Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Regge spectral generator and form factors from hard exclusive amplitudes in holographic QCD

Guy F. de Teramond, Stanley J. Brodsky, Hans Gunter Dosch

Abstract

We show that the infinite tower of hard exclusive amplitudes in holographic light-front QCD leads to a spectral generator $G(α,λ)$ which encodes the full Regge spectrum. The construction assumes a Poisson distribution of Fock-state components, where $λ$ represents the average parton multiplicity above the minimal valence configuration. The resulting generator yields a Regge spectrum invariant under continuous $λ$-deformations and provides an analytic representation of physical form factors, including their time-like interference structure.

Regge spectral generator and form factors from hard exclusive amplitudes in holographic QCD

Abstract

We show that the infinite tower of hard exclusive amplitudes in holographic light-front QCD leads to a spectral generator which encodes the full Regge spectrum. The construction assumes a Poisson distribution of Fock-state components, where represents the average parton multiplicity above the minimal valence configuration. The resulting generator yields a Regge spectrum invariant under continuous -deformations and provides an analytic representation of physical form factors, including their time-like interference structure.
Paper Structure (11 sections, 28 equations, 1 figure)

This paper contains 11 sections, 28 equations, 1 figure.

Table of Contents

  1. Introduction.
  2. Holographic Light-Front QCD and Regge trajectories.
  3. Form factors in holographic light-front QCD.
  4. Mittag--Leffler expansion.
  5. Full form factor from the Regge spectral generator.
  6. Concluding Remarks.
  7. Acknowledgments.
  8. Some useful results
  9. Generating function.
  10. Mittag--Leffler expansion.
  11. Large $x$ expansion.

Figures (1)

  • Figure 1: Experimental data for the pion electromagnetic form factor in the space-like ($q^2 \le 0$) and time-like ($q^2 \ge 4m_\pi^2$) regions compared with the model prediction (gray curve) for $\lambda=0.4$. This value corresponds to an average twist $\langle\tau\rangle \simeq 2.4$, indicating that the form factor is dominated by the valence $q\bar{q}$ configuration. Space-like data are from NA7 NA7:1986vav and JLab Horn:2007ugJeffersonLab:2008jve. Time-like data from BABAR BaBar:2009wpwBaBar:2012bdw.