Regge Trajectories Revisited in the Gauge/String Correspondence

TL;DR

This paper investigates glueball Regge trajectories using gauge/string duality, analyzing spinning strings in confining backgrounds to derive quantum-corrected trajectories that resemble experimental Pomeron data.

Contribution

It provides a semi-classical analysis of spinning strings in KS and MN backgrounds, revealing quantum effects that modify classical Regge trajectories to match experimental features.

Findings

Quantum effects introduce positive intercepts and curvature in Regge trajectories.

Both backgrounds yield similar functional forms, indicating duality to N=1 SYM.

Trajectories align with experimental Pomeron characteristics.

Abstract

We attempt to obtain realistic glueball Regge trajectories from the gauge/string correspondence. To this end we study closed spinning string configurations in two supergravity backgrounds: Klebanov-Strassler (KS) and Maldacena-Nunez (MN) which are dual to confining gauge theories. These backgrounds represent two embeddings of N=1 SYM, in the large rank limit, in string theory. The classical configuration we consider is that of a folded closed string spinning in a supergravity region with vanishing transverse radius (\tau = 0) which is dual to the IR of the gauge theory. Classically, a spinning string yields a linear Regge trajectory with zero intercept. By performing a semi-classical analysis we find that quantum effects alter both the linearity of the trajectory and the vanishing classical intercept: J:=\alpha(t)= \alpha_0 + \alpha' t +\beta\sqrt{t}. Two features of our Regge trajectories are compatible with the experimental Pomeron trajectory: positive intercept and positive curvature. The fact that both KS and MN string backgrounds give the same functional expression of the Regge trajectories suggests that in fact we are observing string states dual to N=1 SYM.