Chiral Phase Transition and Meson Melting from AdS/QCD
Poster summary of paper from Quark Matter 2017
Published in Physical Review D, 2016
Three-field potential for soft-wall AdS/QCD
Published in Physical Review D, 2014.
In this paper, we construct a potential for the background fields for the soft-wall model, rather than the previous ad hoc parametrizations. This gives a more consistent foundation for the soft-wall AdS/QCD model and allow for later incorporation of finite temperature effects.
This previous paper showed how to generate potentials for certain simple forms of the background fields.The results diverge greatly from experiment when this technique is applied to the mesons. The mass differences for the excited vector and axial mesons is far too large. We show that this “axial mass gap problem” is unavoidable for potentials that include only two background fields.
One way to resolve this problem is to add a third background field to the model. We construct a potential that has the necessary behavior in both the the large and small limits of the extra dimension, and allows for the tuning of the axial mass splitting.
We numerically calculate the background fields that solve this potential. The meson spectra for the vector, axial-vector, and pseudoscalar mesons calculated from these background fields match well with experimental data.
The scalar mesons require further analysis because their equations of motion mix with the potential directly. I am currently working on this topic with a summer research student.
Pseudoscalar Mass Spectrum in a Soft-Wall Model of AdS/QCD
Technical abstract and full text
Published in Physical Review D, 2011
This paper builds on the success of the original modified soft-wall AdS/QCD model by extending it to include the pions. We derived the differential equations that determine the energy levels for the pions, consisting of coupled second-order differential equations.
After analytically solving the system in the high-mass limit, we developed a numerical routine that was used calculate the energy levels. We confirmed a long-known result that relates the pion mass to the mass of the quark, an important check on the validity of the model.