Holography, chiral Lagrangian and form factor relations

Abstract

We perform a detailed study of mesonic properties in a class of holographic models of QCD, which is described by the Yang-Mills plus Chern-Simons action. By decomposing the 5 dimensional gauge field into resonances and integrating out the massive ones, we reproduce the Chiral Perturbative Theory Lagrangian up to O(p 6 ) and obtain all the relevant low energy constants (LECs). The numerical predictions of the LECs show minor model dependence, and agree reasonably with the determinations from other approaches. Interestingly, various modelindependent relations appear among them. Some of these relations are found to be the largedistance limits of universal relations between form factors of the anomalous and even-parity sectors of QCD.Xth Quark Confinement and the Hadron Spectrum,

Fingerprints of heavy scales in electroweak effective Lagrangians

“…The structure of the P -even part of the Lagrangian agrees with that found in resonance models of QCD in the Proca formalism [14,71].…”

Holography and chiral Lagrangian

“…The expressions for the full set of LECs can be found in our original paper [5]. Since the theory is defined in the large N C and chiral limit, the couplings for the multi-trace operators and those involving scalar/pseudoscalar sources are vanishing.…”

“…which is shown to be the long-distance manifestation of the relation between the γ * → ππ and π → γγ * form factors [5]. Taken into account that L 9 = −L 10 , this is also the infrared limit of the Son-Yamamoto relation between the transverse triangle structure function and the left-right correlator [7].…”

“…which is a manifestation of the relation between certain form factors involving the axial source [5]. The constant Z is present only when the corresponding operators involve at least five fields, namely O W 12 , O W 16 and O W 17 , and is supposed to originate from some higher order terms, e.g., F 3 .…”

Chiral effective theories from holographic QCD with scalars

“…[23,24]. In these analyses, the bulk scalar fields are not present so the effect of the explicit breaking of chiral symmetry via the current quark masses is not included.…”