V-QCD: Spectra, the dilaton and the S-parameter

Nov, 2012
12 pages
Published in:
  • Phys.Lett.B 720 (2013) 219-223
  • Published: Mar 13, 2013
e-Print:
Report number:
  • CCTP-2012-19

Citations per year

2012201520182021202402468
Abstract: (Elsevier)
Zero temperature spectra of mesons and glueballs are analyzed in a class of holographic bottom-up models for QCD (named V-QCD), as a function of x=N_fN_c with the full back-reaction included. It is found that spectra are discrete and gapped (modulo the pions) in the QCD regime, for x below the critical value x_c where the conformal transition takes place. The masses uniformly converge to zero in the walking region x->x_c due to Miransky scaling. The ratios of masses all asymptote to non-zero constants as x->x_c and therefore there is no ''dilaton'' in the spectrum. The S-parameter is computed and found to be of O(1) in the walking regime.
Note:
  • 11 pages, 6 figures
  • temperature: 0
  • quantum chromodynamics
  • dilaton
  • back reaction
  • holography
  • conformal
  • glueball
  • scaling
  • meson