A model for pion-pion scattering in large-N QCD

作者：Veneziano G^*; Yankielowicz S; Onofri E

来源：The Journal of High Energy Physics, 2017, 2017(4): 151.

DOI：10.1007/JHEP04(2017)151

• 1/N Expansion
• Bosonic Strings
• Scattering Amplitudes

Following up on recent work by Caron-Huot et al. we consider a generalization of the old Lovelace-Shapiro model as a toy model for 7171 scattering satisfying (most of) the properties expected to hold in ('t Hooft's) large-N limit of massless QCD. In particular, the model has asymptotically linear and parallel Regge trajectories at positive t, a positive leading Regge intercept alpha o < 1, and an effective bending of the trajectories in the negative-t region producing a fixed branch point at J = 0 for t < to < 0. Fixed (physical) angle scattering can be tuned to match the power-like behavior (including logarithmic corrections) predicted by perturbative QCD: A(s, t) similar to s(-beta) log(s)(-gamma) F(theta). Tree-level unitarity (i.e. positivity of residues for all values of s and J) imposes strong constraints on the allowed region in the alpha(0)-beta-gamma parameter space, which nicely includes a physically interesting region around alpha o = 0.5, beta = 2 and gamma = 3. The full consistency of the model would require an extension to multi-pion processes, a program we do not undertake in this paper.

• 出版日期2017-4-26