten-dimensional string theory. This field is dual to the operator q¯sigma munuq; its real part gives rise to a tower of JPC = 1+-- states, whose lowest modes we identify with h1/b 1 mesons. The imaginary part gives rise to a second tower of (heavier) rho-like (JPC = 1--) states. We fix the undetermined coupling of the two-tensor field by comparison to high- q2 QCD correlators, and find that the spectrum and decay constants of the resulting modes agrees favorably with experimental data and lattice simulations.