Gravitational effects in ultrahigh-energy string scattering

Understand

Ultrahigh-energy string scattering is investigated to clarify the relative role of string and gravitational effects, and their possible contributions to nonlocal behavior.

• Different regimes can be characterized by varying the impact parameter at fixed energy.
• In the regime where momentum transfers reach the string scale, string effects appear subdominant to higher-loop gravitational processes, approximated via the eikonal.
• At smaller impact parameters, "diffractive" or "tidal" string excitation leads to processes dominated by highly excited strings.